In
psychophysics, the faintest (lowest-intensity) stimulus
of a given sensation (such as sound or light) that an individual
can detect. For contrast, see difference threshold. (p.
263)
accommodation
In
Piaget's theory of cognitive development, the change that
occurs in an existing mental scheme or set of schemes as
a result of the assimilation of the experience of a new
event or object. See also assimilation. (p. 409)
action
potentials
Neural
impulses; the all-or-nothing electrical bursts that begin
at one end of the axon of a neuron and move along the axon
to the other end. (p. 165)
actor-observer
discrepancy
The
observation that a person who performs an action (the actor)
is likely to attribute the action to the environmental situation,
whereas the person who observes the same action (the observer)
is likely to attribute it to the actor's inner characteristics
(personality). See also attribution. (p. 492)
additive
color mixing
The
mixing of colored lights (lights containing limited ranges
of wavelengths) by superimposing them to reflect off the
same surface. It is called additive because each light adds
to the total set of wavelengths that are reflected to the
eye. For contrast, see subtractive color mixing. (p. 247)
algorithm
A
rule specifying a set of steps that, if followed correctly,
is guaranteed to solve a particular class of problem. For
contrast, see heuristic. (p. 389)
alleles
Different
genes that can occupy the same locus on a pair of chromosomes
and thus can potentially pair with one another. (p. 59)
altruism
In
sociobiology, a type of helping behavior in which an individual
increases the survival chance or reproductive capacity of
another individual while decreasing its own survival chance
or reproductive capacity. For contrast, see cooperation.
(p. 89)
amplitude
The
amount of physical energy or force exerted by a physical
stimulus at any given moment; for sound, this physical measure
is related to the psychological experience of loudness.
(p. 235)
amygdala
A
brain structure that is part of the limbic system and is
particularly important for evaluating the emotional and
motivational significance of stimuli and generating emotional
responses. (pp. 153, 224)
analogy
In
ethology and comparative psychology, any similarity among
species that is not due to common ancestry, but rather has
evolved independently because of some similarity in their
habitats or lifestyles. For contrast, see homology. (p.
77)
anxiety
disorders
The
class of mental disorders in which fear or anxiety is the
most prominent symptom. It includes generalized anxiety
disorder, obsessive-compulsive disorder, panic disorder,
phobias, and posttraumatic stress disorder. (p. 610)
aphasia
Any
loss in language ability due to brain damage. See also Broca's
aphasia, Wernicke's aphasia. (p. 162)
arousal
response
A
pattern of measurable physiological changes (including tense
muscles, increased heart rate, and secretion of certain
hormones) that helps prepare the body for the possible expenditure
of a large amount of energy. (p. 218)
assertiveness
training
In
behavior therapy, a direct method of training people to
express their own desires and feelings and to maintain their
own rights in interactions with others, while at the same
time respecting the others' rights. (p. 674)
assessment
In
clinical practice, the process by which a mental health
professional gathers and compiles information about a client
for the purpose of describing the person's problems or disorder
and developing a plan of treatment. (p. 647)
assessment
interview
A
dialogue through which a mental health professional learns
about a client. (p. 647)
assimilation
In
Piaget's theory of cognitive development, the process by
which experiences are incorporated into the mind, or, more
specifically, into mental schemes. See also accommodation.
(p. 409)
association
areas
Areas
of the cerebral cortex that receive input from the primary
or secondary sensory areas for more than one sensory modality
(such as vision and hearing) and are involved in associating
this input with stored memories, in the processes of perception,
thought, and decision making. (p. 154)
association
by contiguity
See
law of association by contiguity.
association
by similarity
See
law of association by similarity.
attachment
The
long-lasting emotional bonds that infants develop toward
their principal caregivers. More broadly, the long-lasting
emotional bonds that any individual develops toward any
other individual or object. (p. 447)
attention
In
perception, the process or set of processes by which the
mind chooses from among the various stimuli that strike
the senses at any given moment, allowing only some of those
stimuli to enter into higher stages of information processing.
(p. 302) In the modal model of the mind, the process that
controls the flow of information from the sensory store
into working memory. More broadly, any focusing of mental
activity along a specific track, whether that track consists
purely of inner memories and knowledge or is based on external
stimuli. (p. 322)
attitude
Any
belief or opinion that has an evaluative component--a belief
that something is good or bad, likable or unlikable, attractive
or repulsive. (p. 487)
attribution
In
social cognition, any inference about the cause of a person's
behavioral action or set of actions. More generally, any
inference about the cause of any observed action or event.
(p. 488)
auditory
masking
The
phenomenon by which one sound (usually a lower-frequency
sound) tends to prevent the hearing of another sound (usually
a higher-frequency sound). (p. 239)
auditory
nerve
The
cranial nerve that contains the sensory neurons for hearing
and the vestibular sense (important for balance). (p. 237)
auditory
neurons
The
sensory neurons for hearing, which run from the cochlea
of the inner ear, through the auditory nerve, into the brain.
(p. 237)
autism
A
congenital (present-at-birth) disorder, typically marked
by severe deficits in social interaction, severe deficits
in language acquisition, a tendency to perform repetitive
actions, and a restricted focus of attention and interest.
(p. 425)
autonomic
motor system
The
set of motor neurons that act upon visceral muscles and
glands. (p. 147)
aversion
treatment
In
behavior therapy, a method for eliminating an undesired
habit by applying some painful or unpleasant stimulus immediately
after the unwanted response occurs or immediately after
the person has experienced stimuli that would normally elicit
the response. (p. 673)
axon
A
thin, tubelike extension from a neuron that is specialized
to carry neural impulses (action potentials) to other cells.
(p. 144)
axon
terminal
A
swelling at the end of an axon that is designed to release
a chemical substance (neurotransmitter) onto another neuron,
muscle cell, or gland cell. (p. 145)
B
basal
ganglia
The
large masses of gray matter in the brain that lie on each
side of the thalamus; they are especially important for
the initiation and coordination of deliberate movements.
(p. 152)
basilar
membrane
A
flexible membrane in the cochlea of the inner ear; the wavelike
movement of this structure in response to sound stimulates
the receptor cells for hearing. See also hair cells. (p.
236)
behavior
The
observable actions of an individual person or animal. (p.
3)
behavioral
genetics
The
study of the effects of genes on behavior. (p. 49)
behavioral
monitoring
Any
assessment procedure that involves counting or recording
actual instances of desired or undesired behaviors. (p.
650)
behavior
therapy
The
psychotherapy approach based on the philosophy of behaviorism
and rooted in basic behavioral research on learning. In
this approach, psychological problems are considered to
stem from learned habits, and learning techniques are used
to treat them. (p. 670)
behaviorism
A
school of psychological thought that holds that the proper
subject of study is observable behavior, not the mind, and
that behavior should be understood in terms of its relationship
to observable events in the environment rather than in terms
of hypothetical events within the individual. (pp. 14, 100)
bias
A
technical term referring to nonrandom (directed) effects
on research results, caused by some factor or factors extraneous
to the research hypothesis. For contrast, see error. (p.
42)
biased
sample
A
subset of the population under study that is not representative
of the population as a whole. (p. 42)
binocular
disparity
The
cue for depth perception that stems from the separate (disparate)
views that the two eyes have of any given visual object
or scene; the farther away the object is, the more similar
are the two views of it. (p. 289)
biofeedback
training
A
variety of operant conditioning in which a signal, such
as a tone or light, is made to come on whenever a certain
desirable physiological change occurs, and the person is
instructed to try to keep the signal on for increasing periods
of time. It is used as a treatment for such problems as
headaches and high blood pressure. (p. 113)
bipolar
cells
The
class of neurons in the retina that receive input from the
receptor cells (rods and cones) and form synapses on ganglion
cells (which form the optic nerve). (p. 245)
bipolar
disorder
A
mood disorder characterized by episodes of extreme depression
alternating with episodes of extreme mania. (pp. 614, 619)
blind
In
scientific research, the condition in which those who collect
the data are deliberately kept uninformed about aspects
of the study's design (such as which subjects have had which
treatment) that could lead them either unconsciously or
consciously to bias the results. See also bias, observer-expectancy
effect. (p. 45)
blind
spot
The
place in the retina of the eye where the axons of visual
sensory neurons come together to form the optic nerve. Because
the blind spot lacks receptor cells, light that strikes
it is not seen. (p. 243)
blocking
effect
In
classical conditioning, the failure of a new stimulus to
become a conditioned stimulus if it is accompanied by an
already-effective conditioned stimulus during the conditioning
trials. (p. 123)
blood-brain
barrier
The
tight capillary walls and the surrounding glial cells that
prevent many chemical substances from entering the brain
from the blood. (p. 178)
bottom-up
processes
In
theories of perception, mental processes that bring the
individual stimulus features recorded by the senses together
to form a perception of the larger object or scene. For
contrast, see top-down processes. (p. 276)
brainstem
The
primitive, stalklike portion of the brain that can be thought
of as an extension of the spinal cord into the head; it
consists of the medulla, pons, and midbrain. (p. 150)
Broca's
aphasia
A
specific syndrome of loss in language ability that occurs
due to damage in a particular part of the brain called Broca's
area; it is characterized by telegraphic speech in which
the meaning is usually clear but the small words and word
endings that serve grammatical purposes are missing; also
called nonfluent aphasia. For contrast, see Wernicke's aphasia.
(p. 162)
C
catatonic
behavior
A
symptom of schizophrenia in which the person is unresponsive
to the environment. It may take the form of active resistance,
excited motor activity, or a complete lack of movement or
awareness of the environment. (p. 631)
cell
body
The
widest part of a neuron, which contains the cell nucleus
and other basic machinery common to all cells. (p. 144)
cell
membrane
The
thin, porous outer covering of a neuron or other cell that
separates the cell's intracellular fluid from extracellular
fluid. (p. 165)
central
drive system
According
to the central-state theory of drives, a set of neurons
in the brain that, when active, most directly promotes a
specific motivational state, or drive. (p. 188)
central
executive
In
Baddeley's theory, a component of the mind responsible for
coordinating all the activities of working memory and for
bringing new information into working memory. (p. 319)
central
nervous system
The
brain and spinal cord. (p. 144)
central
route to attitude construction
The
logical analysis of available information for the purpose
of developing or modifying an attitude. For contrast, see
peripheral route to attitude construction. (p. 517)
central
traits
In
trait theories of personality, the relatively small set
of basic traits (personality characteristics) that are inferred
from statistical intercorrelations among various surface
traits. See also surface traits. (p. 564)
central-state
theory of drives
The
theory that the most direct physiological bases for motivational
states, or drives, lie in neural activity in the brain.
According to most versions of this theory, different drives
correspond to activity in different, localizable sets of
neurons. See also central drive system. (p. 188)
cerebellum
The
relatively large, conspicuous, convoluted portion of the
brain attached to the rear side of the brainstem; it is
especially important for the coordination of rapid movements.
(p. 152)
cerebral
cortex
The
outermost, evolutionarily newest, and (in humans) by far
the largest portion of the brain; it is divisible into two
hemispheres (right and left), and each hemisphere is divisible
into four lobes--the occipital, temporal, parietal, and
frontal. (p. 154)
chromosomes
The
structures within the cell nucleus that contain the genetic
material (DNA). (p. 56)
chunking
A
strategy for improving the ability to remember a set of
items by grouping them mentally to form fewer items. (p.
339)
circadian
rhythm
Any
cyclic physiological or behavioral change in a person or
other living thing that has a period of about one day even
in the absence of external cues signaling the time of day.
