The purpose of this prospective, within-subject randomized cross-over design study is to determine if a computer training program (Speed of Processing Training - SOPT) improves safe pedestrian behavior in patients with Parkinson's disease and in healthy older adults in a virtual reality pedestrian environment. Pedestrian injury poses significant risk to healthy older adults and patients with Parkinson's disease. Several age-related changes, including slowing of visual processing speed, increase risky pedestrian behavior. This study will determine if SOPT improves pedestrian behavior in patients with Parkinson's disease and healthy older adults and evaluate the persistence of the SOPT training effects.

Pedestrian injury poses significant risk to healthy older adults and patients with Parkinson's disease. Several age-related changes, including slowing of visual processing speed, increase risky pedestrian behavior. Persons with Parkinson's disease (PD) are at even higher risk of pedestrian injury due to motor and non-motor symptoms. Parkinson's disease (PD) is a progressive neurodegenerative disorder characterized by motor symptoms including slowness, tremor, stiffness, and balance problems. Visual processing speed abnormalities, anxiety, and cognitive problems are common non-motor symptoms.

The Useful Field of View (UFOV®) test is a measure of visual processing speed. The UFOV® test is performed on a touch-screen computer that displays objects in the central and peripheral visual fields for brief durations. Successful performance on the test requires integration of visual sensory information and higher-order cognitive processing. Our own research has shown that the UFOV® test performance correlates with pedestrian behavior in PD patients.

Speed of Processing Training (SOPT) is a computer-based training that uses visual exercises to improve cognitive processing. The training involves identifying and localizing visual information quickly in increasingly demanding visual displays. SOPT has been demonstrated to improve performance on the UFOV test in healthy older adults and PD patients. It is hypothesized that SOPT training will improve pedestrian safety in healthy older adults and PD patients.

In the proposed study, we will use a within-subject, randomized, controlled, cross-over design to evaluate if a computer training program (Speed of Processing Training - SOPT) improves safe pedestrian behavior in patients with Parkinson's disease and in healthy older adults in a virtual reality pedestrian environment and if the effects of training persist long-term.

Inclusion Criteria Parkinson's disease Subjects:

• Subjects with a clinical diagnosis of idiopathic Parkinson's disease based on the presence of bradykinesia and one or both of the following: rest tremor and/or rigidity
• On stable medications for at least 4 weeks prior to entering the study and expected to not need any medication changes for the duration of the study
• Age ≥50 at the time of entry into the study
• Age of onset of Parkinson's disease 45 - 85 years old
• Asymmetric onset of PD
• Progressive motor symptoms of PD
• Hoehn and Yahr stages 1-4
• Ability to walk up and down a single stair step
• Access to a computer with internet

Exclusion Criteria Parkinson's disease Subjects:

• Atypical features indicative of a Parkinson's Plus disorder (Progressive Supranuclear Palsy, Multiple Systems Atrophy, Corticobasal Degeneration) including cerebellar signs, supranuclear gaze palsy, apraxia, prominent autonomic failure, or other cortical signs.
• Neuroleptic treatment at time of onset of Parkinsonism
• Active treatment with a neuroleptic at time of study entry
• History of multiple strokes with stepwise progression of Parkinsonism
• History of multiple head injuries
• Inability to walk without assistance, including a cane, wheelchair, or walker
• Cognitive dysfunction that would prevent subject's ability to perform virtual reality simulation, speed of processing training, or complete questionnaire
• Blindness
• Any medical condition that, based on discretion of the PI, would prevent the subject's ability to participate in the study

Inclusion Criteria Control Subjects:

• Age ≥50 at the time of entry into the study
• On stable medications for at least 4 weeks prior to entering the study and expected to not need any medication changes for the duration of the study
• Ability to walk up and down a single stair step
• Access to a computer with internet

Exclusion criteria Control Subjects:

• Parkinson's disease or other neurodegenerative disorder
• Inability to walk without assistance, including a cane, wheelchair, or walker
• Cognitive dysfunction that would prevent subject's ability to perform virtual reality simulation, speed of processing training, or complete questionnaires
• Blindness
• Any medical condition that, based on the discretion of the PI, would prevent the subject's ability to participate in the study