Structural and Functional Connectivity Changes Following Cognitive Remediation: A Systematic Review

Abstract

Cognitive remediation (CR) is a learning-based intervention that aims to address the cognitive deficits in schizophrenia, which largely accounts for poor functional outcomes. Studies to understand the neurobiological adaptations after CR, especially on a network scale, have now emerged. We aim to provide an up-to-date review of neuroimaging studies of CR in schizophrenia, by conducting a systematic search of the electronic database till September 2018 to identify studies that included an active patient control group and a sample size of at least ten subjects per group. Eleven studies (four task-based fMRI, four resting-state fMRI, one diffusion tensor imaging, and one structural MRI) were identified, with a majority adopting a brain region-of-interest approach. The outcomes of the findings were largely positive, with most studies observing a group-by-time effect, and an association between brain changes and cognitive improvements. The synthesis of findings to identify common CR-evoked brain changes is hampered by the small number of studies till date and the high variability in CR approach, for instance, the domains of cognition targeted, presence of therapist, duration of CR, and environment in which CR is carried out. While the current findings demonstrate that CR can remodel the neurocircuitries in schizophrenia regardless of the phase of illness, the clinical utility of using neuroimaging markers to predict CR response will hinge on continued work to concurrently identify the active ingredients of CR and neuroimaging tools that can reliably detect subtle CR-led brain changes.