A dyscalculic patient with selectively impaired processing of the numbers 7, 9, and 0.
A patient (J.C) had particular difficulties with the numbers 7, 9, and 0 in aurally and visually presented calculations. These problems were explained in terms of a modified version of the McCloskey, Caramazza, & Basili (1985) model of calculation processes. His calculation difficulties were attributed to degraded semantic representations of the numbers 7 and 9 and to lost knowledge of rules governing calculations involving the number 0. Use of "noncalculation" number processing tasks confirmed that his 7/9 problem was not at the level of acoustic analysis, the auditory input lexicon, the phonological output lexicon, visual analysis, or the orthographic output lexicon.
Weddell
R A
RA
Department of Surgical Neurology, Morriston Hospital, Swansea, United Kingdom.
Davidoff
J B
JB
D001930:Brain Injuries / Q000523:psychology; D006801:Humans; D008297:Male; D008568:Memory; D008606:Mental Processes; D008875:Middle Aged; D008960:Models, Psychological; D009484:Neuropsychology; D012660:Semantics