(p. 211)
classical
conditioning
A
training procedure or learning experience in which a neutral
stimulus (the conditioned stimulus) comes to elicit a reflexive
response through its being paired with another stimulus
(usually an unconditioned stimulus) that already elicits
that reflexive response; originally studied by Pavlov. See
also conditioned response, conditioned stimulus, unconditioned
response, unconditioned stimulus. (p. 102)
client-centered
therapy
The
humanistic approach to psychotherapy developed by Rogers,
in which the therapist refrains from offering advice or
leading the course of therapy, but rather listens to the
client with empathy and respect and reflects the client's
thoughts and feelings back to him or her. (p. 664)
clinical
psychology
The
field of practice and research that is directed toward helping
people who suffer from psychological problems and disorders.
(p. 641)
closure
principle
See
Gestalt principles of grouping.
cochlea
A
coiled structure in the inner ear in which the receptor
cells for hearing are located. (p. 236)
cochlear
implant
A
type of hearing aid used to treat sensorineural deafness;
it transforms sounds into electrical impulses and directly
stimulates the tips of auditory neurons within the cochlea.
(p. 237)
coding
In
sensation, the process by which information about the quality
and quantity of a stimulus is preserved in the pattern of
action potentials sent through sensory neurons to the central
nervous system. (p. 233)
cognitive
dissonance theory
Festinger's
theory that people seek to relieve the discomfort associated
with the awareness of inconsistency between two or more
of one's own cognitions (beliefs or bits of knowledge).
(p. 510)
cognitive
map
The
mental representation of the spatial layout of a familiar
environment, inferred from the individual's ability to move
in that environment as if guided by a map. (p. 126)
cognitive
psychology
The
study of people's ability to acquire, organize, remember,
and use knowledge to guide behavior; it involves the construction
of hypothetical mental processes to explain observable behavior.
(pp. 22, 119)
cognitive
therapy
An
approach to psychotherapy that begins with the assumption
that people disturb themselves through their own thoughts
and that they can overcome their problems through changing
the way they think about their experiences. (p. 667)
cognitive-behavior
therapy
The
psychotherapy approach that stems from a union of cognitive
and behavioral theory; it usually characterizes psychological
problems as learned habits of thought and action, and its
approach to treatment is to help people change those habits.
See also behavior therapy, cognitive therapy. (p. 671)
common
movement principle
See
Gestalt principles of grouping.
concept
A
rule or other form of mental information for categorizing
stimuli into groups. (p. 121)
conceptual
priming
The
class of priming in which the priming stimulus makes certain
mental concepts more accessible to one's flow of thoughts.
See priming. For contrast, see perceptual priming. (p. 346)
concordance
In
behavioral genetics research, an index of heritability that
is found by identifying a set of individuals who have a
particular trait or disorder and then determining the percentage
of some specific class of their relatives (such as identical
twins) who have the same trait or disorder. (p. 633)
concrete-operational
scheme
In
Piaget's theory, the type of mental stimulus that allows
a child to think logically about reversible actions (operations)
but only when applied to objects with which the child has
had direct (concrete) experience. See also operations. (p.
411)
conditioned
reflex
In
classical conditioning, a reflex that occurs only because
of previous conditions in the individual's experience; a
learned reflex. For contrast, see unconditioned reflex.
(p. 102)
conditioned
response
In
classical conditioning, a reflexive response that is elicited
by a stimulus (the conditioned stimulus) because of the
previous pairing of that stimulus with another stimulus
(the unconditioned stimulus) that already elicits a reflexive
response. For contrast, see unconditioned response. (p.
102)
conditioned
stimulus
In
classical conditioning, a stimulus that comes to elicit
a reflexive response (the conditioned response) because
of its previous pairing with another stimulus (the unconditioned
stimulus) that already elicits a reflexive response. For
contrast, see unconditioned stimulus. (p. 102)
conduction
deafness
Deafness
that occurs when the ossicles of the middle ear become rigid
and cannot carry sounds inward from the tympanic membrane
to the cochlea. (p. 237)
cone
vision
The
high-acuity color vision that occurs in moderate-to-bright
light and is mediated by cones in the retina; also called
photopic or bright-light vision. See cones. For contrast,
see rod vision. (p. 243)
cones
The
class of receptor cells for vision that are located in and
near the fovea of the retina, operate in moderate-to-bright
light, and are most important for the perception of color
and fine detail. For contrast, see rods. (p. 242)
consciousness
In
perception, the experiencing of percepts or other mental
events in such a manner that one can report on them to others.
(p. 302)
content
morphemes
Words,
including nouns, verbs, adjectives, and adverbs, that are
most essential to the meaning of a sentence. For contrast,
see grammatical morphemes. (p. 428)
context-dependent
memory
The
improved ability to retrieve information from memory that
occurs when an individual is in the same environment as
that in which the memory was originally encoded. (p. 337)
contingency
contract
In
behavior therapy, a formal, usually written agreement in
which certain specified services or rewards provided by
one party are made contingent upon the actions of the other
party. (p. 674)
control
processes
In
the modal model of the mind, the mental processes that operate
on information in the memory stores and move information
from one store to another. See attention, encoding, retrieval.
(p. 316)
conversion
disorder
A
category of somatoform disorder in which the person, for
psychological reasons, loses some bodily function. (p. 621)
cooperation
In
sociobiology, a type of helping behavior in which interaction
among two or more individuals increases the survival chance
or reproductive capacity of each individual involved in
the interaction. For contrast, see altruism. (p. 89)
cornea
The
curved, transparent tissue at the front of the eyeball that
helps to focus light rays as they first enter the eye. (p.
242)
corpus
callosum
A
massive bundle of axons connecting the right and left hemispheres
of the higher parts of the brain, including the cerebral
cortex. (p. 160)
correlational
study
Any
scientific study in which the researcher observes or measures
(without directly manipulating) two or more variables to
find relationships between them. Such studies can identify
lawful relationships but cannot determine whether change
in one variable is the cause of change in another. (p. 34)
correlation
coefficient
A
numerical measure of the strength and direction of the relationship
between two variables. (pp. 39, A-7)
cranial
nerve
A
nerve that extends directly from the brain. See nerves.
For contrast, see spinal nerve. (p. 147)
creole
language
A
new language, with grammatical rules, that develops from
a pidgin language in colonies established by people who
had different native languages. See pidgin language. (p.
435)
critical
period
A
relatively restricted time period in an individual's development
during which a particular form of learning can best occur.
See imprinting. (p. 136)
crystallized
intelligence
In
Cattell's theory, the variety of intelligence that derives
directly from previous experience. It includes one's accumulated
knowledge and verbal skills. For contrast, see fluid intelligence.
(p. 361)
cultural
psychology
The
study of the relationship between the culture in which a
person develops and the person's thoughts, feelings, and
behavior. Cultural psychologists may focus on just one culture
or may compare people living in different cultures. (p.
20)
cyclothymia
A
mood disorder similar to bipolar disorder but involving
less extreme depression and mania. See bipolar disorder.
(p. 619)
D
dark
adaptation
The
increased visual sensitivity that occurs when the eyes are
exposed for a period of time to dimmer light than was present
before the adaptation period. For contrast, see light adaptation.
(p. 244)
deductive
reasoning
Logical
reasoning from the general to the specific; the reasoner
begins by accepting the truth of one or more general premises
or axioms and uses them to assert whether a specific conclusion
is true, false, or indeterminate. For contrast, see inductive
reasoning. (p. 382)
defense
mechanisms
In
psychoanalytic theory, self-deceptive means by which the
mind defends itself against anxiety. See displacement, projection,
rationalization, reaction formation, repression, sublimation.
(p. 585)
deindividuation
The
reduced sense of personal responsibility that can occur
when in a crowd or when distracted by highly arousing external
stimulation, which can lead a person to perform actions
that run counter to his or her personal beliefs or morals.
(p. 535)
delusion
A
false belief that is maintained despite compelling evidence
to the contrary. (p. 630)
dendrites
The
thin, tubelike extensions of a neuron that typically branch
repeatedly near the neuron's cell body and are specialized
for receiving signals from other neurons. (p. 144)
dependent
variable
In
an experiment, the variable that is believed to be dependent
upon (affected by) another variable (the independent variable).
In psychological experiments, it is usually some measure
of behavior. (p. 33)
depressive
disorders
The
class of mood disorders characterized by prolonged or frequent
bouts of depression. See dysthymia, major depression. (p.
614)
deprivation
experiment
An
experiment in which animals are raised in ways that deprive
them of some of their usual experiences in order to determine
what experiences are essential (or not) for a particular
species-typical behavior to develop. (p. 76)
descriptive
statistics
Mathematical
methods for summarizing sets of data. (p. 38)
descriptive
study
Any
study in which the researcher describes the behavior of
an individual or set of individuals without systematically
investigating relationships between specific variables.
(p. 35)
deterministic
fallacy
The
mistaken belief that genes control, or determine, behavior
in a manner that is independent of environmental influences.
(p. 91)
developmental
psychology
The
branch of psychology that charts changes in people's abilities
and styles of behaving as they get older and tries to understand
the factors that produce or influence those changes. (p.
401)
difference
threshold
In
psychophysics, the minimal difference that must exist between
two otherwise similar stimuli for an individual to detect
them as different; also called the just-noticeable difference
(jnd). (p. 265)
differential
lighting of surfaces
A
pictorial cue for perceiving depth in which the amount of
light reflecting on different surfaces indicates the position
of objects relative to the light source. (p. 293)
direct-perception
theory
The
theory that perceptual mechanisms register directly the
critical stimulus relationships that are present in the
external environment, such that perception is not dependent
upon mental inference. For contrast, see unconscious-inference
theory of perception. (p. 299)
discrimination
training
The
procedure, in both classical and operant conditioning, by
which generalization between two stimuli is diminished or
abolished by reinforcing the response to one stimulus and
extinguishing the response to the other. See extinction,
generalization, reinforcement. (pp. 105, 138)
discriminative
stimulus
In
operant conditioning, a stimulus that serves as a signal
that a particular response will produce a particular reinforcer.
(p. 115)
disorganized
speech
A
symptom of schizophrenia in which the person's speech contains
loose associations and logical inconsistencies that are
believed to reflect an underlying disorganization in thought.
(p. 631)
displacement
The
defense mechanism by which a drive is diverted from one
goal to another that is more realistic or acceptable. Also
called sublimation in cases where the goal toward which
the drive is diverted is highly valued by society. (p. 586)
dissociation
A
process by which some portion of a person's experiences
are cut off mentally from the rest of his or her experiences,
such that they cannot be recalled or can only be recalled
under special conditions. (p. 627)
dissociative
disorders
The
class of mental disorders that are characterized by dissociation.
They include dissociative identity disorder, dissociative
amnesia, and dissociative fugue. (p. 628)
dissociative
identity disorder
A
mental disorder in which two or more distinct personalities
or self-identities are manifested in the same person at
different times. Formerly called multiple-personality disorder.
(p. 628)
dominant
gene
A
gene that will produce its observable effects in either
the homozygous or the heterozygous condition. (p. 59)
double
blind experiment
An
experiment in which both the observer and the subjects are
blind with respect to the subjects' treatment conditions.
See also blind. (p. 46)
drive
See
motivational state.
drug
abuse
The
persistent taking of a drug in a way that is harmful to
the self or that causes one to behave in a way that is harmful
or threatening to others. (p. 624)
drug
dependence
The
condition, which may or may not stem from physiological
withdrawal symptoms, in which a person feels compelled to
take a particular drug on a regular basis; also called drug
addiction. (p. 625)
drug
tolerance
The
phenomenon by which a drug produces successively smaller
physiological and behavioral effects, at any given dose,
if it is taken repeatedly. (p. 179)
dualism
The
philosophical theory that two distinct systems--the material
body and the immaterial soul--are involved in the control
of behavior. For contrast, see materialism. (p. 4)
dysthymia
A
mental disorder characterized by feelings of depression
that are less severe than those in major depression, but
which last for at least a 2-year period. See also major
depression. (p. 615)
E
early-selection
theories
Theories
of attention that posit that the selective process of attention
occurs relatively early in the mind's analysis of sensory
information, before the information has been analyzed for
meaning. For contrast, see late-selection theories. (p.
