Visuospatial Memory in Healthy Elderly, AD and MCI: A Review

Abstract

In the literature it is commonly reported that several spatial abilities decline with normal aging, even though such a decline is not uniform. So far, it is not yet clear which spatial components present a normal age-related decline, which ones are preserved and at what point the deficit is so severe to represent an index of mild cognitive impairment (MCI) or a symptom of potential degenerative progression as in the early-stage Alzheimer's disease (AD). In particular, AD (from early onset) is characterised by impairments in constructive abilities, visuospatial intelligence, spatial short-term memory deficits, and disorders of spatial orientation (topographical disorientation). MCI indicates a condition, generally affecting older individuals, characterized by cognitive deficits including memory and/or non memory impairments and at high risk of progression to dementia. Three MCI subgroups have been distinguished and a very high risk of developing AD is associated to the amnestic MCI subtypes. Further, recent studies have suggested that the allocentric component of spatial memory might be taken as predictor of AD from MCI. Given the frequency of visuospatial deficits in early-stage AD, evaluation of visuospatial processes is a promising approach to find predictive markers of AD. Here we report a review of the literature exploring specific visuospatial components in normal aging, MCI, and AD. In this way we could shed some light on the role of these components in the progression from MCI to AD and pave the way for future studies.

Development of egocentric and allocentric spatial representations from childhood to elderly age

“…Results revealed a deficit of the allocentric component in AD and amnesic-MCI patients (see also Dawson, Anderson, Uc, Dastrup, & Rizzo, 2009;Laczó et al, 2012). This suggests that a severe drop in the allocentric capacity could be a prodromic sign of a neurodegenerative disease (Hort et al, 2007;Iachini et al, 2009a).…”

“…Spatial memory efficiency is associated with structural and functional integrity of the spatial memory neural network (i.e., hippocampus, parahippocampal gyrus, retrosplenial, postero-cingulate cortex, parietal lobe and frontal areas) that involves the allocentric encoding (hippocampus and surrounding areas) and also executive functions (Burgess, 2008;Cabeza & Dennis, 2012;Galati et al, 2010;Iachini et al, 2009a;Moffat, 2009;Vann, Aggleton, & Maguire, 2009). Much research has documented that normal aging is characterized by reductions in the volume of the hippocampus and the frontal cortex, such as to produce allocentric (e.g., Rodgers et al, 2012) and egocentric (e.g., Head & Isom, 2010;Wilkniss et al, 1997) difficulties and a general decline in executive and attentional functions (Iachini et al, 2009a;Lithfous et al, 2013;Salthouse, 1996). Executive functions are necessary to acquire, combine and select spatial strategies, to plan and monitor behavioral motor responses according to environmental requirements (Lithfous et al, 2013;Vasilyeva & Lourenco, 2012).…”

“…As concerns the effect of aging on spatial memory, a decline in selective spatial abilities is often reported in healthy people; whereas severe spatial disorders are associated with neurodegenerative syndromes (for reviews see Iachini, Iavarone, Senese, Ruotolo, & Ruggiero, 2009a;Moffat, 2009). The age-related normal decline is often attributed to functional changes of the posteromedial, the medio-temporal and the frontal areas (Cabeza & Dennis, 2012;Lithfous, Dufour, & Després, 2013;Moffat, 2009).…”

Spatial updating of multiple targets: Comparison of younger and older adults

“…Mixed results have been found for age effects when learning locations from maps and small-scale arrays not requiring physical movement to explore. While some have found clear evidence of spatial decline (Iachini et al, 2009; Kirasic, 2000; Moffat & Resnick, 2002), others have shown preservation when memory prompts are present (Yamamoto & DeGirolamo, 2015) or a mix of preservation and decline depending on alignment of perspective (Borella, Meneghetti, Muffato, & De Beni, 2015). The encoding and retention of spatial layouts by older adults clearly merits further examination, as in the present studies.…”

Investigating virtual reality navigation in amnestic mild cognitive impairment using fMRI

“…Having the condition is widely considered to be a highly predictive risk factor for the development of Alzheimer's Disease (AD; Morris et al, 2001;Petersen, 2004) and there is therefore diverse research into identifying aMCI patients, understanding their cognitive impairments, and predicting later conversion to dementia (Blennow, Hampel, Weiner, & Zetterberg, 2010;Prvulovic, Bokde, Faltraco, & Hampel, 2011;Sperling, 2011;Wolk & Detre, 2012). There has been a recent emphasis on investigating spatial navigation in normal and pathological aging (Gazova et al, 2012;Iachini, Iavarone, Senese, Ruotolo, & Ruggiero, 2009;Lithfous, Dufour, & Després, 2013;Moffat, 2009). Spatial navigation impairments occur early in the progress of AD, where patients can be disoriented even in familiar surroundings (Henderson, Mack, & Williams, 1989;Monacelli, Cushman, Kavcic, & Duffy, 2003).…”