The Social ABCs is an evidence-based, developmentally informed, caregiver-mediated behavioural intervention for toddlers with suspected or confirmed Autism Spectrum Disorder (ASD). It is based on principles of Pivotal Response Treatment (PRT, grounded in Applied Behaviour Analysis), and responsive parenting. The two key targets of this program are functional verbal communication and positive caregiver-child affect sharing. This intervention takes place in the context of play and daily routines, and in all contexts is made to be fun, natural and motivating for the child.

In both a pilot study and a recently completed randomized control trial, toddlers whose caregivers received training in the Social ABCs intervention showed significant gains in early language development (both responsivity and initiations), increased child smiling (mediated by parent smiling), and a trend toward increased social orienting (one important manifestation of social attention).

Despite the social-communication benefits demonstrated through the Social ABCs, the research team is also motivated to foster the attentional abilities of toddlers with emerging ASD in response to compelling evidence that early attentional control abilities may play a central role in the emergence of ASD. Based on this knowledge, the current study targets not only social-communication challenges and affect sharing (as per the existing Social ABCs intervention), but also attentional control in toddlers with suspected or confirmed ASD. Using a structured, computerized attention-training protocol, this RCT evaluates the impact of supplementing the standard Social ABCs intervention with pre-intervention attentional control training.

The Social ABCs intervention was developed to meet the need for evidence-based, feasible, and sustainable interventions for toddlers with emerging ASD. Unlike other more comprehensive programs, the Social ABCs selectively targets only two key developmental areas (i.e., functional spoken language and positive affect). These domains were selected in order to promote developmental progress in areas thought to be central at this developmental stage in ASD. By targeting only two core domains, this program maximizes feasibility and portability (i.e., reduces resource demand) while effecting meaningful change with potential for collateral effects in untargeted, but related, areas.

Bolstered by evidence of acceptability, feasibility, and promise from a pilot study, the Social ABCs was subsequently evaluated in a two-site RCT, demonstrating the efficacy of this caregiver-mediated intervention for toddlers with suspected or confirmed ASD. This study found increases in child vocal responsiveness, vocal initiations, parent smiling, and a trend toward increased social orienting in toddlers with suspected or confirmed ASD. Findings also demonstrated that caregivers attained fidelity relatively quickly, rated the intervention as highly acceptable, reported increased feelings of self-efficacy, and did not report increased stress associated with the burden of learning and providing the intervention.

While the Social ABCs intervention effectively targets social-communication skills and positive caregiver-child affect sharing, the previous RCT demonstrated a promising, but non-significant trend toward increased social attention (orienting), which depends on attentional control; the investigators argue that this is another important developmental domain often impaired in ASD. Improving attentional control may reduce or even prevent expression of ASD-related impairments such as emotion dysregulation and impaired social engagement, due to hypothesized relationships in both typical development and ASD. By targeting early attentional control abilities, this research not only also has the potential to enhance understanding of the fundamental mechanisms that drive behavioural dysregulation in ASD, but also to enhance early development in high-risk toddlers.

Wass and Johnson (2011) have successfully used a brief battery of gaze-contingent computer tasks to enhance cognitive control, sustained attention, and attentional disengagement of typically developing infants. This attention training paradigm has now been adapted for use with toddlers with suspected or confirmed ASD, and its impact will be evaluated as part of this study. Participants will be randomized into one of two groups: Enhanced Social ABCs (Social ABCs plus attention training) or Standard Social ABCs (Social ABCs with placebo). A third group, comprised of a convenience sample of age-equivalent toddlers who meet clinical eligibility criteria but are otherwise unable or unwilling to participate in the interventions, will be used as a Treatment as Usual comparison group.

Toddlers in the Enhanced Social ABCs group will receive eight attention training sessions, taking place in-home or in-clinic, which will be twice weekly for four weeks prior to beginning the Social ABCs. The attention training sessions use a computer-based program that is designed to provide practice in disengaging and shifting attention between competing visual stimuli. The Standard Social ABCs group will be allocated to an adjunct sham computer attention training condition in which they will interact with study staff and be exposed to identical computer equipment for the same schedule and duration of visits. However, this paradigm will involve a display of interesting moving on-screen objects without a gaze-contingent component (i.e., placebo). Both programs track the toddlers' gaze behaviours. Toddlers in both conditions will complete the same pre- and post-training testing assessments. The caregivers will be blind to whether children received the attention training or placebo.

Following the attention/placebo phase, caregivers of both groups will receive Social ABCs caregiver coaching with a Social ABCs coach blind to the participants' attention training (vs. placebo) condition. Social ABCs intervention will include 12 weeks of 1.5-hour home visits of tapering frequency, with follow-up visits at key time points. Home visits include a didactic session based on the Social ABCs manual, followed by practice and live coaching (see Brian et al., 2016, for further information).

In response to the 2020 global COVID-19 pandemic, the intervention has shifted to an online format, with sessions being completed virtually with participant families. The delivery schedule and session design remains the same. Follow-up assessment protocol measures that can be collected via mail or virtually are completed at the original time points.

Data from the Treatment as Usual group will be used to compare Standard and/or Enhanced Social ABCs to developmental trajectories of those not receiving this active intervention. These data include scores from standardized measures and eye-tracking data from one portion of the pre- and post-attention training assessments (i.e., a gap-overlap task).

This project is highly relevant to improving early treatment models, and thus, outcomes for toddlers with emerging ASD. Early action capitalizes on brain plasticity, potentially interrupting the negative developmental cascade, and optimizing outcomes in this high-risk group.

Inclusion Criteria:

• The child must be 12-30 months of age with clinically significant signs of ASD (must be under 30 months at study enrollment to be included)
• The toddler and parents must live together, and no more than 50km from the study site
• Child is at home with the caregiver at least 50% of the time (no more than 2.5 days a week in child care, nanny, family care, etc.)
• The child must not be involved in other behavioural interventions, such as ABA/IBI and the Hanen programs, for the duration of the study
• The child may participate in no more than 1 hour per week (monthly average) of the following interventions: speech/language, occupational, and physical therapy, for the duration of the study
• The child's diet and medications have not recently been drastically altered, and are not intended to be altered throughout the study.
• The child does not have other neurological disorders (including epilepsy), genetic syndromes that have known association with ASD (e.g., Fragile X syndrome), significant uncorrected sensory impairments (vision, hearing, etc.), or low birth weight (under 2500g).
• The child is not actively experiencing a regression of skills
• The caregiver is conversant in English and could be coached in English
• The child's eyes are successfully tracked with the eye-tracking technology used throughout the study.

Exclusion Criteria:

• Participant fails to meet any of the above listed Inclusion Criteria.