CALCULATION AND NUMBER PROCESSING IN MILD ALZHEIMERS-DISEASE

Calculation and number processing abilities in 17 patients suffering from a mild form of dementia of Alzheimer's a type (DAT) were studied by means of a. standardized multitask assessment battery, the EC301 (Deloche et al., 1994). Patients were selected from a larger sample by using a specific visuo-perceptive task to control the confounding effects of deficits in analysing digit serial older. Language and memory skills were evaluated by means of standardized testing procedures. The EC301 overall score: showed impaired performance in 12 cases. Calculation and number processing scores were highly correlated with Mini-Mental State Examination and language performance. However, multiple single-case analyses indicated heterogeneous patterns of preserved / impaired abilities with respect to the three cognitive areas under investigation (calculation. memory, and language) and to the different components of the calculation and number processing system.