Infant eye movement asymmetries: temporal-nasal asymmetry is reversed at isoluminance in 2-month-olds.
Tested monocularly with luminance-modulated stimuli, young infants classically show a directional asymmetry of eye movements: optokinetic nystagmus (OKN) and OKN-like eye movements are more reliably elicited by temporo-nasally- (T-N) than by naso-temporally- (N-T) directed stimuli. In the present experiment, 2-month-old infants were tested with isoluminant red-green gratings. A reverse asymmetry was found: at isoluminance, directionally appropriate eye movements were more readily elicited by N-T- than by T-N-directed stimuli. The results suggest the presence of a reverse asymmetry in the ensemble of direction-selective neurons that controls young infants' immature eye movements in response to isoluminant stimuli.
Epelbaum
M
M
Department of Psychology NI-25, University of Washington, Seattle 98195, USA.
Teller
D Y
DY
D003118:Color Perception / Q000502:physiology; D015350:Contrast Sensitivity / Q000502:physiology; D005133:Eye Movements / Q000502:physiology*; D006801:Humans; D007223:Infant; D008029:Lighting; D009039:Motion Perception / Q000502:physiology; D017120:Nystagmus, Optokinetic / Q000502:physiology*; D010364:Pattern Recognition, Visual / Q000502:physiology; D015349:Vision, Monocular / Q000502:physiology