Figure 8.

Bilateral time and phase differences. For all graphs, negative head velocities indicate that the rat’s head is turning to the right. Negative time and phase differences indicate that the left whisker array peaks before (leads) the right. A, The largest correlation (r = 0.34) between left–right whisker time differences and head velocity was found for protractions, with the head velocity averaged over 52 ms following the protraction. A duration of 52 ms was chosen because a brute-force windowing analysis showed that it yielded the largest correlation with protraction time differences (see Results). Data for retractions are not shown because they yielded an even weaker correlation than that found for protraction. B, The phase difference between the whisker arrays (time lag as a fraction of the whisking cycle) was not well correlated with the head velocity. C, The phase difference between the two arrays does not depend on whisking frequency (p = 0.47, slope not significantly different from zero). deg, Degree.