Patterns of looking behavior in full-term and low birth weight infants at 40 weeks post-conceptional age.
Given the usefulness of visual behavior as an assessment method in older infants, a simple method of visual behavioral evaluation applicable in clinical settings was utilized to gather descriptive data on 42 infants at term. Using an "infant control" method for determining the duration of stimulus presentation, a series of four patterned targets was presented to 25 healthy full-term (FT) and 17 low birth weight (LBW) infants at 40 weeks postconceptional age. Infants were examined in their nursery cribs, and each stimulus was presented until the infant reached a criterion of a 50% or greater decrement in looking time. LBW infants looked for longer time periods, without pause, than FT infants; LBW mean trial length was twice that of FTs. Although total looking time was longer for the LBW group, LBW infants took twice the length of time as FTs to reach the decrement criterion for the first target and thus viewed fewer targets than FT infants. Despite the longer looking of LBW infants, only 41%, as compared to 56% of the FT group, showed an increase in looking time when a new stimulus was presented. The quality of LBW infants' visual behavior was more often marked by long, continuous looking at the same pattern, in contrast to shorter, more discrete and rapidly decrementing looks by the FT newborn. While there was a large variability within groups, the differential patterns of visual behavior are considered likely to reflect variations in processing of information, possibly associated with differences in integrity or maturation of the visual system.
D002652:Child Behavior; D005260:Female; D005556:Form Perception; D005865:Gestational Age; D006801:Humans; D007230:Infant, Low Birth Weight; D007231:Infant, Newborn; D008297:Male; D013997:Time Factors; D014785:Vision, Ocular