Figure 2.

(a) A schematic of a typical electrophysiological experiment investigating the cortical correlates of motor learning. An electrode records changes in neural activity from a cortical area that (A1) may not be causally related to behavioral changes observed in behavioral output or (A2) may not be directly connected with the behavioral output. (b) A schematic of a typical neural interface experiment in which a multielectrode array records signals from the same cortical areas as in a. In this case, changes in neural activity are causally related to the output behavior of the device being controlled by the neural interface.