Brain activity supporting working memory accuracy in patients with paranoid schizophrenia: a functional magnetic resonance imaging study.
Wolf C., Linden S., Jackson MC., Healy D., Baird A., Linden DE., Thome J.
BACKGROUND: Dysfunctional working memory (WM) has been recognized as one of the most consistent deficits in schizophrenia. Studies that investigated the neural correlates of WM-related pathology by comparing patients with schizophrenia and control participants have produced controversial results, reporting task-related hyper- or hypoactivity in frontoparietal networks. METHOD: We addressed this question by comparing BOLD signals for accurate responses during a WM task for emotional faces between a homogeneous group of high-performing patients and a control group. RESULTS: Our results confirm previous findings of left prefrontal hyperactivity contrasted with hypoactivity in right prefrontal cortex to support WM performance. We also extend previous work by reporting enhanced activity in higher visual areas of patients during encoding and maintenance. CONCLUSION: Our findings and those of the literature can be integrated into a model, where preserved visual cognition in high-functioning patients with hypofrontality is explained by activation of contralateral homologue areas combined with enhanced recruitment of sensory areas.