Amount Of Time Infants Research Articles

Car Seats, Infant Carriers, and Swings

The recent increase in incidence of deformational plagiocephaly is commonly believed to be associated with the American Academy of Pediatrics' “Back to Sleep” campaign. Other factors, however, may contribute to the development of this condition. During the past decade, we have seen a number of infants whose deformities seem to be associated with the extended use of car seats, infant carriers, bouncy seats, and infant swings. Having recognized that notes about usage were being routinely recorded in the margins of our clinical records, we began collecting information on the amount of time infants were spending in these devices. In this report, we describe our findings and document the related cranial deformities. The data and photographs were collected between 1998 and 2000 and reviewed to determine the amount of time children with deformational plagiocephaly spent in these devices. During the three-year study period, 56.6% of the infants spent less than 1.5 hrs, 28.6% spent 1.5 to 4 hrs, and 14.8% spent more than 4 hrs/day in these devices. In addition, 5.7% slept in one of these devices during their first several months of life, frequently because of problems with reflux. These infants often developed an increase in posterior head height and “squaring” or “cornering” of the head. Normal use of car seats, carriers, swings and bouncy seats is not a concern; however, caution is warranted for infants who spend extended periods of time in these devices. The constant pressure these devices apply to the back of the cranium may perpetuate the deformation.

Responses of Free-ranging Rhesus Monkeys to a Natural Form of Social Separation. I. Parallels with Mother-Infant Separation in Captivity

Observations of 23 free-ranging rhesus monkey infants on Cayo Santiago, Puerto Rico, indicated that mothers' first postpartum estrous periods were marked by large increases in the amount of time infants were separated from their mothers, by disturbances in mother-infant relationships, and by increases in infant distress behavior. When their mothers resumed mating, most infants showed signs of agitation; a few briefly showed indications of depression. Male infants responded to their mothers' resumption of mating by playing more, whereas females engaged in less play and more allogrooming. The results suggest (a) that basic parallels exist between the behavioral responses of rhesus infants to their mothers' resumption of mating in the field and to forcible separation from their mothers in captivity and (b) that early separation experiences may play a role in the normal development or manifestation of sex differences in behavior.

Ecological constraints on the development of infant independence in rhesus.

Mother-infant dyads were observed among three populations of rhesus monkeys (Macaca mulatta) in India and Nepal. This research had three purposes: 1) to examine the influences of maternal activities (ie, feeding, locomotion, and rest) and arboreality on the early development of infant independence; 2) to determine whether interpopulation differences in the development of infant independence can be accounted for by correlated differences in maternal time budgets and the amount of time infants spent on the ground; and 3) to explore how patterns of maternal care may or may not mitigate increased risk of infant mortality resulting from human harassment. Despite significant interpopulation differences in maternal time budgets, the amount of time infants spent on the ground, and the degree of harassment the animals experienced, few interpopulation differences in infant development could be found. The application of a multiple regression/ correlation analysis revealed that the development of infant independence was affected by the above factors but that those factors were acting in complementary ways to constrain development and to minimize the differences across populations.

The Relation between the Amount of Time Infants Spend at Various States and the Development of Visual Behavior

The Relation between the Amount of Time Infants Spend at Various States and the Development of Visual Behavior