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Perception of everyday life events relies mostly on multisensory integration. Hence, studying the neural correlates of the integration of multiple senses constitutes an important tool in understanding perception within an ecologically valid framework. The present study used magnetoencephalography in human subjects to identify the neural correlates of an audiovisual incongruency response, which is not generated due to incongruency of the unisensory physical characteristics of the stimulation but from the violation of an abstract congruency rule. The chosen rule—“the higher the pitch of the tone, the higher the position of the circle”—was comparable to musical reading. In parallel, plasticity effects due to long-term musical training on this response were investigated by comparing musicians to non-musicians. The applied paradigm was based on an appropriate modification of the multifeatured oddball paradigm incorporating, within one run, deviants based on a multisensory audiovisual incongruent condition and two unisensory mismatch conditions: an auditory and a visual one. Results indicated the presence of an audiovisual incongruency response, generated mainly in frontal regions, an auditory mismatch negativity, and a visual mismatch response. Moreover, results revealed that long-term musical training generates plastic changes in frontal, temporal, and occipital areas that affect this multisensory incongruency response as well as the unisensory auditory and visual mismatch responses.

Can learning capacity of the human brain be predicted from initial spontaneous functional connectivity (FC) between brain areas involved in a task? We combined task-related functional magnetic resonance imaging (fMRI) and resting-state fMRI (rs-fMRI) before and after training with a Hindi dental-retroflex nonnative contrast. Previous fMRI results were replicated, demonstrating that this learning recruited the left insula/frontal operculum and the left superior parietal lobe, among other areas of the brain. Crucially, resting-state FC (rs-FC) between these two areas at pretraining predicted individual differences in learning outcomes after distributed (Experiment 1) and intensive training (Experiment 2). Furthermore, this rs-FC was reduced at posttraining, a change that may also account for learning. Finally, resting-state network analyses showed that the mechanism underlying this reduction of rs-FC was mainly a transfer in intrinsic activity of the left frontal operculum/anterior insula from the left frontoparietal network to the salience network. Thus, rs-FC may contribute to predict learning ability and to understand how learning modifies the functioning of the brain. The discovery of this correspondence between initial spontaneous brain activity in task-related areas and posttraining performance opens new avenues to find predictors of learning capacities in the brain using task-related fMRI and rs-fMRI combined.