Figure 5.

Comparison of activity characteristics of individual neurons between different tasks. A, Mean discharge frequency averaged over all selected strides of flat surface walking is plotted against the mean frequency observed during standing. B, Mean discharge frequency averaged over all selected strides of walking along the ladder is plotted against that of flat surface walking. C, Mean depth of frequency modulation during walking along the ladder is plotted against that of flat surface walking. In A–C, the abscissa of each point shows the values observed during one task and ordinate shows values seen during the other task. Differently shaped symbols represent neurons with RFs on different segments of the forelimb: ■, neurons with RFs on the arm and/or forearm, which did not respond to stimulation of the wrist or paw; ♦, neurons with RFs on the arm and/or forearm that were also responsive to stimulation of the wrist and/or paw; ▴, neurons with RFs confined to the wrist and/or paw; ●, neurons with an RF that encompassed most of the limb and neurons with incompletely mapped RFs. Neurons with characteristics that were statistically significantly different during the two tasks (see Materials and Methods) are shown with filled symbols.