Interindividual Variation in Fornix Microstructure and Macrostructure Is Related to Visual Discrimination Accuracy for Scenes But Not Faces. / Postans, Mark; Hodgetts, Carl J; Mundy, Matthew E; Jones, Derek K; Lawrence, Andrew D; Graham, Kim S.

In: The Journal of Neuroscience, Vol. 34, No. 36, 03.09.2014, p. 12121-12126.

Research output: Contribution to journalArticle

Published
  • Mark Postans
  • Carl J Hodgetts
  • Matthew E Mundy
  • Derek K Jones
  • Andrew D Lawrence
  • Kim S Graham

Abstract

Transection of the nonhuman primate fornix has been shown to impair learning of configurations of spatial features and object-in-scene memory. Although damage to the human fornix also results in memory impairment, it is not known whether there is a preferential involvement of this white-matter tract in spatial learning, as implied by animal studies. Diffusion-weighted MR images were obtained from healthy participants who had completed versions of a task in which they made rapid same/different discriminations to two categories of highly visually similar stimuli: (1) virtual reality scene pairs; and (2) face pairs. Diffusion-MRI measures of white-matter microstructure [fractional anisotropy (FA) and mean diffusivity (MD)] and macrostructure (tissue volume fraction, f) were then extracted from the fornix of each participant, which had been reconstructed using a deterministic tractography protocol. Fornix MD and f measures correlated with scene, but not face, discrimination accuracy in both discrimination tasks. A complementary voxelwise analysis using tract-based spatial statistics suggested the crus of the fornix as a focus for this relationship. These findings extend previous reports of spatial learning impairments after fornix transection in nonhuman primates, critically highlighting the fornix as a source of interindividual variation in scene discrimination in humans.

Original languageEnglish
Pages (from-to)12121-12126
Number of pages6
JournalThe Journal of Neuroscience
Volume34
Issue number36
DOIs
Publication statusPublished - 3 Sep 2014
This open access research output is licenced under a Creative Commons Attribution-NonCommercial-NoDerivs 3.0 Unported License.

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