Presence Hallucination in Parkinson's Disease

Inclusion Criteria:

• Diagnosed with Parkinson's disease

• Able to understand instructions and provide informed consent.

• Native speaking language of experimental site (or acquisition of language ofexperimental site before 6 years old).

• Montreal Cognitive Assessment (Nasreddine & Patel, 2016) with score ≥ 22.

• Able to manipulate the robotic device.

Exclusion Criteria:

• Neurological comorbidities other than Parkinson's disease (e.g. Alzheimer's disease,vascular dementia, multiple sclerosis, stroke, traumatic brain injury, epilepsy,chronic migraine, etc.)

• History or current condition of substance abuse and/or dependence (e.g., alcohol,drugs).

• Suffering from or diagnosed with psychiatric illnesses according to DSM-V criteria (e.g., schizophrenia, bipolar disorders, autism, personality disorders, phobia etc.).

• Family history (1st and 2nd degree) of psychiatric disorders (e.g., schizophrenia orbipolar disorders).

• Severe somatic illnesses (e.g., cancer).

• Severe tremors or physical disability preventing optimal use of robotic device.

• Participating in a pharmacological study.

• Local or general anaesthesia 30 days prior experiment

• Inability to provide informed consent (legal guardianship)

• The following are due to the MRI scanner: body weight exceeding 160kg, implantedmetallic devices, foreign metallic objects, unstable angina, cardio-vascular diseases,tattoos with metallic components, external metallic objects, claustrophobia,pregnancy.