Retrosplenial cortex and its role in spatial cognition

Abstract

Retrosplenial cortex is a region within the posterior neocortical system, heavily interconnected with an array of brain networks, both cortical and subcortical, that is, engaged by a myriad of cognitive tasks. Although there is no consensus as to its precise function, evidence from both human and animal studies clearly points to a role in spatial cognition. However, the spatial processing impairments that follow retrosplenial cortex damage are not straightforward to characterise, leading to difficulties in defining the exact nature of its role. In this article, we review this literature and classify the types of ideas that have been put forward into three broad, somewhat overlapping classes: (1) learning of landmark location, stability and permanence; (2) integration between spatial reference frames; and (3) consolidation and retrieval of spatial knowledge (schemas). We evaluate these models and suggest ways to test them, before briefly discussing whether the spatial function may be a subset of a more general function in episodic memory.

Keywords: Learning; cingulate cortex; default mode network; electrophysiology; hippocampal formation; immediate-early genes; memory; neuroimaging; primate; thalamus.

Figure 1.

Schematic of the RSC as seen in midsagittal section and located just posterior to the corpus callosum, in humans, rhesus monkeys and rats. Source: Figure by Jeffery (2017); available at: https://doi.org/10.6084/m9.figshare.5414179.v1 under a CC-BY 4.0 licence.

Figure 2.

A schematic diagram detailing the gross connectivity of retrosplenial cortex. As depicted in the figure, RSC serves as an interconnected hub for neocortical, hippocampal, parahippocampal and thalamic regions that are functionally involved in the processing of mammalian perceptions important for direction, location, landmarks and navigation. Different shading is used for effect only.