ar 2008b eda bfbk physiol
DESCRIPTION
Dr. Ernesto Korenman's presentation about Electro dermal activity biofeedbackTRANSCRIPT
1
Stress Management and Biofeedback Stress Management and Biofeedback
WorkshopWorkshop
ElectroElectro--dermal Activity (EDA) Physiologydermal Activity (EDA) Physiology
By: Dr. Ernesto Sh. Korenman, July/By: Dr. Ernesto Sh. Korenman, July/20082008Dr. Ernesto Sh. Korenman, 2008
2
Sweat Gland Physiology Sweat Gland Physiology
Dr. Ernesto Sh. Korenman, 2008
3
SkinSkin
Outermost Layer: EpidermisOutermost Layer: Epidermis
Middle Layer: DermisMiddle Layer: Dermis
Deepest Layer: HypodermisDeepest Layer: Hypodermis
Neural innervationsNeural innervations
Blood VesselsBlood Vessels
Sweat GlandSweat Gland
Dr. Ernesto Sh. Korenman, 2008
4
Sweat Sweat GlandsGlands•• Glands secrete Glands secrete 99 99 % water with % water with
dissolved salts, traces of ammonia, dissolved salts, traces of ammonia, and other metabolic byand other metabolic by--products.products.
•• Can collectively produce up to Can collectively produce up to 77--8 8 liters a day.liters a day.
•• Humans contain about Humans contain about 22..5 5 million million sweat glands in our body.sweat glands in our body.
Dr. Ernesto Sh. Korenman, 2008
5
•• One type of sweat gland occurs in the palms, One type of sweat gland occurs in the palms, soles, forehead, and armpitssoles, forehead, and armpits
›› Control body temperatureControl body temperature
›› Function in cold sweats = responses made Function in cold sweats = responses made when you are frightened, nervous or when you are frightened, nervous or embarrassedembarrassed
•• Other sweat glands occur on other body Other sweat glands occur on other body surfacessurfaces
Sweat Glands: typesSweat Glands: types
Dr. Ernesto Sh. Korenman, 2008
6
Control of Eccrine Sweat GlandsControl of Eccrine Sweat Glands
•• Activation is controlled directly by the Activation is controlled directly by the Sympathetic Division of the Autonomic Nervous Sympathetic Division of the Autonomic Nervous System System
•• Paradoxically receive primarily sympathetic Paradoxically receive primarily sympathetic cholinergic fibers (Acetylcholine releasing)cholinergic fibers (Acetylcholine releasing)
2
Dr. Ernesto Sh. Korenman, 2008
7
Skin Conductance and sweatSkin Conductance and sweat
•• Skin conductance Skin conductance begins to change begins to change before moisture before moisture level level
•• As duct fills with As duct fills with sweat, skin sweat, skin conductance conductance increasesincreases
Sweat glandSweat gland
Dr. Ernesto Sh. Korenman, 2008
8
Emotional SweatingEmotional Sweating
Dr. Ernesto Sh. Korenman, 2008
9
SweatSweat--emotion link: the Limbic System emotion link: the Limbic System
•• Limbic System activates the sweating pathway controlled by Limbic System activates the sweating pathway controlled by
the Hypothalamus.the Hypothalamus.
•• Affected by, and responds to, emotional stimulus, such as Affected by, and responds to, emotional stimulus, such as
emotionally charged questionsemotionally charged questions
ThalamusThalamus CortexCortex
MedullaMedullaCerebellumCerebellum
HyppocampusHyppocampus
AmygdalaAmygdala
HypothalamusHypothalamus
Dr. Ernesto Sh. Korenman, 2008
10
Sweat Gland response to stressing soundSweat Gland response to stressing sound
Threatening SoundThreatening Sound
ThalamusThalamus
Auditory CortexAuditory Cortex
Limbic SystemLimbic System
HypothalamusHypothalamus
Sweat Gland responseSweat Gland response
Dr. Ernesto Sh. Korenman, 2008
11
Electrodermal Activity (EDA) Electrodermal Activity (EDA) RecordingRecording
Dr. Ernesto Sh. Korenman, 2008
12
EDA electrodesEDA electrodes
3
Dr. Ernesto Sh. Korenman, 2008
13
What is skin conductance?What is skin conductance?
