Visually guided performance of simple tasks using simulated prosthetic vision.

Abstract:

:Loss of photoreceptor cells is one of the major causes of blindness. Several groups are exploring the functional replacement of photoreceptors by a retinal prosthesis. The goal of this study was to simulate the vision levels that recipients of retinal prostheses with 4 x 4, 6 x 10, and 16 x 16 electrode arrays may experience, and to test the functionality of this vision. A PC video camera captured images that were converted in real time into dots ("pixels"). The PC monitor and a head-mounted display worn by test subjects displayed the pixelized images. To assess performance of normally sighted individuals with each array, we designed a set of tasks including: four-choice orientation discrimination of a Sloan letter E, object recognition and discrimination, a cutting task, a pouring task, symbol recognition, and two reading tasks. In the letter E task, subjects were found to have visual acuities of 20/1,810, 20/1,330, and 20/420 with the 4 x 4, 6 x 10, and 16 x 16 arrays, respectively. Most subjects were able to read fonts as small as 36 point with the 16 x 16 array, corresponding with a visual acuity of 20/600 in our system. The test subjects partially overcame the visual limitation of the system by scanning the video camera over the letters allowing spatial and temporal integration of visual information. In all categories, subjects performed best with the 16 x 16 array and least well with the 4 x 4 array. Even with the lowest resolution array, however, some subjects could recognize simple objects and symbols.

journal_name

Artif Organs

journal_title

Artificial organs

authors

Hayes JS,Yin VT,Piyathaisere D,Weiland JD,Humayun MS,Dagnelie G

doi

10.1046/j.1525-1594.2003.07309.x

subject

Has Abstract

pub_date

2003-11-01 00:00:00

pages

1016-28

issue

11

eissn

0160-564X

issn

1525-1594

pii

7309

journal_volume

27

pub_type

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