Differential Responses in Perceptual Ability Among Mentally Retarded Brain-Injured Children

Abstract

BRAIN-INJURED children have been described by various workers in field as having difficulty with visual motor tasks, organization problems, and con cept formation (11). The purpose of this investiga tion was to determine whether mentally retarded brain-injured children show a similar performance on a task involving these functions or if there are differential responses based on specific learning handicaps. The study reported here is related to a series of attempts to investigate feasibility of differential teaching methods in terms of perceptual disabilities based on specific learning handicaps rather than employing a teaching curriculum based on categorization of so-called typical behavior of the organic child. The theoretical background for these inves tig a tions has been work of Dr. Lise Gellner who has stated that primary difficulty in brain damage is brain stem lesions which result in partial perceptu al losses. A summary of her position is as follows: Mental retardation is due to different kinds of learn ing handicaps resulting from structural or biochem ical damage somewhere in cerebral systems of vision and audition. There is a dichotomy of vis ual and auditory pathways in brain which ac counts for existence of two central systems of vision and audition. One of these systems serves integration of visual and auditory impulses eman ating in retina of eye or cochlea of ear, with kinesthetic impulses from all somatic structures (muscles, joints, etc. ) of body; other system serves integration of such visual or auditory impulses with impulses emanating from all autonomie structures (inner organs, blood ves sels, etc. ). Each of these four cerebral s y s te ms extends from respective sense organs, via some important specific ganglia in midbrain to speci fic projection areas in cerebral cortex. If these systems are intact, result is normal seeing or normal hearing, but impairment anywhere in one or several of these four systems results in disturbance of function. (6). Each of these disturbances is termed a disability since there is a direct negative effect on performance of child. Differences in behavior patterns of brain-injured children are due to specific perceptual loss.