Explore the Impacts of One Session and Multiple Session Theta Burst Stimulation Over Cerebellum in Adults With Autism Spectrum Disorder

Inclusion criteria for autistic adults: * Autistic adults (≥18 years old), confirmed by Autism Diagnostic Observation Schedule. * DSM-5 severity level of ASD: level 1 or level 2 Inclusion criteria for typically developing control: * ≥18 years old without autism spectrum disorder Exclusion criteria for all participants: * Previous or current severe neurological disorders, especially epilepsy * Previous or current severe systemic diseases such as cardiovascular disease, diabetes or hypertension * Previous or current severe brain injury * Implementation of metal materials such as a pacemaker or medication pump * Previous or current severe psychiatric disorders such as schizophrenia, bipolar disorder, severe major depressive disorder or substance abuse * Pregnancy * Intracranial space occupied lesions * Previous brain surgery or central nerve system infection * Concurrent use of medications which increased the risk of seizure attack * Participate in another clinical trial within one month * With damaged skin at the stimulated region * With multiple sclerosis * With large ischemic scars * Have experienced sleep disorders during brain stimulation * Severe alcoholism * Concurrent use of antiepileptic drugs * Uncontrollable migraines due to increased intracranial pressure * Unsuitable for MRI (e.g. those with claustrophobia) * Unsuitable for EEG * DSM-5 severity level of ASD: level 3 * Suicidal ideation within one year Withdrawal criteria: * Seizure attack during the study period * Autistic symptoms worsened obviously during the study period (change of DSM-5 severity level) * Extreme agitation or irritability during the study period * Participants request * Clinical symptoms worsened obviously during study period * Start to use antiepileptic drugs during study period * Suicidal ideation or self-harm behaviors during study period