Fig. 7.

Twelve measures of the change in behavior induced by electrical stimulation are projected from a space with 1 dimension for each of the 101 stimulation sites onto a plane containing the first and second principal components (PCs) of the distribution. Closer proximity between points roughly indicates a greater tendency for the measures to covary positively across sites. However, the positioning of the points is not a definitive indicator of the magnitude or sign of the correlation. For the results of an explicit correlation analysis, see Table 2. Noteworthy in this figure is the fact that points representing different effects [percent correct (ΔPC), reaction time (ΔRT), velocity (ΔVEL), and amplitude (ΔAMP)] are more widely separated than points representing the same effect as measured during successive trial phases (e.g., ΔPC1, ΔPC2, and ΔPC3).