The impact of dysexecutive syndrome on use of tools and technical devices.

We present two studies aimed at elucidating why patients with dysexecutive syndrome encounter difficulties with the use of tools and technical devices. Two different groups of patients with dysexecutive syndrome took part in them. Their results were compared with those of two groups of normal controls and in the first study also with those of patients with posterior left or right brain lesions. The first study contrasted single step with multi-step actions and explored the role of novelty and consecutive demands on problem solving. Dysexecutive patients encountered problems only with the multi-step actions. The rank order of strength of impairment corresponded to the presumed rank order of demands on problem solving, but the analysis of individual results demonstrated high variability of this pattern which moreover could not be fully replicated when the same tests were applied in the second study. The second study pursued the hypothesis that maintenance of goals and constraints in working memory is the crucial factor for difficulties of dysexecutive patients. Support for this hypothesis was less ambiguous, but as this study did not include patients with posterior lesions it remains open whether this factor is specific for dysexecutive syndrome and prefrontal brain damage or applies to brain damage regardless of its location.