OBJECTIVE: To assess characteristics of perceptual organization following brain injury. RESEARCH DESIGN: A repeated measures between groups design. METHODS: Perceptual thresholds were compared between 10 persons with brain injury and 10 demographically matched healthy control subjects. Ten young control subjects were also tested to evaluate effects of normal ageing on these processes. Participants viewed stimuli on a computer monitor in which regularities existed in either the spatial or temporal domain. Psychophysical measurements were made of perceptual thresholds, as well as time required to process stimuli. RESULTS: Relative to age-matched control subjects, patients were impaired on all measures, with greatest deficits in conditions that contained a temporal component. Impairment did not occur with normal ageing. CONCLUSIONS: These results reflect cognitive impairment resulting from reduced cortical integrative function as well as reduced information processing speed. Such deficits at this level of processing likely impact subsequent perceptual function, such as object recognition.
OBJECTIVE: To assess characteristics of perceptual organization following brain injury. RESEARCH DESIGN: A repeated measures between groups design. METHODS: Perceptual thresholds were compared between 10 persons with brain injury and 10 demographically matched healthy control subjects. Ten young control subjects were also tested to evaluate effects of normal ageing on these processes. Participants viewed stimuli on a computer monitor in which regularities existed in either the spatial or temporal domain. Psychophysical measurements were made of perceptual thresholds, as well as time required to process stimuli. RESULTS: Relative to age-matched control subjects, patients were impaired on all measures, with greatest deficits in conditions that contained a temporal component. Impairment did not occur with normal ageing. CONCLUSIONS: These results reflect cognitive impairment resulting from reduced cortical integrative function as well as reduced information processing speed. Such deficits at this level of processing likely impact subsequent perceptual function, such as object recognition.