A blind human expert echolocator shows size constancy for objects perceived by echoes

Milne, J.L.; Anello, M.; Goodale, M.A.; Thaler, L.

doi:10.1080/13554794.2014.922994

A blind human expert echolocator shows size constancy for objects perceived by echoes

Milne, J.L.; Anello, M.; Goodale, M.A.; Thaler, L.

Authors

J.L. Milne

M. Anello

M.A. Goodale

Dr Lore Thaler lore.thaler@durham.ac.uk
Associate Professor

Abstract

Some blind humans make clicking noises with their mouth and use the reflected echoes to perceive objects and surfaces. This technique can operate as a crude substitute for vision, allowing human echolocators to perceive silent, distal objects. Here, we tested if echolocation would, like vision, show size constancy. To investigate this, we asked a blind expert echolocator (EE) to echolocate objects of different physical sizes presented at different distances. The EE consistently identified the true physical size of the objects independent of distance. In contrast, blind and blindfolded sighted controls did not show size constancy, even when encouraged to use mouth clicks, claps, or other signals. These findings suggest that size constancy is not a purely visual phenomenon, but that it can operate via an auditory-based substitute for vision, such as human echolocation.

Citation

Milne, J., Anello, M., Goodale, M., & Thaler, L. (2015). A blind human expert echolocator shows size constancy for objects perceived by echoes. Neurocase: The Neural Basis of Cognition, 21(4), 465-470. https://doi.org/10.1080/13554794.2014.922994

Journal Article Type	Article
Acceptance Date	May 6, 2014
Online Publication Date	May 29, 2014
Publication Date	May 1, 2015
Deposit Date	Mar 4, 2014
Publicly Available Date	Sep 8, 2014
Journal	Neurocase: The Neural Basis of Cognition
Print ISSN	1355-4794
Electronic ISSN	1465-3656
Publisher	Taylor and Francis Group
Peer Reviewed	Peer Reviewed
Volume	21
Issue	4
Pages	465-470
DOI	https://doi.org/10.1080/13554794.2014.922994
Keywords	Blindness, Human echolocation, Size constancy, Vision, Multisensory.

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Copyright Statement
This is an Accepted Manuscript of an article published by Taylor & Francis Group in Neurocase on 29/05/2014, available online at: http://www.tandfonline.com/10.1080/13554794.2014.922994.