Yes / We describe a method for deriving the linear cortical
magnification factor from positional error across the
visual field. We compared magnification obtained from
this method between normally sighted individuals and
amblyopic individuals, who receive atypical visual input
during development. The cortical magnification factor
was derived for each subject from positional error at
32 locations in the visual field, using an established
model of conformal mapping between retinal and
cortical coordinates. Magnification of the normally
sighted group matched estimates from previous
physiological and neuroimaging studies in humans,
confirming the validity of the approach. The estimate
of magnification for the amblyopic group was
significantly lower than the normal group: by 4.4 mm
deg 1 at 18 eccentricity, assuming a constant scaling
factor for both groups. These estimates, if correct,
suggest a role for early visual experience in establishing
retinotopic mapping in cortex. We discuss the
implications of altered cortical magnification for
cortical size, and consider other neural changes that
may account for the amblyopic results.
| Identifer | oai:union.ndltd.org:BRADFORD/oai:bradscholars.brad.ac.uk:10454/10182 |
| Date | 02 1900 |
| Creators | Hussain, Z., Svensson, C-M., Besle, J., Webb, B.S., Barrett, Brendan T., McGraw, Paul V. |
| Source Sets | Bradford Scholars |
| Language | English |
| Detected Language | English |
| Type | Article, Published version |
| Rights | © 2015 The Authors. Published by ARVO. Reproduced in accordance with the publisher's self-archiving policy under Creative Commons Attribution-NonCommercial-NoDerivatives License (http://creativecommons.org/licenses/bync-nd/4.0/legalcode), CC-BY-NC-ND |
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