This study tested 20 schizophrenia patients to examine the relationship between facial emotion recognition deficits and visual system functioning. The results showed that schizophrenia patients had impaired contrast sensitivity in the magnocellular visual pathway, which processes low spatial frequencies, compared to the parvocellular pathway. Patients also showed significant impairment in recognizing and differentiating facial emotions. Recognition of happy faces was less impaired than other emotions. Recognition deficits correlated with impaired contrast sensitivity in the magnocellular pathway, suggesting visual system dysfunction contributes to difficulties processing facial emotions in schizophrenia.

1. Joseph Asker, Samia Elahi, Bavica Gummadi, Alanna Tarnacki
School of LS&A, University of Michigan, Ann Arbor, MI 48109
Purpose / Objective / Hypothesis
Methods
DiscussionResults
References
Introduction
Conclusions
Schizophrenia patients experience poor social
functionality due to deficits in their ability to recognize
facial emotion. This type of sensory processing is
conducted primarily via the magnocellular circuit
(sensitive to low spatial stimuli frequency) but also
requires the parvocellular circuit (sensitive to high spatial
stimuli frequency) of the visual system.
This correlational study focuses on the magnocellular
and parvocellular visual circuits, hypothesizing that
schizophrenia patients will exhibit deficiencies in
recognizing facial emotion which correlate with impaired
reception of low spatial frequency stimuli.
The lowered sensitivity to LSF stimuli directly
correlates to the decreased perception of contrast,
which has a corresponding effect on the coding of the
sensory information pertaining to facial emotion
recognition. The data from the experiment testing for
contrast sensitivity supports the main idea that
schizophrenia is characterized more so by a
magnocellular deficit, which is important in facial
emotion discrimination, than a parvocellular deficit.
The emotion processing assays show that while
patients are able to recognize happy faces more so
than other emotions, they struggle in differentiating
intensity of this emotion. In addition, patients had
difficulty in emotion recognition across a range of
emotions, which exemplifies that the deficit is in
generalized sensory input rather than in selective
circuits of emotion processing organs. An implication
of these findings is that schizophrenia patients would
neither show conscious awareness of potential
magnocellular deficiencies and would not show
physical visual impairments. A limitation in this study
is that the patients were taking antipsychotic
medication, which may have affected the results of
study. However, the deficits found in this study have
also been observed in unmedicated schizophrenic
patients. It is important to acknowledge that face
emotion recognition also often depends on auditory
emotion recognition. Thus, a followup study could
explore the combined effect of auditory stimuli and
visual stimuli on facial emotion recognition.
Contrast sensitivity
Results show that the schizophrenic patients differ only
in the lower level of spatial frequency, meaning that
their magnocellular system is different from those of
non-schizophrenic patients.
Emotion Processing
Patients showed significant impairment in both the
Emotion Recognition and the Emotion Differentiation
tasks across all emotions. The recognition results
showed identification deficits for all emotions except
happy (Figure 3A). The Emotion Differentiation task
results showed schizophrenic patients having greater
deficits for happy than for sad faces (figure 3B).
There were greater differences between the control and
the schizophrenic patients in the differential tasks than
the recognition tasks but both remain significant.
Figure 1.1 The
graph shows the
statistical difference
between schizophrenic
patients on the
magnocellular level (.5
SF) but not the
parvocellular level
(7SF and 21SF)
This study tested 20 schizophrenia patients for contrast
sensitivity, emotion recognition, and emotion
differentiation.
Contrast Sensitivity: Participants were randomly shown
horizontal gratings for 32ms at spatial frequencies of .5,
7, or 21 cycles/degree. The gratings were shown on
either the left or right side of their visual display with the
other side having a uniform field. Participants were asked
which side of the display contained the grating. The
contrasts were changed until 2 errors were made.
Emotion Recognition Task: A total of 40 color photos of
faces were shown randomly, with 8 photos each of
varying intensity for expressions of happiness, sadness,
anger, fear or neutral. Participants stated which emotion
was expressed from the 5 choices.
Emotion Differentiation Task: In this task, two faces
depicting the same person and emotion, but with varying
intensity, were shown side by side in order to determine
their ability to differentiate intensity of the emotion. From
the 20 trials for each emotion, participants stated which
of the two faces had a higher intensity of the certain
emotion or if they were equal.
Correlational Analysis:
Significant correlations were found between
contrast sensitivity at 0.5 Spatial Frequency and
Emotion Recognition (Figure 3C) and Emotion
Differentiation (Figure 3D). No significant
correlations were made for contrast sensitivity at 7
or 21 Spacial Frequency.
P.D. Butler, I.Y. Abeles, N.G. Weiskopf, A. Tambini, M. Jalbrzikowski, M.E. Legatt,
V. Zemon, J. Loughead, R.C. Gur, D.C. Javitt
Sensory contributions to impaired emotion processing in schizophrenia
Schizophr. Bull., 35 (6) (2009), pp. 1095–1107
Understanding that sensory processing deficits
contribute to difficulties with social cognition in
schizophrenics is helpful for developing effective
treatments that focus on restoration of the
sensitivities of neurons of the visual circuit.