Extended Data Fig. 3: Decoding of hand velocity from motor cortical activity on control and post-perturbation reaches.
From: Cortical pattern generation during dexterous movement is input-driven
a, Left, scatterplots of decoded versus observed hand velocity in the forward, right, and upward directions on control reaches in an example session from a VGAT-ChR2-eYFP mouse. Only testing trials not used for training the decoder were used. Right, R2 values for the regression of observed on decoded velocities for control reaches in each VGAT-ChR2-eYFP dataset (n = 4 mice, n = 6 sessions). b, Left, scatter plots of decoded versus observed hand velocity for post-laser reaches in the dataset from a. Right, R2 values for the regression of observed on decoded velocities for post-laser reaches in each VGAT-ChR2-eYFP dataset. c, Comparison of the decoder performance in control versus post-laser reaches for the dataset from a, b assessed using the R2 computed after pooling across directions. d, Decoded position trajectories obtained by upsampling and numerically integrating (Simpson's rule) the decoded velocity for control trials (left) and laser trials (right) for the dataset in a, b. e–h, Decoder performance for Tlx3-Cre x Ai32 mice (n = 3 mice, n = 7 sessions), organized as in a–d. i–l, Decoder performance for Sim1-Cre x Ai32 mice (n = 2 mice, n = 3 sessions), organized as in a–d. m, Decoding performance for control testing trials on all sessions, by decoding method used (n = 9 mice, n = 16 sessions; all perturbation types aggregated). PCAavg refers to PCA coefficients extracted on lift-aligned trial averages with single trials projected onto these coefficients; PCAcat refers to PCA coefficients extracted on concatenated trial data; MU refers to multiunit activity; and SU refers to single units. For each method, the number of neural dimensions used for decoding was cross-validated (see Methods). Box plot shows the median and the 25th and 75th percentiles. n, Decoding performance for the PCAavg MU method, by the standard deviation of the Gaussian kernel used to extract firing rates (n = 9 mice, n = 16 sessions).
