The purpose of this research is to examine effects of movement training with the aid of rhythmic auditory stimulation (RAS) on reducing severity of dyskinesia and bradykinesia in at-risk individuals and schizophrenia patients. The investigators hypothesize that training with the aid of RAS reduced severity of bradykinesia and dyskinesia in at-risk individuals as well as in schizophrenia patients.

For at-risk individuals:

The inclusion criteria for at-risk individuals are:

1. A score of or above 9 in the Chinese version of the 16-item Prodromal Questionnaire (CPQ-16), or a score of or above 8.18 in the Chinese version of Community Assessment of Psychic Experiences with 15 items (CAPE-C15), or a score of or above 17 in Schizotypal Personality Questionnaire-Brief (SPQ-B);
2. A score of or above 22 in the Hong Kong version of Montreal Cognitive Assessment (HK-MoCA) to ensure that they can understand instructions;
3. A score of or above 60 in the Chinese Version of Edinburgh Handedness Inventory to ensure that they are right-handed.
4. The age ≥ 13 years.

The inclusion criteria for healthy controls are:

1. A score below the cut-off score of CPQ-16, CAPE-C15, and SPQ-B;
2. A score of or above 22 in MoCA;
3. A score of or above 60 in the Chinese Version of Edinburgh Handedness Inventory;
4. No first-degree family members having a diagnosis of mental illnesses.
5. The age ≥ 13 years.

At-risk participants and healthy controls will be excluded if they have any neurological / musculoskeletal dysfunction that may affect their upper-limb movements.

For schizophrenia patients:

The inclusion criteria for schizophrenia patients are:

1. A diagnosis of schizophrenia without other psychiatric diseases;
2. Having stable psychotic symptoms;
3. A score of or above 22 in HK-MoCA;
4. A score of or above 60 in the Chinese Version of Edinburgh Handedness Inventory.
5. The age ≥ 18 years.

The inclusion criteria for healthy controls are:

1. A score below the cut-off score of CPQ-16, CAPE-C15, and SPQ-B;
2. A score of or above 22 in MoCA;
3. A score of or above 60 in the Chinese Version of Edinburgh Handedness Inventory;
4. No first-degree family members having a diagnosis of mental illnesses.
5. The age ≥ 18 years.

Patients and healthy controls will be excluded if they have any neurological / musculoskeletal dysfunction that may affect their upper-limb movements.