Increased stress responsivity in schizotypy leads to diminished spatial working memory performance

Past research has emphasized the association between stress and the manifestation of psychotic symptoms in schizophrenia, yet relatively little is known about how environmental stressors affect cognitive processes in the illness. The present study sought to determine the effects of a loud noise stressor on a range of cognitive tasks, including spatial working memory (SWM), short-term visual memory, and sustained visual attention. Twenty-nine (29) schizotypic subjects and 45 controls performed the cognitive tasks across four waves of data collection: baseline, a noisy stress condition, and two follow-up conditions. Heart rate (BPM) was measured at each wave and subjective ratings of stress were collected in response to the loud noise stressor. Schizotypic subjects exhibited significantly greater increases in BPM during the loud, noisy stressor in comparison to controls. Additionally, schizotypic subjects' subjective ratings of stress in response to the loud noise were significantly greater than the controls' ratings. As hypothesized a priori, schizotypic subjects experienced significant decreases in SWM from baseline to the noisy stress condition in comparison to controls. Performance on non-SWM cognitive tasks did not significantly differ during the noisy stress condition and SWM performance did not significantly differ during noise-free conditions. Results from the present study highlight SWM as being particularly susceptible to loud noise stressors in a schizotypic population. Although the source of the induced impairment is not clear, one possibility is that the encoding stage of SWM was negatively affected by the loud noise.