This study aimed to pilot test a non-pharmacological (behavioral) treatment program targeting improved cognition through improving 24-h sleep-wake cycle in people with mild cognitive impairment (MCI) or mild Alzheimer's disease. A treatment program incorporating bright light therapy and a modified cognitive behavioral therapy for insomnia will be developed to address 24-hour patterns of sleep. We will then pilot test its feasibility and explore its preliminary effects on improving sleep/napping and cognition in patients with MCI or mild Alzheimer's disease.