Crossmodal transfer of object information in human echolocation
Last modified: 2011-08-22
Abstract
In active echolocation, reflections from self-generated acoustic pulses are used to represent the external environment. This ability has been described in some blind humans to aid in navigation and obstacle perception[1-4]. Echoic object representation has been described in echolocating bats and dolphins[5,6], but most prior work in humans has focused on navigation or other basic spatial tasks[4,7,8]. Thus, the nature of echoic object information received by human practitioners remains poorly understood. In two match-to-sample experiments, we tested the ability of five experienced blind echolocators to identify objects haptically which they had previously sampled only echoically. In each trial, a target object was presented on a platform and subjects sampled it using echolocation clicks. The target object was then removed and re-presented along with a distractor object. Only tactile sampling was allowed in identifying the target. Subjects were able to identify targets at greater than chance levels among both common household objects (p < .001) and novel objects constructed from plastic blocks (p = .018). While overall accuracy was indicative of high task difficulty, our results suggest that objects sampled by echolocation are recognizable by shape, and that this representation is available across sensory modalities.
References
1 Kellogg, W. N. Sonar system of the blind. Science 137, 399-404 (1962).
2 Rice, C. E., Feinstein, S. H. & Schusterman, R. J. Echo-Detection Ability of the Blind: Size and Distance Factors. Journal of experimental psychology 70, 246-255 (1965).
3 Teng, S. & Whitney, D. The acuity of echolocation: Spatial resolution in sighted persons compared to the performance of an expert who is blind. Journal of Visual Impairment & Blindness 105, 20-32 (2011).
4 Thaler, L., Arnott, S. R. & Goodale, M. A. Neural correlates of natural human echolocation in early and late blind echolocation experts. PLoS ONE 6, e20162, doi:10.1371/journal.pone.0020162PONE-D-11-04391 [pii] (2011).
5 Firzlaff, U., Schuchmann, M., Grunwald, J. E., Schuller, G. & Wiegrebe, L. Object-oriented echo perception and cortical representation in echolocating bats. PLoS biology 5, e100, doi:06-PLBI-RA-1898R3 [pii]10.1371/journal.pbio.0050100 (2007).
6 Pack, A. A. & Herman, L. M. Sensory integration in the bottlenosed dolphin: immediate recognition of complex shapes across the senses of echolocation and vision. The Journal of the Acoustical Society of America 98, 722-733 (1995).
7 Hughes, B. Active artificial echolocation and the nonvisual perception of aperture passability. Human movement science 20, 371-400 (2001).
8 Supa, M., Cotzin, M. & Dallenbach, K. M. "Facial Vision": The Perception of Obstacles by the Blind. The American Journal of Psychology 57, 133-183 (1944).
2 Rice, C. E., Feinstein, S. H. & Schusterman, R. J. Echo-Detection Ability of the Blind: Size and Distance Factors. Journal of experimental psychology 70, 246-255 (1965).
3 Teng, S. & Whitney, D. The acuity of echolocation: Spatial resolution in sighted persons compared to the performance of an expert who is blind. Journal of Visual Impairment & Blindness 105, 20-32 (2011).
4 Thaler, L., Arnott, S. R. & Goodale, M. A. Neural correlates of natural human echolocation in early and late blind echolocation experts. PLoS ONE 6, e20162, doi:10.1371/journal.pone.0020162PONE-D-11-04391 [pii] (2011).
5 Firzlaff, U., Schuchmann, M., Grunwald, J. E., Schuller, G. & Wiegrebe, L. Object-oriented echo perception and cortical representation in echolocating bats. PLoS biology 5, e100, doi:06-PLBI-RA-1898R3 [pii]10.1371/journal.pbio.0050100 (2007).
6 Pack, A. A. & Herman, L. M. Sensory integration in the bottlenosed dolphin: immediate recognition of complex shapes across the senses of echolocation and vision. The Journal of the Acoustical Society of America 98, 722-733 (1995).
7 Hughes, B. Active artificial echolocation and the nonvisual perception of aperture passability. Human movement science 20, 371-400 (2001).
8 Supa, M., Cotzin, M. & Dallenbach, K. M. "Facial Vision": The Perception of Obstacles by the Blind. The American Journal of Psychology 57, 133-183 (1944).