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

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 3 T 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.

Aberrant brain network connectivity in presymptomatic and manifest Huntington's disease: A systematic review

“…Regarding networks subserving cognitive functions, the ECN showed consistent alterations in manifest HD patients (Figure 2), which might be linked with working memory deficits, one aspect of cognition often impaired in HD (Dumas et al, 2012;Possin et al, 2017;You et al, 2014). Conversely, in pre-HD individuals, the ECN showed no connectivity changes.…”

F7 Spatial memory in huntington’s disease: a comparative review of human and animal data

“…In relation to spatial memory, the hippocampus is a key structure that facilitates allocentric learning and memory, whereas the striatum supports egocentric-based learning. The interplay between the striatum and the hippocampus has been suggested to explain the nature of spatial memory impairments seen in different stages of HD (Ciamei and Morton, 2009;Possin et al, 2017;Voermans et al, 2004). Essentially, in premanifest and early stages, when striatal degeneration is well underway, the hippocampus, which is then less affected, is thought to compensate for the lost striatalmediated function.…”

Hippocampal and striatal volumes correlate with spatial memory impairment in Huntington’s disease

“…A second study that examined the relationship between HD neuropathology and spatial memory by Possin et al. (2017) showed a double dissociation between caudate nucleus and hippocampal volumes in egocentric/allocentric spatial working memory in premanifest HD. Using Postle and D’Esposito (2003) spatial working memory tests, which require participants to represent locations relative to their own position (egocentric) or relative to a landmark (allocentric), Possin found that people with premanifest HD ( n = 14) were more impaired on the egocentric than the allocentric working memory test.…”