Do multiple sclerosis patients demonstrate increasing deficits on a phonemic-fluency task as a function of time and is this deficit associated with slowed psycho-physiologicat processing?

摘要

This study investigates whether typical deficits on a phonemic-fluency task evidenced by individuals with multiple sclerosis become more pronounced as a function of time. The study further examines the relationship between this letter-fluency test and a measure of psycho-physiological processing speed. The research was conducted using archival data from the study Measures of Corpus Callosum Function in Multiple Sclerosis: Development of an Outcome Measure. Phonemic fluency was measured with the F, A, S, portion of the Controlled Oral Word Association Test (COWAT). Psycho-physiological information processing was assessed by a temporal tactile threshold (TTT) apparatus. It was hypothesized that MS patients would produce fewer responses on the COWAT, and that their deficits would become more pronounced in the later time-segments of each trial. It was further hypothesized that the MS patients would show deficits on the TTT, and that performance on this measure would be significantly related to their scores on the COWAT. Salthouse's processing speed theory of adult age differences in cognition, which posits a relationship between cognitive decline and cognitive processing efficiency, was applied to the MS population. Findings indicated that although the MS group produced fewer words and evidenced higher temporal tactile thresholds, there was no relationship between these two measures. Furthermore, the difference in word production could not be explained as a function of time. Implications of these results are discussed.