Goal-directed imitation in patients with Ideomotor Apraxia

Abstract

The present study compared imitation performance in patients with ideomotor apraxia (IMA), eight right hemispheric-damaged patients, and eight control participants without neurological damage in three experiments. Experiment 1 confirmed in the Goldenberg test that IMA patients were particularly impaired in hand gestures and combined finger and hand gestures, but not in the imitation of finger gestures, compared to the other two groups. Experiment 2, however, demonstrated that finger selection is not per se preserved in imitative behaviour in patients with IMA. Experiment 3 confirmed this finding in an experiment under visual control. Together, the results add evidence to the idea that imitation should be viewed from a goal-directed rather than a body-mapping perspective, and that highest priority is given to more distal aspects of imitation as reaching for the correct object, rather than the means used to achieve the goal of a modelled action.

Acknowledgments

The authors wish to thank all patients and staff of the clinics in Kipfenberg, Bad Aibling, and Bad Heilbrunn that participated in these studies. The authors would like to thank Georg Goldenberg for detailed information about the gestures used in Experiment 1. We also thank Rafaella Rumiati, Glyn Humphreys, and an anonymous reviewer for improving previous versions of the manuscript. IST-grant 2000-29689 supported the first author.