Epidemiological data provides evidence for the manifold increase in rates of depression and anxiety in individuals diagnosed with multiple sclerosis, relative to the general population. Such impaired affective processes, including deficits in emotion regulation have been linked to greater cognitive deficits, a lower quality of life, and greater disease progression in this population. Despite evidence of the deleterious impact of affective functioning on prevalence rates of mood and anxiety disorders; on poor cognitive functioning; and reduced quality of life, much of the targeted intervention research in MS has not directly tested the feasibility, and subsequent efficacy of a psychosocial intervention in improving affective regulation in this population. Thus, the investigators propose to conduct a randomized feasibility study of mindfulness training relative to an active cognitive training control group and waitlist control group in improving emotional regulation in individuals with MS. All individuals that contact the Clinical Neuroscience Laboratory (CNLab) with interest in this study will undergo a phone screening assessing inclusion/exclusion criteria. Those participants meeting I/E criteria will be invited for an online daily diaries portion of the study examining daily engagement in worry and rumination. After completing the week-long daily diary portion of the study, the participant will attend 1-2 in-person pre-assessment sessions, which will also be completed at the completion of the four week intervention. The pre-assessment will involve a thorough assessment of emotion regulation skills, both through self-report questionnaires and behavioral paradigms, and cognitive functioning. Following the assessment sessions, which will be conducted by blind assessors, participants will be randomized to the three groups. The 4-week mindfulness program will be closely modeled after the protocol developed by Dr. Jon Kabat-Zinn, where investigators will have the participants attend once-per-week sessions for 2 hours and complete around 40 minutes a day of homework assignments. The four weeks of mindfulness involve the practice of concentrative attention, where different objects are used as the focus of practices. For example, for the first two weeks, the investigators use breath as an anchor for the mind. With repeated practices, the objects of sensations, emotions, and thought processes are introduced. The classes are a mixture of experiential practices, discussions surrounding the experiences, and didactics on mindfulness. The control group, which will be used to compare the effects of mindfulness training on emotional and cognitive functioning of MS patients, will comprise of a cognitive training group, which will provide an attentional-training based approach. In this group, our focus will be to provide the individuals with cognitive training tasks to complete that have been shown to improve attentional ability. Homework will be reading and practicing using the cognitive video game exercises for the same duration, around 40 minutes daily, as the mindfulness group. Following the four weeks of the intervention, the questionnaires, week-long daily diaries, and behavioral tests from the pretest will be repeated a second time to obtain post-test data for comparison.