A DEFICIT FOR ARITHMETICAL PROCEDURES - LACK OF KNOWLEDGE OR LACK OF MONITORING

A patient is described with a specific deficit for arithmetical proced ures. Unlike in previously described cases, where the observed problem s could be attributed to the systematic application of disturbed algor ithms, this patient's difficulty seems to stem from an inability to mo nitor the sequence of operations that calculation procedures specify. Criteria are provided for distinguishing impairments in written calcul ation due to the application of defective knowledge of the procedures from those determined by lack of monitoring. The role of monitoring an d control processes in different calculation components is also discus sed.