Assessment of calculation and number processing by adults: Cognitive and neuropsychological issues

Calculation and number processing abilities were assessed in normal (n=138) and traumatic brain-injured (n=15) Brazilian literate subjects. The study aimed (i) to analyse the effects of demographic factors and to provide tent ative norms adjusted for the relevant variables, (ii) to examine the factor ial structure of the battery and to evaluate its clinical validity for diag nosis purposes, and (iii) to question the power of current models to accoun t for effects and dissociations found for these groups. Analysis indicated a main effect of education on most subtests and of sex on three, but none f or age. Cut-off scores for normality were defined at Percentile 10 with ref erence to education. The sensitivity of the battery to the presence of arit hmetical impairments was considered satisfactory since 11 out of the 15 pat ients showed pathological scores. A principal component analysis indicated that the different subtests were grouped into three factors, which were ten tatively interpreted with reference to current information-processing model s. The multiple single-case analysis of dissociations in patients' performa nce suggested some limits with respect to anatomo-functional models of calc ulation and number processing.