Context effects in haptic perception of roughness

Exp Brain Res. 2009 Apr;194(2):287-97. doi: 10.1007/s00221-008-1697-x. Epub 2009 Jan 21.


The influence of temporal and spatial context during haptic roughness perception was investigated in two experiments. Subjects examined embossed dot patterns of varying average dot distance. A two-alternative forced-choice procedure was used to measure discrimination thresholds and biases. In Experiment 1, subjects had to discriminate between two stimuli that were presented simultaneously to adjacent fingers, after adaptation of one of these fingers. The results showed that adaptation to a rough surface decreased the perceived roughness of a surface subsequently scanned with the adapted finger, whereas adaptation to a smooth surface increased the perceived roughness (i.e. contrast after effect). In Experiment 2, subjects discriminated between subsequent test stimuli, while the adjacent finger was stimulated simultaneously. The results showed that perceived roughness of the test stimulus shifted towards the roughness of the adjacent stimulus (i.e. assimilation effect). These contextual effects are explained by structures of cortical receptive fields. Analogies with comparable effects in the visual system are discussed.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptation, Physiological
  • Analysis of Variance
  • Choice Behavior
  • Female
  • Fingers
  • Humans
  • Male
  • Physical Stimulation
  • Psychophysics
  • Sensory Thresholds*
  • Touch Perception*
  • Young Adult