ABSTRACT

Introduction ......................................................................................................... 161 General-Purpose and Special-Purpose Sensory Substitution ....................... 163 Theoretical Framework for Special-Purpose Sensory Substitution ............. 164

Step 1: Identifying Informational Requirements for a Task ..................... 164 Step 2: Coupling Task Information with the Substituting Modalities ........................................................................................................ 165

Bases for Sensory Substitution .......................................................................... 170 Functional Equivalence through Spatial Isomorphism ............................ 171 Functional Equivalence through Amodal Representations ..................... 173 Synesthesia: Exploiting Natural Correspondences ................................... 175 Rote Learning .................................................................................................. 177 Cortical Plasticity............................................................................................ 178 Image Preprocessing and Artificial Intelligence ........................................ 179

Implications of Processing Differences between Blind and Sighted People ..................................................................................................... 180 Recommendations for the Design Process ...................................................... 181

Understanding the Information Flow from Function to Display ............ 182 Considering the End-User from the Starting Point Onward ................... 182

Concluding Remarks .......................................................................................... 183 Acknowledgments .............................................................................................. 184 References ............................................................................................................. 184

losing vision is a significant decrement in performance of actions that rely on the spatial resolution and wide field of view that vision provides, particularly under tight temporal constraints (see Chapters 2 and 4). Returning a tennis serve or driving in city traffic are examples. Nonetheless, the ability of many blind people to perform tasks that we generally think of as visually guided, like steering a bicycle around obstacles (using echolocation), is testimony to the potential of other sources of information to substitute for visual input. This form of sensory substitution, allowing one or more of the remaining spatial senses to take the place of vision, is possible because hearing and touch are also informative about the environment. Expanding these natural sensory substitutions with compensatory strategies and theoretically motivated technologies would no doubt enhance the capabilities of blind and low-vision individuals.