Brief Report: Two Day-Date Processing Methods in an Autistic Savant Calendar Calculator.
An autistic savant calendar calculator flips between math rules and memory, depending on whether the date lies ahead or behind.
01Research in Context
What this study did
De Marco et al. (2016) watched one autistic savant name the day of the week for dates across 40 years.
They timed each answer and asked about both past and future dates.
The team wanted to see if he used the same trick every time or switched strategies.
What they found
The man was right 98 % of the time.
Future dates took longer the farther out they were, but past dates stayed quick.
The pattern shows he uses a math rule for the future and memory for the past.
How this fits with other research
Lecavalier et al. (2006) saw random errors and said savants do not use rules.
The new study agrees errors can happen, but only when the rule is hard.
Allen (1981) first showed timing patterns in calendar calculators.
De Marco et al. (2016) now prove those patterns mean two clear strategies, not one.
Why it matters
If a client with autism shows calendar skills, test both past and future dates.
Slow future answers mean they are building the rule on the spot.
You can teach the rule step-by-step or let them keep using memory for past dates.
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02At a glance
03Original abstract
Special ability in computing the day of week for given dates was observed in a 24 year-old male (FB) diagnosed with Asperger syndrome. FB performed almost flawlessly (98.2%) both with past and future dates, over a span of 40 years. Response latency was slower as temporal remoteness of future dates increased. Within the future timespan, FB's performance was consistent with the active use of calendar regularities. On the contrary, within the past timespan (for which no remoteness effect was seen), his performance was mainly linked to memory retrieval of personal events. The case presented here complements the existent literature on calendar calculators, as, for first time, two distinct day-date processing styles are described in the same individual.
Journal of autism and developmental disorders, 2016 · doi:10.1007/s10803-015-2626-z