The investigators will conduct a pilot study investigating the effectiveness of a computerized response inhibition training program at reducing the response inhibition difficulties often seen in children with Williams syndrome ages 10-17. The investigators hypothesize that after completing the training program, children with Williams syndrome will show improvement on computerized measures of response inhibition and on parent measures of impulsivity.

Behavioral characteristics of individuals with Williams syndrome include eagerness to approach and interact with others (including strangers), repeated questions especially about upcoming events, and difficulties with attention, impulsivity, and inhibition. There is very little systematic research about the kinds of interventions that are most useful for children with Williams syndrome to support optimal psychosocial functioning, and of the effectiveness of such interventions. We will conduct a pilot study of a potential intervention to address the response inhibition difficulties associated with Williams syndrome. The investigators will examine the utility of an online, web-based computerized cognitive retraining program aimed at addressing impulsivity and inhibition difficulties in 20 children, ages 10-17, with WS. The engaging training program has shown some utility in other populations, including children with tic disorders and trichotillomania. The investigators will examine the acceptability and feasibility of the treatment approach, as well as its impact on performance on experimental measures of impulsivity and on everyday psychosocial functioning as rated by parents; this study will consist of a small-scale pilot Randomized Clinical Trial with wait list. Through this novel work, we hope to develop and tune this approach for optimal outcomes and to demonstrate the promise of this intervention to address common challenges of people with Williams syndrome in the area of inhibition.

Inclusion Criteria:

• Williams syndrome (diagnosed with genetic testing)
• Ages 10-17
• First language and main language spoken in the home is English
• Possess computer in the home that has internet access, and a second electronic device with access to Skype (e.g., smartphone, ipad, additional computer, ipod touch)

Exclusion Criteria:

• First language and main language spoken in the home is NOT English (because study measures and instructions are all in English)
• No computer in the home with internet access (because the study is being conducted via the internet)
• Comorbid severe illnesses or major surgery within the past 6 months
• Four or more previous sessions of inhibition training