Search

Infants' oculomotor tracking develops rapidly but is poorer when there are horizontal and vertical movement components. Additionally, persistence of objects moving through occlusion emerges at 4 months but initially is absent for objects moving obliquely. In two experiments, we recorded eye movements of thirty‐two 4‐month‐old and thirty‐two 6‐month‐old infants (mainly Caucasian‐White) tracking horizontal, vertical, and oblique trajectories. Infants tracked oblique trajectories less accurately, but 6‐month olds tracked more accurately such that they tracked oblique trajectories as accurately as 4‐month olds tracked horizontal and vertical trajectories. Similar results emerged when the object was temporarily occluded. Thus, 4‐month olds' tracking of oblique trajectories may be insufficient to support object persistence, whereas 6‐month olds may track sufficiently accurately to perceive object persistence for all trajectory orientations. [ABSTRACT FROM AUTHOR]

Previous research suggesting an association between maternal prenatal docosahexaenoic acid (DHA) intake and infant cognition has yet to assess whether there is a critical trimester for the observed effects. We used a comprehensive Food Frequency Questionnaire to estimate DHA levels during both the second and third trimesters of pregnancy, in a sample of 125 pregnant women. Infants were assessed at 4.5 months and 9 months post-partum using specific tests of visual acuity, habituation, and visual attention. Based on maternal DHA levels during pregnancy, mothers were subdivided into high, medium, and low groups, and their infants compared for task performance using one-way ANOVAs with maternal DHA groups. On the 9 month visual acuity test, infants whose mothers were in the medium DHA group performed significantly better than those with mothers in the low or high DHA groups (p = 0.008). However, no significant finding was found for any of the other cognitive assessment measures. Despite a number of studies reporting a positive effect of higher DHA levels on cognitive development, this study fails to support those conclusions. We can, however, conclude that it appears to be DHA intake in the third trimester specifically, which is influencing the development of visual acuity towards the end of the first postnatal year. [ABSTRACT FROM AUTHOR]

Highlights • The work indicates that the intersensory correspondence between auditory pitch and spatial height can support young infants' perception of object persistence across occlusion. • The results indicate that auditory information for location can support perception of persistence of an object moving on a vertical trajectory. • This is the first demonstration that an intersensory correspondence supports veridical perception by infants. Abstract Perception of object persistence across occlusion emerges at around 4 months of age for objects moving horizontally or vertically. In addition, congruent auditory information for movement enhances perception of persistence of an object moving horizontally. In two experiments, we examined the effect of presenting bimodal (visual and auditory) sensory information, both congruently and incongruently, for a vertical moving object occlusion event. A total of 68 4-month-old infants (34 girls) were tested for perception of persistence of an object moving up and down, passing at each translation behind a centrally placed occluder. Infants were exposed to these visual events accompanied by no sound, spatially colocated sound, or congruent or incongruent pitch–height correspondence sounds. Both spatially colocated and congruent pitch–height auditory information enhanced perception of trajectory continuity. However, no impairment occurred when pitch–height sound information was presented incongruently. These results highlight the importance of taking a multisensory approach to infant perceptual development. [ABSTRACT FROM AUTHOR]

This study investigated maternal prenatal docosahexaenoic acid (DHA) intake and infant cognitive development at 22 months. Estimates for second- and third-trimester maternal DHA intake levels were obtained using a comprehensive Food Frequency Questionnaire. Infants (n = 67) were assessed at 22 months on a novel object search task. Mothers' DHA intake levels were divided into high or low groups, with analyses revealing a significant positive effect of third-trimester DHA on object search task performance. The third trimester appears to be a critical time for ensuring adequate maternal DHA levels to facilitate optimum cognitive development in late infancy. [ABSTRACT FROM AUTHOR]

In two experiments with 47 4-month-olds, we investigated attention to key aspects of events in which an object moved along a partly occluded path that contained an obstruction. Infants were familiarized with a ball rolling behind an occluder to be revealed resting on an end wall, and on test trials an obstruction wall was placed in the ball's path. In Experiment 1, we did not find longer looking when the object appeared in an impossible location beyond the obstruction, and infants did not selectively fixate the object in this location. In Experiment 2, after rolling one or two balls, we measured infants' fixations of a two-object outcome with one ball in a novel but possible resting position and the other in a familiar but impossible location beyond the obstruction. Infants looked longer at the ball in the possible but novel location, likely reflecting a looking preference for location novelty. Thus we obtained no evidence that infants reasoned about obstruction and identified a violation on that basis. [ABSTRACT FROM AUTHOR]