Rapid functional reorganization in human cortex following neural perturbation.

Despite the human brain's ability to rapidly reorganize neuronal activity patterns in response to interactions with the environment (e.g., learning), it remains unclear whether compensatory mechanisms occur, on a similar time scale, in response to exogenous cortical perturbations. To investigate this, we disrupted normal neural function via repetitive transcranial magnetic stimulation and assessed, using fMRI, activity changes associated with performance on a working memory task. Although transcranial magnetic stimulation disrupted neural activity in task-related brain regions, performance was not affected. Critically, another brain region not previously engaged by the task was recruited to uphold memory performance. Thus, functional reorganization of cortical activity can occur within minutes of neural disruption to maintain cognitive abilities.