Deciphering components of impaired working memory in multiple sclerosis

To identify working memory (WM) impairment by examining components of auditory working memory with the same sample of individuals with multiple sclerosis (MS). Although individuals with MS have consistently demonstrated WM impairments, the specific components involved (i.e., central executive versus storage/maintenance) remain unclear. Individuals with MS with and without cognitive impairment and healthy controls were administered a task primarily assessing storage and rehearsal/maintenance (auditory n-back) and a task with a significant central executive component (Paced Auditory Serial Addition Task). Results indicate when the phonological loop is minimally challenged, maintenance of information is generally efficient. However, the addition of a central executive component to processing appears to be the key factor in differentiating individuals with MS with cognitive impairment from those without cognitive impairment and healthy controls. Results indicated that the primary WM impairment in MS is within the central executive rather than the phonological loop.