Measuring autonomic responses to changes in affect in undergraduate laboratory settings: electroderm

1
Measuring autonomic responses to changes in
affect in undergraduate laboratory settings
electro-dermal activity.

• Caroline Brown
• University of the West of England

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The theoretical background

• James-Lange theory
• Bodily reactions to events determine the emotion
  felt
• See somatic theory of emotion, Papanicolaou, 1989
• Cannon-Bard theory
• Subjective emotion and physiological response are
  independent responses
• Textbook Psychology The Science of Mind and
  Behaviour. 2009. Passer et al

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Development of theory

• Schacter (1966) two-factor theory of emotion
• Intensity of physiological arousal strength of
  feeling
• Situational cues labels what we feel
• Parkinson (1995) four-factor theory of emotion

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Other areas of related theory

• Grays (1982) reinforcement sensitivity theory
• Carver White (1994) Behavioral inhibition /
  behavioral activation systems (BIS/BAS)

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Electrodermal activity (EDA)

• Skin conductance
• Skin resistance
• Potential difference
• Reference book(s)
• Stern et al (2001). Psychophysiological
  Recording. Oxford OUP
• Andreassi (2000). Psychophysiology human
  behaviour and physiological response. Hillsdale
  Lawrence Erlbaum

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Autonomic arousal

• Effects based on affective response
• amygdala ? hypothalamus ? ANS
• ?SNS ?cholinergic pathways ?eccrine glands
• EDA quick rise time (1-2s)
• c.f. HR gt 2s, BP gt 5s (recording dependent)
• Simplest of measures to collect
• Little recording noise (c.f. EEG)
• Relatively simple to analyse

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The psychophysiology

• Eccrine sweat glands in palms, soles of feet
  groin
• In many other places but maximal here AND
  responsive to affective stimuli
• ACh driven affective response in SNS
• (usually associated with PsNS)

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Bradley 2009
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Teaching issues

• Large numbers of students
• Appropriate number of amplifiers
• Adequate teaching support
• Simple measures greater understanding

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The EDA practical

• Students work in groups of 4
• 2 x experimenters
• and 2 x participants
• Experimenter 1 takes the psychophysiology
  measures
• Experimenter 2 takes the subjective measures

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Independent Variable

• Affect
• Use a selection of the International Affective
  Pictures System (Lang et al 1994)
• Care to ensure pictures rate similarly on arousal
  and affect within category
• Three levels
• Negative Neutral Positive
• or
• Two levels
• Negative Neutral

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Dependent Variable(s)

• Skin conductance response
• Integral or mean measure over 4-5 seconds
• Subjective ratings of arousal, affect and
  dominance (Lang et al 1994)
• Care is needed here though, as the SAMS ratings
  are scaled and normalised to the IAPS pictures.

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The Self Assessment Manikin scales, Lang et al
1980
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Subjective measures

• Depending on
• year of study
• Level of statistical analysis knowledge
• Size of class
• Affect
• Arousal
• Dominance

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Where to stick the electrodes on the
non-dominant hand
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The IAPs Powerpoint show
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(No Transcript)
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How to run the practical

• Biopac software and MP30 or MP35 amplifiers
• Student experimenter 1 instructed to start
  recording continous to end
• Marks onset and offset of pictures with marker
  keys
• Stimulus presentation
• Student experimenter 2 starts automated
  powerpoint slide show

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Example of recording
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Analysing EDA
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Analysis of data

• Students highlight EDA trace for each stimulus
  event
• Take mean value or integral value
• Record score for slide
• Mean values created for Positive, Neutral and
  Negative conditions
• Alternatives include taking values at 1s, 2s, 3s
  etc intervals after onset of stimulus

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Discussion of lab practical issues 1

• This method is relatively simple to run and
  understand
• Results are variable, and dependent on the times
  of measures used
• For best results use only first 5 seconds
• Methodology can be varied in many ways
• Comparison between genders
• Needs some theoretical development for rationale

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Discussion of lab practical issues 2

• Presentation of stimuli can be through any means
• We use Powerpoint because its as much as we can
  stretch too technically!
• With the current move towards affective and
  social neuroscience, simple measures of autonomic
  arousal are a useful (and cost-effective) means
  of introducing students to neuroscience

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References
Andreassi, J. (2000). Psychophysiology human
behaviour and physiological response. Hillsdale
Lawrence Erlbaum Cannon, W.B. (1927). The
James-Lange theory of emotion A critical
examination and an alternative theory. American
Journal of Psychology, 39, 106-124 Carver, C. S.,
White, T. L. (1994). Behavioral inhibition,
behavioral activation, andaffective responses to
impending reward and punishment The BIS/BAS
scales. Journal of Personality and Social
Psychology, 67, 319333. Gray, J. A. (1982). The
neuropsychology of anxiety An enquiry into the
functions of the septo-hippocampal system.
Oxford Oxford University Press. James, W.
(1950). Principles of psychology (Vol 2). New
York Dover. (Original work published 1890) Lang,
P.J. (1980). Behavioral treatment and
bio-behavioral assessment Computer applications.
In J.B. Sidowski, J.H. Johnson, T.A. Williams
(Eds.), Technology in mental health care
delivery Norwood, NJ. Ablex. Pp 119-137. Lang,
P.J., Greenwald, M.K., Bradley, M.M. Hamm, A.O.
(1993). Looking at pictures Affective, facial,
visceral, and behavioural reactions.
Psychophysiology, 30 261-273 Papanicolaou, A.C.
(2007). What aspects of experience can functional
neuroimaging be expected to reveal? International
Journal of Psychophysiology, 64 (1)
101-105 Passer et al (2009). Psychology The
Science of Mind and Behaviour. London
McGraw-Hill Higher Education Schacter, S. (1966).
The interaction of cognitive and physiological
determinants of emotional state. In C.D.
Spielberger (Ed.), Anxiety and behavior. New
York Academic Press Stern, R et al (2001).
Psychophysiological Recording. Oxford OUP