A small study conducted in Germany showed that men with schizophrenia recognize emotions less well than healthy people from body movements and from facial expressions presented as simple moving dots. The work was published in the journal Schizophrenia.
The ability to understand other people's emotions and intentions from nonverbal signals is important for communication. In people with mental disorders, this process may malfunction. In depression and bipolar disorder, recognition of individual emotions, such as sadness, is impaired, while in schizophrenia, difficulties are thought to be broader - patients read emotions less well from the eyes, facial expressions and body movements.
To study this without interference such as clothing or facial features, scientists use point-light displays: only a few white dots move on a screen, positioned at the locations of joints or facial features. Healthy people usually recognize emotions from such patterns, while in schizophrenia accuracy is lower.
The study author, Annika Resch of the University of Tubingen, and her colleagues compared 28 men with schizophrenia or related disorders (mean age 32) and 28 healthy men of the same age. Most patients had a diagnosis of paranoid schizophrenia, eight had schizoaffective disorder (a combination of schizophrenia symptoms and a mood disorder). Almost all were taking medication, and more than half had other conditions, mainly related to substance use.
In the body task, participants watched two-second videos of a walking figure made of 15 dots and decided whether the gait expressed anger or was neutral (144 trials). In the face task, they were shown faces made of 50 dots and asked to determine whether the face was happy or angry (108 trials). Accuracy and response speed were recorded.
Men with schizophrenia made errors more often in both tasks, especially in recognizing faces: about 59% correct responses versus 76% in healthy men. In the body task - approximately 55% versus 63% (50% would correspond to random guessing). Patients also responded more slowly. Both groups performed better with faces than with bodies. The body task proved difficult for everyone mainly because of the angry gait: here the groups did not differ, but patients recognized the neutral gait less well. In faces, they recognized both joy and anger less well.
The scientists call the impairment global: patients show the same overall pattern as healthy people - the same emotions are easier or harder, but with lower accuracy. Among men with schizophrenia, those who performed better on the body task also performed better on the face task; in healthy men there was no such link. In both groups, response speed in one task was associated with speed in the other.
The authors suggest that schizophrenia may affect general mental processes needed for reading both faces and bodies, so difficulties with one go hand in hand with difficulties in the other. However, they emphasize: the sample is small, few emotions were used, only men took part, almost all patients were taking medication and had comorbid conditions. It is unknown whether the difficulties reflect social cognition specifically or more general cognitive problems. Results in larger samples and with a broader set of emotions may differ.