Figure 5.

Sample size and temporal dependencies. Neural activity was recorded from PMd and PMv (monkey D) by 14 microelectrodes and 14 SUs during 283 trials. Prediction accuracy, combined for reach direction and grasp type, was estimated. MUA recordings provided the most accurate predictions at all tested numbers of trials, numbers of channels, bin sizes, and window locations. A, Number-of-trials dependency. For each sample size, 20 subsets of distinct trials were randomly sampled and the average predictions plotted with 99% Gaussian confidence limits (2.58 SEM). B, Number-of-channels dependency. Random subsets of distinct channels were sampled 20 times for each sample size. Predictions based on LFP were similar to those based on SU or MSP for up to six channels and then approached a plateau. C, Bin-size dependency. For each trial, neural activity in an 800 ms window centered on movement onset was divided into 1–200 bins (4–800 ms long) and prediction accuracies were estimated. D, Temporal window dependency. Predictions were based on neural activity in a 400 ms window, moved in 50 ms increments from 1600 ms before movement onset (vertical red line) until 400 ms after.