Neural components of topographical representation
Abstract
Studies of patients with focal brain damage suggest that topographical representation is subserved by dissociable neural subcomponents. This article offers a condensed review of the literature of “topographical disorientation” and describes several functional MRI studies designed to test hypotheses generated by that review. Three hypotheses are considered: (i) The parahippocampal cortex is critically involved in the acquisition of exocentric spatial information in humans; (ii) separable, posterior, dorsal, and ventral cortical regions subserve the perception and long term representation of position and identity, respectively, of landmarks; and (iii) there is a distinct area of the ventral occipitotemporal cortex that responds maximally to building stimuli and may play a role in the perception of salient landmarks. We conclude with a discussion of the inferential limitations of neuroimaging and lesion studies. It is proposed that combining these two approaches allows for inferences regarding the computational involvement of a neuroanatomical substrate in a given cognitive process although neither method can strictly support this conclusion alone.
Footnotes
-
↵ * To whom reprint requests should be addressed. e-mail: despo{at}mail.med.upenn.edu.
-
This paper was presented at a colloquium entitled “Neuroimaging of Human Brain Function,” organized by Michael Posner and Marcus E. Raichle, held May 29–31, 1997, sponsored by the National Academy of Sciences at the Arnold and Mabel Beckman Center in Irvine, CA.
-
↵ † The parahippocampal gyrus is comprised of several, distinct cortical fields, including the entorhinal cortex, the parahippocampal cortex (areas TH and TF) and perirhinal cortex (34). Our use of the specific term “parahippocampal cortex” and the general term “parahippocampal gyrus” (when more specific anatomical statements cannot be made) is deliberate.
- ABBREVIATION:
- fMRI,
- functional MRI
- Copyright © 1998, The National Academy of Sciences
