Preferential-looking assessment of fusion and stereopsis in infants aged 1-6 months.
The ability of infants to discriminate zero-disparity stimuli from both reverse contrast (rivalrous) and disparate (stereoscopic) stimuli was investigated in a two-alternative, forced-choice, preferential-looking paradigm. Few infants under 4 months of age demonstrated discrimination for any stimulus pairing. Of the infants tested at 4 months of age, approximately 70% preferred zero-disparity stimuli to reverse contrast stimuli, and 82% preferred stereoscopic stimuli to zero-disparity stimuli. Nearly 100% of 5- and 6-month-old infants exhibited these preferences. These findings suggest that sensory fusion is not present at birth but develops rapidly over the first 6 months of life. The time course for the development of sensory fusion was similar to the time course for the development of stereopsis in nine infants tested longitudinally.
D000328:Adult; D004192:Discrimination, Psychological / Q000502:physiology*; D005425:Flicker Fusion; D006801:Humans; D007223:Infant; D008875:Middle Aged; D010364:Pattern Recognition, Visual; D014785:Vision, Ocular / Q000502:physiology; D014792:Visual Acuity