Psychophysics of Reading in Normal and Low Vision Book

Preface and Acknowledgments     xiii
Vision and Reading   Gordon E. Legge     1
Complete Citations for the 20 Articles in the Psychophysics of Reading Series     5
Citations to M. A. Tinker's Classic Series of 13 Articles     7
Measuring Reading Speed   Gordon E. Legge     9
Three Methods for Measuring Reading Speed     9
Drifting Text Method     10
RSVP Method     12
Flashcard Method     13
Clinical Potential of the Flashcard Method     15
Subtleties in the Measurement of Reading Speed     16
Text Difficulty, Word Length, and Carver's Metric     16
Instructions to Participants     16
Oral and Silent Reading of Short and Long Passages     17
Context Effects     18
How Fast Do People Read?     20
Reading Speeds of Normally Sighted People     20
Speed Reading     23
Role of the Magnocellular Pathway in Reading and Dyslexia     24
Effect of Age on Normal Reading Speed     28
Low-Vision Reading Speed     30
Auditory and Tactile Reading Speed     30
Characteristics of Braille     32
Is Reading Speed Limited by Motor Movements,Sensory Coding, or Cognition?     35
Comparison of Reading Speed to Other Measures of Reading Performance     36
Comprehension     36
Eye Movements     38
Reading Accuracy, Visual Search, and Visual Comfort     39
Visual Mechanisms in Reading   Gordon E. Legge     43
Two Important Properties of Letters in Text: Contrast and Size     44
Contrast Definitions     45
Size Definitions     46
The Effect of Character Size in Normal and Low Vision     48
Normal Vision     48
Low Vision     51
Contrast Effects in Normal and Low Vision     52
Normal Vision     52
Low Vision     55
The CSF Model of Reading     56
The Spatial-Frequency Channel Model of Reading     59
Reading with Peripheral Vision     66
The Visual Span     67
Historical Antecedents of the Visual Span     68
Two Methods for Measuring the Visual Span     72
The Impact of Contrast and Character Size on the Visual Span     76
Three Determinants of the Size of the Visual Span     79
Central-Field Loss and Reading Difficulty     83
Macular Degeneration and Central-Field Loss     83
Central-Field Loss Usually Means Slow Reading     84
Why Do People With Central Scotomas Read Slowly?     86
Implications for Rehabilitation     88
Linking Letter Recognition to Reading Speed     91
A Model Based on Letter Recognition     91
Word Shape     94
Is There a Visual Word Form Area?     96
Bottom-Up and Top-Down Processes in Word Recognition     98
Dual-Route Theory     100
Summary and Conclusions     103
Displaying Text   Gordon E. Legge     107
Text Legibility     107
Definition     107
Fonts for Highway Signs     109
Legibility Metric     111
Font Effects in Normal and Low Vision     112
Influence of Font Design     112
Influence of Spacing     115
Fonts for Low vision     116
Display Resolution     117
Effects of Sample Density and Spatial-Frequency Bandwidth     117
Implications for Text Displays     123
Defocused Text     125
Reading and Myopia     127
Sampled Displays and Low Vision     129
Pixelized Vision as a Prosthetic for Blind People     132
The Window-Size Effect and Page Navigation     137
Relation to Visual Span     141
Navigating Through Text     145
Eye Movements in Reading     145
Small Displays     147
Navigating Through Text with Magnifiers     149
Using Large Print or Short Viewing Distance to Magnify     149
Reading with Magnifiers     151
Hypertext Retrieval with Low vision and the Local-Global Problem     155
Color and Luminance Effects in Normal and Low Vision     158
Color     158
Colored Overlays     160
Luminance     162
Page Luminance and Illuminance     163
Guidelines for Legible Text     164
Critical Values for Reading Speed     165
Font Characteristics     165
Color and luminance     166
The MNREAD Acuity Chart   J. Stephen Mansfield   Gordon E. Legge     167
Introduction     167
The MNREAD Acuity Chart     168
Design principles     171
Print Size and Resolution     172
Typeface Properties     173
Text Properties     174
Sentence Composition      175
Physical Properties of the Charts     176
Guidelines for Using the MNREAD Acuity Chart     176
Conditions for Testing     176
Testing Procedure     177
Scoring Guidelines     177
Calculating Reading Acuity     177
Sample Calculation of Reading Acuity and Reading Speed     179
Calculation of Reading Speed     182
CPS and Maximum Reading Speed     182
Reliability and Validity     183
Concluding Remarks     184
Source Code     185
Print Size Definitions and Conversions   J. Stephen Mansfield   Gordon E. Legge     193
Glossary of Technical Acronyms     199
References     201
Author Index     217
Subject Index     225