304)
echoic
memory
Sensory
memory for the sense of hearing. (p. 317)
ecological
perspective
In
research on learning, the view that different learning mechanisms
have developed through natural selection to serve different
survival needs and that these mechanisms are best understood
in relation to daily life in the natural environment. (p.
130) More generally, the view that behavioral or mental
capacities are best understood by considering how they serve
the individual's needs in the environment. (p. 385)
elaboration
The
process of thinking about an item of information in such
a way as to tie the item mentally to other information in
memory, which helps to encode the item into long-term memory;
also called elaborative rehearsal. (p. 325)
elaboration
likelihood model
A
theory of persuasion postulating that people are more likely
to think logically about a message (that is, elaborate upon
the message) if it is personally relevant than if it is
not. (p. 518)
electroencephalogram
(EEG)
A
record of the electrical activity of the brain that can
be obtained by amplifying the weak electrical signals picked
up by recording electrodes pasted to the person's scalp.
It is usually described in terms of wave patterns. (p. 206)
emotion
A
subjective feeling, the intensity of which is typically
related to the degree of physiological arousal that accompanies
it. (p. 219)
empiricism
The
idea that all human knowledge and thought ultimately come
from sensory experience; the philosophical approach to understanding
the mind that is based on that idea. For contrast, see nativism.
(p. 6)
encoding
In
the modal model of the mind, the mental process by which
long-term memories are formed. See also long-term memory.
(p. 322)
encoding
rehearsal
Any
active mental process by which a person strives to encode
information into long-term memory. For contrast, see maintenance
rehearsal. (p. 325)
encoding-specificity
principle
The
principle that the stimuli that were most prominent in a
person's experience at the time of encoding a specific item
of information into long-term memory are powerful cues for
subsequent retrieval of that item from long-term memory.
(p. 337)
endocrine
glands
Glands
that are specialized to secrete hormones into the circulatory
system. (p. 174)
environmentality
The
proportion of the variability in a particular characteristic,
in a particular group of individuals, that is due to environmental
rather than genetic differences among the individuals. For
contrast, see heritability. (p. 369)
episodic
memory
Explicit
memory of past events (episodes) in one's own life. For
contrast, see semantic memory, implicit memory. (p. 343)
error
A
technical term referring to random variability in research
results. For contrast, see bias. (p. 41)
ethology
The
study of animal behavior in the natural environment, which
uses evolutionary adaptation as its primary explanatory
principle. (pp. 16, 72)
excitatory
synapse
A
synapse at which the neurotransmitter increases the likelihood
that an action potential will occur, or increases the rate
at which they are already occurring, in the neuron on which
it acts. For contrast, see inhibitory synapse. (p. 168)
experiment
A
research design for testing hypotheses about cause-effect
relationships, in which the researcher manipulates one variable
(the independent variable) in order to assess its effect
on another variable (the dependent variable). (p. 33)
explication
In
Karmiloff-Smith's theory, the mental process by which previously
implicit memories are transformed into explicit memories.
(p. 417)
explicit
memory
The
class of memory that can be consciously recalled and used
to answer explicit questions about what one knows or remembers.
See episodic memory, semantic memory. For contrast, see
implicit memory. (p. 343)
exposure
treatment
Any
method of treating fears--including flooding and systematic
desensitization--that involves exposing the client to the
feared object or situation (either in reality or imagination)
so that the process of extinction or habituation of the
fear response can occur. (p. 671)
extinction
In
classical conditioning, the gradual disappearance of a conditioned
reflex that results when a conditioned stimulus occurs repeatedly
without the unconditioned stimulus. (p. 105) In operant
conditioning, the decline in response rate that results
when an operant response is no longer followed by a reinforcer.
(p. 114) See classical conditioning, operant conditioning.
eyebrow
flash
A
momentary raising of the eyebrows, lasting about one-sixth
of a second, which is a nonverbal sign of greeting in cultures
throughout the world. (p. 74)
F
fact
An
objective statement, usually based on direct observation,
that reasonable observers agree is true. In psychology,
facts are usually particular behaviors, or reliable patterns
of behaviors, of persons or animals. (p. 31)
factor
analysis
A
statistical procedure for analyzing the correlations among
various measurements (such as test scores) taken from a
given set of individuals; it identifies hypothetical, underlying
variables called factors that could account for the observed
pattern of correlations and assesses the degree to which
each factor is adequately measured by each of the measurements
that was used in the analysis. (p. 359)
Fechner's
law
The
idea that the magnitude of the sensory experience of a stimulus
is directly proportional to the logarithm of the physical
magnitude of the stimulus. For contrast, see power law.
(p. 266)
field
study
Any
scientific research study in which data are collected in
a setting other than the laboratory. (p. 36)
field
theory
Lewin's
broad social psychological theory that each person exists
in a field of psychological forces--made up of the person's
own desires, goals, and abilities and the person's perceptions
of others' expectations or judgments--that act simultaneously
to push or pull the person in various directions. (p. 529)
figure
In
perception, the portion of a visual scene that draws the
perceiver's attention and is interpreted as an object rather
than as the background. For contrast, see ground. (p. 281)
fixed
action pattern
Ethologists'
term for a behavior that occurs in essentially identical
fashion among most members of a species (though it may be
limited to one sex or the other), is elicited by a specific
environmental stimulus, and is typically more complex than
a reflex. (p. 73)
flooding
A
behavior therapy technique for treating phobias in which
the person is presented with the feared object or situation
until the fear response is extinguished or habituated. (p.
672)
fluid
intelligence
In
Cattell's theory, the variety of intelligence that enables
one to perceive relationships independent of previous specific
practice or instruction concerning those relationships.
For contrast, see crystallized intelligence. (p. 360)
foot-in-the-door
technique
A
technique for gaining compliance in which one first asks
for some relatively small contribution or favor before asking
for a larger one. Complying with the first request predisposes
the person to comply with the second. (p. 542)
formal-operational
scheme
In
Piaget's theory, the type of mental stimulus that allows
a person to reason about abstract concepts and hypothetical
ideas. See also operations, schemes. (p. 412)
four-walls
technique
A
sales trick in which the salesperson asks a set of leading
questions that cause the potential customer to say things
that would contradict (and cause cognitive dissonance with)
a subsequent refusal to purchase the product that the salesperson
is trying to sell. (p. 542)
fovea
The
pinhead-size area of the retina of the eye in which the
cones are concentrated and that is specialized for high
visual acuity. (p. 242)
fraternal
twins
Two
individuals who developed simultaneously in the same womb,
but who originated from separate zygotes (fertilized eggs)
and are therefore no more genetically similar to one another
than are nontwin siblings; also called dizygotic twins.
For contrast, see identical twins. (p. 59)
free
association
In
psychoanalysis, the procedure in which a patient relaxes,
frees his or her mind from the constraints of conscious
logic, and reports every image and idea that enters his
or her awareness. (p. 649)
free
nerve endings
The
sensitive tips of sensory neurons, located in the skin and
other peripheral tissues, that are not surrounded by specialized
end organs and are involved in the sense of pain. (p. 258)
frequency
For
any form of energy that changes in a cyclic or wave- like
way, the number of cycles or waves that occur during a standard
unit of time. For sound, this physical measure is related
to the psychological experience of pitch. (p. 235)
frequency
distribution
A
table or graph depicting the number of individual scores,
in a set of scores, that fall within each of a set of equal
intervals. (p. A-2)
frontal
lobe
The
frontmost lobe of the cerebral cortex, bounded in the rear
by the parietal and temporal lobes; it contains the motor
area and parts of the association areas involved in planning
and making judgments. (pp. 154, 224)
functionalism
A
school of psychological thought, founded by William James
and others, that focuses on understanding the functions,
or adaptive purposes, of mental processes. For contrast,
see structuralism. (p. 11)
G
ganglion
cells
The
sensory neurons for vision; their cell bodies are located
in the retina, and their axons run by way of the optic nerve
into the brain. (p. 245)
gate-control
theory
Melzack
and Wall's theory that pain will be experienced only if
the input from peripheral pain neurons passes through a
"gate" located at the point that the pain-carrying neurons
enter the spinal cord or lower brainstem. (p. 259)
gender
identity
A
person's subjective sense of being male or female. (p. 465)
general
intelligence
In
Spearman's theory of intelligence (and in other theories
based on Spearman's), the underlying mental ability that
affects performance on a wide variety of mental tests and
accounts for the statistical correlation among scores on
such tests; also called g. (p. 359)
generalization
In
classical conditioning, the phenomenon by which a stimulus
that resembles a conditioned stimulus will elicit the conditioned
response even though it has never been paired with the unconditioned
stimulus. (p. 105) In operant conditioning, the phenomenon
by which a stimulus that resembles a discriminative stimulus
will increase the rate at which the animal produces the
operant response, even though the response has never been
reinforced in the presence of that stimulus. (p. 138)
generalized
anxiety disorder
A
mental disorder characterized by prolonged, severe anxiety
that is not consistently associated in the person's mind
with any particular object or event in the environment or
any specific life experience. (p. 610)
genotype
The
set of genes inherited by the individual. See also phenotype.
(p. 56)
Gestalt
principles of grouping
The
rules, proposed by Gestalt psychologists, concerning the
manner by which the perceptual system groups sensory elements
together to produce organized perceptions of whole objects
and scenes. They include the principles of (a) proximity
(nearby elements are grouped together), (b) similarity (elements
that resemble one another are grouped together), (c) closure
(gaps in what would otherwise be a continuous border are
ignored), (d) good continuation (when lines intersect, those
segments that would form a continuous line with minimal
change in direction are grouped together), (e) common movement
(elements moving in the same direction and velocity are
grouped together), and (f) good form (elements are grouped
in such a way as to form percepts that are simple and symmetrical).
(pp. 280-281)
Gestalt
psychology
A
school of psychological thought, founded in Germany, which
emphasizes the idea that the mind must be understood in
terms of organized wholes, not elementary parts. For contrast,
see structuralism. (pp. 12, 279)
gland
Any
bodily structure designed to secrete a chemical substance.
See also endocrine glands. (p. 147)
good
continuation principle
See
Gestalt principles of grouping.
good
form principle
See
Gestalt principles of grouping.
grammar
The
entire set of rules that specify the permissible ways that
smaller units can be arranged to form morphemes, words,
phrases, and sentences in a language. (p. 429)
grammatical
morphemes
The
class of words, suffixes, and prefixes that serve primarily
to fill out the grammatical structure of a sentence rather
than to carry its main meaning. For contrast, see content
morphemes. (p. 428)
grossly
disorganized behavior
A
symptom of schizophrenia in which the person's behaviors
are strikingly inappropriate for the situation. (p. 631)
ground
In
perception, the portion of a visual scene that is interpreted
as the background rather than as the object of attention.
For contrast, see figure. (p. 281)
group
polarization
The
tendency for a group of people who already share a particular
opinion to hold that opinion more strongly--or in a more
extreme form--after discussing the issue among themselves.
(p. 539)
groupthink
A
model of thinking in which members of a group are more concerned
with group cohesiveness and unanimity than with realistic
appraisal of the actions being considered. (p. 541)
H
habituation
The
decline in the magnitude or likelihood of a reflexive response
that occurs when the stimulus is repeated several or many
times in succession. (p. 101)
hair
cells
The
receptor cells for hearing, which are arranged in rows along
the basilar membrane of the cochlea in the inner ear. (p.
