UvA-DARE ( Digital Academic Repository ) Relative finger position influences whether you can localize tactile stimuli

To investigate whether the relative positions of the fingers influence tactile localization, participants were asked to localize tactile stimuli applied to their fingertips. We measured the location and rate of errors for three finger configurations: fingers stretched out and together so that they are touching each other, fingers stretched out and spread apart maximally and fingers stretched out with the two hands on top of each other so that the fingers are interwoven. When the fingers contact each other, it is likely that the error rate to the adjacent fingers will be higher than when the fingers are spread apart. In particular, we reasoned that localization would probably improve when the fingers are spread. We aimed at assessing whether such adjacency was measured in external coordinates (taking proprioception into account) or on the body (in skin coordinates). The results confirmed that the error rate was lower when the fingers were spread. However, there was no decrease in error rate to neighbouring fingertips in the fingers spread condition in comparison with the fingers together condition. In an additional experiment, we showed that the lower error rate when the fingers were spread was not related to the continuous tactile input from the neighbouring fingers when the fingers were together. The current results suggest that information from proprioception is taken into account in perceiving the location of a stimulus on one of the fingertips.

[1]  R. Johansson.  Tactile sensibility in the human hand: receptive field characteristics of mechanoreceptive units in the glabrous skin area. , 1978, The Journal of physiology.

[2]  John W. Lane,et al.  Receptive Field (RF) Properties of the Macaque Second Somatosensory Cortex: RF Size, Shape, and Somatotopic Organization , 2006, The Journal of Neuroscience.

[3]  C. Spence,et al.  Tactile selective attention and body posture: Assessing the multisensory contributions of vision and proprioception , 2004, Perception & psychophysics.

[4]  S. Soto-Faraco,et al.  Changing Reference Frames during the Encoding of Tactile Events , 2008, Current Biology.

[5]  O. Hikosaka,et al.  Converging patterns of finger representation and complex response properties of neurons in area 1 of the first somatosensory cortex of the conscious monkey , 1983, Experimental Brain Research.

[6]  J. Kaas,et al.  What, if anything, is SI? Organization of first somatosensory area of cortex. , 1983, Physiological reviews.

[7]  James C Craig,et al.  The effect of hand position and pattern motion on temporal order judgments , 2003, Perception & psychophysics.

[8]  S. Kitazawa,et al.  Reversal of subjective temporal order due to arm crossing , 2001, Nature Neuroscience.

[9]  Roland S. Johansson,et al.  Receptive field sensitivity profile mechanosensitive units innervating the glabrous skin of the human hand , 1976, Brain Research.

[10]  Glyn W Humphreys,et al.  The Role of Somatotopy and Body Posture in the Integration of Texture Across the Fingers , 2010, Psychological science.

[11]  J B J Smeets,et al.  Haptic search is more efficient when the stimulus can be interpreted as consisting of fewer items. , 2008, Acta psychologica.

[12]  B. Whitsel,et al.  Anterior parietal cortical topographic organization in macaque monkey: a reevaluation. , 1982, Journal of neurophysiology.

[13]  T. Natsoulas,et al.  INFERRING THE LOCUS AND ORIENTATION OF THE PERCEIVER FROM RESPONSES TO STIMULATION OF THE SKIN. , 1964, The American journal of psychology.

[14]  O. Hikosaka,et al.  Functional subdivisions representing different finger regions in area 3 of the first somatosensory cortex of the conscious monkey , 1983, Experimental Brain Research.

[15]  J. Marshall.  THE SKIN SENSES , 1969 .

[16]  R. Johansson,et al.  Properties of cutaneous mechanoreceptors in the human hand related to touch sensation. , 1984, Human neurobiology.

[17]  C Braun,et al.  Distribution of mislocalizations of tactile stimuli on the fingers of the human hand. , 2000, Somatosensory & motor research.

[18]  Brigitte Röder,et al.  Assessing the effect of posture change on tactile inhibition-of-return , 2002, Experimental Brain Research.

[19]  B. Röder,et al.  Spatial remapping of touch: confusion of perceived stimulus order across hand and foot. , 2006, Proceedings of the National Academy of Sciences of the United States of America.

[20]  S Weinstein,et al.  Intensive and extensive aspects of tactile sensitivity as a function of body part, sex, and laterality , 1968 .

[21]  C. Riper,et al.  An experimental study of the Japanese illusion. , 1935 .

[22]  Niels Birbaumer,et al.  The distribution of mislocalizations across fingers demonstrates training-induced neuroplastic changes in somatosensory cortex , 2001, Experimental Brain Research.

[23]  C. Spence,et al.  Effect of posture change on tactile perception: impaired direction discrimination performance with interleaved fingers , 2005, Experimental Brain Research.

[24]  P. Haggard,et al.  The brain’s fingers and hands , 2006, Experimental Brain Research.