Optic flow sensitivity in neonates

The present research investigates neonatal sensitivity to optic flow. Twenty five 3-day-old infants were placed inside a dark room and observed while presented with a 10 s bilateral and backward peripheral optic motion. Seven constant flow velocity conditions were used (2.5, 5.0, 10.0, 15.0, 20.0, 25.0 and 30.0 degrees per second) and were compared to a baseline motionless condition. Sagittal deviation of the head was computer-sampled at 60 Hz frequency with pressure transducers. As indicated by the mean head pressure during optic flow exposure, infants reacted with backward leaning of the head whose magnitude was linearly related to the optic flow velocity. Additionally, isolated head postural responses were identified. The magnitude of these responses was clearly related to the optic flow velocity. (C) 2000 Elsevier Science Inc. All rights reserved.