Wayfinding tasks in visually impaired people: the role of tactile maps

Adults' spatial scaling of tactile maps: Insights from studying sighted, early and late blind individuals

The current study investigated spatial scaling of tactile maps among blind adults and blindfolded sighted controls. We were specifically interested in identifying spatial scaling strategies as well as effects of different scaling directions (up versus down) on participants' performance. To this aim, we asked late blind participants (with visual memory, Experiment 1) and early blind participants (without visual memory, Experiment 2) as well as sighted blindfolded controls to encode a map including a target and to place a response disc at the same spot on an empty, constant-sized referent space. Maps had five different sizes resulting in five scaling factors (1:3, 1:2, 1:1, 2:1, 3:1), allowing to investigate different scaling directions (up and down) in a single, comprehensive design. Accuracy and speed of learning about the target location as well as responding served as dependent variables. We hypothesized that participants who can use visual mental representations (i.e., late blind and blindfolded sighted participants) may adopt mental transformation scaling strategies. However, our results did not support this hypothesis. At the same time, we predicted the usage of relative distance scaling strategies in early blind participants, which was supported by our findings. Moreover, our results suggested that tactile maps can be scaled as accurately and even faster by blind participants than by sighted participants. Furthermore, irrespective of the visual status, participants of each visual status group gravitated their responses towards the center of the space. Overall, it seems that a lack of visual imagery does not impair early blind adults' spatial scaling ability but causes them to use a different strategy than sighted and late blind individuals.

Cognitive map formation in the blind is enhanced by three-dimensional tactile information

For blind individuals, tactile maps are useful tools to form cognitive maps through touch. However, they still experience challenges in cognitive map formation and independent navigation. Three-dimensional (3D) tactile information is thus increasingly being considered to convey enriched spatial information, but it remains unclear if it can facilitate cognitive map formation compared to traditional two-dimensional (2D) tactile information. Consequently, the present study investigated the impact of the type of sensory input (tactile 2D vs. tactile 3D vs. a visual control condition) on cognitive map formation. To do so, early blind (EB, n = 13), late blind (LB, n = 12), and sighted control (SC, n = 14) participants were tasked to learn the layouts of mazes produced with different sensory information (tactile 2D vs. tactile 3D vs. visual control) and to infer routes from memory. Results show that EB manifested stronger cognitive map formation with 3D mazes, LB performed equally well with 2D and 3D tactile mazes, and SC manifested equivalent cognitive map formation with visual and 3D tactile mazes but were negatively impacted by 2D tactile mazes. 3D tactile maps therefore have the potential to improve spatial learning for EB and newly blind individuals through a reduction of cognitive overload. Installation of 3D tactile maps in public spaces should be considered to promote universal accessibility and reduce blind individuals' wayfinding deficits related to the inaccessibility of spatial information through non-visual means.

Cognitive map formation supported by auditory, haptic, and multimodal information in persons with blindness

For efficient navigation, the brain needs to adequately represent the environment in a cognitive map. In this review, we sought to give an overview of literature about cognitive map formation based on non-visual modalities in persons with blindness (PWBs) and sighted persons. The review is focused on the auditory and haptic modalities, including research that combines multiple modalities and real-world navigation. Furthermore, we addressed implications of route and survey representations. Taking together, PWBs as well as sighted persons can build up cognitive maps based on non-visual modalities, although the accuracy sometime somewhat differs between PWBs and sighted persons. We provide some speculations on how to deploy information from different modalities to support cognitive map formation. Furthermore, PWBs and sighted persons seem to be able to construct route as well as survey representations. PWBs can experience difficulties building up a survey representation, but this is not always the case, and research suggests that they can acquire this ability with sufficient spatial information or training. We discuss possible explanations of these inconsistencies.

