Brain Connectivity and Laplacian Transformation in Profoundly Deaf Subjects

Vibrotactile discrimination represents a viable alternative to training patients with profound bilateral deafness in language acquisition. However, more information is needed about the impact of vibrotactile discrimination training (VTDT) on the temporal dynamics of neural substrates involved, probably due to several limitations of traditional analysis methods while evaluating the brain's electrical activity. In the present study, a methodology based on the EEG analysis was implemented to localize brain electrical changes at a cortical level by using Laplacian operators to build spatiotemporal reconstructions in a realistic-geometry head model to compare the effect of VTDT in ten prelingual profoundly deaf and ten normal-hearing control subjects, while performing a vibrotactile discrimination task of pure tones. The VTDT prompted distinctive activation of specific temporoparietal zones in deaf individuals, concordant with previous studies on the perceptual integration of auditory-vibrotactile stimuli as a probable effect of a cross-modal interaction in auditory cortices. In brief, the results confirm the methodology's usefulness, which could be used further to study the neurofunctional dynamic underlying vibrotactile discrimination learning.