Study title

World Wide

Individual

Participants comprised three different groups: autistic-savants, autistic-nonsavants, and controls.Participants were recruited from two sources. Three of the 44 autistic-savants were recruited from The Savant Network, which is a group of individuals with a self-re- ported savant skill who have expressed an interest in taking part in research studies. The remaining autistic-savants were recruited from the Cambridge Autism Research Database (CARD). All autistic-nonsavant individuals and all controls also came from CARD, which holds status information of both autism and typical participants. Participants volunteered to take part in our study in response to an email advertisement. Materials and Procedure: Participants were sent a URL link via email, which sent them to a website where they were shown the information page and consent form. Participants then completed the following tests: assessing whether they had ASC, whether they had a savant skill, and finally a battery of questionnaires and a calendar calculation task.To determine ASC status, all participants responded to a self-report question which asked "Have you received a formal diagnosis of any of the following: Autism, Asperger Syndrome, Pervasive developmental disorder not otherwise specified; ‘Other’?” Although we did not administer a diagnostic test ourselves, our question specifically stated that a formal diagnosis must have been given, and we used responses to classify participants according to their ASC status. Participants with ASC from the Cambridge Autism Research Database additionally are required to record that their ASC diagnosis was given by a psychiatrist, clinical psychologist, neurologist, or paediatrician, as well as the name of the recognised clinic where this took place. Participants then completed a short questionnaire about savant skills, in this we provided a definition of savant syndrome and asked whether participants had any talents beyond those seen in the general population. If participants responded ‘yes’ they were given a list of nine categories of savant skills, with definitions, and could use check boxes to indicate as many as were relevant to them. They were also given space to specify other skills, and any other relevant information (e.g. how they acquired their skill). After the savant-skills questionnaire, participants followed a URL link to our assessments which included all of our questionnaires. Participants completed the calendar calculation task following a similar procedure.