The structure of savant calendrical knowledge.

AIM: We aimed to explore the organization of the calendar knowledge base underlying date calculation by assessing the ability of savant calendar calculators to free recall a series of date lists. METHOD: Four experiments are reported that assessed recall of structural and non-structural features of the calendar in eight savant calendar calculators (seven males; one female; median age 34 y 6 mo; age range 27-47 y), five of whom had a diagnosis on the autism spectrum. The inclusion criterion was a genuine calculation ability rather than an interest in dates. RESULTS: Mean recall was facilitated for material organized according to the structural features of a calendar (leap years, dates falling on the same weekday, dates occurring at 28 y intervals) but not for a non-structural calendar feature (Easter Sunday). INTERPRETATION: Distinctions are drawn between two sources of savant calendar-related knowledge, structural and event related. It has been suggested that structural knowledge plays a key role in the acquisition and operation of savant date calculation skills.

Creativity in savant artists with autism.

Individuals with autism spectrum disorder (ASD) often display impairments in creativity, yet savant artists with ASD are reported to produce highly novel and original artistic outputs. To explore this paradox, we assessed nine savant artists with ASD, nine talented art students, nine non-artistically talented individuals with ASD, and nine individuals with mild/moderate learning difficulties (MLD) on tasks in and out of their domain of expertise. This was to ascertain whether the performance of the savant artists was related to their artistic ability, their diagnosis of ASD or their level of intellectual functioning. Results demonstrated that the responses of the art students were more creative (as assessed on measures of fluency, originality, elaboration, and flexibility) than the savant, ASD, and MLD groups on a drawing task. Although the savants did produce more elaborative responses than the ASD and MLD groups, no differences were observed on the other indices of creativity. On a non-drawing task, the savants produced more original outputs than the ASD and MLD groups (scoring similarly to the art students), but group differences were not observed on the other measures.

Local and global processing in savant artists with autism.

We explored the hypothesis that an enhanced local processing style is characteristic of both art and autism spectrum disorder (ASD) by examining local and global processing in savant artists with ASD. Specifically, savant artists were compared against non-talented individuals with ASD or mild/moderate learning difficulties (MLD), as well as artistically talented or nontalented students, on the block-design task and meaningful and abstract versions of the embedded figures test (EFT). Results demonstrated that there were no significant differences between the meaningful and abstract versions of the EFT, in any of the groups. This suggests that the primary process governing performance on this task was perceptual (local), rather than conceptual (global). More interestingly, the savant artists performed above the level of the ASD and MLD groups on the block-design test, but not the EFT. Despite both the block-design task and the EFT measuring local processing abilities, we suggest that this result is due to the block-design task being an active construction task (requiring the conversion of a visual input into a motor output), whereas the EFT is a passive recognition task. Therefore, although an enhanced local processing style is an important aspect of savant artistic talent, motor control also appears to be a necessary skill.

Numbers and letters: exploring an autistic savant's unpracticed ability.

This paper describes an individual with autism and high-level calendar calculation ability who could perform a set of unpracticed letter/number association tasks. The savant's performance was compared with that of two control participants, one a departmental secretary and the other a professor of mathematics. The facility with which the savant could master the rules governing the relationships between the series of items suggests that he possessed a flexibility of mental processing transcending his ability of calendar calculation. Furthermore, he could recalibrate previous knowledge to solve new hitherto unpracticed tasks. When presented with novel problems, the savant, unlike the mathematician, made no initial errors at all on any of the presented tasks, thereby indicating his fast and spontaneous recognition of new rules and of new relationships between items. It is concluded that a cognitive style of 'weak central coherence' as adopted by autistic savants may protect single representations from being retained in the form of stable enduring wholes, and that such a segmentation strategy may allow for the transformation, reorganization and reconstruction of the relationship between single items of information.