This study evaluates the efficacy of the Companion Mind-Drawing Cooperative Game Program, a parent-mediated, home-based structured play intervention targeting social cognitive development in young children with autism spectrum disorder (ASD).

Children with ASD in the intervention group will receive a structured program in which parents attend an in-person training session (approximately 2.5 hours) at the hospital, where parents are taught to administer a series of researcher-designed cooperative game paradigms at home. Parents then deliver the intervention daily for at least 30 minutes per session over a period of six months. Monthly online video reviews by a clinician provide parents with individualized feedback and guidance to ensure program fidelity and quality.

Children with ASD in the comparison group will continue to receive usual care and will not receive the program during the study period.

Social cognitive outcomes - including emotion recognition, theory of mind, empathy, joint attention, self-perception, and social communication - will be assessed at baseline and at 12-month follow-up using behavioral experimental tasks and eye-tracking paradigms. This study aims to provide evidence for the efficacy of a scalable, family-implemented social cognition intervention for young children with ASD.

Background Social cognitive impairments - including difficulties in emotion recognition, theory of mind (ToM), empathy, joint attention, self-perception, and social communication - are hallmark features of ASD and significantly impact children's everyday social functioning. Despite the recognized importance of early social cognitive intervention, scalable and family-implemented programs that systematically target multiple social cognitive domains remain limited.

Intervention: "Companion Mind-Drawing Cooperative Game" Program

The "Companion Mind-Drawing Cooperative Game" program is a researcher-designed, parent-mediated intervention comprising a series of structured cooperative game paradigms, each targeting a specific social cognitive domain. The intervention is delivered in three phases:

1. Parent Training (In-Person) Parents attend a structured training session of approximately 2.5 hours at the clinical site. During training, parents are taught the theoretical rationale for each game paradigm, the specific social cognitive skills targeted, and standardized procedures for home delivery.
2. Home-Based Delivery Following training, parents deliver the intervention at home daily for a minimum of 30 minutes per session over a period of six months. The program targets six social cognitive domains: emotion recognition, theory of mind, empathy, joint attention, self-perception, and social communication.
3. Monthly Clinician Supervision Once per month throughout the six-month intervention period, a clinician reviews video recordings submitted by parents and conducts an online video session to provide individualized feedback, address implementation challenges, and reinforce correct delivery techniques.

Comparison Group Participants in the comparison (treatment-as-usual) group continue to receive any existing therapies or educational support received prior to study enrollment. Participants in the comparison group do not receive the "Companion Mind-Drawing Cooperative Game" program during the study period.

Assessments All participants are assessed at two timepoints: baseline (prior to intervention commencement) and 12-month follow-up. Assessments include behavioral experimental tasks and eye-tracking paradigms targeting each of the six social cognitive domains addressed by the intervention.

Inclusion Criteria:

Children：

• Aged 2.5 to 14 years at time of enrollment, with a primary recruitment focus on children aged 3 to 10 years.
• Meets diagnostic criteria for autism spectrum disorder (ASD) according to the Diagnostic and Statistical Manual of Mental Disorders, Fifth Edition (DSM-5), confirmed by a specialist clinician.
• Full-scale intelligence quotient (FSIQ) ≥ 70 as assessed by an age-appropriate Wechsler intelligence scale administered.
• Possesses sufficient verbal ability to engage with structured play-based intervention activities, as judged by the recruiting clinician.
• Resides with and is cared for by a participating parent or legal guardian who meets the caregiver eligibility criteria below.

Caregiver：

• Is the primary caregiver (parent or legal guardian) of the enrolled child and resides in the same household.
• Is able and willing to attend an in-person parent training session (approximately 2.5 hours) at the study site prior to intervention commencement.
• Is able and willing to commit to administering the structured intervention program to the child for a minimum of 30 minutes per day throughout the 6-month intervention period.
• Is able and willing to participate in monthly online video supervision sessions with the study clinician.
• Has sufficient literacy and comprehension ability to understand program training materials and follow intervention procedures.
• Provides written informed consent on behalf of the child and for their own participation prior to any study procedures.

Exclusion Criteria:

Children：

• Known diagnosis of a genetic syndrome associated with ASD or intellectual disability, including but not limited to Fragile X syndrome, Down syndrome, tuberous sclerosis complex, or Rett syndrome.
• Presence of a neurological disorder, including epilepsy (unless fully controlled with stable medication for ≥ 12 months), acquired brain injury, cerebral palsy, or other significant neurological condition that may confound assessment of social cognition.
• Uncorrected vision or hearing impairment that would preclude participation in behavioral or eye-tracking assessments.
• Currently enrolled in another interventional clinical study targeting social cognition, communication, or behavioral outcomes.
• Any medical, psychiatric, or developmental condition that, in the opinion of the recruiting clinician, would interfere with the child's ability to participate in or benefit from the intervention.

Caregiver：

• Unable to attend the in-person parent training session at the study site due to geographic, occupational, or other constraints.
• Unable to commit to the daily home-based intervention schedule or monthly online supervision sessions for the full 6-month intervention period.
• Presence of significant mental health difficulties or other circumstances that, in the opinion of the recruiting clinician, would substantially impair the caregiver's ability to deliver the intervention with adequate fidelity.

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