Uncovering a visuospatial network at rest

Abstract

Introduction The posterior cingulate cortex (PCC) is a crucial region for visuospatial memory and is one of the main connector hubs in the brain, playing a pivotal role in the coordination of information flow [1]. With fMRI, the PCC can be reliably activated using the Roland Hometown Walking Task (RHWT) [2], [3]. Other sites are also routinely activated during RHWT, namely those within bilateral parahippocampal gyrus (PH), middle occipital gyrus (MOG), BA29/30 (PCC), precuneus (BA7) and middle frontal gyrus (BA6). This is referred to as a “visuospatial” network (VSN) [2] and is very useful for pre-surgical mapping given its widespread activation profile. However, eliciting the VSN depends on the subject’s participation which can be difficult in patient populations. Our goal was thus two-fold: (1) To investigate whether resting-state (RS) fMRI can be used to recover the VSN and (2) identify which of the 5 bilateral sites acts as the main connector hub.