236)
hallucination
A
false sensory perception; the experience of seeing, hearing,
or otherwise perceiving something and believing it to be
present, when in fact it is not present. (p. 631)
helping
In
sociobiology, any behavior that increases the survival chance
or reproductive capacity of another individual. See also
altruism, cooperation. (p. 89)
heritability
The
proportion of the variability in a particular characteristic,
in a particular group of individuals, that is due to genetic
rather than environmental differences among the individuals.
For contrast, see environmentality. (p. 368)
heritability
coefficient
A
measure of heritability, which can vary from 0 (no heritability)
to 1 (complete heritability); specifically, variance due
to genes divided by total variance. See heritability. (p.
368)
heterozygous
The
condition in which a pair of genes occupying the same locus
on a pair of chromosomes are different from one another.
For contrast, see homozygous. (p. 58)
heuristic
A
shortcut in problem solving; a rule for reducing the number
of mental operations (or information-processing steps) taken
to solve a problem. For contrast, see algorithm. (p. 390)
higher-order
stimuli
In
direct-perception theory, those stimulus relationships that
the perceptual system detects directly with no mental calculations
necessary. (p. 300)
hippocampus
A
structure in the limbic system of the brain that is essential
for encoding explicit memories for long-term storage. (p.
153)
homeostasis
The
constancy in the body's internal environment that must be
maintained through the expenditure of energy. (p. 187)
homology
In
ethology and comparative psychology, any similarity among
species that exists because of the species' common ancestry.
For contrast, see analogy. (p. 77)
homozygous
The
condition in which a pair of genes occupying the same locus
on a pair of chromosomes are identical to one another. For
contrast, see heterozygous. (p. 59)
hormone
Any
chemical substance that is secreted naturally by the body
into the blood and can influence physiological processes
at specific target tissues (such as the brain) and thereby
influence behavior. (p. 174)
humanistic
psychology
An
approach to understanding the human personality that emphasizes
(a) the person's subjective mental experiences, (b) a holistic
view of the person, and (c) the person's inner drive toward
higher psychological growth. (pp. 19, 592)
hypnosis
A
social interaction in which one person (the subject) voluntarily
experiences a loss of control over his or her own perceptions,
thoughts, or actions and instead perceives, thinks, or acts
in accordance with another person's (the hypnotist's) suggestions.
(p. 341)
hypothalamus
A
small brain structure lying just below the thalamus, connected
directly to the pituitary gland and to the limbic system,
that is especially important for the regulation of motivation,
emotion, and the internal physiological conditions of the
body. (p. 154)
hypothesis
A
specific prediction about what will be observed in a research
study, usually derived from a more general conception or
theory. See also theory. (p. 31)
I
iconic
memory
Sensory
memory for the sense of vision. (p. 317)
identical
twins
Two
individuals who are genetically identical to one another
because they originated from a single zygote (fertilized
egg); also called monozygotic twins. For contrast, see fraternal
twins. (p. 59)
implicit
memory
Memory
that influences one's behavior or thought but does not itself
enter consciousness. See priming, procedural memory. For
contrast, see explicit memory. (p. 344)
impression
management
The
entire set of ways by which people either consciously or
unconsciously attempt to influence other people's impressions
(perceptions and judgments) of them. (p. 531)
imprinting
Ethologists'
term for a relatively sudden and irreversible form of learning
that can occur only during some critical period of the individual's
development. See critical period. (p. 136)
incentive
Any
object or end that exists in the external environment and
toward which behavior is directed. Also called a reinforcer,
reward, or goal. (p. 186)
independent
variable
In
an experiment, the condition that the researcher varies
in order to assess its effect upon some other variable (the
dependent variable). In psychology, it is usually some condition
of the environment or of the organism's physiology that
is hypothesized to affect the individual's behavior. (p.
33)
induction
In
Hoffman's typology of discipline styles, a form of verbal
reasoning in which a parent (or other caregiver) induces
the child to think about his or her actions and the consequences
they have for other people. (p. 458)
inductive
reasoning
Logical
reasoning from the specific to the general; the reasoner
begins with a set of specific observations or facts and
uses them to infer a more general rule to account for those
observations or facts; also called hypothesis construction.
For contrast, see deductive reasoning. (p. 380)
inferential
statistics
Mathematical
methods for helping researchers determine how confident
they can be in drawing general conclusions (inferences)
from specific sets of data. (p. 38)
informational
influence
The
class of social influence that derives from the use of others'
behavior or opinions as information in forming one's own
judgment about the objective nature of an event or situation.
For contrast, see normative influence. (p. 535)
inhibitory
synapse
A
synapse at which the neurotransmitter decreases the likelihood
that an action potential will occur, or decreases the rate
at which they are already occurring, in the neuron upon
which it acts. For contrast, see excitatory synapse. (p.
168)
inner
ear
The
portion of the ear lying farthest inward in the head; it
contains the cochlea (for hearing) and the vestibular apparatus
(for the sense of balance). (p. 236)
insufficient-justification
effect
A
change in attitude that serves to justify an action that
seems unjustified in the light of the previously held attitude.
(p. 512)
interneuron
A
neuron that exists entirely within the brain or spinal cord
and carries messages from one set of neurons to another.
(p. 144)
interview
A
self-report method of data collection in which the individual
being studied (or assessed) answers questions in an oral
dialogue; often used for clinical assessment. (p. 37)
intoxicating
effects of a drug
The
relatively short-term effects on mood and behavior that
stem from the immediate physiological effects of a drug
and that subside as the amount of the drug in the body diminishes.
(p. 625)
introspection
The
process of looking inward to examine one's own conscious
experience; the method used by Titchener and other structuralists.
(p. 10)
iris
The
colored (usually brown or blue), doughnut-shaped, muscular
structure in the eye, located behind the cornea and in front
of the lens, that controls the size of the pupil and in
that way controls the amount of light that can enter the
eye's interior. (p. 242)
J
just-noticeable
difference (jnd)
See
difference threshold.
just-world
bias
The
tendency to believe that life is fair, which can lead people
to assume that individuals who suffer misfortune deserve
their misfortune. (p. 514)
K
kin
selection theory of altruism
The
sociobiological theory that apparent acts of altruism have
come about through natural selection because such actions
are disproportionately directed toward close genetic relatives
and thus promote the survival of others who have the same
genes. See also altruism. (p. 90)
L
laboratory
study
Any
research study in which the subjects are brought to a specially
designated area (laboratory) that has been set up to facilitate
the researcher's ability to control the environment or collect
data. (p. 36)
language-acquisition
device (LAD)
Chomsky's
term for the special, innate characteristics of the human
mind that allow children to learn their native language;
it includes innate knowledge of basic aspects of grammar
that are common to all languages and an innate predisposition
to attend to and remember the critical, unique aspects of
the language. (p. 435)
language-acquisition
support system (LASS)
The
term used by social-learning theorists to refer to the simplification
of language and the use of gestures, that occur when parents
or other language users speak to young children, which helps
children learn language; developed as a complement to Chomsky's
concept of the LAD (language-acquisition device). (p. 437)
latent
learning
Learning
that is not demonstrated in the subject's behavior at the
time that the learning occurs but can be inferred from its
effect on the subject's behavior at some later time. (p.
128)
late-selection
theories
Theories
of attention that maintain that the selective process of
attention occurs relatively late in the mind's analysis
of sensory information, after the information has been analyzed
for meaning. For contrast, see early-selection theories.
(p. 304)
law
of association by contiguity
Aristotle's
principle that if two environmental events (stimuli) occur
at the same time or one right after the other (contiguously),
those events will be linked together in the mind. (pp. 104,
335)
law
of association by similarity
Aristotle's
principle that objects, events, or ideas that are similar
to one another become linked (associated) in the person's
mind (structure of memory), such that the thought of one
tends to elicit the thought of the other. (p. 335)
law
of complementarity
The
observation that certain pairs of limited-wavelength lights
that produce different colors (such as red and green) alone
will produce the perception of white (no color) when mixed.
See also additive color mixing. (p. 248)
law
of effect
Thorndike's
principle that responses that produce a satisfying effect
in a particular situation become more likely to recur in
that situation, and responses that produce a discomforting
effect become less likely to recur in that situation. (p.
110)
learning
The
process or set of processes through which sensory experience
at one time can affect an individual's behavior at a future
time. (p. 99)
leptin
A
hormone produced by fat cells that acts in the brain to
inhibit hunger and regulate body weight. (p. 193)
lesion
Any
localized area of damage in biological tissue, such as in
the brain. (p. 189)
light
adaptation
The
decreased visual sensitivity that occurs when the eyes are
exposed for a period of time to brighter light than was
present before the adaptation period. For contrast, see
dark adaptation. (p. 244)
lightness
constancy
The
tendency to perceive a surface as having the same degree
of lightness or darkness regardless of the amount of light
that illuminates it; also called whiteness constancy. (p.
298)
limbic
system
An
interconnected set of brain structures (including the amygdala
and hippocampus) that form a circuit wrapped around the
thalamus and basal ganglia, underneath the cerebral cortex.
These structures are especially important for the regulation
of emotion and motivation and are involved in the formation
of long-term memories. (p. 153)
linear
perspective
A
pictorial cue for perceiving depth in which the convergence
of parallel lines indicates the distance of objects. Parallel
lines appear to converge as they become more distant. (p.
293)
linguistic
relativity
Whorf's
theory that people who have different native languages perceive
the world differently and think differently from each other
because of their different languages. (p. 391)
localization
of function
The
concept that different, localizable parts of the brain serve
different, specifiable functions in the control of mental
experience and behavior. (p. 7)
locus
In
genetics, a position on a chromosome that contains the DNA
of a single gene. (p. 59)
locus
of control
According
to Rotter, a person's perception of the typical source of
control over rewards. Internal locus of control refers to
the perception that people control their own rewards through
their own behavior, and external locus of control refers
to the perception that rewards are controlled by external
circumstances or fate. (p. 588)
long-term
memory
In
the modal model of the mind, information that is retained
in the mind for long periods (often throughout life). For
contrasts, see sensory memory, short-term memory. (p. 323)
loudness
That
quality of the psychological experience (sensation) of a
sound that is most directly related to the amplitude of
the physical sound stimulus. (p. 235)
M
maintaining
causes of a mental disorder
Those
consequences of a mental disorder--such as the way other
people treat the person who has it--that help keep the disorder
going once it begins. See also precipitating and predisposing
causes of a mental disorder. (p. 607)
maintenance
rehearsal
Any
active mental process by which a person strives to hold
information in short-term memory for a period of time. For
contrast, see encoding rehearsal. (p. 325)
major
depression
A
mental disorder characterized by severe depression that
lasts essentially without remission for at least 2 weeks.
(p. 615)
materialism
Hobbes's
theory that nothing exists but matter and energy. For contrast,
see dualism. (p. 6)
mean
The
arithmetic average of a set of scores, determined by adding
the scores and dividing the sum by the number of scores.
(pp. 38, A-3)
median
The
center score in a set of scores that have been rank-ordered.
(pp. 38, A-3)
medulla
The
lowest portion of the brainstem, bounded at one end by the
spinal cord and at the other by the pons. It is responsible,
with the pons, for organizing reflexes more complex than
spinal reflexes. (p. 150)
meiosis
The
form of cell division involved in producing egg or sperm
cells, which results in cells that are genetically dissimilar
and that each have half the number of chromosomes of the
original cell. (p. 57)
melatonin
A
hormone secreted by the pineal gland that contributes to
the daily rhythm of sleep and arousal. (p. 216)
memory
1.
