Psychophysical studies have reported the efficacy of phosphene-based prosthetic vision in partly recovering the visual function of blind individuals. However, results by far have been based on evenly aligned phosphene arrays, which neglected the complicated visuotopy in the visual prosthesis system. In this study, we investigated how the objects were recognized under the stimuli with distorted phosphene arrays simulated by transformations of barrel distortion, rotation, or translation. The results revealed that distortions significantly decreased the accuracy of categorization (CA) and showed distinct interactive effects with the factors of object category and phosphene array density. Moreover, the CA changed differently with the increase of distortion levels. Regression analysis suggested a phosphene array of at least 10 × 10 be the essential for achieving a CA over the threshold value (CA(t)=62.5%) under distorted prosthetic vision. It is recommended that discriminative features be extracted to improve the performance of prosthetic vision.
© 2010, Copyright Shanghai Jiao Tong University. Artificial Organs © 2010, International Center for Artificial Organs and Transplantation and Wiley Periodicals, Inc.