Pupil Dilation and Reported Emotional Response in Schizotypy

1
Pupil Dilation and Reported Emotional Response in
Schizotypy
Linda Brewer, M.A. Stuart Quirk, Ph.D. Joshua
Scott Central Michigan University
2
Abstract

• The purpose of this study was to investigate the
  relative correspondence between emotional
  reactions as indexed by pupil dilation and
  reported arousal in response to evocative
  pictures among individuals high in schizotypy.
  Within-subject correlation analyses from 17 high
  and 17 low SPQ scorers indicated that SPQ scores
  moderated the relationship between arousal
  reports and pupillary response such that high
  scorers showed greater correspondence between
  reports and pupillary reactions. Schizotypal
  individuals may be more in tune with their
  early emotional reactions to activating stimuli.
  Such heightened reactivity may help explain the
  vulnerability to emotional dysregulation, the
  tendency to become overwhelmed, and the
  withdrawal from intense social-emotional
  situations observed in many schizotypic
  individuals.

3
Introduction

• Schizotypal individuals
• Are defined by the presence of sub-clinical
  schizophrenia symptoms including unusual
  perceptions and unconventional beliefs.
• have impaired attention and cognitive functioning
  similar in type (but of less severity) than
  schizophrenia patients (e.g., Lenzenweger, 1998).
• show emotional dysfunction such as interpersonal
  oddness and hostility when emotionally activated
  (e.g., Shean Wais, 2000).
• are clinically described as avoidant with a
  tendency to withdraw into fantasy under emotional
  stress.

4
Introduction

• Information processing deficit models of
  schizophrenia spectrum pathology suggest high
  schizotypic individuals thin grasp on consensual
  reality and cognitive deficits may impair their
  ability to accurately assess and report their
  emotional experiences
• In contrast, psychodynamic notions of schizotypal
  retreat into fantasy presume such defensive
  maneuvers are fueled by a hypersensitivity and
  awareness of internal states of activation
  (McWilliams, 1994).

5
Introduction

• Pupillary responses are useful indices of
  emotional activation and information processing
  (Granholm Steinhauer, 2004).
• The coordination or correspondence between
  emotional response systems was investigated by
  examining the concordance between pupil dilation
  and self-reported arousal responses to emotion
  eliciting pictures.
• There is a modest positive correspondence between
  reported levels of activation and
  psychophysiological measures of arousal in
  response to evocative pictures in non-clinical
  populations (Lang et al., 1997).
• However, these within person correlations are
  highly varied suggesting the presence of
  important individual difference variables may
  influence this correspondence.

6
Hypothesis

• We expected that schizotypy scores would help
  account for variability in the reported
  arousal-activation/engagement correspondence.
• Decreased emotional correspondence among those
  scoring higher on schizotypy would support a
  deficit model of diminished attunement or ability
  to scan and label states of emotional activation.
  
• Greater correspondence among high scoring
  individuals would be consistent with
  psychodynamic ideas of increased emotional
  sensitivity that, in part, motivates
  interpersonal avoidance and retreat into fantasy.

7
Sample

• 1100 undergraduate students were screened using
  the Schizotypal Personality Questionnaire (Raine,
  1991).
• 47 individuals (20 with SPQ scores over 37)
  participated in the second phase of data
  collection. Participants were 53 female, 82
  white with a mean age of 19.
• Usable pupil data were obtained from 34
  participants (17 high SPQ scorers).

8
Methods

• After obtaining written informed consent,
  participants visual acuity was assessed and they
  completed a brief set of questionnaires.
• Participants were seated 24 inches from a 17
  monitor. To minimize head movements during pupil
  recording, participants were placed in adjustable
  chin rest and strapped against a forehead bar.
• Thirty picture slideshow was shown in
  pseudorandom order
• Each picture was shown for 10 seconds
• A 3 second blank screen between images allowed
  participants to return to baseline activation.
• Pictures included pleasant, unpleasant, and
  neutral valenced pictures that were matched for
  overall luminance level.
• Participants were then removed from the head rest
  and presented with the images a second time for a
  period of 6 seconds each and asked to provide
  valence and arousal ratings using Self-Assessment
  Manikin (Lang, 1980).

9
Analyses

• Pupil dilation responses were obtained by
  subtracting the baseline pupil size (mean size
  during the second prior to image display) from
  (1) the initial dilation response within the
  first two seconds of image viewing and from (2)
  the peak pupil size during the remaining 8
  seconds of viewing.
• Within subject correlations were computed by
  correlating each participants pupil reactions
  with their corresponding arousal reports for
  affective images (pleasant and unpleasantly
  evocative pictures). These correlation
  coefficients were then used as correspondence
  scores which were correlated with schizotypy
  symptom scores.

10
Schizotypy Domains and Image Ratings
SPQ Domains
11
Schizotypy and Pupil Response Variables
SPQ Domains
12
Self-Report Results

• Schizotypy scores were weakly related to arousal
  and valence reports with the exception of
  disorganization symptoms.
• Higher levels of disorganization symptoms were
  associated with a pattern of diminished arousal
  reports to pleasant but heightened arousal
  reports to unpleasant images. A multiple
  dependent correlation analysis (Steiger, 1980)
  was used to determine that these correlations
  were significantly different from each other
  given the positive correlation between reported
  arousal to pleasant and unpleasant images, r
  .34,T2(44) -2.76, plt.01.

13
Pupillary Results

• Higher levels of schizotypy were associated with
  diminished peak pupillary reactions to unpleasant
  images.
• The hypothesis that schizotypy scores would
  moderate the relationship between arousal reports
  and pupillary reactions was supported.
• Within subject correlations between reported
  arousal and pupillary responses were greater for
  those reporting more schizotypy symptoms

14
Conclusions

• Greater correspondence between arousal reports
  and pupillary response for those higher in
  schizotypy may indicate greater sensitivity to
  emotionally activating stimuli.
• This notion is consistent with psychodynamic
  models suggesting that schizotypes may be
  hypersensitive to emotional stimulation and tend
  to retreat into fantasy as a way of regulating
  activation.
• Schizotypy was also associated with diminished
  positive arousal reports compared to higher
  reported arousal to unpleasant images.

15
Conclusions

• That schizotypy was associated with diminished
  peak pupil reactions to unpleasant images (but
  not initial pupillary response) may suggest a
  cognitive disengagement during the viewing of
  highly upsetting and activating unpleasant
  images.
• Additional analyses of the time course of
  pupillary reactions would help reveal such a
  pattern.
• If heightened attunement is replicated in
  additional emotional response domains (such as
  skin conductance), these findings pose intriguing
  questions in light of somatosensory deficits
  observed in schizotypy (e.g, Lenzenweger, 2000)

16
References

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