The investigators are examining how aspects of daily function are perceived in persons with PD and in those who interact with them on a regular basis. If eligible, participants will receive a set of online questionnaires by email. The questionnaires will take about 1 hour to complete, and can be done at the participant's convenience. The investigators are looking for volunteers who have a diagnosis of Parkinson's disease without dementia (age 40 or older and proficient English speakers). If a spouse, family member, significant other or other close associate is available (age 18 or older, proficient English speakers), the investigators will send them questionnaires as well. There is no monetary or other compensation for this study. For more information, please contact the Vision and Cognition Laboratory at vcognition@gmail.com or 617-358-1377.

Inclusion Criteria:

• Diagnosed with Parkinson's disease without dementia OR close associate of someone with Parkinson's disease
• 40 years or older
• Proficient English speaker
• Access to a computer
• 8+ years of education

Exclusion Criteria:

• Co-existing active neoplasm, serious cardiac disease, other serious chronic medical illness
• Prior intracranial surgery
• History of traumatic brain injury
• Psychiatric or neurological diagnoses other than Parkinson's disease
• History of alcoholism or other drug abuse
• History of treatment with electroshock therapy

Participants are accepted regardless of location, community, clinic, etc.