Figure 6.

Mutual modulation of activity during action execution and observation: cell-class and areal specificities

(A) Example of neurons showing a positive (Neurons 1 and 2), negative (Neurons 3 and 4), or flat (Neurons 5 and 6) MMD index during the movement epoch (aligned to the movement onset). Black curves represent the MMD time course, and colored trace represents the average ± SE net soft-normalized firing rates aligned to movement onset for EXE and OBS.

(B) Heatmaps show the MMD time course for each neuron within areas and cell class (see color scale bar on the bottom right corner); black curves represent the average MMD values. Yellow marks represent average ± SD of object pulling time. Asterisks above each curve indicate sets of at least 5 consecutive time bins (200 ms in steps of 20 ms) of significantly increased MMD relative to the first 5 bins of the investigated period (one-tailed paired-sample t tests, p < 0.05). Each panel in the last row and column represents the time course of MMD index averaged across cell classes and areas, respectively; gray shadings represent SEs. Vertical black bars centered on the yellow shaded region represent average ± SD of pulling onset. The distribution and properties of neurons in each class depending on their modulation in EXE and OBS are shown in Figure S7.

(C) Histograms show the mean MMD index (±SE) for each class. A 3 × 3 factorial ANOVA (factor: class and area) showed significant main effect of the factor cell class, and Newmann-Keuls post hoc tests revealed greater MMD of class 2 neurons relative to class 3 (p < 0.002).