The Right-Ear Advantage for Dichotic Listening of Speech-Related Stimuli Is Predicted by Both Attentional and Structural Factors: Results from Machine-Learning Analysis of Neuroimaging Data

Vincent J. Schmithorst¹, Rola Farah², Robert W. Keith²

During dichotic presentation of speech-related stimuli, most individuals show a right-ear advantage (REA), recalling with greater accuracy stimuli presented to their right ear. We used multi-voxel pattern analysis (MVPA) on fMRI and DTI data to predict REA or left-ear advantage (LEA) for dichotic listening in children. REA was predicted by lesser axial diffusivity (AD) in the sublenticular part of the left internal capsule, and greater functional activation in the left frontal eye fields (BA 8) for the contrast of diotic vs. dichotic word presentations. Results suggest that REA is not fully explained either by a structural or an attentional model.