The mind's ability to retain information over time. 2. Information
retained in the mind over time. (p. 315)
memory
stores
In
cognitive psychology, hypothetical constructs that are conceived
of as places where information is held in the mind. (p.
316)
mental
disorder
A
disturbance in a person's emotions, drives, thought processes,
or behavior that (a) involves serious and relatively prolonged
distress and/or impairment in ability to function, (b) is
not simply a normal response to some event or set of events
in the person's environment, and (c) is not explainable
as an effect of poverty, prejudice, or other social forces
that prevent the person from behaving adaptively, nor as
a deliberate decision to act in a way that is contrary to
the norms of society. (p. 599)
mental
set
A
habit of perception or thought, stemming from previous experience,
that can either help or hinder a person in solving a new
problem. (p. 387)
method
of magnitude estimation
Stevens's
psychophysical method in which people are asked to estimate
the magnitude of a subjective experience (such as the perceived
loudness of a sound), usually by assigning a number to it.
(p. 267)
midbrain
The
upper portion of the brainstem, bounded at its lower end
by the pons and at its upper end by the thalamus, that contains
neural centers that organize basic movement patterns. (p.
150)
middle
ear
The
air-filled cavity, separated from the outer ear by the eardrum;
its main structures are three ossicles (tiny bones) that
vibrate in response to sound waves and stimulate the inner
ear. (p. 236)
mind
1.
The entire set of an individual's sensations, perceptions,
memories, thoughts, dreams, motives, emotional feelings,
and other subjective experiences. (p. 3) 2. In cognitive
psychology, the set of hypothesized information-processing
steps that analyze stimulus information and organize behavioral
responses. (pp. 17-18)
mitosis
The
form of cell division involved in normal body growth, which
produces cells that are genetically identical to each other.
(p. 56)
Müller-Lyer
illusion
A
visual size illusion in which a horizontal line looks longer
if attached at each end to an outward-extending, V-shaped
object, and looks shorter if attached at each end to an
inward-extending, V-shaped object. (p. 294)
MMPI
The
Minnesota Multiphasic Personality Inventory. A psychometric
personality test that is commonly used for clinical assessment.
See assessment, psychometric personality test. (p. 648)
modal
model of the mind
A
depiction of the mind as a set of memory storage compartments
and control processes for manipulating and moving information.
It has long served as the standard framework for thinking
about the human mind. (p. 316)
mode
The
most frequently occurring score in a set of scores; in a
frequency distribution, the interval that contains the highest
frequency of scores. (p. A-3)
modeling
The
process of teaching a person what to do, or how to do it,
by having the person watch another person (the model) engage
in that behavior. (p. 675)
monogamy
A
mating system in which one female and one male bond only
with each other. For contrast, see polyandry, polygyny,
polygynandry. (p. 83)
monozygotic
twins
See
identical twins.
mood
disorders
A
class of mental disorders characterized by prolonged or
extreme disruptions in mood. It includes the depressive
disorders and bipolar disorders. (p. 614)
moon
illusion
The
illusion by which the moon appears larger when seen near
the horizon and smaller when seen near the zenith, even
though it is objectively the same size and distance from
the viewer in either location. (p. 295)
morphemes
The
smallest meaningful units of a verbal language; words, prefixes,
or suffixes that have discrete meanings. (p. 427)
motion
parallax
The
cue for depth perception that stems from the changed view
one has of a scene or object when one's head moves sideways
to the scene or object; the farther away an object is, the
smaller is the change in view. (p. 292)
motivation
The
entire constellation of factors, some inside the organism
and some outside, that cause an individual to behave in
a particular way at a particular time. See also incentive,
motivational state. (p. 185)
motivational
state
An
internal, reversible condition in an individual that orients
the individual toward one or another type of goal (such
as food or water). This condition is not observed directly
but is inferred from the individual's behavior; also called
a drive. (p. 185)
motor
neuron
A
neuron that carries messages from the brain or spinal cord,
through a nerve, to a muscle or gland. (p. 144)
mutations
Errors
that occasionally and unpredictably occur during DNA replication,
producing a "replica" that is different from the original.
Mutations are believed to be the original source of all
genetic variability. (p. 67)
myelin
sheath
A
casing of fatty cells wrapped tightly around the axon of
some neurons. (p. 144)
N
nativism
The
idea that certain elementary ideas are innate to the human
mind and do not need to be gained through experience; the
philosophical approach to understanding the mind that is
based on that idea. For contrast, see empiricism. (p. 6)
natural
selection
The
selective breeding that results from the obstacles to reproduction
that are imposed by the natural environment; it is the driving
force of evolution. See selective breeding. For contrast,
see artificial selection. (p. 67)
naturalistic
fallacy
The
mistaken belief that whatever is natural (and particularly
whatever is a product of natural selection) is right, good,
or moral. (p. 91)
naturalistic
observation
Any
data-collection procedure in which the researcher records
subjects' ongoing behavior in a natural setting, without
interfering with that behavior. (p. 37)
nature-nurture
debate
The
long-standing controversy as to whether the differences
among people are principally due to their genetic differences
(nature) or differences in their past and present environment
(nurture). (p. 367)
negative
contrast effect
In
operant conditioning, the decline in response rate, when
the size of a reinforcer (or reward) is reduced, to a rate
below that which occurs for subjects that had been receiving
the smaller reinforcer all along. For contrast, see positive
contrast effect. (p. 125)
negative
punishment
In
operant conditioning, the type of punishment in which the
removal of a stimulus (such as taking food or money) when
a response occurs decreases the likelihood that the response
will recur. For contrast, see positive punishment. (p. 117)
negative
reinforcement
In
operant conditioning, the condition in which a response
results in removal of a negative reinforcer. See negative
reinforcer. (p. 117)
negative
reinforcer
In
operant conditioning, a stimulus (such as electric shock
or loud noise) that is removed after a response and whose
removal increases the likelihood that the response will
recur. (p. 117)
negative
symptoms
The
class of symptoms of schizophrenia that are characterized
by the absence of, or reduction in, expected behaviors,
thoughts, feelings, and drives. (p. 631)
nerves
Large
bundles containing the axons of many neurons. Located in
the peripheral nervous system, they connect the central
nervous system with muscles, glands, and sensory organs.
(p. 147)
neural
convergence
In
a sensory system, the funneling of the activity of many
receptor cells upon fewer sensory neurons; high convergence
increases sensitivity at the expense of acuity. More generally,
any case in which a single neuron receives synaptic input
from more than one other neuron. (p. 246)
neurohormone
A
chemical substance that is similar to a neuro-transmitter
in that it is secreted from the axon terminals of neurons
but is classed as a hormone because it is secreted into
blood vessels rather than onto other neurons. (p. 175)
neurons
Single
cells in the nervous system that are specialized for carrying
information rapidly from one place to another and/or integrating
information from various sources; also called nerve cells.
(p. 144)
neurotransmitter
A
chemical substance released from the axon terminal of a
neuron, at a synapse, that influences the activity of another
neuron, a muscle cell, or a glandular cell; also called
a transmitter. (p. 145)
nonregulatory
drive
Any
motivational state (such as the sex drive) that serves some
function other than that of preserving some constancy of
the body's internal environment. For contrast, see regulatory
drive. (p. 188)
normal
distribution
A
bell-shaped frequency distribution in which the mean, median,
and mode are identical and the frequency of scores tapers
off symmetrically on both sides, as defined by a specific
mathematical equation. See frequency distribution. (pp.
64, A-2)
normative
influence
The
class of social influence that derives from people's concern
about what others will think of them if they behave in a
certain way or express a certain belief. For contrast, see
informational influence. (p. 536)
nucleus
In
neuroanatomy, a cluster of cell bodies of neurons within
the central nervous system (not to be confused with the
cell nucleus within each cell). (p. 150)
O
object
permanence
Piaget's
term for the understanding that an object still exists even
when it is out of view. (p. 406)
objective
questionnaire
In
clinical assessment or in personality research, a questionnaire
on which a client or research subject checks off adjectives
or statements that describe his or her own behaviors, thoughts,
or feelings. (p. 647)
observational
learning
Learning
by watching others. See also modeling. (p. 128)
observational
method
Any
data-collection procedure in which the researcher directly
observes the behavior of interest rather than relying on
subjects' self-descriptions. (p. 37)
observer-expectancy
effect
Any
bias in research results that derives from the researcher's
desire or expectation that a subject or set of subjects
will behave in a certain way. See bias, subject-expectancy
effect. (p. 44)
obsessive-compulsive
disorder
A
mental disorder characterized by a repeated, disturbing,
irrational thought (the obsession) that can only be terminated
(temporarily) by performing some action (the compulsion).
(p. 612)
occipital
lobe
The
rearmost lobe of the cerebral cortex, bounded in front by
the temporal and parietal lobes; it contains the visual
area of the brain. (p. 154)
occlusion
A
pictorial cue for perceiving depth in which the closer object
occludes (cuts off) part of the view of the more distant
object. (p. 293)
operant
conditioning
A
training or learning process by which the consequence of
a behavioral response affects the likelihood that the individual
will produce that response again; also called instrumental
conditioning. (pp. 108, 111)
operant
response
Any
behavioral response that produces some reliable effect on
the environment that influences the likelihood that the
individual will produce that response again; also called
instrumental response. (pp. 108, 111)
operation
Piaget's
term for a reversible action that can be performed either
in reality or mentally upon some object or set of objects.
For example, rolling a clay ball into a clay sausage is
an operation, because the sausage can be rolled back again
to form the ball. (p. 410)
opponent-process
theory of color vision
Designed
by Hering to explain the law of complementarity, this theory
holds that units (neurons) that mediate the perception of
color are excited by one range of wavelengths and inhibited
by another (complementary) range of wavelengths. According
to the theory, such units cancel out the perception of color
when two complementary wavelength ranges are superimposed.
See also law of complementarity. (p. 250)
optic
nerve
The
cranial nerve that contains the sensory neurons for vision,
which run from the eye's retina into the brain. (p. 242)
ossicles
Three
tiny bones (the hammer, anvil, and stirrup) in the middle
ear, which vibrate in response to sound waves and stimulate
the inner ear. (p. 236)
outer
ear
The
pinna (the visible, external portion of the ear) and the
auditory canal (the air-filled opening that extends inward
from the pinna to the middle ear). (p. 236)
overjustification
effect
The
phenomenon in which a person who initially performs a task
for no reward (except the enjoyment of the task) becomes
less likely to perform that task for no reward after a period
during which he or she has been rewarded for performing
it. (p. 126)
P
panic
disorder
A
mental disorder characterized by the repeated occurrence
of panic attacks at unpredictable times and with no clear
relationship to environmental events. Each attack involves
an intense feeling of terror, which usually lasts several
minutes and is accompanied by signs of high physiological
arousal. (p. 613)
parallel
processing
In
perception, the early (unconscious) steps in the analysis
of sensory information that act simultaneously on all (or
at least many) of the stimulus elements that are available
at any given moment. For contrast, see serial processing.
(p. 277)
parasympathetic
division of the autonomic motor system
The
set of motor neurons that act upon visceral muscles and
glands and mediate many of the body's regenerative, growth-promoting,
and energy-conserving functions. For contrast, see sympathetic
division of the autonomic motor system. (p. 148)
parental
investment
The
time, energy, and risk to survival involved in producing,
feeding, and otherwise caring for each offspring. (p. 83)
parietal
lobe
The
lobe of the cerebral cortex that lies in front of the occipital
lobe, above the temporal lobe, and behind the frontal lobe;
it contains the somatosensory area of the brain. (p. 154)
partial
reinforcement
In
operant conditioning, any condition in which the response
sometimes produces a reinforcer and sometimes does not.
