By Galen Huffcutt and Chris Warren

Vestibular Autonomic Interaction During Galvanic Vestibular Stimulation

Vestibular Autonomic Interaction During Galvanic Vestibular Stimulation PDF File


  • Galvanic Vestibular Stimulation (GVS) is a technique used to improve a person's balance.
  • Small electrodes are placed behind the ears and an electric current is applied.
  • How specific is the current to the vestibular system?
  • Branches of the sympathetic nervous system (SNS) are nearby
  • Salivary alpha amylase is a hormonal marker that increases when the transcutaneous vegas nerve has been stimulated
  • If it increases with GVS, then the SNS has also been stimulated
  • Hypothesis: GVS also stimulates the SNS
  • Null hypothesis: It has no effect


  • Sample size: 40
  • 2 60-minute sessions separated by at least 3 days at a maximum of 9 days
  • During one session GVS will be applied, during the other it will be a sham stimulation
  • Saliva will be collected at various times and later assayed for salivary alpha amylase
  • A balance test is also done


  • The project will begin shortly once it is approved by the IRB
  • Either was the results lean, it will still be significant
Person with electrode in ear.
These pictures show the position of the electrodes for taVNS and sham stimulation
This chart shows the schedule of the study
Time Relative to Arrival Activity Stimulation/Sham Time Relative to Stimulation
0 Arrive/Orientation   -32
4 Informed Consent   -28
8 Demographics   -24
12 Saliva Sample 1 (Baseline)   -20
16 Balance Test 1 (Baseline)   -16
20 Set up Device   -12
24   -8
28 Calibrate   -4
32 Balance Test 2 On 0
36 Break Off 4
40 Break On 8
44 Break Off 12
48 Break On 16
52 Break Off 20
56 Break On 24
60 Break Off 28
64 Balance Test 3 On 32
68 Break Off 36
72 Saliva Sample 2 On 40
76 Break Off 44
80 Break On 48
84 Break Off 52
88 Saliva Sample 3 On 56
92 Break Off 60
96 Break On 64
100 Break Off 68
104 Saliva Sample 4 On 72
108 Remove Device   76
112 Balance Test 4   80
116 Debrief   84
120 Leave   88
Man standing on stability plate.
This shows a man standing on a force plate, which increases the stability of a person's center of gravity.
Man spitting into small tube.
The subject will salivate in a marked tube which will later be analyzed for alpha amylase secretion
Vegas nerve.
This shows the auricular branch of the vegas nerve, where we will be stimulating
Time compared to Amylase Secretions.  taVNS increase quick than Sham.
This chart shows the effects of taVNS on alpha amylase secretion. We expect to see similar results