Although the recent development of objective measures of mobility performance has provided a tool for the study of the behaviour of blind pedestrians, subsidiary measures are required to investigate the nature of the perceptual processes which limit the execution of this complex skill. The present research was conducted to determine the role played by information processing load in mobility skill. A possible source of additional load for the blind traveller is his limited ability to anticipate environmental events in comparison to his sighted counterpart. The type and amount of anticipatory information available to three groups of subjects was manipulated as they walked a simulated travel route. Performance on a choice RT task performed simultaneously with the mobility task was used as a measure of processing load. Load was significantly reduced by the introduction of verbal preview of environmental events and by the availability of a memorial representation of the mobility route. The secondary task measure also was shown to be sensitive to the apparent complexity of the travel environment. Furthermore, mobility performance was enhanced by the provision of anticipatory information. The implications of the roles of processing load and preview for the design of mobility aids are discussed in view of these results.
展开▼