See reinforcer. (p. 114)
percentile
rank
For
any single score in a set of scores, the percentage of scores
in the set that are equal to or lower than that score. (pp.
A-5 to A-6)
perception
The
recognition, organization, and meaningful interpretation
of sensory stimuli. For contrast, see sensation. (pp. 229,
275)
perceptual
priming
The
class of priming in which the priming stimulus improves
one's ability to identify a specific test stimulus based
on its physical features. See priming. For contrast, see
conceptual priming. (p. 345)
peripheral
nervous system
The
entire set of cranial and spinal nerves that connect the
central nervous system (brain and spinal cord) to the body's
sensory organs, muscles, and glands. (p. 144)
permanent
effects of a drug
Irreversible
forms of bodily damage, including brain damage, that result
from drug use. (p. 625)
personal
identity
The
portion of the self-concept that pertains to the self as
a distinct, separate individual. For contrast, see social
identity. (p. 504)
personal
myth
The
ever-changing self-told story of an individual that gives
a sense of direction and meaning to one's life. (p. 594)
personality
The
relatively consistent patterns of thought, feeling, and
behavior that characterize each person as a unique individual.
(p. 563)
person
bias
The
tendency to attribute a person's behavior too much to the
person's inner characteristics (personality) and not enough
to the environmental situation. Sometimes called the fundamental
attribution error. For contrast, see situation bias. (p.
489)
person
perception
In
social psychology, the processes by which people perceive
and understand each other and themselves. (p. 487)
phenomenological
reality
Humanistic
theorists' term for each person's conscious understanding
of his or her world. (p. 592)
phenomenology
The
study of subjective mental experiences; a theme of humanistic
theories of personality. (p. 592)
phenotype
The
observable properties of an individual's body and behavior.
See also genotype. (p. 56)
phobia
Any
mental disorder characterized by a strong, irrational fear
of some particular category of object or event. (p. 611)
phonemes
The
various vowel and consonant sounds that provide the basis
for a spoken language. (p. 428)
phonological
loop
In
Baddeley's theory, a component of working memory responsible
for holding verbal information. (p. 319)
physiological
psychology
The
study of the physiological mechanisms, in the brain and
elsewhere, that mediate behavior and psychological experiences.
(p. 17)
pictorial
cues for depth perception
The
depth cues that operate not only when viewing real scenes
but can also operate when viewing pictures. They include
occlusion, relative image size for familiar objects, linear
perspective, texture gradient, differential lighting of
surfaces, and (for outdoor scenes) position relative to
the horizon. (pp. 292-293)
pidgin
language
A
primitive system of communication that emerges when people
with different native languages colonize the same region;
it uses words from the various native languages and has
either no or minimal grammatical structure. See also creole
language. (p. 435)
pineal
gland
An
endocrine gland, located above the brainstem, that secretes
the hormone melatonin. (p. 216)
pitch
The
quality of the psychological experience (sensation) of a
sound that is most related to the frequency of the physical
sound stimulus. (p. 235)
PKU
Abbreviation
for phenylketonuria, a genetic disorder caused by a recessive
gene and characterized by the body's inability to break
down phenylalanine (an amino acid found in most protein-containing
foods). (p. 62)
placebo
In
drug studies, an inactive substance given to subjects assigned
to the nondrug group. (p. 46)
placebo
effect
In
psychological research, any effect on a subject's behavior
or feelings that stems from the subject's expectations as
to how he or she should behave or feel as a result of a
particular treatment. (p. 679)
polyandry
A
mating system in which one female bonds with more than one
male. For contrast, see monogamy, polygyny, polygynandry.
(p. 83)
polygenic
characteristic
Any
trait or characteristic for which the observed variation
is affected by many genes. (p. 64)
polygynandry
A
mating system in which a group consisting of more than one
male and more than one female mate with one another. For
contrast, see monogamy, polygyny, polyandry. (p. 83)
polygyny
A
mating system in which one male bonds with more than one
female. For contrast, see monogamy, polyandry, polygynandry.
(p. 82)
pons
The
portion of the brainstem bounded at its lower end by the
medulla and its upper end by the midbrain that is responsible,
with the medulla, for organizing reflexes more complex than
spinal reflexes. (p. 150)
Ponzo
illusion
A
visual size illusion in which two converging lines cause
objects between the two lines to look larger near the converging
ends of the lines and smaller near the diverging ends. (p.
294)
position
relative to the horizon
A
pictorial cue for perceiving depth in which objects nearer
the horizon seem farther away than objects displaced from
the horizon. (p. 293)
positive
contrast effect
In
operant conditioning, the increase in response rate, when
the size of the reinforcer (or reward) is increased, to
a rate that increases above that which occurs for subjects
that had been receiving the larger reinforcer all along.
For contrast, see negative contrast effect. (p. 125)
positive
punishment
In
operant conditioning, the type of punishment in which the
presentation of a stimulus (such as an electric shock or
scolding) when a response occurs decreases the likelihood
that the response will recur. For contrast, see negative
punishment. (p. 117)
positive
reinforcement
In
operant conditioning, the condition in which a response
results in a positive reinforcer. (p. 117)
positive
reinforcer
In
operant conditioning, a stimulus (such as food or money)
that is presented after a response and that increases the
likelihood that the response will recur. (p. 117)
positron
emission tomography (PET)
A
visual display of brain activity that is based upon the
uptake of a radioactive form of oxygen into active areas
of the brain. (p. 164)
posttraumatic
stress disorder
A
mental disorder that is directly and explicitly tied to
a particular traumatic incident or set of incidents (such
as torture) that the affected person has experienced. (p.
613)
power
law
In
psychophysics, Stevens's idea that the intensity of a sensation
is directly proportional to the intensity of the physical
stimulus raised by a constant power. For contrast, see Fechner's
law. (p. 267)
precipitating
causes of a mental disorder
The
events that most immediately bring on a mental disorder
in a person who is sufficiently predisposed for the disorder.
See also maintaining and predisposing causes of a mental
disorder. (p. 607)
predisposing
causes of a mental disorder
Those
conditions that are in place well before the onset of a
mental disorder and that make the person susceptible to
the disorder. They may include genetic predisposition, early
childhood experiences, and the sociocultural environment
in which one develops. See also maintaining and precipitating
causes of a mental disorder. (p. 607)
preoperational
scheme
In
Piaget's theory, mental structures that permit the child
to symbolize objects and events that are absent, but do
not permit the child to think about the operations that
can be performed on objects. See also operations, schemes.
(p. 411)
primary
motor area
An
area in the rear part of the frontal lobe of the cerebral
cortex that is directly involved in the control of movements,
especially finely coordinated movements of small muscles,
as in the fingers and vocal apparatus. (p. 154)
primary
reinforcer
In
operant conditioning, a stimulus, such as food or water,
that is innately reinforcing. See reinforcer. For contrast,
see secondary reinforcer. (p. 116)
primary
sensory areas
Specialized
areas of the cerebral cortex that receive input from sensory
nerves and tracts by way of the relay nuclei in the thalamus.
They include the visual area (in the occipital lobe), auditory
area (in the temporal lobe), and somatosensory area (in
the parietal lobe). (p. 154)
priming
The
implicit memory process by which a stimulus (the priming
stimulus) activates (makes more retrievable) one or more
memories that already exist in a person's mind. See conceptual
priming, implicit memory, perceptual priming. (p. 345)
prisoner's
dilemma games
A
class of laboratory games in which the tendency to compete
can be pitted against the tendency to cooperate. In such
games, the highest combined payoff to the two players occurs
if both choose the cooperative response, but the highest
individual payoff goes to a player who chooses the competitive
response on a play in which the other chooses the cooperative
response. (p. 550)
proactive
interference
The
loss of memory for one set of information that results from
the prior learning of another (usually similar) set of information.
For contrast, see retroactive interference. (p. 333)
procedural
memory
The
class of implicit memory that enables a person to perform
specific learned skills or habitual responses. See implicit
memory. (p. 344)
projection
The
defense mechanism by which a person consciously experiences
his or her own unconscious emotion or wish as though it
belongs to someone else or to some part of the environment.
(p. 586)
projective
tests
Psychological
tests involving free association, in which the person being
tested is presented with an ambiguous stimulus and is asked
to tell a story or to say quickly, without logical explanation,
what the stimulus looks like. See also free association,
projection. (p. 649)
proximate
explanations
Explanations
of behavior that state the immediate environmental conditions
or the mechanisms within the individual that cause the behavior
to occur. For contrast, see ultimate explanations. (p. 70)
proximity
principle
See
Gestalt principles of grouping.
psychoactive
substance-use disorder
The
class of mental disorders characterized by drug abuse or
dependence. (p. 624)
psychoanalysis
1.
The theory of the mind developed by Freud, which emphasizes
the roles of unconscious mental processes, early childhood
experiences, and the drives of sex and aggression in personality
formation; also called psychoanalytic theory. (pp. 18, 583)
2. Freud's therapy technique in which such methods as free
association, dream analysis, and analysis of transference
are used to learn about the person's unconscious mind; the
goal is to make the unconscious conscious. (p. 657)
psychodynamic
theories of personality
Any
theory that describes personality and its development in
terms of inner mental forces that are often in conflict
with one another and are shaped by experiences in early
childhood. (p. 583)
psychodynamic
therapy
Any
approach to psychotherapy that is based on the premise that
psychological problems are manifestations of inner mental
conflicts and that conscious awareness of those conflicts
is a key to recovery. See also psychoanalysis. (p. 657)
psychological
reactance
A
social psychological phenomenon in which too much pressure
to respond a certain way pushes the person to behave in
the opposite way. (p. 544)
psychology
The
science of behavior and the mind. (p. 3)
psychometric
personality test
An
objective questionnaire that has been developed through
systematic, statistically based methods (usually involving
factor analysis) to assess a wide range of personality characteristics.
See MMPI. (p. 648)
psychophysics
The
scientific study of the relationship between physical characteristics
of stimuli and the psychological (sensory) experiences that
the stimuli produce. (p. 231)
psychotherapy
Any
formal, theory-based, systematic treatment for mental problems
or disorders that uses psychological means (such as dialogue
or training) rather than physiological means (such as drugs)
and is conducted by a trained therapist. (p. 657)
punishment
In
operant conditioning, the process through which the consequence
of a response decreases the likelihood that the response
will recur. For contrast, see reinforcement. (p. 117)
pupil
The
hole in the center of the iris of the eye through which
light passes. See iris. (p. 242)
Q
questionnaire
A
self-report method of data collection or clinical assessment
method in which the individual being studied (or assessed)
checks off items on a printed list, answers multiple-choice
questions, or writes out answers to essay questions aimed
at producing a self-description. (p. 37)
R
rationalization
The
defense mechanism by which a person uses conscious reasoning
to justify or explain away his or her harmful or irrational
behaviors or thoughts. (p. 586)
rational-emotive
therapy
A
type of cognitive therapy developed by Albert Ellis, based
on the idea that people's irrational interpretations of
their experiences, not the experiences themselves, cause
their negative emotions. (p. 667)
reaction
formation
The
defense mechanism by which the mind turns a frightening
wish into its safer opposite. (p. 586)
receptive
field
For
any neuron in the visual system, that portion of the retina
that, when stimulated by light, results in a change in electrical
activity in the neuron. More generally, a property of a
neuron in any sensory system; it is the area of sensory
tissue (or set of receptor cells) that, when stimulated
by an appropriate stimulus, produces an electrical change
in the neuron in question. (p. 245)
receptor
potential
The
electrical change that occurs in a receptor cell (such as
a rod or cone in the eye, or a hair cell in the inner ear)
in response to the energy of a physical stimulus (such as
light or sound). (p. 233)
receptors
Specialized
biological structures--which in some cases are separate
cells and in other cases are the sensitive tips of sensory
neurons--that respond to physical stimuli by producing electrical
changes that can initiate neural impulses. (p. 232)
recessive
gene
A
gene that will produce its observable effects only in the
homozygous condition, that is, only when paired with a gene
that is identical to it. (p. 59)
reciprocity
norm
The
widespread sense of obligation that people have to return
favors. (p. 543)
reciprocity
theory of altruism
The
sociobiological theory that apparent acts of altruism have
come about through natural selection because they are actually
forms of long-term cooperation rather than true altruism.
