Egocentric and allocentric visuospatial working memory in premotor Huntington's disease: A double dissociation with caudate and hippocampal volumes

Neuropsychologia. 2017 Jul 1;101:57-64. doi: 10.1016/j.neuropsychologia.2017.04.022. Epub 2017 Apr 17.

Abstract

Our brains represent spatial information in egocentric (self-based) or allocentric (landmark-based) coordinates. Rodent studies have demonstrated a critical role for the caudate in egocentric navigation and the hippocampus in allocentric navigation. We administered tests of egocentric and allocentric working memory to individuals with premotor Huntington's disease (pmHD), which is associated with early caudate nucleus atrophy, and controls. Each test had 80 trials during which subjects were asked to remember 2 locations over 1-sec delays. The only difference between these otherwise identical tests was that locations could only be coded in self-based or landmark-based coordinates. We applied a multiatlas-based segmentation algorithm and computed point-wise Jacobian determinants to measure regional variations in caudate and hippocampal volumes from 3T MRI. As predicted, the pmHD patients were significantly more impaired on egocentric working memory. Only egocentric accuracy correlated with caudate volumes, specifically the dorsolateral caudate head, right more than left, a region that receives dense efferents from dorsolateral prefrontal cortex. In contrast, only allocentric accuracy correlated with hippocampal volumes, specifically intermediate and posterior regions that connect strongly with parahippocampal and posterior parietal cortices. These results indicate that the distinction between egocentric and allocentric navigation applies to working memory. The dorsolateral caudate is important for egocentric working memory, which can explain the disproportionate impairment in pmHD. Allocentric working memory, in contrast, relies on the hippocampus and is relatively spared in pmHD.

Keywords: Caudate; Navigation; Visuospatial; Working memory.

MeSH terms

  • Adult
  • Algorithms
  • Analysis of Variance
  • Caudate Nucleus / diagnostic imaging*
  • Female
  • Hippocampus / diagnostic imaging*
  • Humans
  • Huntington Disease / diagnostic imaging
  • Huntington Disease / psychology*
  • Imaging, Three-Dimensional
  • Magnetic Resonance Imaging
  • Male
  • Memory, Short-Term*
  • Middle Aged
  • Neuropsychological Tests
  • Organ Size
  • Self Concept*
  • Social Perception*
  • Spatial Memory
  • Visual Perception