<qa>  What is the most sensitive to AMPA blockade?Clinical endpoint. This pilot study will identify information on the best TMS interstimulus interval or intervals for measuring changes in cortical excitability after AMPA blockade, as well as the EEG frequency band most sensitive to AMPA blockade with talampanel. Because talampanel is a highly selective AMPA receptor antagonist, we will be able to infer that the parameters that are sensitive to talampanel can be used as empirical assays of AMPA receptor function in humans. 