Milne, J.L. and Goodale, M.A. and Arnott, S.R. and Kish, D. and Thaler, L. (2015) 'Parahippocampal cortex is involved in material processing via echoes in blind echolocation experts.', Vision research., 109 (Part B). pp. 139-148.
Some blind humans use sound to navigate by emitting mouth-clicks and listening to the echoes that reflect from silent objects and surfaces in their surroundings. These echoes contain information about the size, shape, location, and material properties of objects. Here we present results from an fMRI experiment that investigated the neural activity underlying the processing of materials through echolocation. Three blind echolocation experts (as well as three blind and three sighted non-echolocating control participants) took part in the experiment. First, we made binaural sound recordings in the ears of each echolocator while he produced clicks in the presence of one of three different materials (fleece, synthetic foliage, or whiteboard), or while he made clicks in an empty room. During fMRI scanning these recordings were played back to participants. Remarkably, all participants were able to identify each of the three materials reliably, as well as the empty room. Furthermore, a whole brain analysis, in which we isolated the processing of just the reflected echoes, revealed a material-related increase in BOLD activation in a region of left parahippocampal cortex in the echolocating participants, but not in the blind or sighted control participants. Our results, in combination with previous findings about brain areas involved in material processing, are consistent with the idea that material processing by means of echolocation relies on a multi-modal material processing area in parahippocampal cortex.
|Keywords:||Human echolocation, Material, Texture, Vision, Audition, Multisensory, Neuroplasticity, Blindness, fMRI.|
|Full text:||(AM) Accepted Manuscript|
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|Publisher Web site:||https://doi.org/10.1016/j.visres.2014.07.004|
|Publisher statement:||NOTICE: this is the author’s version of a work that was accepted for publication in Vision Research. 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 Vision Research, 109, Part B, April 2015, 10.1016/j.visres.2014.07.004.|
|Record Created:||12 Aug 2014 09:35|
|Last Modified:||01 Mar 2017 10:28|
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