Virtual supermarket shopping task for cognitive rehabilitation and assessment of psychiatric patients: Validation in chronic schizophrenia

Abstract

Objectives. Schizophrenia has a debilitating impact on a patient's cognitive functioning and everyday activities. As a part of the treatment, schizophrenia patients attend sessions of cognitive remediation to restore impaired cognitive abilities. To combine cognitive and real life training, this study presents a virtual task to use in cognitive rehabilitation and assessment. Virtual Supermarket Shopping Task (VSST) simulates a shopping activity, in which participants have to memorize and collect items from a virtual supermarket. The aim of this study is to establish its validity for use in clinical practice. Sample and setting. Twenty patients suffering from chronic schizophrenia and twenty healthy controls were tested. Each participant completed the task and a battery of standard neuropsychological tests. Statistical analyses. Groups’ results were compared by Student’s t-tests. Validity of VSST was examined using correlations with standard neuropsychological measures. Several VSST metrics, such as trial difficulty, distances and times, and the effect the extraneous variables have on VSST measures were investigated using analyses of variance and mixed effect models. Results. The analyses demonstrate that patients perform worse in VSST than healthy controls and their performance corresponds to their mnemonic abilities measured by standard neuropsychological tests. VSST performance relates to the level of executive functioning only in patients. There was no effect of gaming experience on VSST performance. While potential gender effect has to be addressed in future studies, age seems to play a role in the additional VSST measures (trial time and distance). Study limitations. Subjects were tested only once and therefore long term benefits of using VSST in rehabilitation could not be investigated. Only schizophrenia patients were included in the sample, which reduces generalizability of results to other psychiatric and neurologic conditions.