EVIDENCE FOR VISUOMOTOR PRIMING EFFECT

'WHILE seated, the patient took a glass, gave it to the examiner and t hen picked up a jug. He poured water into the glass and, having put do wn the jug, took the glass ...'. This compulsive behaviour, described by Lhermitte in patients with frontal lobe lesions, is an example of h ow, without any internal motivation, visual stimuli may impel a patien t to act and 'grasp the objects presented and use them'. We investigat ed whether this behaviour is a pathological manifestation of a normal, automatic object to action transformation. To test this, we primed no rmal subjects, while ready to execute a grasping movement, by visually presenting them with drawings irrelevant to the task to be executed. Drawings visually congruent with the object to be grasped markedly red uced the reaction time for grasping. These data represent the first ev idence for the existence of a visuomotor priming. Seeing an object fac ilitates an action congruent with the visual properties of that object .