Figure 7. Response type correlated activity of vocalization- and hand-correlated neurons preceding cued and spontaneous responses.

Left and right column represent the activity in ‘cued’ and ‘spontaneous’ trials of two example hand- and vocalization-correlated neurons, respectively (A,B,D,E). Vocalization-correlated neurons show significantly increased or decreased activity prior to instructed calls but not prior to spontaneously uttered vocalizations. (C,F) Averaged and normalized population activity of 44 hand-correlated and 14 vocalization-correlated neurons that were recorded during ‘cued’ and ‘spontaneous’ trials. Hand-correlated neurons show a significantly different activity prior to cued ‘manual’ responses compared to ‘spontaneous manual’ responses (activity tested in 450 ms before response onset; Wilcoxon signed rank test: p<0.001). Similarly, vocalization-correlated neurons show a significantly different activity prior to ‘cued vocal’ responses compared to ‘spontaneous vocal’ responses (Wilcoxon signed rank test; p<0.01). Shaded area around the curves depicts s.e.m.