Parkinson's disease (PD) impacts different types of neural oscillations in the brain, including beta (13-30Hz) and gamma oscillations (30-80Hz), which contributes to PD's cardinal symptoms of resting tremor, rigidity, bradykinesia (slowness of movement), and gait instability. The investigators' lab has developed a non-invasive method of increasing gamma power in the brain using Gamma Entrainment Using Sensory Stimulation (GENUS) through light, sound, and tactile stimulation devices. For this study, 40 participants with mild Parkinson's disease will be recruited, and the investigators will assess their brain waves with electroencephalogram (EEG) before, during, and after light, sound, and tactile stimulation to determine the safety, feasibility, and optimization of GENUS as a potential therapy in the PD population.

It is known that Parkinson's disease (PD) patients have disruptions in brain waves, specifically the beta frequency (13 - 30Hz) and gamma frequency (~30 - 100 Hz), due to the death of dopaminergic neurons in certain parts of the brain. These disruptions of brain rhythms contribute to the cardinal symptoms of Parkinson's (resting tremor, rigidity, bradykinesia or slowness of movement and gait stability) in different ways. The investigators' lab has developed a non-invasive method of neuromodulation called Gamma Entrainment Using Sensory Stimulation (GENUS), which could be used for patients suffering from motor symptoms due to PD. GENUS is administered via light, sound, and tactile stimulation devices which emit light, audio, and tactile frequencies respectively. GENUS has been tested on cognitively normal individuals and individuals with mild Alzheimer's Disease (AD), and the device was found to be safe for use and effective for entrainment in both populations.

Investigators hypothesize that boosting gamma oscillations using 40Hz GENUS will augment movement and improve tremor and bradykinesia in PD patients. Thus, the purpose of this study is to determine whether gamma entrainment through non-invasive 40Hz sensory stimulation can be observed in patients with PD as measured by electroencephalogram (EEG) during an acute stimulation session. Investigators also hope to determine whether the GENUS devices are safe and easy to use in the PD population.

The investigators will recruit 40 participants diagnosed with mild PD who will be randomly assigned to two study arms: control stimulation and active 40Hz stimulation. Participants will be asked to do a series of movement exercises while wearing an actigraphy watch that tracks their activity before the stimulation session. Cognitive and mental health evaluations and memory tests will also be performed on all participants before and after exposure to the GENUS devices, which can deliver light, sound, and tactile waves at different frequencies. The first GENUS device is composed of a panel with light-emitting diode (LED) illumination and speakers for auditory stimulation, whilst the second device is composed of a small vibrating speaker for tactile stimulation. Each of the two groups will have different combinations of light, sound, and tactile settings.

Inclusion Criteria:

• Subject has Idiopathic PD defined by the cardinal sign, bradykinesia, plus the presence of at least 1 of the following: resting tremor or rigidity and without any other known or suspected cause of Parkinsonism (according to Movement disorder society (MDS) clinical diagnostic criteria for Parkinson's disease confirmed by a fellowship trained movements disorder specialist
• Subject is Hoehn & Yahr stage 2 to 3
• Subject has a Montreal Cognitive Assessment (MOCA) score ≥26.
• Subject is > 45 and <90 years of age.
• proficient in speaking, reading, and understanding English
• capable of providing informed written consent
• Subject is on a stable dose (at least 1 month prior to baseline visit) of antiparkinsonian agents and willing to remain on this dose for the duration of the study. If on a cholinesterase inhibitor, a stable dose without changes for 1 month is required.
• Subject has undergone a brain CT or MRI prior to rule out underlying structural lesions

Exclusion criteria:

• Subject has atypical Parkinson's syndrome(s) due to drugs, metabolic neurogenetic disorders (e.g., Wilson's Disease), encephalitis, cerebrovascular disease, or degenerative disease (e.g., Progressive Supranuclear Palsy, Multiple System Atrophy, Corticobasal Degeneration, Lewy Body dementia)
• history of any psychiatric illness that would pose a safety risk
• diagnosis of dementia or other neurological conditions
• currently taking sedative medications that are clinically contraindicated
• has undergone recent change (<1 month) in medication
• recent drug or alcohol abuse or dependence
• laboratory results the would pose safety risk
• concurrently or has participated in other clinical trial investigation within 3 months
• pregnant
• no healthcare
• history of epilepsy, stroke, or seizure in past 24 months
• diagnosis of migraines
• have certain implantable medical devices
• contraindications for MRI
• life expectancy of less than 2 years