While developmental experts strongly recommend for parents to play and talk to their five-month old baby, many wonder if the child remembers any of it a day later.

Now, a new Brigham Young University study suggests the infant remembers the good times, if not more.

The study, published in the journal Infant Behavior and Development, shows that babies are more likely to remember something if there is a positive emotion, or affect, that accompanies it.

“People study memory in infants, they study discrimination in emotional affect, but we are the first ones to study how these emotions influence memory,” said Professor Ross Flom, lead author of the study.

Although the five-month-olds can’t talk, there are a number of different ways that researchers can analyze how the babies respond to testing treatments.

In this particular study, they monitored the infants’ eye movements and how long they look at a test image.

The babies were set in front of a flat paneled monitor in a closed off partition and then exposed to a person on screen speaking to them with either a happy, neutral, or angry voice. Immediately following the emotional exposure, they were shown a geometric shape.

To test their memory, the researchers did follow-up tests five minutes later and again one day later. In the follow-up test, babies were shown two side-by-side geometric shapes: a brand new one, and the original one from the study.

Investigators then recorded how many times the baby looked from one image to the next and how long they spent looking at each image.

They discovered babies’ memories didn’t improve if the shape had been paired with a negative voice, but they performed significantly better at remembering shapes attached to positive voices.

“We think what happens is that the positive affect heightens the babies’ attentional system and arousal,” Flom said. “By heightening those systems, we heighten their ability to process and perhaps remember this geometric pattern.”

Source: Brigham Young University