Background: Patients with schizophrenia consistently demonstrate information processing abnormalities assessed with visual masking (VM) tasks, and these deficits have been linked to clinical and functional severity. It has been suggested that VM impairments may be a vulnerability marker in individuals at risk for developing psychosis.
Method: Forward and backward VM performance was assessed in 72 first-episode (FE) psychosis patients, 98 subjects at risk (AR) for psychosis and 98 healthy controls (HC) using two identification tasks (with either a high- or low-energy mask) and a location task. VM was examined for stability in a subgroup (FE, n=15; AR, n=35; HC, n=21) and assessed relative to clinical and functional measures.
Results: In the identification tasks, backward VM deficits were observed in both FE and AR relative to HC whereas forward VM deficits were only present in FE patients compared to HC. In the location task, AR subjects demonstrated superior performance in forward VM relative to HC. VM performance was stable over time, and VM deficits were associated with baseline functional measures and predicted future negative symptom severity in AR subjects.
Conclusions: Visual information processing deficits, as indexed by backward VM, are present before and after the onset of frank psychosis, and probably represent a stable vulnerability marker that is associated with negative symptoms and functional decline. Additionally, the paradoxically better performance of AR subjects in select forward tasks suggests that early compensatory changes may characterize an emerging psychotic state.