In this project, the investigator will test the effect of augmenting an evidence based joint attention intervention (JASPER) with a motor-sound system intervention (PROMPT) compared to JASPER only on speech and language outcomes. The investigator will model change over a year to determine the percentage of children who cross the hurdle from single words to word combinations by Kindergarten. The proposed research will foster the understanding of the mechanisms underlying speech heterogeneity in ASD, thereby ultimately contributing to the development of more personalized, efficacious interventions.

Upon qualification to the study (after entry assessments), the child will be randomized to receive JASPER alone (play-based intervention) or JASPER plus PROMPT (both play-based and speech-based interventions). The active intervention will last for 12 weeks, 60 minute sessions twice a week. There are assessments scheduled at entry (6.5 hours), end of study (exit-2.5 hours), 3 month follow up (2 hours), and when the child turns 6 years of age (2 hours). The total time commitment per participant is 37 hours.

Children will be recruited through local school districts and early intervention service providers, approximately 20 children per year for a total of 80 children. Parents interested in the study will call the lab and be screened. If children pass the screen, they will be invited to go to UCLA for a series of assessments. The process will take 2-3 days. The following assessments and data will be collected: ADOS-2, ADI-R, Mullen Scales of Early Learning (MSEL), Demographic & Medical Questionnaires, Vineland-III Interview, ELSA Language Sample, PLS-5,SPA, Repetitive Behaviors RBS-R, SSP, ABC-2, ESCS, BOSCC, KSPT, EEG, and saliva sample. Eligibility for the study will then evaluated. Each child's clinical diagnosis of ASD will be validated by administration of the Autism Diagnostic Observation Schedule-2 (ADOS-2) and the Autism Diagnostic Interview-Revised (ADI-R) by a research-reliable lab staff. Children will participate in a language sample (eligible if < 20 words), and the Mullen Scales of Early Learning (MSEL) to evaluate nonverbal mental age (eligible if > 12 months).

After qualifying to the study, the screening data will be entered into Biostatistics and Epidemiology Data Analytics Center (BEDAC), secured website. Randomization will then occur. Children will be randomly assigned to one of two intervention options: JASPER + PROMPT versus JASPER only.

JASPER is a naturalistic, developmental, behavioral intervention (NDBI) that focuses on developing social communication and language skills in the context of a play based intervention.

Intervening on oral motor skills may improve speech. In Los Angeles, a fairly common community intervention delivered by certified speech language pathologists (SLP) is Prompts for Restructuring Oral Muscular Phonetic Targets (PROMPT). PROMPT has a growing evidence base among a number of clinical populations with language delays related to oral motor deficits (although not ASD).

1. JASPER only: Child will receive 2, 60 minute sessions per week at UCLA. or
2. JASPER + PROMPT: Child will receive 2, 60 minute sessions per week at Santa Monica's SSLP, Inc.

Recruitment, screening assessments, consents, and treatment will occur in this Santa Monica location for this group. All these procedures will be done by the UCLA staff, except the PROMPT treatment. PROMPT will be done by the SLPs in the Scheflen Speech-Language Pathology, Inc.

All assessments, consent forms, measures, recruitment material will be the same for both conditions.

Interventions will occur for 12 weeks, 3 months. After the 3 months, there will be exit assessments (ELSA Language Sample, PLS-5, ESCS, BOSCC and EEG). There will also be assessment follow up at 3-months post exit, and when the child turns 6 years of age. The following assessments will be done at these time points: ELSA Language Sample, ESCS, BOSCC, PLS-5 at 3 mo-FU and ELSA Language Sample, ESCS, BOSCC, PLS-5 when child turns 6.

Inclusion Criteria:

• Children meeting ADOS-2 and ADI-R criteria for ASD
• age 42-66 months
• have had > 3 months of early intervention/preschool (to ensure that children already have been exposed to some community interventions)
• walked prior to 24 months
• use < 20 functional words (i.e., non-echoed, non-scripted). Number of functional spoken words will be totaled in a language sample assessment. The functional word criterion is based on a 2010 NIH workgroup definition of 'minimally verbal' in school-aged children. The same definition may also apply to younger children with limited language.
• stable medication over the past 6 months
• nonverbal mental age of >12 months on the Mullen Scales of Early Learning (visual reception and fine motor subscales).

Exclusion Criteria:

• We will exclude children who are deaf, blind or with cerebral palsy.
• We will not exclude on the basis of known genetic disorder associated with ASD (ex: TSC), but expect few will actually participate, in part due to rarity of these disorders, and because for some there are other trials available at UCLA (ex: TSC).
• We will exclude children in other intervention trials; in other words, we will not double enroll children into intervention trials.