Figure 2.

Comparison of EMG magnitude in the two behaviors. A, B, Comparison of the normalized magnitude of selected EMGs from cats MC28 (A) and MC29 (B). EMG magnitude is normalized by integrating the amplitude of the EMG in a burst of activity (1 ms bins) and then dividing by the duration of the burst. Data are illustrated in the form of histograms of EMG magnitude, density curves, and box plots in which the box indicates the mode and the first and third interquartile levels (i.e., it encompasses 50% of the values). Values for the magnitudes of the EMG are arbitrary but are comparable for the two behaviors. For each muscle, we indicate the ratio of the mean EMG magnitude during reach as a function of that during locomotion. Probability was calculated on the basis of two sample t tests. Data are taken from the same trials used to create Figure 1. N indicates number of trials in reach/locomotion.