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Updated: Feb 22, 2026
07:32
Measurement of Vibration Detection Threshold and Tactile Spatial Acuity in Human Subjects
Published on: September 1, 2016
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Mapping the internal geometry of tactile space
Matthew R Longo1, Olga Golubova1
1Department of Psychological Sciences, Birkbeck, University of London.
Summary
Perceived tactile distance on the hand is distorted, stretching along the width (medio-lateral axis) but not the length (proximo-distal axis). This spatial distortion is geometrically coherent across the skin surface.
Area of Science:
- Neuroscience
- Psychology
- Somatosensation
Background:
- Research indicates spatial distortions in tactile distance perception on human skin.
- Perceived tactile distance varies with skin sensitivity and stimulus orientation (e.g., medio-lateral vs. proximo-distal axes).
Purpose of the Study:
- To investigate the spatial coherence of tactile distance distortions.
- To reconstruct the internal geometry of tactile space using multidimensional scaling (MDS).
Main Methods:
- Participants verbally estimated perceived distances between sequentially applied tactile stimuli on the left hand.
- Multidimensional scaling (MDS) was used to create perceptual maps of tactile space.
- Experiments were conducted on the dorsum and palmar surface of the hand.
Main Results:
- Perceptual maps of the hand dorsum showed a good fit to actual stimulus locations but revealed significant spatial distortion, stretched along the medio-lateral axis.
- Experiment 2 confirmed these distortions on the hand dorsum but found no such distortion on the palmar surface.
- Tactile spatial distortions are geometrically simple and coherent.
Conclusions:
- Distortions in perceived tactile distance exhibit geometrically simple and coherent deformations of tactile space.
- The internal geometry of tactile space is likely influenced by the receptive field geometry in the somatosensory cortex.
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