Correlation between the time course of the first PSC (C1(t)) and finger position. A, A single trial showing C1(t) in an associated electrode and thumb movement, demonstrating delay from the cortex to movement onset, from subject 10. B, Correlation in the electrode-movement pair from A as a function of latency between the two, over the full 10 min period. C, The correlation between C1(t) and paired finger movement was 0.37 (SD = 0.16, N = 24) across eight of the subjects, three electrodes each (subjects 2 and 8 excluded, because their movement-associated cortical change was poorly separated; supplemental Fig. S7, available at www.jneurosci.org as supplemental material). D, The mean latency between C1(t) and finger movement was 84 ms (SD = 39 ms, N = 24).