Visual integration deficits associated with psychosis are independent of diagnosis

Evidence of altered visual processing is well-established in schizophrenia. Visual integration deficits have been highlighted as a potential diagnostic biomarker to distinguish schizophrenia from other psychiatric disorders. Motivated by the current lack of cross-diagnostic assessments of visual integration performance, the current study used the Jittered Orientation Visual Integration (JOVI) task to assess contour integration performance in 85 psychiatric inpatients split into "schizophrenia spectrum" (n = 40) and "other psychiatric disorders" (n = 45), and healthy controls (n = 43). The study also examined attentional and working memory ability using the Digit Span Task. JOVI accuracy scores were found to be significantly impaired relative to healthy controls for both the schizophrenia (p < 0.001) and other psychiatric (p < 0001) patient groups. In line with a transdiagnostic deficit, no differences in JOVI accuracy were seen between the patient groups (p = 0.97) with reduced JOVI accuracy correlating with worsening psychosis regardless of diagnosis (r = -0.32, p < 0.05). Schizophrenia spectrum patients also showed reduced Digit Span Forward (p < 0.001) and Backward scores (p < 0.001). The other psychiatric (p = 0.024) group were similarly found to be impaired in the Digit Span Backward relative to healthy controls, however no differences were seen between the patient groups. The findings indicate that contour integration deficits are not specific to schizophrenia spectrum disorders, and instead the neurobiological underpinnings of visual integration impairment may share commonality with psychosis more generally. The findings are also consistent with cognitive factors playing a potential role in JOVI performance and highlight the difficulty in teasing apart altered perceptual and cognitive function in psychiatric patient groups.