TY - JOUR
T1 - Variability in velocity profiles during free-air whisking behavior of unrestrained rats
AU - Towal, R. Blythe
AU - Hartmann, Mitra J Z
N1 - Copyright:
Copyright 2009 Elsevier B.V., All rights reserved.
PY - 2008/8
Y1 - 2008/8
N2 - During exploratory behaviors, the velocity of an organism's sensory surfaces can have a pronounced effect on the incoming flow of sensory information. In this study, we quantified variability in the velocity profiles of rat whisking during natural exploratory behavior that included head rotations. A wide continuum of profiles was observed, including monotonic, delayed, and reversing velocities during protractions and retractions. Three alternative hypotheses for the function of the variable velocity profiles were tested: 1) that they produce bilateral asymmetry specifically correlated with rotational head velocity, 2) that they serve to generate bilaterally asymmetric and/or asynchronous whisker movements independent of head velocity, and 3) that the different profiles - despite increasing variability in instantaneous velocity - reduce variability in the average whisking velocity. Our results favor the third hypothesis and do not support the first two. Specifically, the velocity variability within a whisk can be observed as a shift in the phase of the maximum velocity. We discuss the implications of these results for the control of whisker motion, horizontal object localization, and processing in the thalamus and cortex of the rat vibrissal system.
AB - During exploratory behaviors, the velocity of an organism's sensory surfaces can have a pronounced effect on the incoming flow of sensory information. In this study, we quantified variability in the velocity profiles of rat whisking during natural exploratory behavior that included head rotations. A wide continuum of profiles was observed, including monotonic, delayed, and reversing velocities during protractions and retractions. Three alternative hypotheses for the function of the variable velocity profiles were tested: 1) that they produce bilateral asymmetry specifically correlated with rotational head velocity, 2) that they serve to generate bilaterally asymmetric and/or asynchronous whisker movements independent of head velocity, and 3) that the different profiles - despite increasing variability in instantaneous velocity - reduce variability in the average whisking velocity. Our results favor the third hypothesis and do not support the first two. Specifically, the velocity variability within a whisk can be observed as a shift in the phase of the maximum velocity. We discuss the implications of these results for the control of whisker motion, horizontal object localization, and processing in the thalamus and cortex of the rat vibrissal system.
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U2 - 10.1152/jn.01295.2007
DO - 10.1152/jn.01295.2007
M3 - Article
C2 - 18436634
AN - SCOPUS:55249102884
VL - 100
SP - 740
EP - 752
JO - Journal of Neurophysiology
JF - Journal of Neurophysiology
SN - 0022-3077
IS - 2
ER -