Emotion and Connectionism

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Emotion and Connectionism

• CS6795 Introduction to Cognitive Science
• April 16, 2003
• Peter Jensen

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First some qualifications

• I have very limited neurobiological knowledge
  please correct me if confuse anything
• If you can do a much better job of explaining
  some aspect, please speak up

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Non-technical definitions

• DEPERSONALIZATION - A distortion in how one's own
  body and self feel
• DEREALIZATION - A distortion in how the external
  world is perceived 2
• "Have you ever experienced deja vu?" The response
  if often "Yes" and is described as an
  uncomfortable fleeting shift in perception,
  somewhat odd, but not troubling. I then ask,
  "Imagine if an experience like deja vu never went
  a way, if that perceptual shift remained for the
  rest of your life?"

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Depersonalization and Derealization

• depersonalization coined by Dugas in the late
  19th century
• Felt that the lack of the feeling of agency
  led to a failure in the personalization of
  behavior
• DSM-IV depersonalization is an alteration in
  the perception or experience of the self so that
  one feels detached from, and as if one is in an
  outside observer of, ones mental processes or
  body (e.g., feeling like one is in a dream)

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• Sierra and Berrios use depersonalization to
  refer to both phenomena, as there is no
  conclusive evidence that they are different

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DP as an expression of a biological mechanism

• Two arguments given
• DP-like symptons reported in conjunction with
  Temporal Lobe Epilepsy (TLE)
• Evolutionary view that DP is a vestigial response
  to life-threatening situations
• TLE connection is tenuous but provides insights
• Most results are old and many havent been
  repeated

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Evolutionary Views

• Mayer-Gross (1935), Roth and Argyle (1988) all
  report that DP is something like a pre-formed
  response
• Noyes and Kletti (1977) 66 of subjects report
  partial or complete DP when exposed to
  life-threatening situations conclude that DP
  appears to be an adaptive mechanism for survival
• I couldnt find out what they meant by
  life-threatening situations

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How is DP related to emotions?

• Sherer 1993 among other things, emotions can be
  viewed as a composite of subjective feeling,
  motor expression, and autonomic change
• The dissociation that occurs suggests independent
  modules of control
• It appears that some subset of these elements are
  selectively altered in DP

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Lack of emotional feelings- no fear, affection,
pleasure, etc
Lack of autonomic response- DP patients tend to
have low heart rates, etc
Motor expression- disconnected able to look at
a corpse with no real reaction
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Neurobiology of Emotional Processing

• suggests that the amygdala, anterior
  cingulate, and medial prefrontal cortex are
  salient components of a parallel distributed
  network that integrates emotional responses
  (LeDoux 1994, Devinsky et al 1995).
• Assessment of emotional significance seems to be
  an unconscious process

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Assessment of Emotional Significance

• The fact that feelings of immediacy and
  vividness seem to accompany perceptions that are
  fragmentary and cognitively underprocessed also
  supports the view that emotional feelings play a
  crucial role in the way reality is experienced.
• i.e. emotion is a collective experience DP
  symptoms could be caused by disconnections
  between brain parts

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DP can be limited to certain modalities

• Mayer-Gross(1935) reported that some patients are
  only derealized to visual images closing their
  eyes brings back feelings
• Sierra and Berrios infer that the segregation of
  experiences means that dissociation happens at a
  low level of emotional processing

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Studies on reaction to pain

• DP subjects have a higher threshold for pain than
  others
• Some evidence that they actually feel the pain
  but lack the emotional and motor capabilities to
  give any evidence of it

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SBs Neurobiological Model of Depersonalization

• DP is a hard-wired vestigial response for
  dealing with extreme anxiety combining a state of
  increased alertness with a profound inhibition of
  the emotional response system.

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The Model (page 904, Sierra Berrios)
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Model continued

• Emotional inhibition and vigilant alertness
• Might have evolved to cope with things like
  earthquakes or other dangers which are easy to
  pinpoint
• CNS lesions wont necessarily produce good copies
  of DP, but things will be close
• Model is very simple for now and is limited by
  understanding of underlying neurological
  functioning

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Summary

• A study of depersonalization provides some
  insights into how emotions work thoughts and
  perceptions seem to be emotionally tagged
• New tech that allows for better study of
  individual brain areas with regard to emotions
  will advance this area

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Questions?
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References

• Sierra, Mauricio and Berrios, German E.
  Depersonalization Neurobiological
  Perspectives. Society of Biological Psychiatry,
  vol 44, pages 898-908, 1998.
• http//www.behavenet.com/capsules/disorders/depers
  dis.htm
• http//www.dreamchild.net/mydp.html