title: Estimating the position of simulated phosphenes using a tactile guide.
abstract: A visual prosthesis provides usable visual information to the patient in the form of phosphenes, that is, punctate photic sensations seen after electrical stimulation. Stimulation via different electrodes results in phosphenes in different positions within the visual field. Simulation studies can provide data on the possible limitations of prosthetic stimulation. We used a head mounted screen to monocularly present constant or flickering light spots of different sizes, or luminance to normally sighted subjects. Subjects were asked to judge the location of the spots using a polar coordinate tactile guide; positioning average error and dispersion were analyzed. With the increase of eccentricity, the positioning average error and dispersion were also increased. The performances under large, stable and high luminance conditions were better than that under small, flickering and low luminance conditions, respectively. Repeated training sessions were shown to significantly improve the positioning performance.
authors.affiliation: Department of Biomedical Engineering, School of Life Sciences and Biotechnology, Shanghai Jiao Tong University, Shanghai 200240, China.
authors.forename: Yanyu
authors.initials: Y
authors.lastname: Lu
authors.forename: Jin
authors.initials: J
authors.lastname: Fan
authors.forename: Chunaqing
authors.initials: C
authors.lastname: Zhou
authors.forename: Ying
authors.initials: Y
authors.lastname: Zhao
authors.forename: Jing
authors.initials: J
authors.lastname: Wang
authors.forename: Chen
authors.initials: C
authors.lastname: Tao
authors.forename: Qiushi
authors.initials: Q
authors.lastname: Ren
authors.forename: Xinyu
authors.initials: X
authors.lastname: Chai
mesh_terms: D000328:Adult; D003213:Conditioning, Psychological; D004599:Electric Stimulation Therapy; D005403:Fixation, Ocular; D006801:Humans; D008029:Lighting; D008962:Models, Theoretical; D010719:Phosphenes; D010775:Photic Stimulation / Q000379:methods*; D012984:Software; D055698:Touch Perception; D015349:Vision, Monocular; D014794:Visual Fields; D057488:Visual Prosthesis; D055815:Young Adult