Fig. 2.

The TMS-adaptation paradigm. (a) Each test block begins with a period of adaptation, with the objective of differentially affecting the initial states of functionally distinct neural populations. In this study by Cattaneo and Silvanto (2008b), subjects were adapted to either leftward or rightward moving motion stimulus. Adaptation is followed by a block of experimental trials; in this study subjects were presented with motion stimuli moving either in the adapted direction (i.e., congruent targets) or targets moving in the opposite targets (i.e., incongruent trials). At least 24 experimental trials can be run after each period of adaptation without TMS significantly weakening the strength of adaptation (Cattaneo and Silvanto 2008b). (b) The state-dependent effect of TMS. In the No TMS condition, subjects were worse in detecting the adapted direction (i.e. congruent trials) relative to the nonadapted direction (i.e., incongruent trials), demonstrating that adaptation was behaviorally effective. This effect was reversed when TMS was applied over the motion-selective area V5/MT (a region known to contain motion-selective neurons), with TMS facilitating the detection of the adapted stimuli relative to the nonadapted stimuli. As neurons encoding the adapted direction of motion were less active than neurons encoding other attributes at the time of stimulation, this finding implies that TMS behaviorally facilitates the less active neural populations