Development of directional motion symmetry in the monocular visually evoked potential of infant monkeys

• Published in: Vision research (Oxford) Vol. 38; no. 9; pp. 1253 - 1263
• Main Authors: Brown, Rick J., Wilson, James R., Norcia, Anthony M., Boothe, Ronald G.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.05.1998; Elsevier Science
• Subjects: Aging; Animals; Biological and medical sciences; Development; Evoked Potentials, Visual; Eye and associated structures. Visual pathways and centers. Vision; Fundamental and applied biological sciences. Psychology; Macaca mulatta; Monkey; Motion asymmetry; Motion Perception - physiology; Pattern Recognition, Visual - physiology; Space life sciences; Vertebrates: nervous system and sense organs; Vision, Monocular; Visually evoked potentials; Development; Motion asymmetry; Visually evoked potentials; Monkey; Stimulus movement; Electrophysiology; Visual evoked potential; Monocular vision; Macaca mulatta; Vertebrata; Visual stimulus; Mammalia; Asymmetry; Newborn animal; Information processing; Primates; Simioidea; Perception; Developmental stage; Stimulus direction
• ISSN: 0042-6989; 1878-5646
• DOI: 10.1016/S0042-6989(97)00289-7

Motion processing in humans and monkeys exhibit a directional asymmetry during infancy which is not present in adults except following abnormal visual rearing conditions. To characterize the time course for maturation of a symmetric response, we measured the monocular visually evoked potential (MVEP) response to 0.26 c/deg gratings oscillating horizontally at 6 Hz in 13 infant rhesus monkeys between 1 and 52 weeks of age. An asymmetric (F1) and a symmetric (F2) frequency component were extracted from the MVEP using Fourier analysis. At early ages the asymmetric F1 component measured from the two eyes exhibited a 180 deg interocular phase shift, demonstrating that there was a directional bias in opposite directions between the left and right eyes. Although our methods could not determine whether the bias was in the nasal or temporal direction, our results would be consistent with a nasal bias, as has been observed in previous motion studies. Magnitude of the asymmetry was quantified in the form of an asymmetry index, F1 ( F1+ F2) . Based on developmental changes in the asymmetry index, and phases and amplitudes of F1 and F2, we conclude that the MVEP loses its directional asymmetry at 6 weeks of age. The development of directional motion symmetry observed in monkeys over the first 6 weeks is similar to that observed in humans over the first 5 months.