Comparing the Effects of Congenital and Late Visual Impairments on Visuospatial Mental Abilities

Abstract

This study compared participants who were congenitally visually impaired and those who became visually impaired later in life in a spatial memory task. The latter showed less efficient visuospatial processes than did the former. However, these differences were of a quantitative nature only, indicating common cognitive mechanisms that can be clearly differentiated from those of people who are congenitally blind.

Spatial Coding of Individuals With Visual Impairments

“…It should be mentioned, however, that in the present study the performance of participants with tunnel vision (loss of peripheral vision) was not compared to that of participants with loss of central vision (they had peripheral vision). The reasons for this are twofold: (a) the small sample size would not allow the comparison to arrive to safe conclusions and (b) participants were free to move their heads; thus, peripheral and tunnel vision do not determine differences in perception (Millar & Al-Attar, 2005;Monegato et al, 2007). Monegato et al (2007) noted a marginal role for the residual field of view in static spatial memory tasks.…”

“…There are several studies that have examined the ability of people with visual impairments in spatial coding and spatial representation of near space (Hollins, 1985;Hollins & Kelley, 1988;Millar, 1979;Monegato, Cattaneo, Pece, & Vecchi, 2007;Pasqualotto & Newell, 2007;Postma et al, 2007;Vanlierde & Wanet-Defalque, 2004) with significant findings. The majority of the researchers who compared the spatial performance of individuals with and without visual impairments or individuals with blindness to peers with residual vision come to the conclusion that visual experience influences decisively spatial behavior.…”

The Impact of Residual Vision in Spatial Skills of Individuals With Visual Impairments

“…Near space has been defined as the space stretching out to an arm's reach (Warren, 1994, p. 102). Various research has been implemented for the evaluation of the ability in spatial coding and spatial representation of near space, for both sighted individuals (Kappers, 2007;Mou et al, 2004;Mou, Fan, McNamara, & Owen, 2008;Mou, Xiao, & McNamara, 2008;Nardini, Burgess, Breckenridge, & Atkinson, 2006;Newell, Woods, Mernagh, & Bülthoff, 2005;Newport, Rabb, & Jackson, 2002;Pasqualotto & Newell, 2007;Platsidou, 1993;Waller, Lippa, & Richardson, 2008) and individuals with visual impairments (Hollins & Kelley, 1988;Millar, 1979;Monegato et al, 2007;Pasqualotto & Newell, 2007;Postma et al, 2007;Ungar et al, 1995). All these studies used similar tests, even if different research aims were set or certain differences existed in the method and design of the experiments.…”

“…Individuals with early blindness seem to organize the attributes haptically perceived into spatial representations (Marmor & Zaback, 1976). Monegato, Cattaneo, Pece, and Vecchi's (2007) research of near-space encoding is of great significance. The goal of this research was to examine the visuospatial processes of individuals with visual impairment.…”

“…Thus, visual cortices process spatial information delivered by other sensory modalities in 1 a different way (Cattaneo et al, 2008;Cohen et al, 1999;Sadato et al, 1998;Thinus-Blanc & Gaunet, 1997) and a range of compensatory strategies are activated for spatial information to be encoded (for a review, see Dulin, Hatwell, Pylyshyn, & Chokron, 2008). It is worth mentioning that the magnitude of compensation may result from the type or the extent (Despres, Candas, & Dufour, 2005) or even the life span of the visual impairment (Monegato et al, 2007).…”