See also altruism, cooperation. (p. 90)
reference
group
A
group of people with whom an individual compares himself
or herself for the purpose of self-evaluation. See also
social comparison. (p. 501)
reflex
A
simple, relatively automatic, stimulus-response sequence
mediated by the nervous system. See response, stimulus.
(p. 101)
reflexology
An
approach to understanding human behavior, developed by physiologists
in the nineteenth century, that was based on the premise
that all behavior occurs through reflexes. (p. 7)
regulatory
drive
Any
motivational state (such as hunger or thirst) that helps
maintain some constancy of the body's internal environment
that is necessary for survival. For contrast, see nonregulatory
drive. (p. 188)
reinforcement
In
operant conditioning, the presentation of a positive reinforcer
or removal of a negative reinforcer when a response occurs,
which increases the likelihood that the subject will repeat
the response. See negative reinforcer, positive reinforcer.
For contrast, see punishment. (p. 117)
reinforcer
In
operant conditioning, any stimulus change that occurs after
a response and tends to increase the likelihood that the
response will be repeated. See negative reinforcer, positive
reinforcer.
relative
image size for familiar objects
A
pictorial cue for perceiving depth in which one infers the
distance of familiar objects based upon their known actual
sizes and the size of their retinal images. (p. 293)
reliability
The
capacity of a measurement system to produce similar results
each time it is used with a particular subject or set of
subjects under a particular set of conditions. (p. 43)
REM
(rapid eye movement) sleep
The
recurring stage of sleep during which the EEG resembles
that of an alert person, rapid eye movements occur, the
large muscles of the body are most relaxed, and true dreams
are most likely to occur. It is sometimes called emergent
stage 1. For contrast, see slow-wave sleep. (p. 208)
repression
The
defense mechanism by which the mind prevents anxiety-provoking
ideas from becoming conscious. (p. 585)
resting
potential
The
constant electrical charge that exists across the membrane
of an inactive neuron. (p. 166)
retina
A
thin membrane of cells that lines the rear interior of the
eyeball; it contains the receptor cells for vision (rods
and cones). (p. 242)
retrieval
In
the modal model of the mind, the mental process by which
long-term memories are brought into working memory where
they become part of the flow of thought. See also long-term
memory, working memory. (p. 322)
retrieval
cue
A
word, phrase, or other stimulus that helps one retrieve
a specific item of information from long-term memory. (p.
335)
retroactive
interference
The
loss of memory for one set of information that results from
the subsequent learning of another (usually similar) set
of information. For contrast, see proactive interference.
(p. 333)
reversible
figure
A
visual stimulus (usually a picture) in which any given part
is seen sometimes as the figure and other times as the ground.
(p. 282)
rhodopsin
The
photochemical in rods that undergoes structural changes
in response to light and thereby initiates the transduction
process for rod vision. (p. 242)
rod
vision
The
low-acuity, high-sensitivity, noncolor vision that occurs
in dim light and is mediated by rods in the retina of the
eye. For contrast, see cone vision. (p. 243)
rods
The
class of receptor cells for vision that are located in the
peripheral portions of the retina (away from the fovea)
and are most important for seeing in very dim light. For
contrast, see cones. (p. 242)
Rorschach
test
A
widely use projective test in which symmetrical inkblots
are presented and the person is asked what the inkblots
look like. (p. 650)
S
schema
The
mental representation of a concept; the information stored
in long-term memory that allows a person to identify a group
of different events or items as members of the same category.
(p. 339)
schemes
Piaget's
term for the mental entities that provide the basis for
thought and that change in a stagelike way through development.
They contain information about the actions that one can
perform on objects, either in reality or symbolically in
the mind. (p. 409)
schizophrenia
A
serious class of mental disorder that is characterized by
disrupted perceptual and thought processes, often including
hallucinations and delusions. (p. 630)
science
An
approach to answering questions that is based on the systematic
collection and logical analysis of objectively observable
data. (p. 3)
script
A
variety of schema that represents in memory the temporal
organization of a category of event (such as the sequence
of occurrences at a typical birthday party). (p. 339)
seasonal
affective disorder (SAD)
A
mood disorder characterized by severe depression in the
fall and winter, apparently caused by reduced daylight.
(p. 619)
secondary
reinforcer
In
operant conditioning, a stimulus that has acquired reinforcing
capacity through previous training, usually through serving
as a discriminative stimulus for some other reinforced response.
See reinforcer. For contrast, see primary reinforcer. (p.
116)
selective
breeding
The
mating of those members of a strain of animals or plants
that manifest a particular characteristic, which may or
may not be done deliberately, to affect the genetic makeup
of future generations of that strain; can be used to assess
heritability. (p. 65)
self-actualization
In
humanistic psychology, the fulfillment of drives that go
beyond one's survival needs and pertain to psychological
growth, creativity, and self-expression. (p. 593)
self-conscious
emotions
The
feelings of guilt, shame, embarrassment, and pride, which
are linked to thoughts about the self or one's own actions.
(p. 526)
self-efficacy
A
person's subjective sense of his or her own ability to perform
a particular task or set of tasks. (p. 589)
self-monitoring
A
personality characteristic defined as sensitivity to other
people's immediate reactions to oneself, combined with a
desire and ability to control those reactions. (p. 532)
self-report
method
A
data-collection method in which the people being studied
are asked to rate or describe their own behaviors or mental
states. See also interview, questionnaire. (p. 37)
self-serving
attributional bias
The
tendency of people to attribute their successes to their
own qualities and their failures to the situation. (p. 503)
semantic
memory
One's
storehouse of explicit general knowledge, that is, of knowledge
that can be expressed in words and is not mentally tied
to specific experiences in one's own life. Semantic memory
includes, but is not limited to, one's knowledge of word
meanings. For contrasts, see episodic memory, implicit memory.
(p. 343)
sensation
The
psychological experience associated with a sound, light,
or other simple stimulus and the initial information-processing
steps by which sense organs and neural pathways take in
stimulus information from the environment. For contrast,
see perception. (p. 229)
sensorimotor
scheme
In
Piaget's theory, the type of mental structure that enables
an infant to act on objects that are immediately present
but does not permit thought about objects that are absent.
See also schemes. (p. 411)
sensorineural
deafness
Deafness
due to damage to the cochlea, the hair cells, or the auditory
neurons. (p. 237)
sensory
adaptation
The
temporary decrease in sensitivity to sensory stimulation
that occurs when a sensory system is stimulated for a period
of time, and the temporary increase in sensitivity that
occurs when a sensory system is not stimulated for a period
of time. See also dark adaptation, light adaptation. (p.
233)
sensory
areas of the cerebral cortex
See
primary sensory areas.
sensory
memory
In
the modal model of the mind, the memory trace that preserves
the original information in a sensory stimulus for a brief
period (less than 1 second for sights and up to 3 seconds
for sounds) following the termination of the stimulus; it
is experienced as if one is still sensing the original stimulus.
For contrasts, see long-term memory, short-term memory.
(p. 317)
sensory
neuron
A
neuron that carries messages from a sensory organ, through
a nerve, into the brain or spinal cord. (pp. 144, 232)
sensory
physiological psychology
The
scientific study of the relationship between physiological
responses in sensory organs and the nervous system and the
psychological (sensory) experiences that accompany those
responses. (p. 231)
sensory
physiology
The
scientific study of the relationship between environmental
stimuli and the physiological responses they produce in
sensory organs and the nervous system. (p. 231)
sensory
store
The
first memory store in the modal model of the mind; the hypothetical
place in the mind where information is retained in its original
sensory form for a very brief period. (p. 317)
serial
processing
The
steps in the processing of sensory information that operate
sequentially, an item at a time, on the available sensory
information. For contrast, see parallel processing. (p.
278)
shape
constancy
The
tendency to perceive an object as having the same shape
even though the retinal image changes shape when the object
is viewed from different positions. (p. 298)
shaping
An
operant-conditioning procedure in which successively closer
approximations to the desired response are reinforced until
the response finally occurs. See reinforcement. (p. 113)
short-term
memory
See
working memory. (p. 318)
sign
stimulus
Ethologists'
term for any stimulus (well-defined environmental event)
that elicits a fixed action pattern. See fixed action pattern.
(p. 73)
similarity
principle
See
Gestalt principles of grouping.
situation
bias
The
tendency to attribute a person's behavior too much to the
environmental situation and not enough to the person's inner
characteristics. For contrast, see person bias. (p. 491)
size
constancy
The
perceptual ability to see an object as the same size despite
change in image size as it moves farther away or closer.
(pp. 294, 298)
skeletal
motor system
The
set of peripheral motor neurons that act upon skeletal muscles.
(p. 147)
skeletal
muscles
The
muscles attached to bones, which produce externally observable
movements of the body when contracted. For contrast, see
visceral muscles. (p. 147)
slow-wave
sleep
Stages
2, 3, and 4 of sleep characterized by the prominent occurrence
of slow (delta) waves in the EEG. For contrast, see REM
(rapid eye movement) sleep. (p. 208)
social
comparison
Any
process in which an individual evaluates his or her own
abilities, characteristics, ideas, or achievements by comparing
them with those of other people. See also reference group.
(p. 501)
social
development
The
person's developing capacity for social relationships and
the effects of those relationships on further development.
(p. 443)
social
dilemma
A
situation in which a particular action will (a) benefit
the individual who takes it, (b) harm the individuals who
don't, and (c) cause more harm than benefit to everyone
if everyone takes it. See prisoner's dilemma games. (p.
549)
social
facilitation
The
tendency to perform a task better in front of others than
when alone. For contrast, see social interference. (p. 533)
social
identity
The
portion of the self-concept that pertains to the social
categories or groups of which the person is a part. For
contrast, see personal identity. (p. 504)
social
impact theory
Latané's
social psychological theory concerning the amount of social
impact that the actual or imagined presence of others will
have on a person. (p. 530)
social
interference
The
tendency to perform a task worse in front of others than
when alone. For contrast, see social facilitation. (p. 533)
social
loafing
The
tendency of people involved in a group effort to slack off
if their individual contributions are not identifiable to
others. (p. 534)
social
phobia
Any
phobia in which the basic fear is of being scrutinized or
evaluated by other people. For contrast, see specific phobia.
(p. 611)
social
pressure
The
entire set of psychological forces that are exerted on an
individual by other people or by the individual's beliefs
about other people. (p. 529)
social
psychology
The
branch of psychology that attempts to understand how the
behavior and subjective experiences of individuals are influenced
by the actual or imagined presence of other people. (pp.
21, 487)
social
referencing
The
process by which infants use the nonverbal emotional expressions
of a caregiver as cues to guide their behavior. (p. 404)
social
skills training
In
behavior therapy, a direct method for training people to
interact more effectively with other people. See also assertiveness
training. (p. 674)
social-cognitive
theories of personality
Theories
of personality that emphasize the roles of beliefs and habits
of thought that are acquired through one's unique experiences
in the social environment. Also called social-learning or
social-cognitive-learning theories. (p. 588)
sociobiology
The
study of social systems in animals from an evolutionary
perspective. (p. 82)
somatization
disorder
A
category of somatoform disorder that is characterized by
vague, unverifiable complaints about many different medical
conditions. (p. 621)
somatoform
disorders
The
class of mental disorders in which the person experiences
bodily ailments in the absence of any physical disease that
could cause them. It includes conversion disorder and somatization
disorder. (p. 621)
somatosensation
The
set of senses that derive from the whole body--such as from
the skin, muscles, and tendons--as opposed to those senses
that come from the special sensory organs of the head. (p.
