There are more than 3.3 million Americans with low vision, most of whom have reading difficulties. Many suffer from macular degeneration and associated loss of central vision. The primary purpose of this proposal is to develop principled training methods to enhance low-vision reading, particularly for those with macular degeneration Our research indicates that decrease in the size of the visual span is a key factor explaining reduced reading speed in low vision. The visual span for reading refers to the number of letters, arranged side-by-side as in text that can be recognized accurately without moving the eyes. Structure of the retina and cortical magnification of the central visual field produce a small visual span, even for normal vision. This small visual span is further diminished as a consequence of eye disease. In a series of psychophysical studies, we will build on our prior research on the visual span to develop principled training methods to enhance low-vision reading. The three forms of training to be evaluated include: 1) Vertical reading in cases where the vertical visual span exceeds the horizontal visual span;2) Oculomotor training of eye fixations to maximize the information transfer rate through the visual span;and 3) Perceptual Learning which is focused on enlarging the size of the visual span. The applications to reading rehabilitation will benefit from our exploration of the sensory factors determining the size of the visual span and its role in reading. We will examine spatial factors (crowding, positional uncertainty) and temporal factors determining the size of the visual span in central and peripheral vision. We will use fMRI to localize the neural site of word and letter recognition within the visual span and the influence of perceptual learning on its size. These studies will inform our psychophysical exploration of the visual- processing capacity of the preferred retinal locus (PRL), the region of peripheral retina used for reading by many people with macular degeneration.

Public Health Relevance

There are more than 3.3 million Americans with low vision, most of whom have reading difficulties. Our broad goal is to use findings from vision science to understand the reading difficulties of people with low vision. A major goal of the current proposal is to develop principled training methods to enhance low-vision reading, particularly for people with macular degeneration.

Agency
National Institute of Health (NIH)
Institute
National Eye Institute (NEI)
Type
Research Project (R01)
Project #
5R01EY002934-32
Application #
8312612
Study Section
Central Visual Processing Study Section (CVP)
Program Officer
Wiggs, Cheri
Project Start
1979-09-01
Project End
2014-08-31
Budget Start
2012-09-01
Budget End
2014-08-31
Support Year
32
Fiscal Year
2012
Total Cost
$358,776
Indirect Cost
$121,176
Name
University of Minnesota Twin Cities
Department
Psychology
Type
Schools of Arts and Sciences
DUNS #
555917996
City
Minneapolis
State
MN
Country
United States
Zip Code
55455
He, Yingchen; Kwon, MiYoung; Legge, Gordon E (2018) Common constraints limit Korean and English character recognition in peripheral vision. J Vis 18:5
Gupta, Anshul; Mesik, Juraj; Engel, Stephen A et al. (2018) Beneficial Effects of Spatial Remapping for Reading With Simulated Central Field Loss. Invest Ophthalmol Vis Sci 59:1105-1112
Xiong, Ying-Zi; Lorsung, Ethan A; Mansfield, John Stephen et al. (2018) Fonts Designed for Macular Degeneration: Impact on Reading. Invest Ophthalmol Vis Sci 59:4182-4189
Granquist, Christina; Wu, Yueh-Hsun; Gage, Rachel et al. (2018) How People with Low Vision Achieve Magnification in Digital Reading. Optom Vis Sci 95:711-719
Xiong, Ying-Zi; Calabrèse, Aurélie; Cheong, Allen M Y et al. (2018) Reading Acuity as a Predictor of Low-Vision Reading Performance. Invest Ophthalmol Vis Sci 59:4798-4803
He, Yingchen; Baek, Sori; Legge, Gordon E (2018) Korean reading speed: Effects of print size and retinal eccentricity. Vision Res 150:8-14
Calabrèse, Aurélie; To, Long; He, Yingchen et al. (2018) Comparing performance on the MNREAD iPad application with the MNREAD acuity chart. J Vis 18:8
Wang, Hui; Legge, Gordon E (2018) Comparing the minimum spatial-frequency content for recognizing Chinese and alphabet characters. J Vis 18:1
Husk, Jesse S; Yu, Deyue (2017) Learning to recognize letters in the periphery: Effects of repeated exposure, letter frequency, and letter complexity. J Vis 17:3
Calabrèse, Aurélie; Liu, Tingting; Legge, Gordon E (2017) Does Vertical Reading Help People with Macular Degeneration: An Exploratory Study. PLoS One 12:e0170743

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