The purpose of this protocol is to gain insight into the mechanisms underlying motor memory formation by MT+AO. We plan to perform two different types of experiments: In experiment 1, we will modulate activity in PMv using TMS to investigate the role of this cortical area on motor memory formation induced by MT+AO. In experiment 2, we will test the effects of single doses of (a) the NMDA receptor antagonist dextromethorphan, (b) the muscarinic receptor antagonist scopolamine, both known to disrupt LTP, and (c) the cholinesterase inhibitor rivastigmine, which enhances LTP.