<qa>  What is the first step to try to develop strategies to enhance encoding processes in patients withRecent functional imaging studies showed that memory retrieval is associated with activation in the prefrontal cortex during the encoding process. However, a cause-effect link between prefrontal activity and encoding has not been demonstrated. The purpose of this protocol is to test the hypothesis that inhibitory repetitive transcranial magnetic stimulation rTMS over left prefrontal cortex interferes with encoding of verbal items words into episodic memory, thereby identifying this region as a substrate mediating verbal encoding. Identification of the role of the prefrontal cortex in verbal memory encoding is the first step to try to develop strategies to enhance such encoding processes in patients with memory impairments, an issue of relevance in neurorehabilitation. 