The purpose of this study is to evaluate the application of an evidence-based, manualized treatment for children with Autism Spectrum Disorder (ASD) (Pivotal Response Treatment, PRT) to children ages four through six years of age with ASD. Specifically, children will be randomly assigned to receive either (1) 10 hours per week of intervention services, including two hours per week of parent education, and eight hours per week of direct clinician-delivered services, or (2) a treatment as usual control. Intervention will focus on enhancing the following developmental skills: expressive and receptive language, play, and social interaction. Outcome measures will address changes in the aforementioned domains during structured observation and standardized assessment.

Inclusion Criteria:

• Inclusion Criteria:

Participants will:

1. Fit the age requirement: age 4-35
2. Have been diagnosed previously with an ASD and meet criteria for ASD when characterized by research team.
3. Be in good medical health
4. Be cooperative with testing
5. English is a language spoken in the family
6. Successfully complete an fMRI and EEG scan
7. Full-scale IQ>50

Exclusion Criteria:

• Exclusion Criteria:

Participants may not have:

1. Any metal or electromagnetic implants, including:

   1. Cardiac pacemaker
   2. Defibrillator
   3. Artificial heart valve
   4. Aneurysm clip
   5. Cochlear implants
   6. Shrapnel
   7. Neurostimulators
   8. History of metal fragments in eyes or skin

2. Significant hearing loss or other severe sensory impairment

3. A fragile health status.

4. Current use of prescription medications that may affect cognitive processes under study.

5. A history of significant head trauma or serious brain or psychiatric illness