Galvanic skin response & The
polygraph
2010. 05. 26. Ji-Won Kim
Galvanic skin response
GSR


Referred to as the galvanic skin resistance
varies in accordance with the emotional state
of the subject
Feeble electric current is applied between two
electrode
GSP


Referred to as the galvanic skin potential
varies in accordance with the emotional state
of the subject
Two electrode is connected to a suitable
voltage amplifier
GSR의 원리
A change in autonomic tone
(Sympathic nerve system), occuring
in the skin and subcutaneous tissue

Sweating and cutaneous blood flow
GSR의 원리
The increase in sweat lowers the
electrical resistance of the skin


Sweat contain water and electrolyte
Water and electrolyte increase electrical
conductivity of the skin
Various application of GSR
거짓말 탐지기
감성마켓팅
1
2
Various application of GSR
Sports
Polygraph
Literal meaning


Many measures
Poly-many, Graph-write
Be combined with the detection and
recording of other autonomicdependent psychophysiological
variables

Heart rate, respiratory rate and blood pressure
Experimental objectives
Record the GSR
Observe and record changes in
respiratory rate, heart rate and skin
resistance


Associated with somatic and special sensory
stimuli
Associated with cognitive behavior and
emotion
Analyze a 3-channel polygram
recorded under various experimental
conditions
ELECTROOCULOGRAM (EOG)
Visual fixation
 Visual fixation

One of the most important
function the eye
 Two primary
mechanisms


Voluntary fixation mechanism
 Fixation on another person
from across a crowded
room
Involuntary fixation
mechanism
Involuntary movements
Tremor

30-80Hz (cycles/sec)
Slow drifts

Drifting movements of the eyes
Flicking movements

The image is once again projected onto the
fovea
Tracking movements and saccades
Tracking movements


When you wish to follow a moving object
Smooth motion and tracking an object in your
visual field
Saccades


When you read or when objects are streaming
past you
Eye jumps from point to point
 A rate of about three jumps per second
EOG(electrooculogram)
Eye movement can be recorded as an
electrooculogram

Recording of changes in voltage that occur
with eye position
Eye is a spherical “battery”




Positive: front at the cornea
Negative: behind at the retina
Potential: about 0.4~1.0mV
Up to ±70°
EOG(electrooculogram)
EOG(electrooculogram)
Experimental objectives
Fixated on a stationary object vs.
tracking objects
Measure duration of saccades and
fixation during reading
Record spatial position of eye
movements
Thank you
Question?