Effects of environmental explanation using three-dimensional tactile maps for orientation and mobility training

We developed a new kit to assemble three-dimensional (3D) tactile maps for orientation and mobility (O&M) training provided to persons with visual impairments. This study evaluated the effects of verbal explanations combined with 3D tactile map kits in improving understanding, recall, and walking along an unfamiliar route in comparison with the effects of only verbal explanation. The 3D tactile maps provided participants having severe visual impairments and little experience with tactile maps with a better understanding and recall of the environmental information concerning the route and landmarks. Participants who used the 3D tactile maps could find specific landmarks set as tasks more accurately and arrive at the destination alone getting lost less frequently. Tactile maps composed of 3D points, lines, and areal parts are useful as a support aid for O&M training because they have high tactile readability and can provide the environmental information that individuals with visual impairment require.

Environmental Information Required by Individuals with Visual Impairments Who Use Orientation and Mobility Aids to Navigate Campuses

Introduction:

This study investigated the user requirements of individuals with visual impairments regarding the information to be included in orientation and mobility (O&M) aids in order for optimally useful audio-tactile maps of campuses to be developed. In addition, this study aimed at investigating the importance (usefulness) that individuals with visual impairments attribute to environmental information of campuses.

Methods:

The researchers listed 213 pieces of environmental information concerning campuses and address them in survey by conducting a respective questionnaire. Participants were asked to evaluate the information, regarding the importance or usefulness of the information in regard to safety, location of services, and orientation and wayfinding during movement. Through convenience sampling 115 adults (aged from 18 to 64 years) with visual impairments from four countries (Greece, Cyprus, Turkey, and Germany) took part in the research.

Results:

Pieces of environmental information, sorted in descending order starting with the most useful ones, have been listed. A repeated measures analysis of variance yielded a significant main effect for the type of information (safety, location of services, and wayfinding and orientation): F(2, 228) = 70.868, p < .001.

Discussion:

This study resulted in the specification of the most significant or useful information that should be included in O&M aids of campuses for individuals with visual impairments.

Implications for practitioners:

The results of this study will hold the interest of developers of O&M aids, O&M practitioners, rehabilitation teachers, and instructors who design and construct O&M aids. Moreover, the context for appropriately designed tactile or audio-tactile maps for campuses is provided, and campuses around the world could rely on this study for the creation of a valuable accessibility aid.

Does Knowledge of Spatial Configuration in Adults with Visual Impairments Improve with Tactile Exposure to a Small-scale Model of Their Urban Environment?

This study assessed the efficiency of a model of a familiar urban area for enhancing knowledge of the spatial environment by adults with visual impairments. It found a significant improvement in knowledge of spatial configuration after exposure to the model, suggesting that models are powerful means of developing cognitive mapping in people who are visually impaired.

Orientation and mobility aids for individuals with blindness: Verbal description vs. audio-tactile map

Individuals with visual impairment face significant challenges traveling in the physical environment. Independent movement is directly connected to the quality of someone's life, and thus, orientation and mobility issues are always listed among the top priorities of research in the field. The aim of the present research was to examine the level of accuracy of the cognitive map developed through the use of a verbal description versus the cognitive map developed using an audio-tactile map. A comparison of the effectiveness of the two mobility aids in detecting specific points of interest in the physical environment was an objective of the research. The procedure involved the study of a map using the two mobility aids, and an assessment through the transfer to the corresponding physical environment. The results suggest that an individual with visual impairment can acquire and use a functional cognitive map through the use of an audio-tactile map, while relying on a verbal description entails greater difficulty in detecting specific points of interest when he/she comes into the physical environment.

Haptic recognition of two-dimensional raised-line patterns by early-blind, late-blind, and blindfolded sighted adults

We investigated the role of visual experience and visual imagery in the processing of two-dimensional (2-D) tactile patterns. The performance of early-blind (EB), late-blind (LB), and blindfolded sighted (S) adults in the recognition of 2-D raised-line patterns was compared. We also examined whether recognition of 2-D tactile patterns depends on the type of memory strategy (eg spatial, visuo-spatial, verbal, and kinesthetic) used by EB, LB, and S participants to perform the task. Significant between-group differences in the recognition performance have not been found despite significant between-group differences in self-reported memory strategies. Recognition performance does not vary significantly with the strategy, but correlates positively with visuo-spatial imagery abilities in the S participants. These findings may be taken to suggest that the difficulties some blind people experience with tactile pictures are not due to difficulties in processing 2-D tactile patterns.