Mental body representations retain homuncular shape distortions: evidence from Weber’s Illusion

Article English OPEN
Miller, L.E. ; Longo, Matthew R. ; Saygin, A.P. (2016)

Mental body representations underlying tactile perception do not accurately reflect the body’s true morphology. For example, perceived tactile distance is dependent on both the body part being touched and the stimulus orientation, a phenomenon called Weber’s illusion. These findings suggest the presence of size and shape distortions, respectively. However, whereas each morphological feature is typically measured in isolation, a complete morphological characterization requires the concurrent measurement of both size and shape. We did so in three experiments, manipulating both the stimulated body parts (hand; forearm) and stimulus orientation while requiring participants to make tactile distance judgments. We found that the forearm was significantly more distorted than the hand lengthwise but not widthwise. Effects of stimulus orientation are thought to reflect receptive field anisotropies in primary somatosensory cortex. The results of the present study therefore suggest that mental body representations retain homuncular shape distortions that characterize early stages of somatosensory processing.
  • References (43)
    43 references, page 1 of 5

    Alloway, K. D., Rosenthal, P., & Burton, H. (1989). Quantitative measurements of receptive field changes during antagonism of GABAergic transmission in primary somatosensory cortex of cats. Experimental Brain Research, 78(3), 514-532.

    Anema, H. A., Wolswijk, V. W., Ruis, C., & Dijkerman, H. C. (2008). Grasping Weber's illusion: the effect of receptor density differences on grasping and matching. Cogn Neuropsychol, 25(7-8), 951-967.

    Bassolino, M., Finisguerra, A., Canzoneri, E., Serino, A., & Pozzo, T. (2015).

    Dissociating effect of upper limb non-use and overuse on space and body representations. Neuropsychologia, 70, 385-392.

    Bolognini, N., & Maravita, A. (2007). Proprioceptive alignment of visual and somatosensory maps in the posterior parietal cortex. Current Biology, 17(21), 1890- 1895.

    Brown, P. B., Fuchs, J. L., & Tapper, D. N. (1975). Parametric studies of dorsal horn neurons responding to tactile stimulation. Journal of Neurophysiology, 38(1), 19-25.

    (2013). Tool-use reshapes the boundaries of body and peripersonal space representations. Experimental Brain Research, 228(1), 25-42.

    Cholewiak, R. W. (1999). The perception of tactile distance: influences of body site, space, and time. Perception, 28(7), 851-875.

    Cody, F. W., Garside, R., Lloyd, D., & Poliakoff, E. (2008). Tactile spatial acuity varies with site and axis in the human upper limb. Neurosci Lett, 433(2), 103-108.

    (2014). Reversible deactivation of higher-order posterior parietal areas. I.

  • Metrics
    0
    views in OpenAIRE
    0
    views in local repository
    9
    downloads in local repository

    The information is available from the following content providers:

    From Number Of Views Number Of Downloads
    Birkbeck Institutional Research Online - IRUS-UK 0 9
Share - Bookmark