Simon Ungar

The Construction of Cognitive Maps by Children with Visual Impairments

The way in which children who have visual impairments construct cognitive maps of their environment is of considerable theoretical and practical importance. It sheds light on the role of sensory experience in the development of spatial cognition which can in turn suggest how spatial skills might be nurtured in visually impaired children. In most of the studies reviewed here, groups of children who lost their sight early in life perform less well on a variety of spatial tasks than sighted children or children who lost their sight later in life. We will argue that it is not the lack of visual experience in itself which produces this pattern, but rather the effect of lack of vision on the spatial coding strategies adopted by the children. Finally we will discuss a number of methods for encouraging visually impaired children to use coding systems which are appropriate for the construction of flexible and integrated cognitive maps, with particular reference to the use of tactile maps.

Mental Rotation of a Tactile Layout by Young Visually Impaired Children

Mental rotation tasks have been used to probe the mental imagery both of sighted and of visually impaired people. People who have been blind since birth display a response pattern which is qualitatively similar to that of sighted people but tend to respond more slowly or with a higher error rate. It has been suggested that visually impaired people code the stimulus and its (or their own) motion in a different way from sighted people—in particular, congenitally blind people may ignore the external reference framework provided by the stimulus and surrounding objects, and instead use body-centred or movement-based coding systems. What has not been considered before is the relationship between different strategies for tactually exploring the stimulus and the response pattern of congenitally blind participants. Congenitally blind and partially sighted children were tested for their ability to learn and recall a layout of tactile symbols. Children explored layouts of one, three, or five shapes which they then attempted to reproduce. On half the trials there was a short pause between exploring and reproducing the layouts. In an aligned condition children reproduced the array from the same position at which they had explored it; in a rotated condition children were asked to move 90° round the table between exploring and reproducing the layout. Both congenitally blind and partially sighted children were less accurate in the rotated condition than in the aligned condition. Five distinct strategies used by the children in learning the layout were identified. These strategies interacted with both visual status and age. We suggest that the use of strategies, rather than visual status or chronological age, accounts for differences in performance between children.

The role of tactile maps in mobility training

Tactile maps can have both immediate and long term benefits in helping visually impaired children to find their way through their environment and to acquire spatial abilities. In a series of studies (1991-92), reported in this article, the authors established that young visually impaired children can understand and use tactile maps. The children adopted a variety of strategies for acquiring information from a map, some of which were more effective than others. In the final study, it was established that training in a simple strategy can improve childrens performance in a map task.

The world of touch: an international survey of tactile maps. Part 1: production

This paper reports the findings of an international survey that collected data on production methods, techniques, outputs and design preferences among tactile map producers, designers and researchers worldwide. A number of consistencies and inconsistencies are identified and we speculate on the extent to which the current state of tactile map production is likely to meet the needs of the client population. In this first part of the report we describe the sample on which the report is based, and describe the output in terms of quantity of maps produced, choice of production method, types of environment mapped and intended uses of maps.

An empirical approach on the design of tactile maps and diagrams: The cognitive tactualization approach

Tactile maps and diagrams need to be carefully designed in order to be readable by the visually impaired user. In the Tactile Inkjet Mapping Project, we attempt to provide a new orientation for tactile map design through a rigorous programme of experimental research on design issues (cognitive tactualization approach). In this article we discuss three of our studies. The first study evaluates the use of different background materials for tactile graphics. The second study looks at the minimal perceptible distance between two lines. The third study investigates the optimal elevation (height off the paper) at which graphics are produced. We argue that experimental studies like these represent a necessary basis for the design of tactile maps.

Visually impaired children's strategies for memorising a map

This article describes research carried out in 1993. 24 children with visual impairments and 22 sighted children (aged seven to 13 years) were asked to learn a tactile map and then reconstruct it from memory. While the children were learning the map they gave a continuous commentary on what they were doing and thinking. The commentaries and map reconstructions were analysed to identify and assess the learning strategies which the children used to memorise the map. Overall, the reconstructions made by children with visual impairments were less accurate than the ones made by sighted children. However, it was noted that most of the children with visual impairments used strategies which were inappropriate for the task. It is suggested that teaching appropriate learning strategies would improve the ability of visually impaired children to encode information from tactile maps.

Developing the blind child's cognition of the environment: the role of direct and map-given experience

Abstract For the blind, ‘spatial entities which can never be seen fully’ are not just the large entities discussed elsewhere in this special issue, but include immediate geographical spaces. This paper briefly reviews the ways the blind child constructs space, challenges the long-held belief among mobility teachers that a well-developed body image provides the frame of reference for spatial cognition, and discusses techniques for encouraging movement in space as a basis for such cognitions. Indirect experience is also an important way of establishing and developing frames of reference: and this paper discusses the role of maps, models and computer simulations in orientation and mobility training. We argue that tactile maps, etc. should be seen as both a navigational and a conceptual aid for the blind. An interactive mapping system such as NOMAD, and intelligent real-world guidance systems such as REACT indicate the direction of future developments in giving the blind child a greater chance to move at will through their environment.

An introduction to the use of inkjet for tactile diagram production

The three common methods for producing tactile diagrams are mixed-media, swell paper and thermoform. This paper describes a new innovative method for producing tactile diagrams using piezoelectric inkjet technology that overcomes some of the limitations of these methods. A photocuring acrylic polymer ink is repeatedly printed onto a thermoplastic substrate and exposed to ultraviolet light which bonds the ink to the substrate and cures it to a hard state. The speed and precision of the process means that diagrams with fine, yet easily discriminated tactile features will be available to the user relatively cheaply. The process is allied to work in the printed circuit board and rapid prototyping industries, which are using similar inkjet technology to engineer highly toleranced components. It is hoped that the newly available tactile maps will facilitate psychological, psychophysical and cartographic research.

An evaluation of tactile directional symbols

Symbols that could effectively designate direction have the potential to show routes, geographic phenomena, aid scientific explanation and generally enhance understanding of tactile maps and diagrams. In this study, 41 tactile symbols, including subsets of arrow symbols and stair symbols, were investigated for effectiveness at indicating direction. The symbols were presented to blind or blindfolded participants, and qualitative and quantitative responses regarding the symbol orientation and meaning were recorded. The arrow symbols with the greatest agreement across participants as to which direction the symbol intended to convey were basic arrows and the arrowhead. In the case of a line with a saw-tooth surface profile that felt rough when traced by the finger in one direction and smooth in the opposite, participants were split between those intuitively thinking the rough or the smooth was the direction being indicated. Stair symbols with a greater degree of threedimensionality gave marginally increased agreement as to which way was up.

Producing tactile maps using new inkjet technology: An introduction

Abstract Three common methods for producing tactile maps are mixed media, microcapsule paper and thermoform. This paper describes a new method for producing tactile diagrams using piezoelectric inkjet. To produce diagrams a photo-curing acrylic polymer ink is repeatedly printed onto a thermoplastic substrate and exposed to ultraviolet light which bonds the ink to the substrate and cures it solid. The speed and precision of the process means maps with fine, easily discriminated tactile features will be readily available to users. The new process will facilitate further psychological, psychophysical and cartographic research.