Figure 1. Potential fMRI signatures of learning in a specific brain area.

Each panel shows hypothetical activation for the six trained sequences (red) and the six untrained sequences (blue) in the space of two hypothetical voxels. (a) Activation could increase during learning across voxels, indicating additional recruitment of resources involved in skilled behavior. (b) Activation could decrease across voxels, implying that the region performs its function more efficiently. (c) Some voxels (x-axis) could increase activation with training, while others (y-axis) could decrease. This would lead to a shift of the overall activity pattern in the region without an overall net change in activation. (d) Activation patterns specific to each trained sequence could undergo more change than untrained sequences, reflective of plastic reorganization of the sequence representation. Arrow length in the figure indicates the amount of reorganization. (e) One specific form of such reorganization would be increasing dissimilarities (pattern separation) between activity patterns for individual trained sequences.