Learning is based on neuroplasticity, i.e. on the capability of the brain to adapt to new experiences. Different
mechanisms of neuroplasticity have been described, ranging from synaptic remodeling to changes in
complex neural circuitry. To further study the relationship between changes in neural activity and changes in
gray matter density associated with learning, we performed a combined longitudinal functional and
morphometric magnetic resonance imaging (MRI) study on healthy volunteers who learned to decipher
Morse code. We investigated 16 healthy subjects using functional MR imaging (fMRI) and voxel-based
morphometry (VBM) before and after they had learned to decipher Morse code. The same set of Morse-code
signals was presented to participants pre- and post-training. We found an increase in task-specific neural
activity in brain regions known to be critically involved in language perception and memory, such as the
inferior parietal cortex bilaterally and the medial parietal cortex during Morse code deciphering.
Furthermore we found an increase in gray matter density in the left occipitotemporal region, extending
into the fusiform gyrus. Anatomically neighboring sites of functional and structural neuroplasticity were
revealed in the left occipitotemporal/inferior temporal cortex, but these regions only marginally overlapped.
Implications of this morpho-functional dissociation for learning concepts are discussed