The Validation and Biological Index Studies on the Improved Social Function of ASD by 40 Hz tACS

In this proposed study, tACS will be used to intervene in the autism spectrum disorders of children and adolescents, and the efficacy of this intervention method will be evaluated, as well as the internal mechanism of adolescents' autism spectrum disorders will be discussed.

The objective of this clinical study is to investigate the effects and mechanisms of transcranial alternating current stimulation (tACS) on neural modulation in the right temporoparietal junction (rTPJ) of autism spectrum disorders. The primary inquiry it seeks to address is the impact of tACS the treatment of autism spectrum disorders (ASD) through its influence on the rTPJ . Participants will undergo baseline assessments of clinical symptoms and cognitive levels, utilize electroencephalography (EEG) to monitor brain electrical activity during both resting and task states, analyze EEG neurophysiological characteristics, use eye tracking technology to collect data on participants' eye movements during cognitive tasks, employ functional magnetic resonance spectroscopy (fMRS) to detect neurotransmitters such as glutamate + glutamine (Glx), GABA+ macromolecules (GABA+) and taurine in resting state and Theory of Mind task, as well as utilize magnetic resonance imaging (MRI) to detect and analyze functional connectivity and synchronous activation of relevant brain regions during both resting state and task state. Following completion of baseline assessment and examination, participants will be randomly assigned into two groups: a 40 Hz tACS group and a sham stimulation group with 30 patients in each group for a total of 60 patients. Subjects in the tACS group will receive tACS intervention at 2.0mA with a frequency of 40Hz while subjects in the sham group will receive placebo stimulation at a similar location and frequency with no current between periods. Standardized assessment tools along with Theory of Mind tasks will be utilized to evaluate multidimensional changes in clinical symptoms and cognitive levels post-intervention. Additionally, EEG will again be used to monitor brain electrical activity during both resting and task states by analyzing functional E/I values (fE/I) as well as indicators of EEG oscillatory activity such as α- power, γ-power etc., Eye tracker data analysis will also be conducted again for changes in eye fixation during cognitive tasks while fMRS analysis will focus on changes in neurotransmitters. Furthermore, MRI analysis post-intervention aims to examine changes in functional connectivity along with synchronous activation within rTPJ region alongside related brain regions once more. Researchers aim to validate the efficacy \& safety profile associated with 40 Hz tACS intervention within rTPJ for treating social impairment observed within ASD population whilst exploring biological indicators \& mechanisms underlying effective treatment strategies involving 40 Hz tACS intervention program.

Eligibility Criteria:
Inclusion Criteria:

1. Age 6-18 years old.
2. has been clinically diagnosed with autism spectrum disorder by a psychiatrist
3. Meet the diagnostic criteria for ASD recommended by the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5).
4. Consistent with the diagnosis of ASD by used the Autism Diagnostic Interview Tool - Revised Edition (ADI-R) and the Autism Diagnostic Observation Tool (ADOS) assessment.
5. Can cooperate with transcranial alternating current stimulation.

Exclusion Criteria:

b) There is a serious neurological disorder, a clear family history or a potential risk.

c) There are metal implants in the brain, holes or cracks in the skull. e) The presence of a definite or suspected genetic disorder.

1. the presence of common genetic disorders, such as trisomy 21 syndrome
2. The presence of serious physical diseases, such as significant intracranial lesions, thyroid disease, epilepsy, congenital heart disease, severe blood system diseases, systemic lupus erythematosus, audio-visual impairment, etc.
3. meet the diagnosis of other major mental disorders, such as schizophrenia and bipolar disorder.
4. Imaging examination reveals obvious abnormalities in brain structure.
5. Currently taking or have taken benzodiazepine medications or antiepileptic drugs within the past week.