Toddlers in the Enhanced Social ABCs group will receive eight in-home attention training sessions, 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 a home-based 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.