What can my baby see? Is she smart? What’s going on in his infant brain? Every parent has wondered questions like these. And in their quest to understand infant and toddler development, research scientists have found ways to come up with some answers.
Current scientific research utilizes specially designed tests to measure the vision, thinking skills, and other brain-based abilities of a baby or young child in order to provide valuable insights into healthy development and future intelligence. These tests also help researchers assess factors that shape those aptitudes, including nutrition.
Here’s a look at some of the ways that scientists have found to measure the impact of the nutrient DHA (docosahexaenoic acid) in infants and young children.
Tests to Measure Vision
Before children are able to talk, they can’t give vocal answers. But it’s still possible to measure their brain development. Vision tests are important because they reflect healthy development, including whether the retina, which is influenced by DHA, is developing properly. But it’s not your typical eye-chart testing, of course. A test called sweep visual evoked potential (sweep VEP) allows researchers to record a baby’s reactions (through electrical responses in the brain) while the baby watches changing patterns on a screen.
Researchers are very interested in early vision skills as a measure of brain development. A study reported in Developmental Medicine and Child Neurology in 2000 found that among children who had been fed formula that had DHA for the first four months of life, visual acuity at 4 months and mental development index scores at 18 months were improved compared to children who had been fed a (now discontinued) control formula without DHA .
Vision is a key part of attention tests, too. In sustained-attention tests, for example, a baby is shown a series of pictures. How long each is looked at is recorded, along with heart rate. (A drop in heart rate is associated with attention.)
Nonverbal Assessments of Thinking Skills
It’s even possible to directly measure some cognitive abilities in a baby. A series of standardized tests designed for different-age infants is collectively known as the Bayley Scales of Infant Development (BSID). Some Bayley assessments look at physical, sensorimotor, and social skills, while others check mental skills, such as memory, language, classification, and problem solving. The tests involve checking such abilities as walking, matching shapes, and stacking blocks. Abilities are noted on age-based scales.
Another key test is the Willatts means-end problem-solving test (known as the Willatts). Here’s how it was used in an important DHA study in 2009: 9-month-olds were given a rattle to play with for 20 seconds. Then the rattle was covered with a cloth and placed on a blanket, just out of reach. To get to the rattle, babies needed to follow a series of steps: pulling the blanket to bring the toy closer, realizing it’s under the cloth, grasping and removing the cloth, finding the toy, and finally, grabbing the toy Trained testers recorded and scored the baby’s intention level at each of these steps. While it may sound basic, all these efforts actually reveal higher-order thinking skills, like multistep planning, memory, and focus. And, as shown by the Willatts test scores at 9 months, babies who consumed DHA had more successes compared to babies fed a (now discontinued) control formula without DHA .
Other Ways to Measure Cognitive Development
As babies grow into older children, a battery of standardized tests offers deeper insights into intellectual abilities dependent on healthy brain growth. Of special interest is verbal ability and executive function. Executive funtion is the general term for a group of mental processes involving self-control, self-discipline, working memory, and other skills such as initiation, attention, and organization.
There are various tests used to assess these skills:
- Peabody Picture Vocabulary Test (PPVT): Five-year-olds are asked to point to pictures that correspond to spoken words. This method measures receptive language (understanding what you hear), which is linked to reading comprehension, general verbal ability, and IQ. PPVT scores are considered a good predictor of school success.
- Dimensional Change Card Sort: Preschoolers are first asked to sort a series of picture cards by one dimension (such as color) and then by another (such as shape). Children need to follow instructions and organize their thinking to reach the goal.
Test results can be compared with progress at earlier ages and with such factors as nutrition early in life. The findings in key infant nutrition studies: Consuming a formula that has DHA throughout the first year of life supports cognitive skills in infancy and in later preschool years through age 5—as measured by these tests—compared to infants fed the (now discontinued) formula without DHA.