The Influence of Blindness Onset (Congenital and late) on Auditory Emotion Processing

Abstract

In the absence of vision, the brain compensated through cross-modal plasticity that reorgnizes auditory processing to help in emotional understanding. This study looks at whether the onset of blindness: congenital vs. Late vs. sighted differentially modulates perceived emotional arousal and recognition accuracy for emotional speech prosody and instumental music. 57 participants from Ahmedbad (18-40 years) were divided into groups:congenitally blind(n=20), late blind )n=17), and sighted controls (n=20). Participants rated valence (positive or negative) and arousal (0-5) across 32 audio clips. Two mixed design repeated-meausres ANOVAs revelaed a clear hierarchical gradient in perceived arousal: congenitally blind rated all stimuli as significantly more intense than late blind, who in turn rated higher than sighted controls. Music showed significantly higher arousal than prosody across all groups. Additionally, reocgnition accuracy did not differ between groups, indicating that intensity amplification and categorical amplifcantion are independent. Unlike late-blind and sighted, congenitally blind showed no negativity or positivity bias in either arousal or accuracy. These findings suggests that onset of blidness modulates auditiory emotional sensitivity, with the amplification being higher as early as the visual deprivation occurs