Fig. 7.

Classification of trials from one data set into one of two movement direction categories using a pair of simultaneously recorded neurons. Trials are classified correctly (solid) or incorrectly (hollow) as either 180° movements (circles) or 270° movements (triangles). Isoprobability lines represent the joint probability of activity in the two cells conditional on either 180° movements (dashed lines) or 270° movements (solid lines). A, Trials are classified using the independent model in which the two cells are assumed to be uncorrelated. B, Trials are classified using the second-order model in which the covariances between the cells are incorporated into the model.