147)
span
of short-term memory
The
number of pronounceable items of information (such as single,
randomly chosen digits) that a person can retain in short-term
(working) memory at any given time through rote rehearsal.
(p. 319)
spatial
frequency
The
number of repetitions, per unit distance, of the repeating
elements of the image of a pattern on the retina of the
eye. (p. 254)
species-typical
behavior
Any
behavior pattern that is so characteristic of a given species
of animal that it can be used to help identify that species.
(p. 72)
specific
phobia
Any
phobia in which the feared object is a well-defined category
of object (such as snakes) or environmental situations (such
as heights) other than other people. See also phobia. For
contrast, see social phobia. (p. 611)
spinal
nerve
A
nerve that extends directly from the spinal cord. See nerve.
For contrast, see cranial nerve. (p. 147)
spontaneous
recovery
In
both classical and operant conditioning, the return--due
to passage of time with no further testing or training--of
a conditioned response that had previously undergone extinction.
(p. 105)
standard
deviation
A
measure of the variability in a set of scores, determined
by taking the square root of the variance. (pp. 38, A-5)
standardized
score
A
score that is expressed in terms of the number of standard
deviations the original score is from the mean of the original
scores. (p. A-6)
state-dependent
memory
The
improved ability to retrieve information from memory that
occurs when a person is in the same physiological condition
(such as that induced by a drug) that he or she was in when
the memory was originally encoded. (p. 338)
statistical
significance
A
statistical statement of how small the likelihood is that
an obtained result occurred by chance. By convention, research
findings are said to be statistically significant if the
probability is less than 5 percent that the data could have
come out as they did if the research hypothesis were wrong.
(p. 40)
stereotypes
Mental
concepts that people have for particular groups of people
(such as races or ethnic groups) that exaggerate the differences
between groups, minimize the differences among individual
members of the same group, and may provide a basis for prejudice
and discrimination. (p. 495)
strange-situation
test
A
test of an infant's attachment to a particular familiar
person, in which the infant's behavior is observed in an
unfamiliar room while the familiar person and a stranger
move in and out of the room in a preplanned way. (p. 450)
stress-induced
analgesia
The
reduced sensitivity to pain that occurs when one is subjected
to highly arousing (stressful) conditions. (p. 261)
Stroop
interference effect
Named
after J. Ridley Stroop, the effect by which a printed color
word (such as the word red) interferes with a person's ability
to name the color of ink in which the word is printed if
the ink color is not the same as the color named by the
word. (p. 309)
structuralism
A
school of psychological thought, founded principally by
Titchener, whose goal was to identify the basic elements
of the mind and to determine how those elements combine
with one another to produce more complex thoughts. For contrast,
see functionalism. (p. 10)
subject-expectancy
effect
Any
bias in research results that derives from subjects' expectations
or beliefs about how they should feel or behave in response
to the variables imposed in the study. See also bias, observer-expectancy
effect, placebo effect. (p. 46)
sublimation
See
displacement.
subtractive
color mixing
The
mixing of pigments whereby each pigment absorbs a different
set of wavelengths of light that would otherwise be reflected
to the eye. For contrast, see additive color mixing. (p.
247)
superordinate
goals
The
goals shared by two or more groups, which tend to foster
cooperation among the groups. (p. 556)
surface
traits
Traits
(personality characteristics) that are most directly inferred
from a person's external behavior. See also central traits.
(p. 564)
sympathetic
division of the autonomic motor system
The
set of motor neurons that act upon visceral muscles and
glands and mediate many of the body's responses to stressful
stimulation, preparing the body for possible "fight or flight."
For contrast, see parasympathetic division of the autonomic
motor system. (p. 148)
symptom
In
clinical psychology or psychiatry, any characteristic of
a person's actions, thoughts, or feelings that could be
a potential indicator of a mental disorder. (p. 599)
synapse
The
functional connection through which neural activity in the
axon of one neuron influences the action of another neuron,
a muscle cell, or a glandular cell. (p. 145)
syndrome
In
clinical psychology or psychiatry, the entire pattern of
symptoms manifested in an individual's behavior and self-statements,
which, collectively, may constitute evidence of a mental
disorder. (p. 599)
syntax
The
set of grammatical rules for a given language that specifies
how words can be arranged to produce phrases and sentences.
(p. 429)
systematic
desensitization
A
behavior therapy technique for eliminating phobias or fears
in which the client is first trained to relax and then to
imagine various versions of the feared object or scene,
progressing from weak to stronger forms of it, while remaining
relaxed. (p. 671)
T
temporal
lobe
The
lobe of the cerebral cortex that lies in front of the occipital
lobe and below the parietal and frontal lobes that contains
the auditory area of the brain. (p. 154)
temporal-lobe
amnesia
The
loss in memory abilities that occurs as a result of damage
to structures in the limbic system that lie under the temporal
lobe of the cerebral cortex. (p. 348)
texture
gradient
A
pictorial cue for perceiving depth in which the gradual
change in size and density of textured elements (such as
pebbles or blades of grass) indicates depth. (p. 293)
thalamus
The
brain structure that sits directly atop the brainstem; it
functions as a sensory relay station, connecting incoming
sensory tracts to special sensory areas of the cerebral
cortex. (p. 151)
Thematic
Apperception Test (TAT)
A
widely used projective test in which pictures involving
one or more people are presented, and the person being tested
is asked to tell a story about what might be happening in
each picture. (p. 650)
theory
A
belief or set of interrelated beliefs that one has about
some aspect of the universe, which is used to explain observed
facts and to predict new ones. See also hypothesis. (p.
31)
theory
of planned behavior
The
theory that a person's behavioral intention, and hence behavior,
is influenced by (a) the person's own attitude toward the
behavior, (b) the person's belief about other's attitudes
toward the behavior, and (c) the person's sense of his or
her own ability to carry out the behavior. (p. 516)
three-primaries
law
The
observation that one can choose three limited-wavelength
lights (called primaries) and, by mixing them in differing
proportions, match any color that the human eye can see.
See also additive color mixing. (p. 247)
token
In
operant conditioning, a secondary reinforcer (such as money)
that can be saved and turned in later for another reinforcer.
See secondary reinforcer. (p. 116)
token
economy
An
exchange system, adapted for use in a mental hospital or
other institution, in which tokens are awarded for behaving
in specific ways deemed desirable and the tokens can in
turn be exchanged for goods or privileges. (p. 674)
tolerance
See
drug tolerance.
top-down
processes
In
theories of perception, mental processes that bring preexisting
knowledge or expectations about an object or scene to bear
upon the perception of that object or scene. For contrast,
see bottom-up processes. (p. 276)
tract
A
bundle of neural axons coursing together within the central
nervous system; analogous to a nerve in the peripheral nervous
system. (p. 149)
trait
A
hypothetical, relatively stable, inner characteristic that
influences the way a person responds to various environmental
situations. (p. 563)
trait
theories of personality
Theories
of personality that are based on the idea that people can
be described and differentiated in terms of hypothetical
underlying personality dimensions, called traits, which
can be measured by questionnaires or other quantitative
means. (p. 564)
transduction
The
process by which a receptor cell (such as a rod or cone
in the eye, or a hair cell in the inner ear) produces an
electrical change in response to the energy of a physical
stimulus (such as light or sound). (p. 232)
trichromatic
theory of color vision
Proposed
independently by Young and Helmholtz to explain the three-primaries
law of color vision, this theory holds that the human ability
to perceive color is mediated by three different types of
receptors, each of which is most sensitive to a different
range of wavelengths. See also three-primaries law. (p.
249)
U
ultimate
explanations
Functional
explanations of behavior that state the role that the behavior
plays or once played in survival and reproduction, that
is, explanations of why the potential for the behavior was
favored by natural selection. For contrast, see proximate
explanations. (p. 70)
unconditioned
reflex
A
reflex that does not depend upon previous conditions in
the individual's experience; an unlearned reflex. For contrast,
see conditioned reflex. (p. 102)
unconditioned
response
A
reflexive response that does not depend upon previous conditioning
or learning. For contrast, see conditioned response. (p.
102)
unconditioned
stimulus
A
stimulus that elicits a reflexive response without any previous
training or conditioning. For contrast, see conditioned
stimulus. (p. 102)
unconscious-inference
theory of perception
The
theory that perception is the end result of unconscious
reasoning processes in which the mind uses sensory information
as cues to infer the characteristics of objects or scenes
that are being perceived. For contrast, see direct-perception
theory. (p. 288)
V
validity
The
degree to which a measurement system actually measures the
characteristic that it is supposed to measure. (p. 43)
values
The
general, relatively abstract attitudes that people claim
as guiding principles behind their more specific attitudes
and actions; the principled component of the self-concept.
(p. 507)
variance
A
measure of the variability of a set of scores, determined
by obtaining the difference (deviation) between each score
and the mean, squaring each deviation, and calculating the
mean of the squared deviations. (p. A-4)
vestigial
characteristics
Inherited
characteristics of anatomy or behavior that are no longer
useful to the species but were presumably useful at an earlier
time in evolution. (p. 81)
visceral
muscles
Internal
muscles, such as those of the heart, arteries, and gastrointestinal
tract. For contrast, see skeletal muscles. (p. 147)
visual
constancies
Those
characteristics of objects or scenes that remain constant
in our visual perception of them despite changes in the
retinal image. They include size constancy, shape constancy,
and lightness constancy. (p. 298)
visuospatial
sketch pad
In
Baddeley's theory, a component of working memory responsible
for holding visual and spatial information. (p. 319)
W
wavelength
The
physical length of one complete cycle of a wave; for light,
this physical measure is related to the psychological (sensory)
experience of color. (p. 240)
Weber's
law
The
idea that, within a given sensory modality (such as vision),
the difference threshold (amount that the stimulus must
be changed in magnitude to be perceived as different) is
a constant proportion of the magnitude of the original stimulus.
(p. 266)
Wernicke's
aphasia
A
specific syndrome of loss of language ability that occurs
due to damage in a particular part of the brain called Wernicke's
area. Speech in a person with this disorder typically retains
its grammatical structure but loses its meaning due to the
speaker's failure to provide meaningful content words (nouns,
verbs, adjectives, and adverbs); also called fluent aphasia.
For contrast, see Broca's aphasia. (p. 163)
withdrawal
effects
The
physiological, mental, and behavioral disturbances that
can occur when a long-term user of a drug stops taking the
drug. (p. 625)
working
memory
In
the modal model, the memory store that is considered to
be the main workplace of the mind. Among other things, it
is the seat of conscious thought and reasoning. For contrast,
see sensory memory, long-term memory. (p. 318)
Y
Yerkes-Dodson
law
The
idea that the optimal degree of arousal for performing a
task depends on the nature of the task. High arousal is
best for easy tasks and low arousal is best for difficult
tasks. (p. 218)
Z
z
score
The
simplest form of a standardized score; it is the score minus
the mean divided by the standard deviation. (p. A-6)
zone
of proximal development
Vygotsky's
term for the difference between what a child can do alone
and what the child can do in collaboration with a more competent
other. (p. 421)
zygote
The
single cell that is formed when an egg and sperm cell unite;
the first, single-cell form of a newly developing individual.
(p. 58)
