Auditory perception of ambiguous and non-ambiguous sound in early and late blind children: A functional connectivity study

Abstract

Introduction: Auditory perception and associated cognition involve visual and auditory cortical areas for inference of meaningful soundscape.

Objective: To investigate auditory perception of ambiguous and non-ambiguous stimulation in auditory and visual cortical networks for categorical discrimination.

Methodology: Functional mapping was carried out in twenty early (EB), twenty late blind (LB) and fifteen healthy children, during auditory ambiguous and non-ambiguous stimulation task in a 3 T MR scanner to estimate hemodynamic signal alteration and its effect on functional connectivity. The degree of amplitude low-frequency fluctuation (ALFF), correlation analysis and multiple comparison was carried out to map the impact of duration of education and onset of blindness (EB and LB).

Results and discussion: Increased functional connectivity (FC) and cross-modal reorganization was observed in auditory, visual and language networks in EB children. FC was increased in contralateral hemisphere in both the blind children (EB and LB) groups and was positively correlated with duration of education performance. Cognitive assessment scores correlated (p < 0.01) with cluster coefficient of FC and BOLD response.

Conclusion: FC alterations depend on onset age and audio-haptic training in children associated with increased auditory language and memory perception.

Keywords: Ambiguous; Auditory perception; Early blind; Functional connectivity; Late blind; Non– ambiguous; VBM; fMRI.