An integrative view of Luria's perspective on arithmetic problem solving: the two sides of environmental dependency

A. R. Luria was the first author to hypothesize that executive dysfunction can lead to specific deficits in arithmetic problem solving, showing that patients' performance depends on the structure of the tasks. Cummings (1995. Anatomic and behavioral aspects of frontal-subcortical circuits. Annals of the New York Academy of Sciences, 15, 1-13) proposed the term "environmental dependency" to define such behavioral disorders triggered by the characteristics of the test and pointed out also the role of executive impairments. Few studies compare executive functioning and problem solving in brain-damaged patients, and none have examined the question from this point of view. Thus, the main aim of the present paper was to study the relationship between environmental dependency and executive functions.

Fifty neurological patients with frontal, subcortical, and posterior brain lesions were compared to 45 matched healthy controls and were divided into two groups (dysexecutive/nondysexecutive) according to their performances on executive tasks. Then, we confronted the results of the two groups on an experimental protocol designed in accordance with Luria's proposals. We made also comparisons between groups on the basis of lesion location.

Our findings indicate a high association between executive functions and environmental dependency, showing that dysexecutive patients' performances were dependent on task demands. In addition, a specific frontal behavior not associated with executive functions and characterized by the solving of insoluble problems was highlighted.

The discussion focused on the interest to take into account the methodological and clinical contributions of environmental dependency. Based on our findings and theoretical arguments, we highlight the need to fractionate this concept.