The "intelligence" of calendrical calculators.

Strategies of 4 men (WAIS-R range 65 to 76) when making calendar calculations were investigated. Each subject completed a battery of standardized psychological tests. Results suggested that subjects were aware of rules and regularities associated with the calendar, including knowledge of the 14 different calendar templates, one of which describes any calendar year. Their strategies were rigidly applied and could not be modified easily, even when doing so would have facilitated performance. The involvement of practice, memory, anchor dates, eidetic imagery, and mathematical algorithms were discussed. We concluded that these savants relied heavily on memory, with little manipulation of cognitive input, as opposed to transforming stimuli.