Increases in grey matter volume induced by perceptual learning

Abstract

Increases in cortical volume associated with practice have been reported after extensive training in complex motor tasks and following long-term cognitive training (e.g.; learning how to juggle and many years of taxi driving). Recent findings suggest plastic processes occurring also on shorter time-scales and it is an open question whether practice in merely perceptual tasks can have similar effects. In this study participants were trained on a motion-colour conjunction search task for five consecutive days (1 h per day). Task difficulty was held constant throughout the training by continuously adjusting motion coherence levels. After training increases in grey matter volume were found in participants' right posterior superior temporal cortex (pSTS), an area associated with the processing of coherently moving stimuli. These changes were positively correlated with performance improvements in the training task and negatively correlated with improvements in an untrained control task. These findings provide further evidence for the brain's ability to flexibly change its structure in order to deal with current task demands. Moreover, the data suggest that the well-documented effects of perceptual learning on behaviour and brain function are accompanied also by structural adjustments.