Spatial cognition of blind and visually impaired people in their daily living space

Abstract

This research investigates the characteristics of spatial cognition for blind and visually impaired people in their daily living space. Conventional research related to spatial cognition in the field of psychology has not always examined spatial cognition or behavior in a daily living space. This paper focuses on testing whether conventional geographical methods are useful for spatial cognitive studies of blind and visually impaired people. The following two methods were used: 1) estimation of cognitive distance (experimentation for route-based knowledge), and 2) estimation of the bidimensional distribution of cognitive points (experimentation for survey knowledge). The results are summarized as follows. The evaluation of distance estimation revealed that sighted group relatively overestimate shorter trips and underestimate longer trips. Although this seems to reflect an implicit scaling effect, the effect was not confirmed in the case of the congenitally blind and the partially blind/slight groups. It can therefore be said that these groups feel strong resistance toward longer trips. In regard to the slight group, such overestimation of cognitive distance depends on how long they have had the visual impairment. In the case of the congenitally blind group, the overestimation depends on the fact that they must use more spatial cues than slight group for movement in a daily living space. Understanding Euclidean space helps to form new movement routes and also enhances the flexibility of spatial behavior. Difficulty in the understanding of Euclidean space often causes highly distorted cognitive maps. The results of the analyses show large distortions in the bidimensional distribution of cognitive points in the cognitive maps for blind and visually impaired people. The adventitiously blind group and the partially blind group were seen as holding a relative positional relationship with cognitive points. They showed alignment of axes located at right angles to the main streets of the study area. The congenitally blind, on the other hand, did not show such a positional relationship because of their difficulties in understanding the Euclidean map. Consequently visually impaired people show large distortions and errors in their estimation of distance and distribution on cognitive maps. Moreover, such distortions and errors are the results of their visual experience or personal history of impairment, as well as the degree of their impairment. It can therefore be concluded that further attention is required to the relationship between spatial cognition and factors such as the attributes of individuals, the contents of mobility training, and the period of training.