Musical expertise is related to altered functional connectivity during audiovisual integration

Abstract

The present study investigated the cortical large-scale functional network underpinning audiovisual integration via magnetoencephalographic recordings. The reorganization of this network related to long-term musical training was investigated by comparing musicians to nonmusicians. Connectivity was calculated on the basis of the estimated mutual information of the sources' activity, and the corresponding networks were statistically compared. Nonmusicians' results indicated that the cortical network associated with audiovisual integration supports visuospatial processing and attentional shifting, whereas a sparser network, related to spatial awareness supports the identification of audiovisual incongruences. In contrast, musicians' results showed enhanced connectivity in regions related to the identification of auditory pattern violations. Hence, nonmusicians rely on the processing of visual clues for the integration of audiovisual information, whereas musicians rely mostly on the corresponding auditory information. The large-scale cortical network underpinning multisensory integration is reorganized due to expertise in a cognitive domain that largely involves audiovisual integration, indicating long-term training-related neuroplasticity.

Keywords: MEG; cortical plasticity; functional connectivity; multisensory integration; musical training.

Fig. 1.

Paradigm of an audiovisual congruent and incongruent trial. (A) A congruent trial. (B) An incongruent trial. The line “time” represents the duration of the presentation of the auditory and visual part of the stimulus. The last picture of each trial represents the intertrial stimulus in which subjects had to answer if the trial was congruent or incongruent.

Fig. S1.

Behavioral results. Mean d prime of the behavioral responses of musicians (dark gray) and nonmusicians (light gray) discriminate between congruent and incongruent trials. Error bars indicate 95% confidence interval. The between-group difference is significant at P = 0.001.

Fig. 2.

Cortical network underpinning audiovisual integration. (Upper) Statistical parametric maps of the significant networks for the congruent > incongruent comparison. Networks presented are significant at P < 0.001, FDR corrected. The color scale indicates t values. (Lower) Node strength of the significant networks for each comparison. Strength is represented by node size.

Fig. 3.

Cortical network underpinning audiovisual incongruency identification. (Upper) Statistical parametric maps of the significant networks for the incongruent > congruent comparison. Networks presented are significant at P < 0.05, FDR corrected. The color scale indicates t values. (Lower) Node strength of the significant networks for each comparison. Strength is represented by node size.