Fig. 5: Interhemispheric beta-band spike-LFP coherence distinguishes between bimanual-together and bimanual-apart movements.

a Schematic model depicting local and distal inputs and outputs to and from PRR. Mass input and output of PRR is shown as arrows. The axon terminals of most neurons contact other neurons locally (light gray arrows), but some portion project distally, including to the homotopic area in the opposite hemisphere (dark gray arrows). Connections with non-homotopic areas are omitted for clarity. b Identical spike-LFP coherence predictions under interhemispheric communication scenario (black curve) and common input scenario (gray curve). c From 20 to 50 Hz, spike-LFP coherence is consistently high for bimanual-together movements (solid blue), intermediate for unimanual movements (solid green), and low for bimanual-apart movements (solid purple). The distributions of coherence expected by chance were computed by shuffling interspike intervals. The medians of these distributions are shown as dashed traces. The gray shaded region covers 95% of the values expected by chance; values that exceed this are marked by thickened lines (P < 0.05). Values exceeding the light gray line are significant at P < 0.01. Note that there is no effect of movement type on the shuffled coherences. For this reason, data are pooled across movement types for the P < 0.05 and P < 0.01 thresholds. Coherences that are significantly larger for bimanual-together compared to bimanual-apart are indicated by asterisks (two-tailed t-test, P < 0.05). Dashed vertical lines indicate the beta range (20–30 Hz). Coherence was measured during the 800 ms before the go cue. Data are averaged from n = 42 pairs of sites (24 from MkT, 18 from MkZ) recorded simultaneously in the two hemispheres. Only sites with at least 500 spikes are shown. d Schematic model depicting common input to PRR in each hemisphere. Spike-LFP coherence predictions for common input model. e Lagged spike-LFP coherence predictions for direct communication and common input models, respectively. f Extremes of spike-LFP coherence (24–38 Hz) occur when spikes lead LFP by 10–15 ms (gray lines). Positive and negative x axis values indicate the relative temporal relationship between spike times and the LFP in the original data. Source data are provided as a Source Data file.