Using simultaneous tdcs and fmri to investigate how brain stimulation enhances complex perceptual learning through modulation of task-relevant brain networks

Abstract

The purpose of this series of experiments was to determine whether transcranial direct current stimulation (tDCS) accelerates perceptual learning on complex visual attention tasks and what neural mechanisms underlie this cognitive enhancement. The first experiment showed that tDCS augmented both skill acquisition and retention in a complex detection task and that the benefits are rooted in an improvement in sensitivity (d’), rather than changes in response bias (ß). The second experiment used simultaneous functional magnetic resonance imaging (fMRI) and tDCS to identify a link between active tDCS-modulated brain activity during learning and modulated brain activity following training that was found to be correlated with visual search improvement. The final experiment investigated changes in resting state brain activity and improvement-related functional connectivity immediately following visual search training as a result of tDCS. This study found that tDCS increases resting state brain activity but did not result in any changes in functional connectivity.