Abstract
The visual system is well adapted to recognize human motion from point lights attached to the major joints of an actor. Moreover, individuals are able to recognize emotions based on the visual information in such dynamic point-light displays. This ability is important because humans utilize both biological motion and affect recognition for understanding the intentions of others. Previous studies have demonstrated that people with schizophrenia show impaired performance for explicit visual recognition of emotional point-light walkers, which may contribute more generally to social perception deficits seen in this population. However, our interactions with others are governed by both explicit and implicit visual processes, and it is not clear whether people with schizophrenia process explicit and implicit emotion derived from biological motion in the same way as healthy observers. In the current study, healthy community-based controls (N=33) and people with schizophrenia (N=33) were asked to discriminate the emotions of morphed point-light walkers along three dimensions: happy-angry, happy-sad, and sad-angry. Additionally, stimuli were morphed along a continuum, in which the emotional point-light walkers represented both explicit (i.e., 100% happy and 0% angry) and implicit (i.e., 60% happy and 40% angry) emotion presentation. Using a curve-fitting procedure, slopes of the resulting psychometric functions were used to evaluate implicit processing of emotion, while upper and lower asymptotes were utilized to characterize the explicit processing of emotion. Overall, healthy observers and people with schizophrenia were observed to have similar slopes. However, analysis of both lower and upper asymptotes revealed significant differences between the two groups, despite the fact that performance generally was higher for explicit than implicit stimuli. These results suggest that while people with schizophrenia show perceptual deficits in the recognition of explicit emotion classification from point-light walkers, the processing of implicit emotions seems to be preserved.
Meeting abstract presented at VSS 2013