Practical methods for the clinical assessment of information processing speed

The rate at which individuals are capable of processing information is considered a sensitive indicator of brain dysfunction, particularly among clinical populations whose neurocognitive impairments generally are considered relatively mild in nature. Assessment of information processing speed often is confounded, however, by comorbid impairments in other constructs of neurocognition, including attentional capacity, visuospatial perception, language, immediate memory, and motor speed/coordination. This investigation examined the effect of controlling for various potential confounders on the strength of associations among several potential measures of information processing speed. Participants were 64 patients diagnosed with clinically definite multiple sclerosis. Analysis indicated consistent significant and positive associations among measures of processing speed, which generally persisted despite simultaneous statistical control of potential confounding factors. Results imply that examined confounding variables are similarly related to the measures of processing speed. Therefore, any of the measures of information processing speed considered in this study may be used as a proxy for the more direct measure of this construct derived from the Sternberg Memory Scanning Test.