Attention and visual reaction time in schizophrenia

Schizophrenic behavior is sometimes characterized by inefficiency and symptoms possibly attributable to difficulties in coordinating attention. In fact, breakdown in cognitive and perceptual processes may be secondary to an initial disorder in mechanisms which coordinate focused attention. These processes were therefore tested in four subgroups of 10 schizophrenics each and in a normal comparison group (N = 10). A visual reaction time task was designed to operationalize definitions of width of cue utilization (responses to number of cues and position of cues), selective attention (color of cues), and ability to develop a set (probability of cues). Perceptual deficit was most prominent among long term nonparanoid schizophrenics who reduced their observation to central position cues when faced with a large number of potentially distracting stimuli. These patients, as well as short term nonparanoid schizophrenics, often failed to differentiate color even though this stimulus information provided an alternative method for reducing the number of stimuli requiring attention. Short term nonparanoid schizophrenics showed broad but disorganized attention to visual cues and inability to develop a probability set. Paranoid schizophrenics were not deviant in coordinated attention.