Psychophysiology

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Psychophysiology

• Brain Behaviour5PS021

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Aims

• By the end of the session you should be able to
• Define Psychophysiology and describe examples of
  psychophysiological research
• Identify key principles and issues related to
  psychophysiological research
• Discuss the use of psychophysiological measures
  in the polygraph test

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Definitions

• The study of relations between psychological
  manipulations and resulting physiological
  responses, measured in the living organism, to
  promote understanding of the relation between
  mental and bodily processes.
• Andreassi (1995)
• The use of a particular set of
  physiologically-based dependent or independent
  variables to gain insights into psychological
  questions. When done well, psychophysiological
  methods
• provide an independent method
• provide information that is not accessible
  through other psychological methods
• Allen (2004)

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Measures

• Traditional Measures
• Skin conductance
• Cardiovascular measures
• Oculomotor pupilometric measures
• Electromyography
• Electroencephalography
• Event related potentials
• May be lab-based or ambulatory

Newer measures Hormonal measures Brain imaging
techniques Manipulations Biofeedback Trans-crania
l magnetic stimulation
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Examples of Research

• Physiology/behaviour dissociation
• Tranel Damasio (1985, 1988) Prosopagnosic
  patients who were unable to recognise familiar
  faces showed larger Skin Conductance Responses to
  familiar faces.
• Physiological measures as correlates of
  psychological states
• Neural correlates of religious experience, Azari
  et al. (2001) European Journal of Neuroscience,
  13, 1649-1652.

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Examples of Research

• Biological markers for disorder
• Individuals identified as psychopaths have been
  described as showing reduced electrodermal (SC)
  responsiveness (Lykken, 1957) in anticipation of
  aversive events.
• A recent meta-analysis confirmed that lower
  resting and task electrodermal activity was
  associated with psychopathy. Heart rate measures
  were not.
• Lorber (2004). Psychophysiology of Aggression,
  Psychopathy, and Conduct Problems A
  Meta-Analysis. 130(4), July 2004, p 531552
• Fowles (1980) argued that electrodermal
  hyporesponsiveness reflected reduced behavioural
  inhibition.

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Issues

• Concepts
• Stimulus specificity
• Response Stereotypy
• The law of Initial values
• Practical Issues
• Sources of artifact
• Reactivity

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The Polygraph Test

• Typically record
• Skin conductance
• Blood Pressure Heart Rate
• Respiration
• Not allowed in investigations in Europe.
• Commonly used in the US, but defendants
  witnesses cannot be compelled to take a test.
• Widely used in Japan.

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Control Question Test

• Most commonly used technique
• Compares
• Control Questions
• e.g. have you ever told a lie?
• Relevant Questions
• e.g. did you steal money from Fred
• Innocent people expected to respond more to
  control questions
• The guilty person expected to respond more to
  relevant questions

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Evaluation

• Potential bias in studies examining real life
  cases. Test results will influence subsequent
  investigation and the chances of confession.
• Reviews of laboratory studies suggest
• 74-80 of guilty participants correctly
  identified
• 60-84 of innocent participants correctly
  identified.
• Reviews of field studies
• 83-89 of guilty participants correctly
  identified
• 53-75 of innocent participants correctly
  identified
• Studies reviewed by Vrij (2004)

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Guilty Knowledge Test

• Developed by Lykken, (1959, 1974).
• Series of questions describing alternative facts
• e.g. was the murder committed in
• the ballroom?
• the billiard room?
• the kitchen?
• Answer no to every question
• Assumes only the guilty person will recognise,
  and respond to, the correct information.

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Evaluation

• Reviews (Allen, 2004 Ben-Shakhar Elaad, 2003
  Vrij, 2004). generally indicate high correct
  decision rates for innocence (approaching 100),
  lower rates for guilt (around 80)
• Most studies have been lab based, Vrij (2004)
  identified only two field studies. These suggest
  accuracy at detecting guilty participants may be
  lower in the field.
• Various factors, including longer delays before
  testing, are likely to lead to lower correct
  decision rates in real-life situations.
• Any polygraph test may be vulnerable to
  countermeasures. Honts, Hodes, and Raskin (1985)
  showed physical countermeasures can reduce
  detection rates with the CQT.

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ERP measures of Recognition

• Farwell and Donchin (1991) P300 wave in ERPs
• compared
• target stimuli (reponded to)
• Probes (related to targets but not responded to)
• Irrelevant stimuli
• Farwell Donchin reported that there were no
  false positives or false negatives. Around 12.5
  could not be classified.
• Recent lab studies reviewed by Vrij (2004)
  suggest similar detection rates to traditional
  measures.
• Rosenfeld et al. (1991) found detection of guilty
  participants fell from 92 to 37.5 when testing
  occurred one to two weeks after the event, as
  opposed to immediately after.

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Data from Allen, Iacono Danielson (1992) Image
provided by Allen (2004), URL www.sprweb.org/teach
ing/index.htmlLectureMaterials
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fMRI

• Studies are starting to appear using fMRI
• Some use an approach similar to the GKT.
• Others are closer to the CQT.
• Activation in brain areas associated with
  inhibition seems to correlate with lying, but
  there is considerable variation between studies
  and participants.

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Reading

• Ben-Shakhar, G Elaad, E. (2003). The Validity
  of Psychophysiological Detection of Information
  With the Guilty Knowledge Test A Meta-Analytic
  Review. Journal of Applied Psychology, 88(1),
  131-151
• Vrij, A. (2008). Detecting lies and deceit (2nd
  Ed.). Chichester, Wiley.
• The following provide general coverage of
  psychophysiology
• Hugdahl, K. (1995). Psychophysiology The
  Mind-Body Perspective. London Harvard University
  Press.
• Andreassi,J.L. (2000). Psychophysiology Human
  Behavior and Physiological Response (4th Ed.).
  Mahwah, N.J. Lawrence Erlbaum Associates, Inc.
• Stern, R.M., Ray, W.J. Quigley, K.S. (2001)
  Psychophysiological Recording (2nd Ed.) Oxford
  University Press.