, 2011) fashion have been described that may minimize the functional impact of the relatively poor quality of prosthetic vision. For example, Parikh et al. (2013) used feature extraction algorithms to identify the most relevant parts of an image, with a blinking phosphene guiding prosthesis recipient׳s attention to a particular part of the visual field. The authors reported improvements in object avoidance, reductions in head scanning and more rapid object location with the use of cues. In a similar fashion, Mohammadi et al.
(2012) propose the use of a range-finding algorithm to estimate the distance to objects, which would be relayed Selleck ABT263 to the prosthesis wearer using a group of phosphenes reserved for this purpose. The use of more advanced image processing techniques derived from the field
of robotics may provide further improvements in the way in which phosphenes are utilized to represent the physical environment. For example, recognition of the ground plane to clearly identify unobstructed areas when walking may permit better obstacle avoidance (Lui et al., 2012 and McCarthy et al., 2011). Object recognition and location, particularly in complex environments, may be improved by using symbolic or iconographic techniques akin to those used in computer graphics (Lui et al., 2012). Facial recognition in particular may benefit from these techniques, whereby simplistic representations of faces (Lui et al., 2012) could be assembled using far fewer phosphenes than would be possible using an intensity-based method (Bradley et al., 2005). Such techniques may be find more particularly useful in the case of long-term phosphene dropout and map degradation, allowing the available phosphenes to be used to maximal effect. The choice by Brindley and Dobelle to present Braille characters instead of conventional lettering could be considered a conceptually Aspartate similar “repurposing” of a poor quality phosphene map
to maximize its utility (Brindley and Rushton, 1974 and Dobelle, 1974). As demonstrated by the success of Dobelle׳s (2000) last reported patient (in the scientific literature), the ongoing development of image processing techniques applicable to prosthetic vision should continue to provide improvements in the likely outcomes of visual prosthesis recipients, both cortical and retinal. Even further improvements will undoubtedly come from an improved understanding of the encoding of the more complex features of imagery, such as color, form and motion in visual cortex neurons, possibly offering a richer visual experience (Normann et al., 2009). Moreover, with reductions in the size of the stimulated neuron pool, possibly via increases in the density of electrode arrays (e.g. Wark et al., 2013), and a “bioinspired” approach to encoding information into neuronal spike trains, continued improvements in the quality and functional utility of prosthetic vision may be realized in the future.