Neural mechanisms for learning actions in context.

The transition from actions that require effortful attention to those that are exercised automatically reflects the progression of learning. Full automaticity marks the performance of the expert. Research on changes in brain activity from novice to skilled performance has been consistent with this behavioral characterization, showing that a highly practiced skill often requires less brain activation than before practice. Moreover, the decrease in brain activity with practice is most pronounced in the general or executive control processes mediated by frontal lobe networks. Consistent with these human cognitive neuroscience findings, animal neurophysiological evidence suggests that two elementary learning systems support different stages of skill acquisition. One system supports rapid and focused acquisition of new skills in relation to threats and violations of expectancies. The other involves a gradual process of updating a configural model of the environmental context. We collected dense array electroencephalography as participants performed an arbitrary associative ("code learning") task. We predicted that frontal lobe activity would decrease, whereas posterior cortical activity would increase, as the person gains the knowledge required for appropriate action. Both predictions were confirmed. In addition, we found that learning resulted in an unexpected increase in activity in the medial frontal lobe (the medial frontal negativity or MFN). Although preliminary, these findings suggest that the specific mechanisms of learning in animal neurophysiology studies may prove informative for understanding the neural basis of human learning and executive cognitive control.