IMITATION AND UTILIZATION BEHAVIOR

Objective-To investigate the incidence, anatomical correlates, and cli nical features of imitation and utilisation behaviour, which are thoug ht by Lhermitte and coworkers to represent a reliable and frequent ind ex of frontal lobe disease. Methods-78 patients with hemispheric focal lesions were tested in two separate sessions, in which their reaction s to a series of gestures performed by the examiner and to the present ation of a set of objects were recorded. The patients were stratified into a frontal (n = 52) and a non-frontal group (n = 26) on the basis of their CT data. Results and conclusions-Imitation behaviour was pres ent in 39% of the frontal patients and was mainly associated with medi al and lateral lesions, at odds with the claim of Lhermitte et al that it is a constant accompaniment of lower, mediobasal lesions. In the n on-frontal group it was found in three patients, all with damage to th e deep nuclei region. Utilisation behaviour was a much rarer phenomeno n, present in only two patients, both of whom had frontal damage. Neit her imitation behaviour nor utilisation behaviour were found in patien ts with retrorolandic cortical lesions.