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Shape-specific activation of occipital cortex in an early blind echolocation expert

Arnott, S.R.; Thaler, L.; Milne, J.; Kish, D.; Goodale, M.A.

Shape-specific activation of occipital cortex in an early blind echolocation expert Thumbnail


S.R. Arnott

J. Milne

D. Kish

M.A. Goodale


We have previously reported that an early-blind echolocating individual (EB) showed robust occipital activation when he identified distant, silent objects based on echoes from his tongue clicks (Thaler, Arnott, & Goodale, 2011). In the present study we investigated the extent to which echolocation activation in EB's occipital cortex reflected general echolocation processing per se versus feature-specific processing. In the first experiment, echolocation audio sessions were captured with in-ear microphones in an anechoic chamber or hallway alcove as EB produced tongue clicks in front of a concave or flat object covered in aluminum foil or a cotton towel. All eight echolocation sessions (2 shapes×2 surface materials×2 environments) were then randomly presented to him during a sparse-temporal scanning fMRI session. While fMRI contrasts of chamber versus alcove-recorded echolocation stimuli underscored the importance of auditory cortex for extracting echo information, main task comparisons demonstrated a prominent role of occipital cortex in shape-specific echo processing in a manner consistent with latent, multisensory cortical specialization. Specifically, relative to surface composition judgments, shape judgments elicited greater BOLD activity in ventrolateral occipital areas and bilateral occipital pole. A second echolocation experiment involving shape judgments of objects located 20° to the left or right of straight ahead activated more rostral areas of EB's calcarine cortex relative to location judgments of those same objects and, as we previously reported, such calcarine activity was largest when the object was located in contralateral hemispace. Interestingly, other echolocating experts (i.e., a congenitally blind individual in Experiment 1, and a late blind individual in Experiment 2) did not show the same pattern of feature-specific echo-processing calcarine activity as EB, suggesting the possible significance of early visual experience and early echolocation training. Together, our findings indicate that the echolocation activation in EB's occipital cortex is feature-specific, and that these object representations appear to be organized in a topographic manner.


Arnott, S., Thaler, L., Milne, J., Kish, D., & Goodale, M. (2013). Shape-specific activation of occipital cortex in an early blind echolocation expert. Neuropsychologia, 51(5), 938-949.

Journal Article Type Article
Publication Date Apr 1, 2013
Deposit Date Oct 14, 2013
Publicly Available Date Apr 22, 2014
Journal Neuropsychologia
Print ISSN 0028-3932
Publisher Elsevier
Peer Reviewed Peer Reviewed
Volume 51
Issue 5
Pages 938-949
Keywords Auditory, Blind, Echolocation, fMRI, Occipital cortex, Retinotopy.


Accepted Journal Article (660 Kb)

Copyright Statement
NOTICE: this is the author’s version of a work that was accepted for publication in Neuropsychologia. 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 Neuropsychologia, 51, 5, April 2013, 10.1016/j.neuropsychologia.2013.01.024.

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