Basic numerical processes in developmental dyscalculia

Developmental dyscalculia is a specific learning disorder manifested by a failure to achieve adequate proficiency in arithmetic despite normal intelligence, scholastic opportunities, emotional stability and sufficient motivation. These difficulties do not result from a sensorial deficit and interfere significantly with daily life and/ or school success. In our talk we will present the results of studies indicating a possible genetic contribution to this trouble. We will then present a study that shows that developmental dyscalculia is due to a basic dysfunction of number processing. However, this dysfunction does not concern the ability to represent number magnitude but merely to access to that representation from symbolic codes. Possible anatomical-functional peculiarities of the cortical bases related to this dysfunction will be evoked.