- Does visual development get a “head start” in healthy Infants who were born 4 to 6 weeks early?
- Is TV exposure bad for young babies? Can babies improve their vision with video exposure?
Due to modern advances in neonatal medicine that improves survival of infants, the number of preterm infants born is steadily rising. In another line of research (funded by an R01 from NEI with Karen Dobkins), I asked how early experience influences visual development in infants. I studied healthy preterm infants (born 2 to 8 weeks early) to determine if their extra time out of the womb afforded them extra, or “precocious”, visual experience that would accelerate their visual development. Preterm infants open their eyes in utero as early as 26 weeks postconception, and by 30-31 weeks, they exhibit pupillary reactions and signs of subcortical and cortical neural responses (reviewed in Birch & Bosworth, 2005). Hence, preterm infants do receive and are responsive to visual input before term age. Moreover, because so many aspects of visual system and brain are rapidly developing during this period, early visual experience may have particularly strong effects. This provided us with an opportunity to ask whether the precocious visual experience of preterms accelerates cognitive development. Results showed the preterm infants had visual sensitivity for color patterns far superior to that of fullterm infants, when matched in gestational age, which is consistent with a benefit of extra visual experience (Bosworth & Dobkins, 2009; Bosworth, McCleery & Dobkins, 2009; Bosworth & Dobkins, 2013).
Another new exciting line of work that will be submitted for publication in the next few months is a study on perceptual learning in infants. There is currently much controversy over what infants are capable of learning from baby “enrichment” videos, despite a proliferating phenomenon of baby television shows and computer DVD’s marketed to entertain and educate infants. With honors student Christina Farkas, we attempted to determine whether 3-month-old infants show evidence of perceptual learning in contrast detection of luminance and color gratings after a 20-minute video exposure. The experiment took place over 3 days: pre-video testing on Monday, video exposure on Wednesday, and post-video testing on Friday. Psychophysical data was collected with a forced-choice preferential looking paradigm for two stimulus types, each designed to selectively stimulate one of two main pathways from the eye to the LGN to the brain: magnocellular (which mediates dark-light, luminance sensitivity) and parvocellular (which mediates red-green, chromatic sensitivity) pathways. Infants were randomly assigned to 1 of 3 training video groups: luminance training, chromatic training, and no training. Results showed that short term video exposure within a week period did show small training improvements for chromatic, but not luminance sensitivity.
Dobkins, KR, Bosworth, RG, & McCleery, J (2009). Effects of gestational length, gender, postnatal age, and birth order on visual contrast sensitivity in infants. Journal of Vision, 9(10), 19, 1-21.
Bosworth, RG & Dobkins, KR (2009). Chromatic and luminance contrast sensitivity in fullterm and preterm infants. Journal of Vision, 9(13), 15, 1-16.
Tyler, SC, Bosworth, RG & Dobkins, KR (2017, April). Development of temporal order discrimination in children 5-36 months old. Paper to be presented at the Society for Research in Child Development meeting, Austin, Texas.
Bosworth, RG & Dobkins, KR (2013). Effects of prematurity on the development of contrast sensitivity: Testing the visual experience hypothesis. Vision Research, 82(19), 31-41.
Blumenthal E, Bosworth RG, & Dobkins KR (2013). Fast Development of Global Motion Processing in Human Infants. Journal of Vision, 13(13) article 8.