Experience-dependent activation patterns in human brain during visual-motor associative learning.

Multiple brain regions, including parietal and frontal cortical areas, seem to participate in learning and rehearsing associations between spatially defined visual cues and appropriate motor responses. However, because most previous studies have related learning to changes in brain activation according to elapsed time or number of trials but not categories based on performance, it remains unclear how and when areas implicated in learning sensory-motor associations actually participate in the process. The current experiment used functional magnetic resonance imaging to examine changes in brain activation when participants learned to associate an arbitrarily located visual cue with a finger movement. Associative trials were categorized as incorrect, first correct, or subsequent correct. Participants also performed a spatially compatible visual-motor control task. A group analysis revealed four major findings addressing the behavioral processes occurring during forming and rehearsing visual-motor rules. First, brain networks related to processing associative information, through initial learning to rehearsal, yielded more activation in a myriad of neocortical structures than did a simple motor task. Second, we revealed frontal and parietal areas that differentially processed errors and correct responses. Third, we found frontal-parietal networks that seemed to mediate the transition of learning to rehearsing arbitrary visual-motor associations and that this activation exhibited dynamic characteristics. Last, we found a frontal-parietal network that appeared to have a key role in expressing the learned sensory-motor association. The current results provide a foundation for understanding how neocortical structures participate in the various behavioral processes that combine to form and consolidate novel and arbitrary sensory-motor associations.