Visual scanpaths to threat-related faces in deluded schizophrenia

Abstract 

This study examined visuo-cognitive processing of threat-related (anger, fear) and non-threat faces (happy, sad, neutral) in deluded schizophrenia (n=11), non-deluded schizophrenia (n=8), and healthy control (n=22) participants. Focal analyses examined scanpath aberrations for particular facial expressions in sub-groups of schizophrenia patients determined by the presence or absence of overt delusions. Deluded schizophrenia subjects exhibited significantly fewer fixations of shorter duration for all faces, and fewer fixations of reduced duration to the feature areas of negative facial expressions (anger, sad), compared with healthy controls. Compared with non-deluded schizophrenia subjects, deluded subjects exhibited fewer fixations to fear expressions and more fixations to the feature areas of happy expressions. These findings were revealed in the context of restricted scanning (reduced number and duration of fixations, shorter scanpath length and shorter duration of fixations to facial features) in the entire schizophrenia group (n=19) compared with healthy controls. The findings suggest a controlled attentional bias away from the feature areas of negative facial expressions in deluded schizophrenia, that is, specific to threat-related expressions compared with non-deluded schizophrenia subjects. This controlled bias away from negative social stimuli in deluded schizophrenia is discussed in terms of an attentional style of ‘vigilance–avoidance’ operating across early and late stages of information processing.

Keywords:  Visual scanning, Attention, Eye movements, Delusions, Facial affect, Threat