Infant color vision: moving tritan stimuli do not elicit directionally appropriate eye movements in 2- and 4-month-olds.
The purpose of the present study was to investigate the capacity of infants to code the direction of motion of moving tritan-modulated gratings. Infant and adult subjects were tested with 0.2 c/d sinusoidal gratings moving at a speed of 20 deg/sec. Three conditions were tested: luminance-modulated gratings, tritan-modulated gratings, and luminance- vs tritan-modulated gratings superimposed and moving in opposite directions in a chromatic motion nulling paradigm. Two-month-old infants were tested in all three conditions, while 4-month-olds were tested in only the first two conditions. For infant subjects, an adult observer reported the direction of the slow phase of the infant's eye movements; adult subjects judged the perceived direction of motion of the stimuli. Luminance-modulated gratings produced directionally appropriate eye movements (DEM) in all age groups. Tritan gratings presented alone did not produce DEM in either 2- or 4-month-olds, but did so in adults. Mean equivalent luminance contrasts were near zero in 2-month-olds, and small but reliably above zero in adults. In sum, the present study provides no evidence that infants can code the direction of motion of moving tritan gratings.
Teller
D Y
DY
Department of Psychology, University of Washington, Seattle 98195, USA. dteller@u.washington.edu
Brooks
T E
TE
Palmer
J
J
D000328:Adult; D003118:Color Perception / Q000502:physiology*; D015350:Contrast Sensitivity / Q000502:physiology; D005133:Eye Movements / Q000502:physiology*; D005260:Female; D006801:Humans; D007223:Infant; D008297:Male; D009039:Motion Perception / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D011594:Psychometrics; D017949:Retinal Cone Photoreceptor Cells / Q000502:physiology; D012684:Sensory Thresholds / Q000502:physiology