Of the many new experiences that infants have each day, which ones will they remember? A new study entitled “The effects of exposure to dynamic expressions of affect on 5-month-olds’ memory” published in the journal Infant Behavior and Development suggests that infants are more likely to remember a unique geometric shape whenever a positive emotion accompanies it. The study is the first of it’s kind to explore how emotion may influence infant’s memories.

Researchers from Bringham Young University monitored infants’ eye movements and measured how long the babies look at a particular image.

More of the study is described below, taken from an article on Medical Daily written by Susan Scutti:

“To begin their experiment, the researchers enlisted the help of a group of mothers and their 5-month-old babies. The mothers set their infants in front of a monitor. Then, a person appeared on the screen. The person spoke to the baby in either a happy, neutral, or angry tone of voice, and immediately following this, the babies saw a novel geometric shape materialize on the screen.

After this “emotional exposure,” the researchers proceeded to test the babies’ memories. Five minutes after the test, some of the babies saw two side-by-side geometric shapes: a brand new one, and the original one from the study. Here, the researchers recorded how many times the baby looked from one image to the next and also how long they spent looking at each shape. One day later, the researchers conducted the same test with the remaining babies, monitoring their eye movements as they showed them the two images. What did they discover?

The babies performed significantly better at remembering the novel shape when it was attached to positive voices. Following the 5-minute interval, infants exposed to the happy voice showed a “reliable preference” for the novel geometric shape compared to the previously unseen image. The infants who heard a neutral or angry voice did not show this same preference. After the one day interval, though, infants exposed to both the happy and neutral voice showed a reliable preference for the novel geometric shape. However, paired with a negative voice, the shape did not stick in their memories.

“We think what happens is that the positive affect heightens the babies’ attentional system and arousal,” said Dr. Ross Flom, a BYU psychology professor and lead author of the study. “By heightening those systems, we heighten their ability to process and perhaps remember this geometric pattern.”