Fast feedback in active sensing: touch-induced changes to whisker-object interaction

PLoS One. 2012;7(9):e44272. doi: 10.1371/journal.pone.0044272. Epub 2012 Sep 18.

Abstract

Whisking mediated touch is an active sense whereby whisker movements are modulated by sensory input and behavioral context. Here we studied the effects of touching an object on whisking in head-fixed rats. Simultaneous movements of whiskers C1, C2, and D1 were tracked bilaterally and their movements compared. During free-air whisking, whisker protractions were typically characterized by a single acceleration-deceleration event, whisking amplitude and velocity were correlated, and whisk duration correlated with neither amplitude nor velocity. Upon contact with an object, a second acceleration-deceleration event occurred in about 25% of whisk cycles, involving both contacting (C2) and non-contacting (C1, D1) whiskers ipsilateral to the object. In these cases, the rostral whisker (C2) remained in contact with the object throughout the double-peak phase, which effectively prolonged the duration of C2 contact. These "touch-induced pumps" (TIPs) were detected, on average, 17.9 ms after contact. On a slower time scale, starting at the cycle following first touch, contralateral amplitude increased while ipsilateral amplitude decreased. Our results demonstrate that sensory-induced motor modulations occur at various timescales, and directly affect object palpation.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Feedback, Sensory / physiology*
  • Head Movements
  • Male
  • Rats
  • Rats, Wistar
  • Touch Perception / physiology
  • Touch*
  • Vibrissae*

Grants and funding

This work was supported by European Union grant BIOTACT (ICT-215910), the Israeli Science Foundation Grant No. 749/10, the United States-Israel Bi-national Science Foundation Grant No. 2007121, the Minerva Foundation funded by the Federal German Ministry for Education and Research, and the Peter and Patricia Gruber foundation. PMK was supported by a Long-Term Fellowship from the Human Frontier Science Program. EA holds the Helen Diller Family Professorial Chair of Neurobiology. ES was supported by the Horowitz Center for Complexity Science. The funders had no role in study design, data collection and analysis, decision to publish, or preparation of the manuscript.