The tactile perception of stimulus orientation

S. J. Bensmaia, S. S. Hsiao, P. V. Denchev, J. H. Killebrew, J. C. Craig

Research output: Contribution to journalArticle

Abstract

Studies of the visual system suggest that, at an early stage of form processing, a stimulus is represented as a set of contours and that a critical feature of these local contours is their orientation. Here, we characterize the ability of human observers to identify or discriminate the orientation of bars and edges presented to the distal fingerpad. The experiments were performed using a 400-probe stimulator that allowed us to flexibly deliver stimuli across a wide range of conditions. Orientation thresholds, approximately 20° on average, varied only slightly across modes of stimulus presentation (scanned or indented), stimulus amplitudes, scanning speeds, and different stimulus types (bars or edges). The tactile orientation acuity was found to be poorer than its visual counterpart for stimuli of similar aspect ratio, contrast, and size. This result stands in contrast to the equivalent spatial acuity of the two systems (at the limit set by peripheral innervation density) and to the results of studies of tactile and visual letter recognition, which show that the two modalities yield comparable performance when stimuli are scaled appropriately.

Original languageEnglish (US)
Pages (from-to)49-59
Number of pages11
JournalSomatosensory and Motor Research
Volume25
Issue number1
DOIs
StatePublished - Mar 25 2008

Keywords

  • Acuity
  • Discrimination
  • Orientation
  • Psychophysics
  • Somatosensory
  • Tactile

ASJC Scopus subject areas

  • Physiology
  • Sensory Systems

Fingerprint Dive into the research topics of 'The tactile perception of stimulus orientation'. Together they form a unique fingerprint.

  • Cite this

    Bensmaia, S. J., Hsiao, S. S., Denchev, P. V., Killebrew, J. H., & Craig, J. C. (2008). The tactile perception of stimulus orientation. Somatosensory and Motor Research, 25(1), 49-59. https://doi.org/10.1080/08990220701830662