The effect of tobacco use on performance in a structure-from-motion task among patients with psychotic psychopathology.

Psychotic disorders are debilitating, in part, due to psychotic symptoms, like hallucinations or delusions. Additionally, patients with psychotic psychopathology (PwPP) typically display reduced cognitive performance on visual-spatial working memory and attention tasks. More recent work has found deficits in early visual processes among PwPP, including center-surround suppression and contour integration, suggesting that abnormal early sensory processing may contribute to distorted sensory percepts and/or hallucinations. One factor that may be relevant to cognitive and perceptual dysfunction in PwPP is nicotine use. PwPP are 2-3 times more likely to use tobacco, and there is evidence that nicotine use among PwPP may be associated with better cognitive functioning. One theory is that PwPP use nicotine to compensate for impaired attention and working memory. On the other hand, tobacco use might have a causal relationship with psychotic illness, as cigarette use among young people is associated with risk of developing psychosis. In terms of perception, we have found that PwPP report faster switch rates during a bi-stable structure-from-motion (SFM) task and that this is associated with smaller changes in pupil size during perceptual switches. This suggests abnormalities in attentional allocation to visual stimuli in this population. Here, we asked whether nicotine use was related to individual or group differences in SFM task performance among PwPP (n = 14), their biological relatives (n = 4), and healthy controls (n = 1). We found a trend towards a significant correlation between faster switch rates and increased tobacco use across groups. However, we did not see a significant correlation when only looking at the PwPP group or significant differences between users and non-users in overall switch rates. Our results suggest a relationship between higher tobacco consumption and greater perceptual dysfunction in our SFM task.