Development of contrast sensitivity in the human infant

• Published in: Vision research (Oxford) Vol. 30; no. 10; pp. 1475 - 1486
• Main Authors: Norcia, Anthony M., Tyler, Christopher W., Hamer, Russell D.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 1990; Elsevier Science
• Subjects: Adult; Aging - physiology; Biological and medical sciences; Child development; Contrast Sensitivity - physiology; Developmental psychology; Evoked Potentials, Visual - physiology; Fundamental and applied biological sciences. Psychology; Humans; Infant; Infant, Newborn; Pattern Recognition, Visual - physiology; Psychology. Psychoanalysis. Psychiatry; Psychology. Psychophysiology; Psychophysics; Sensory Thresholds - physiology; Visual Acuity - physiology; Visual development Spatial vision Visual evoked potentials Contrast sensitivity Human infants; Visual development Spatial vision Visual evoked potentials Contrast sensitivity Human infants; Human; Electrophysiology; Visual evoked potential; Infant; Space perception; Psychophysics; Contrast; Perceptual development; Spatial frequency; Sensitivity; Vision; Perception; Age
• ISSN: 0042-6989; 1878-5646
• DOI: 10.1016/0042-6989(90)90028-J

Contrast sensitivity and grating acuity were measured using the sweep VEP method in a group of 48 infants from 2 to 40 weeks of age and in a group of 10 adults. Sinusoidal gratings were reversed in contrast at 12 alternations per sec at a space-average luminance of 220 cd/m 2. During 10 sec trials, either The contrast or the spatial frequency was increased in a series of 19 steps. Thresholds were estimated by extrapolation of the VEP response functions to zero amplitude. The contrast threshold at low spatial frequencies developed rapidly from 7% contrast at 2–3 weeks to an asymptote of 0.5% at 9 weeks. For adults, maximum sensitivity at low spatial frequencies was 0.32–0.22%. The sweep VEP estimate of grating acuity showed a gradual increase in spatial frequency with age, starting at 5 c/deg during the first month and reaching 16.3 c/deg at 8 months. The mean adult acuity was 31.9 c/deg. There appeared to be two phases in the development of contrast sensitivity and acuity. Between 4 and 9 weeks overall contrast sensitivity increased by a factor of 4–5 at all spatial frequencies. Beyond 9 weeks, contrast sensitivity at low spatial frequencies remained constant, while sensitivity increased systematically at higher spatial frequencies.