Visual reaction time and its relationship to neuropsychological test performance.

The purpose of this study was to investigate the relationship between simple and choice reaction time (RT) measures and neuropsychological test performance (as assessed by the Impairment Index of the Halstead-Reitan Neuropsychological Test Battery). Both median RT scores and intraindividual variability of RT scores were evaluated in three groups: impaired TBI, nonimpaired TBI, and normal controls. In all three groups, there was a statistically significant correlation between both reaction time measures and level of cognitive functioning. In addition, SRT, speed of information processing (as measured by CRT), and intraindividual variability of RT scores continued to be impaired in many brain-damaged individuals who, according to the Impairment Index, had fully recovered from their cognitive deficits. Median RT scores were better able to discriminate between impaired TBI patients and normal controls; but intraindividual variability of RT scores was better able to discriminate between nonimpaired TBI patients and normal controls. It was concluded that, by adding the two short RT tests to the neuropsychological test battery, more accurate predictions can be made about a patient's level of cognitive functioning and the nature of treatment needed for continued recovery.