[Right hemisphere lesion and directional indication in a visuoconstructive task].
We test the hypothesis that the divergences between Hecaen and Assal (1970) and Gianotti et al (1977) as regards the efficiency of indications supplied together with drawings to patients with unilateral lesion are due to the topological or directional nature of these indicators. We submit subjects with cerebral damage to a test involving copying cubes and non-significant drawings by opposing these two types of indication and also resorting to the procedure of Pillon and Lhermitte (1978). The results demonstrate that the topological or directional character of the indicators used can account for the differences between these two sets of findings. Finally, the results tend to show that the left hemisphere basically controls the manipulatory or executive side of the visuo-constructive task, whilst the right takes over its executive and perceptive aspects in conjunction.