Categorical perception of tactile distance
Le Cornu Knight, F. and Longo, Matthew R. and Bremner, A.J. (2014) Categorical perception of tactile distance. Cognition 131 (2), pp. 254-262. ISSN 0010-0277.
The tactile surface forms a continuous sheet covering the body. And yet, the perceived distance between two touches varies across stimulation sites. Perceived tactile distance is larger when stimuli cross over the wrist, compared to when both fall on either the hand or the forearm. This effect could reflect a categorical distortion of tactile space across body-part boundaries (in which stimuli crossing the wrist boundary are perceptually elongated) or may simply reflect a localised increased in acuity surrounding anatomical landmarks (in which stimuli near the wrist are perceptually elongated). We tested these two interpretations, by comparing a well-documented bias to perceive mediolateral tactile distances across the forearm/hand as larger than proximodistal ones along the forearm/hand at three different sites (hand, wrist, and forearm). According to the ‘categorical’ interpretation, tactile distances should be elongated selectively in the proximodistal axis thus reducing the anisotropy. According to the ‘localised acuity’ interpretation, distances will be perceptually elongated in the vicinity of the wrist regardless of orientation, leading to increased overall size without affecting anisotropy. Consistent with the categorical account, we found a reduction in the magnitude of anisotropy at the wrist, with no evidence of a corresponding specialized increase in precision. These findings demonstrate that we reference touch to a representation of the body that is categorically segmented into discrete parts, which consequently influences the perception of tactile distance.
|Additional Information:||NOTICE: this is the author’s version of a work that was accepted for publication in Cognition. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Cognition, 131(2) May 2014 - DOI: 10.1016/j.cognition.2014.01.005|
|School:||Birkbeck Schools and Departments > School of Science > Psychological Sciences|
|Research Centre:||Brain and Cognitive Development, Centre for (CBCD)|
|Depositing User:||Matthew Longo|
|Date Deposited:||19 Feb 2014 13:45|
|Last Modified:||02 Dec 2016 11:52|
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