Modality-specific aspects of sustained and divided attentional performance in multiple sclerosis.

While the prevalence of cognitive impairment in multiple sclerosis is well documented, few studies have systematically investigated the profile of attentional abilities. In the current study, 30 MS participants were assessed on measures of sustained and divided attention and compared to a sample of 30 neurologically intact healthy controls. Performance on visual and auditory unimodal and bimodal trials were conducted for measures of both forms of attention. A three-factor mixed measures analysis of variance (groupxtaskxmodality) was conducted. MS participants were impaired relative to controls on all measures of speed and accuracy across unimodal and bimodal trials and more impaired on measures of divided attention than on sustained attention measures. Performance on the bimodal trials was also significantly compromised relative to the unimodal trials especially on the divided attention task. The theoretical and clinical implications of these findings are discussed.