Spatial Representation of the Workspace in Blind, Low Vision, and Sighted Human Participants.

Jacob S. Nelson,Jeroen B. J. Smeets,Albert Postma,Irene A. Kuling,Eli Brenner,Monica Gori

doi:10.1177/2041669518781877

Jacob S. Nelson, Jeroen B. J. Smeets + Show 4 more

Open Access

https://doi.org/10.1177/2041669518781877

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Abstract

It has been proposed that haptic spatial perception depends on one’s visual abilities. We tested spatial perception in the workspace using a combination of haptic matching and line drawing tasks. There were 132 participants with varying degrees of visual ability ranging from congenitally blind to normally sighted. Each participant was blindfolded and asked to match a haptic target position felt under a table with their nondominant hand using a pen in their dominant hand. Once the pen was in position on the tabletop, they had to draw a line of equal length to a previously felt reference object by moving the pen laterally. We used targets at three different locations to evaluate whether different starting positions relative to the body give rise to different matching errors, drawn line lengths, or drawn line angles. We found no influence of visual ability on matching error, drawn line length, or line angle, but we found that early-blind participants are slightly less consistent in their matching errors across space. We conclude that the elementary haptic abilities tested in these tasks do not depend on visual experience.

Highlights

The environment is filled with rich, multisensory stimuli
For the comparison of the drawn lines, we looked at drawn line lengths starting from the near and far targets, as well as drawn line angles starting from the near and side targets
We focus our analysis on the magnitudes of the matching errors (Figure 3(b))

Summary

Introduction

The environment is filled with rich, multisensory stimuli. In humans, the visual system plays a crucial role in information processing, especially at distances that cannot be physically reached. Visual information plays an important role in the development of various spatial abilities, as it provides information about the position and arrangement of the surrounding environment that the nervous system would not otherwise necessarily have access to. Early-blind individuals have been shown to have lower spatial thresholds for tactile discrimination of stimuli (Brown & Stratton, 1925; Jones, 1972), contrary to an earlier report (Seashore & Ling, 1918). Jones and Vierck (1973) did not find a difference in threshold between blind and sighted individuals in detecting which of two stimuli pressed against their arm was longer. Some studies did not find superior performance in haptics due to absence of vision. Jones and Vierck (1973) did not find a difference in threshold between blind and sighted individuals in detecting which of two stimuli pressed against their arm was longer. Gori et al (2010) found that visually impaired children (one late-blind and the rest early-blind) were slightly better than sighted children at tactile object size discrimination but that they were drastically worse at object orientation discrimination, perhaps suggesting that orientation perception relies more heavily on the visual system

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