The Active Mind Trial: An Adaptive Randomized Trial to Improve Function and Delay Dementia

Inclusion Criteria: * 55 to 89 years of age * Montreal Cognitive Assessment Score of 18-27 inclusive * History of some change in cognitive function relative to established baseline and either 1) a CDR of 0.5; or 2) CDR of 0 and a clinical diagnosis of mild cognitive impairment (MCI) based on a multidisciplinary evaluation that included standardized neuropsychological testing * If reports use of medications typically prescribed for dementia such as Namenda, Memantine, Namzaric, Donepezil, Aricept, Rivastigmine, Exelon, Razadyne, Galantamine, or Reminyl, dose has been stable for at least 30 days * Adequate auditory capacity to understand normal speech. No greater than moderate hearing loss evident by thresholds less than or equal to 50 dB at 1000 and 2000 Hz in at least one ear determined by an audioscope. * Adequate visual capacity to read from a computer screen at a normal viewing distance as measured by binocular visual acuity of 20/50 or better tested with a standard near visual acuity chart * Reports and shows adequate motor capacity to touch a computer screen or control a computer mouse. * Wiling to complete all study activities * Willing and capable of providing informed consent * Ability to understand study procedures and comply with them for the length of the study Exclusion Criteria: * Currently enrolled in another randomized clinical trial, treatment trial, or another research study that assesses cognition * Dementia diagnosis * Clinical Dementia Rating Scale of 1 or greater * History of large vessel stroke with significant residual motor or cognitive impairment * History of moderate to severe traumatic brain injury with residual cognitive symptoms * History of brain tumor * Undergoing or plans to undergo surgery requiring anesthesia, chemotherapy, or radiation treatment in the six months following screening * Congestive heart failure diagnosis * Primary diagnosis of idiopathic Parkinson's disease * Multiple sclerosis or Amyotrophic lateral sclerosis (ALS) diagnosis * Evidence of a non-neurodegenerative neurological disorder that would interfere with the ability to carry out study activities. * Evidence of any other unstable medical conditions that would interfere with the ability to carry out study activities or cause fluctuations in cognition (e.g., unstable diabetes, chronic obstructive pulmonary disorder dependent on oxygen) * Geriatric Depression short scale score \>5/15. Participants with mood disorders that are treated and stable and have a GDS score \< 6/15 are not excluded. * Any other clinically significant or unstable medical condition (e.g., ongoing alcohol dependency or drug abuse, schizophrenia, psychosis) that in the assessor's opinion would interfere with the ability to carry out study activities. * Previous participation in 10 or more hours of a computerized cognitive intervention program in the past two years * Previous participation in cognitive intervention research at the study site in the past 2 years * Planning on going away or being otherwise unavailable for a period of more than three weeks in the six months following screening * Contraindications to MRI such as pacemaker, metal implants in body, or claustrophobia