Virtual shopping: A viable alternative to direct assessment of real life function?

Objective: Real-life function is markedly impaired in schizophrenia and is an important outcome for interventions, but direct assessment is time consuming and resource intensive. Virtual reality (VR) enables assessment using simulation, akin to real life (RL), but allowing greater experimental control, reliability, and a more timely assessment. This study explores whether VR simulation predicts RL performance in supermarket shopping and how both relate to underlying cognitive abilities. Method: Forty three people with DSM-IV schizophrenia were included in the study. Participants were required to shop for items using a self-directed search in both RL and VR. In each task, accuracy (number of correct items) and efficiency (time taken and number of aisles entered) were measured. IQ, executive function, working memory, spatial memory and social cognition were also assessed. Results: Specific correlations were found between RL accuracy and VR accuracy, and between RL and VR efficiency measures. Multiple regression analyses indicated that VR efficiency measures contributed significant unique variance to RL efficiency outcomes, in addition to that explained by background cognitive measures, with a final model predicting 58% of variance in RL efficiency. Conclusions: VR functional shopping measures may enhance predictions of real life performance, over and above existing cognitive test procedures, and provide a more time-efficient method for evaluating real life outcomes.