Compensation capacities of brain in unilateral and bilateral auditory system damage in children

Abstract

Neuroplasticity is a basic feature of neuronal system which provides function rebuilt or developmental dysfunction repair. Hearing impairment can have an impact on intelligence levels, organization and structure of cognitive processes. Cognitive capacities profiles of deaf people present neuropsychological results of functional reorganization of brain. 208 children were accepted for this study. Experimental group consisted of 126 children suffering from sensorineural hearing insufficiency. 26 children were diagnosed with right-sided hearing loss, 34 children were diagnosed with left-sided hearing loss and 66 children were diagnosed with bilateral hearing loss. Control group consisted of 82 normally hearing children, confirmed in audiometric assessment. In order to establish levels of cognitive abilities and intelligence in patients enrolled for the study polish adaptation of Wechsler Intelligence Scale for Children (WISC-R) was administered. Children with bilateral hearing loss obtained worse results in verbal scale compared to well hearing controls. Verbal intelligence in control group was statistically higher than in right-sided auditory dysfunction group. Control group average result in nonverbal scale was statistically significantly higher compared to left-sided hearing loss patients. Children with right-sided auditory dysfunction obtained higher results in nonverbal scale compared to children with left-sided auditory dysfunction. Left-sided hearing impairment group had higher scores in almost all subtests of verbal scale than right-sided hearing impairment group. Left-sided auditory disability enhances linguistic capacity, which indicates compensation abilities of left hemisphere responsible for verbal processes. Right-sided auditory disability enhances analytic processes, visual synthesis and image reasoning, which indicates compensation abilities of right hemisphere responsible for nonverbal processes.