•• Resistance RResistance R==V/ I (Ohms)V/ I (Ohms)
•• Conductance C Conductance C == 11/ R / R (mho or Siemens)(mho or Siemens)Voltage (V)Voltage (V)
Current (I)Current (I)
BatteryBattery
Dr. Ernesto Sh. Korenman, 2008
14
Sweat gland and skin conductanceSweat gland and skin conductance
Dr. Ernesto Sh. Korenman, 2008
15
Sweat and EDASweat and EDA
•• Phasic skin conduction response (greater conductance) occurs due to filling Phasic skin conduction response (greater conductance) occurs due to filling of the sweat ducts in the epidermis and the constant expulsion of fluids from of the sweat ducts in the epidermis and the constant expulsion of fluids from the sweat poresthe sweat pores
•• Recovery to tonic levels of skin conductance is attributed to deposition of Recovery to tonic levels of skin conductance is attributed to deposition of
moisture on the skin or remoisture on the skin or re--absorption of fluids by the sweat glandsabsorption of fluids by the sweat glands
•• Amount of sweat delivered to the ducts and number of sweat glands that Amount of sweat delivered to the ducts and number of sweat glands that are activated influence the amplitude of the conductance response are activated influence the amplitude of the conductance response
•• Glands on the palmar and plantar surface have been recognized as Glands on the palmar and plantar surface have been recognized as responding to emotional stimuli, with the remainder responding to thermal responding to emotional stimuli, with the remainder responding to thermal
changeschanges
Dr. Ernesto Sh. Korenman, 2008
16
Skin conductance/resistance unitsSkin conductance/resistance units
Dr. Ernesto Sh. Korenman, 2008
17
Skin conductance responseSkin conductance response
•• Skin becomes a better Skin becomes a better conductor of electricity conductor of electricity when external stimuli when external stimuli are presented are presented
Stimulus
Dr. Ernesto Sh. Korenman, 2008
18
Quantification of EDA response (EDR)Quantification of EDA response (EDR)
-- LatencyLatency
-- AmplitudeAmplitude
--RecoveryRecovery
4
Dr. Ernesto Sh. Korenman, 2008
19
SCL graphSCL graph
Cumulated Cumulated stimulistimuli
Recovery Recovery after stimuliafter stimuli
RelaxingRelaxing
Dr. Ernesto Sh. Korenman, 2008
20
Types of real SCL graphTypes of real SCL graph
SteadySteady LabileLabile
Dr. Ernesto Sh. Korenman, 2008
21
Specific (Sp) vs. nonSpecific (Sp) vs. non--specific responsespecific response
Stimulus Stimulus
TW=Time WindowTW=Time Window
SpecificSpecific SpecificSpecific
Non Non SpecificSpecific
Non Non SpecificSpecific
Dr. Ernesto Sh. Korenman, 2008
22
Respiration artifact detectionRespiration artifact detection
InhaleInhale InhaleInhale
SpecificSpecificNon Non SpecificSpecific
Dr. Ernesto Sh. Korenman, 2008
23
SCR to fearful musicSCR to fearful music
Dr. Ernesto Sh. Korenman, 2008
24
Skin
Conduct
ance
Skin
Conduct
ance
Res
ponse
(R
esponse
(µµ
S)
S)
0
1.5
3 Run2
0
1.5
3
10 50 90 130
Time (sec)
Run3
0
1.5
3 Run1
=Tone=Tone
Habituation of SCR to toneHabituation of SCR to tone
5
Dr. Ernesto Sh. Korenman, 2008
25
The EndThe End