Impaired detection of visual motion in schizophrenia patients.
OBJECTIVE
A recent report demonstrated impaired auditory detection and discrimination in schizophrenia patients. It is suggested that a deficit in attention resulted in flatter slopes of the psychometric functions. Here, we investigated whether these patients showed a similar deficit in another sensory modality. Specifically, we examined a subset of the schizophrenia patients in a visual task involving motion detection.


METHODS
A total of 13 schizophrenia patients and 14 normal controls detected the presence of a group of random dots moving in a coherent direction among other dots moving in random directions. Signal intensity varied from trial to trial. Detection sensitivity and bias were computed using signal detection theory.


RESULTS
The schizophrenia patients were less sensitive in detecting motion stimuli, compared to normal subjects. The decrement in sensitivity varies with signal-to-noise ratio. The two groups did not differ in response bias.


CONCLUSIONS
Schizophrenics were impaired in visual, as well as in auditory, attention, in accordance with the idea that attention impairment may represent a core deficit in schizophrenia.
D000293:Adolescent; D000328:Adult; D005260:Female; D006801:Humans; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010775:Photic Stimulation / Q000379:methods; D012044:Regression Analysis; D012559:Schizophrenia / Q000503:physiopathology*