Psychophysics of reading—XVI. The visual span in normal and low vision
نویسندگان
چکیده
The visual span in reading is the number of characters that can be recognized at a glance. The shrinking visual span hypothesis attributes reading deficits in low vision, and slow reading in normal vision at low contrast, to a reduction in the visual span. This hypothesis predicts that reading time (msec/word) becomes increasingly dependent on word length as text contrast decreases. We tested and confirmed this prediction using the rapid serial visual presentation (RSVP) method. Estimates of the visual span ranged from about 10 characters for high-contrast text to less than two characters for low-contrast text. Eye-movement recordings showed that longer reading times at low contrast are partitioned about equally between prolonged fixation times and an increased number of saccades (presumably related to a reduced visual span). RSVP measurements for six out of seven low-vision subjects revealed a strong dependence of reading time on word length, as expected from reduced visual spans.
منابع مشابه
Spatial-frequency requirements for reading revisited
Blur is one of many visual factors that can limit reading in both normal and low vision. Legge et al. [Legge, G. E., Pelli, D. G., Rubin, G. S., & Schleske, M. M. (1985). Psychophysics of reading. I. Normal vision. Vision Research, 25, 239-252.] measured reading speed for text that was low-pass filtered with a range of cutoff spatial frequencies. Above 2cycles per letter (CPL) reading speed was...
متن کاملPsychophysics of reading XX. Linking letter recognition to reading speed in central and peripheral vision
Our goal is to link spatial and temporal properties of letter recognition to reading speed for text viewed centrally or in peripheral vision. We propose that the size of the visual span - the number of letters recognizable in a glance - imposes a fundamental limit on reading speed, and that shrinkage of the visual span in peripheral vision accounts for slower peripheral reading. In Experiment 1...
متن کاملPsychophysics of Reading: Xx. Linking Letter Recognition to Reading Speed in Central and Peripheral Vision1
Our goal is to link spatial and temporal properties of letter recognition to reading speed for text viewed centrally or in peripheral vision. We propose that the size of the visual span the number of letters recognizable in a glance imposes a fundamental limit on reading speed. and that shrinkage of the visual span in peripheral vision accounts for slower peripheral reading. In Experiment 1, we...
متن کاملRelationship between visual span and reading performance in age-related macular degeneration
PURPOSE Visual-span profiles are plots of letter-recognition accuracy as a function of letter position left and right of the point of fixation. Legge, Mansfield, and Chung [Legge, G. E., Mansfield, J. S., & Chung, S. T. L. (2001). Psychophysics of reading-XX. Linking letter recognition to reading speed in central and peripheral vision. Vision Research, 41(6), 725-743] proposed that reduced size...
متن کاملPsychophysics of reading. XV: Font effects in normal and low vision.
PURPOSE Little is known about the effect of font on low-vision reading. In this study, the authors measured the influence of font in reading with normal and low vision. METHODS Reading acuity, maximum reading speed, and critical print size (the smallest print that can be read with maximum speed) were measured in 50 normal subjects and 42 subjects with low vision. Data were collected using ver...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
برای دانلود متن کامل این مقاله و بیش از 32 میلیون مقاله دیگر ابتدا ثبت نام کنید
ثبت ناماگر عضو سایت هستید لطفا وارد حساب کاربری خود شوید
ورودعنوان ژورنال:
- Vision Research
دوره 37 شماره
صفحات -
تاریخ انتشار 1997