This data shows questionnaire and task data for three different groups: autistic-savants, autistic-nonsavants, and controls. The questionnaire data involves topics relating to sensory sensitivities, systemising, obsessions, autistic traits, and savant skills. Savant syndrome is a condition where prodigious talent co-occurs with developmental difficulties such as autism spectrum conditions (ASC). A second data file shows data relating to scores on a test of calendar calculation for the same three groups. Participants were recruited online and filled out our questionnaires and completed our task.In this research programme we will investigate enhanced memory in synaesthesia (e.g. experiencing colours for words). Our general approach is to treat synaesthesia as a 'test case' to address other important research questions. For instance, we consider how synaesthesia can inform general theories of memory. Importantly, not all aspects of memory are enhanced in synaesthesia and this can provide insights into how the memory system is structured. Indeed it is not trivially the case that material that elicits 'extra' sensations are better remembered: some material that does not evoke extra sensations (such as abstract figures) are also better remembered by synaesthetes. We suggest that synaesthetes have widespread changes in their perceptual systems (including but not limited to their extra experiences) and that systems supporting perception can also be engaged in memory. We will use both standard and bespoke tests of memory to explore which aspects of memory are enhanced and we will explore how individual differences in perception (in non-synaesthetes) may relate to performance on certain memory tasks. Our general approach is to treat synaesthesia as a 'test case' to address other important research questions. For instance we consider how synaesthesia can inform general theories of memory. Importantly, not all aspects of memory are enhanced in synaesthesia and this can provide insights into how the memory system is structured. Indeed it is not trivially the case that material that elicits 'extra' sensations are better remembered: some material that does not evoke extra sensations (such as abstract figures) are also better remembered by synaesthetes. We suggest that synaesthetes have widespread changes in their perceptual systems (including but not limited to their extra experiences) and that systems supporting perception can also be engaged in memory. This approach makes contact with a much wider contemporary literature on memory including those arguments derived from animal models and patients with amnesia. In principle, studies of superior ability can be just as informative to models of memory as studies of impaired ability, even though the latter approach predominates. Moreover, cognitive psychology as a discipline has historically tended to dismiss rather than embrace individual difference (classifying it as 'noise' in the data). As such, we seek to tackle important questions relating to memory from a novel angle. An understanding of individual differences in memory functioning, derived from our research on synaesthesia, will have significant impact on other areas. For instance, one claim is that enhanced functioning in general may be protective against pathology or cognitive decline in ageing. We will test whether synaesthesia is a protective factor against age-related memory decline. Another claim is that the kind of 'low level' or 'visualising' cognitive style that we hypothesise to give rise to enhanced memory in synaesthesia may support enhanced memory in other special populations (e.g. savant memory abilities such as those sometimes found in autism). Although we do not test this directly in our main proposal, our findings will be relevant to those working in this domain and will be explored in a linked PhD. To tackle these questions we draw on a wide range of methods in cognitive psychology/neuroscience. We use both standard and bespoke tests of memory to explore which aspects of memory are enhanced. We explore how individual differences in perception (in non-synaesthetes) may relate to performance on certain memory tasks. Finally, we explore how the brain supports enhanced memory in synaesthesia using neuroimaging and non-invasive brain stimulation methods

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.