Cognitive impairment remains a major disability for individuals with multiple sclerosis (MS). The primary objective of this study is to evaluate the efficacy for treating MS-associated cognitive deficits using a unique computer-based plasticity-based and adaptive cognitive remediation treatment (PACR) compared to a computer-based control. This novel cognitive remediation approach has led to striking improvements in cognitive functioning in other disorders (schizophrenia, traumatic brain injury, aging, and dementia) but has never been applied to individuals with MS. The investigators will enroll 136 MS participants who will be randomized in a 2:1 pattern to complete either the treatment or control condition for 60 hours across a 12-week treatment period. Both the treatment and control conditions will be accessed remotely by the subjects from a study-provided laptop computer. Study outcomes will include program compliance, performance on study tasks and neuropsychological measures, quality of life and functional status. Given the success of this program with other disorders and strong preliminary data from our feasibility study, the investigators believe PACR is an exciting untapped opportunity to improve cognition in individuals with MS.