Reaching strategies of very preterm infants at 8 months corrected age

Reaching strategies and kinematics for a group of very preterm infants were investigated and compared with a group of full-term infants when reaching for a moving object. Eight-month-old (corrected-age) infants were presented with small toys moving on a semicircular path in the vertical plane. The trajectories of the target and the hands of the infants were measured using a 3D motion analysis system. No differences were found in how often the infants encountered the target. The very preterm group, however, used bimanual strategies more often and had more curved reaching paths than the full-term group. These results suggest that very preterm infants are equally successful as healthy full-term infants in catching a moving object but their reaching strategies are less efficient compared with full-term infants at 8 months (corrected age)

Occlusion Is Hard: Comparing Predictive Reaching for Visible and Hidden Objects in Infants and Adults

Infants can anticipate the future location of a moving object and execute a predictive reach to intercept the object. When a moving object is temporarily hidden by darkness or occlusion, 6-month-old infants’ reaching is perturbed, but performance on darkness trials is significantly better than occlusion trials. How does this reaching behavior change over development? Experiment 1 tested predictive reaching of 6- and 9-month-old infants. While there was an increase in the overall number of reaches with increasing age, there were significantly fewer predictive reaches during the occlusion compared to visible trials and no age-related changes in this pattern. The decrease in performance found in Experiment 1 is likely to apply not only to the object representations formed by infants but also those formed by adults. In Experiment 2 we tested adults with a similar reaching task. Like infants, the adults were most accurate when the target was continuously visible and performance in darkness trials was significantly better than occlusion trials, providing evidence that there is something specific about occlusion that makes it more difficult than merely lack of visibility. Together, these findings suggest that infants’ and adults’ capacities to represent objects have similar signatures throughout development.Psycholog

Using a head-mounted camera to infer attention direction

A head-mounted camera was used to measure head direction. The camera was mounted to the forehead of 20 6- and 20 12-month-old infants while they watched an object held at 11 horizontal (-80 degrees to + 80 degrees) and 9 vertical (-48 degrees to + 50 degrees) positions. The results showed that the head always moved less than required to be on target. Below 30 degrees in the horizontal dimension, the head undershoot of object direction was less than 5 degrees. At 80 degrees, however, the undershoot was substantial or between 10 degrees and 15 degrees. In the vertical dimension, the undershoot was larger than in the horizontal dimension. At 30 degrees, the undershoot was around 25% in the downward direction and around 40% in the upward direction. The size of the undershoot was quite consistent between conditions. It was concluded that the head-mounted camera is a useful indicator of horizontal looking direction in a free looking situation where the head is only turned moderately from a straight ahead position

Towards Wide-Field Display of the Gripen HUD Interface to Combat Spatial Disorientation

The head-up display (HUD) interface of the Gripen fighter aircraft utilizes a sphere concept for supporting attitude awareness or spatial orientation (SO). With the sphere interface fixed to the gravitational vertical and the attitude variant aircraft positioned in the center of the sphere, the HUD field-of-regard scans parts of the sphere inside. The HUD interface depicts segments of latitude circles with meridian markings that convey integrated information of pitch, roll, and yaw. To enhance pilot-in-the-loop maneuvering and SO we suggest a wide field-of-view interface design of the Gripen concept, emphasizing the inclusion of peripheral vision. The suggested interface is subsequently integrated with peripheral visual flow to improve SO primarily in instrument meteorological conditions. Implemented in future head-up flight displays systems it could perhaps contribute to a more successful combating of pilot spatial disorientation

Development of smooth pursuit tracking in young infants

Eye and head movements were measured in a group of infants at 2, 3, and 5 months of age as they were attentively tracking an object moving at 0.2 or 0.4 Hz in sinus or triangular mode. Smooth pursuit gain increased with age, especially until 3 months. At 2-3 months, the lag of the smooth pursuit was small for the sinusoidal motion but large for the triangular one. At 5 months, smooth pursuit was leading the sinusoidal motion and the lag for the triangular one was small. Head tracking increased substantially with age and its lag was always large. © 1997 Elsevier Science Ltd. Eye movements Infants Smooth pursuit Saccades Head movement