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NMSU psychology professor continues study of infant learning, stress patterns

In the last 30 years in the field of developmental psychology there has been a focus on trying to understand infants' minds and thought processes. As advancements were made in the field, it started to become possible for psychologists to conjecture how to account for the individual differences in learning, even at a very young age.

New Mexico State University professor of psychology Laura Thompson observes 2 month-old Ambrielle Buckley during a memory recognition exercise in the baby lab on campus. (NMSU Photo by Darren Phillips)

Laura Thompson, professor of psychology at New Mexico State University's College of Arts and Sciences, wanted to find out what causes some infants to learn faster than others. Within the past seven years, Thompson and various research teams have performed two large-scale studies on the subject by studying infant understanding (cognition) while taking a look at stress and what causes that stress in the learning environment.

In a round of studies last year, 100 first-time mothers and their babies were brought into a research laboratory in which they performed a variety of simple recognition tests where patterns or graphics were displayed on television screens for the infants to process. The team's findings showed that in their first months of life those babies whose cortisol levels increased during the tests did not learn, which contradicted results from a previous national study. This prompted Thompson to start a new study scheduled to begin in March focusing on babies during various stages of their first year of life.

"We're trying to figure out if there are factors in the environment that cause these differences," Thompson said, adding that one of the biggest factors which is often forgotten is the mother and the way in which she interacts with and parents the child. "Through this grant-funded research, the puzzle we're trying to solve is why in some cases increasing or decreasing stress reactivity is associated with better learning and memory functions," Thompson said. The $1.17 million grant for use over the next four years from the National Institutes of Health will help the researchers cover fees, for example, to retrieve lab test results.

To determine the stress levels, the research team swabs the inside of the infants' cheeks and the amount of cortisol, a stress-causing hormone, is examined from the saliva samples. The saliva samples are collected once prior to the start of the experiment and once after. A higher amount of cortisol could mean the infant was experiencing stress while learning or a heightened level of physiological arousal.

Learning or memory tasks appropriate to the educational level for all of the babies are chosen for them to complete and, in some cases, their mothers also participate. One test, for example, will have the infants observing patterns of shapes and colors on a screen. After a short break, a second screen will show a different pattern. If the baby looks back to the screen with the familiar pattern, for a longer period of time than she looks at a new pattern, she will have shown signs of recognition or learning, Thompson explained. Another test with each mother and her child could involve the pair looking at a screen portraying computer animations. This type of test would examine how the pair interacted with each other and with the items on screen during a learning event, she said.

The mother's sensitivity is measured by filming a 10-minute play session with the mother and her baby. Researchers then play back the footage and determine through interactions and body language the level of sensitivity or synchronous interactions between mother and infant. A computer program then tallies the percentage of synchronous interactions to be analyzed with the rest of the data.

Although not all of the data has yet been complied and analyzed, some of Thompson's findings are clear through her most recent longitudinal study. The infants who showed signs of stress did not learn while those who showed decreased signs of stress did learn, she said. To date, Thompson's team has not found a correlation between the pattern or degree of cortisol reactivity they exhibit during learning events and maternal sensitivity.

Thompson's study beginning this month aims to further explore maternal sensitivity in an infant's life and the factors that influence infants' psychobiological readiness to learn prior to the beginning of a novel event. She will be assisted by lab coordinator Cindy Gutierrez-Barraza, research assistant Lori Wachi, computer programmer John Chadwick, undergraduate psychology student Kellie Jurado and many other students.