The neural basis of visual skill learning: an fMRI study of mirror reading

The learning of perceptual skills is thought to rely upon multiple regionsin the cerebral cortex, but imaging studies have not yet provided evidenceabout the changes in neural activity that accompany visual skill learning.Functional magnetic resonance imaging (fMRI) was used to examine changes inactivation of posterior brain regions associated with the acquisition ofmirror-reading skill for novel and practiced stimuli. Multiple regions inthe occipital lobe, inferior temporal cortex, superior parietal cortex andcerebellum were involved in the reading of mirror-reversed compared tonormally oriented text. For novel stimuli, skilled mirror-reading wasassociated with decreased activation in the right superior parietal cortexand posterior occipital regions and increased activation in the leftinferior temporal lobe. These results suggest that learning to read mirror-reversed text involves a progression from visuospatial transformation todirect recognition of transformed letters. Reading practiced, relative tounpracticed, stimuli was associated with decreased activation in occipitalvisual cortices, inferior temporal cortex and superior parietal cortex andincreased activation in occipito-parietal and lateral temporal regions. Byexamining skill learning and item- specific repetition priming in the sametask, this study demonstrates that both of these forms of learning exhibitshifts in the set of neural structures that contribute to performance.