Figure 1.

Experimental paradigm and regression analysis. A, Rhesus macaques use a robotic manipulandum to control a cross-shaped cursor to track a circular target (2.5 cm diameter) on a computer screen (Paninski et al., 2004; Hewitt et al., 2011; Popa et al., 2012). B, Kinematic parameters (X, Y, VX, VY) are based on cursor motion (red trace). Position error (XE and YE) is the difference between cursor (X, Y) and target center position (X_tg, Y_tg). C, Timing of SS signals encoding a parameter was based on the local maxima of the coefficient of determination (R²) profile determined using the temporal linear regression analysis described previously (Popa et al., 2012). D1, Effects of CS discharge on the SS encoding was assessed by aligning the SS firing (dark blue) and the parameter (green) to CS occurrences. D2, Behavior was then shifted by the peak lead or lag (τ-peak) obtained from the non–CS-aligned linear regression (C). D3, Linear regressions were performed 400 ms before and after CS discharge using a 20 ms step sliding window of 200 ms, generating pre (blue) and post (red) R² profiles that quantify encoding strength.