Reaction times of aging subjects to monaural verbal stimuli: some evidence for a reduction in right-hemisphere linguistic processing capacity.
The purpose of the current study was to investigate the effects of advanced aging on hemispheric organization for linguistic processing. Specifically, it was an attempt to identify whether the neurological substrate responsible for right-hemispheric language analysis diminishes in function. Measures of the influence on reaction time of the hand used to respond versus the hemisphere stimulated were obtained for a geriatric sample in an attempt to obtain an index of right-versus left-hemisphere auditory-verbal processing ability. Twenty-four right-handed geriatric subjects responded to monaurally presented verbal stimuli with their right and left hands at separate times. Reaction times were significantly faster when subjects heard the words in their right ears, regardless of the hand used to respond. Such findings were consistent with a strict model of neurolinguistic organization that suggests that the left hemisphere was responsible solely for language processing in the present group of elderly subjects. Compared to data previously gathered for young subjects, the current findings were interpreted to suggest that right-hemispheric language processing ability is inhibited in the more advanced stages of life.
D000368:Aged; D000375:Aging / Q000502:physiology*; D002540:Cerebral Cortex / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006225:Hand / Q000502:physiology; D006801:Humans; D007802:Language; D008297:Male; D011597:Psychomotor Performance / Q000502:physiology; D011930:Reaction Time