Overview

The current study will test whether age-related cognitive and mood changes in older adults and those with Parkinson disease will be affected by near infrared (NIR) stimulation. The overall hypothesis, drawn from previous literature, is that exposure to NIR stimulation will have positive effects on brain health and will result in better cognitive and mood performance.

Eligibility

Inclusion Criteria:

• No evidence of dementia or Mild Cognitive Impairment based on cognitive screening (i.e., Montreal Cognitive Assessment (MoCA) scores within normal limits for age , education, and sex using the NACC Uniform Data Set (UDS) norms or Dementia Rating Scale (DRS-2) scores <5thile), and age-appropriate delayed Story recall (i.e., WMS-III Logical Memory) and confrontation naming (Boston Naming Test)
• Able to provide informed consent and perform cognitive and mood measures on a computer
• At least 8th grade education and/or ability to read at 8th grade level
• Willingness to be randomized to Sham or Real intervention
• Can devote 12 weeks to the intervention, and additional time for pre and post testing
• On stable doses of major medications; Since some older adults with subjective memory complaints may be prescribed acetylcholinererase inhibitors or related medications by their primary care physicians (i.e., donepezil, rivastigmine, galantaominhe, memantime, or other potential memory-enhancing agent(s), we will not exclude them as long as they have been on stable medications for at least two months and plan to continue this medication during study participation.
• Normal functional behavior in terms of daily activities

Exclusion Criteria:

• Previous major strokes or other known significant brain abnormalities or diseases affecting cognition (i.e., multiple sclerosis, seizure disorder, brain surgery, moderate TBI, etc.). No history of brain surgery. Exceptions are a diagnosis of Parkinson's disease for the PD subgroup.
• Unstable and uncontrolled medical conditions (metabolic encephalopathy, HIV, moderate to severe kidney or liver disease)
• Current or past history of major psychiatric disturbance including schizophrenia, or active psychosis, bipolar disorder, current major depressive episode, current alcohol or substance abuse or history thereof within the past six months. The study team is not excluding individuals who are taking antidepressants or anti-anxiety medications, however, use of antidepressants and anxiolytics will be recorded and data will be analyzed in post-hoc analyses
• Use of antipsychotics, sedatives, or other medications with significant anticholinergic properties (due to potential influence on memory)
• Use of photo-sensitive medications such as steroids or retin-A within 15 days of the study intervention
• Diagnosis of active cancer
• Significant motor or visual disturbance that would prevent one from using a computer or detecting colors
• Previous participation in a cognitive training study within the last 3 months or current involvement in another study involving cognitive training or intervention at the time of participation
• Inability to undergo brain imaging due to claustrophobia or implants such as pacemakers, heart valves, brain aneurysm clips, orthodontics, non-removable body jewelry, or shrapnel containing ferromagnetic metal

Additional criteria for participants in Parkinson group

• Participants must have a diagnosis of idiopathic Parkinson's disease by a movement disorders specialist based on UK Brain Bank criteria
• No previous history of brain surgery (DBS, pallidotomy, thalamotomy, or fetal cell implants).
• May have difficulties with activities of daily living, but this is due to physical symptoms of Parkinson disease and not because of cognitive problems
• Hoehn-Yahr staging between .5 and 3.5