Memories in training

By Nathalie Vallerand

Memory develops as the brain matures, so children are naturally able to retain more information as they get older.

Babies form their earliest memories even before being born. The sounds and other stimulations they experience in the womb leave behind traces in the brain. “This helps them distinguish between what’s familiar and what’s new,” explains neuropsychologist Sarah Lippé, a professor at the Université de Montréal whose research focuses on cerebral mechanisms for learning in children. “It’s how newborns are able to recognize their parents’ voices and faces.”

It’s also how babies recognize their mother’s smell, or remember nursery rhymes they heard repeatedly during the final trimester of pregnancy.

Using this capacity for recognition, toddlers are able to retain information for a certain amount of time. This was demonstrated in a study in which babies were connected to a mobile by tying a ribbon to their ankles. When the babies kicked their legs, the mobile would move. On average, the 2month-olds remembered the game for 3 days, while 6month-olds remembered it for 14 days. In general, a child can remember a sequence of actions with an object for a full year by the age of 20 months.

A time and place for every memory

People have not one but several types of memories, and each plays a different role.

Sensory memory

Sensory memory processes information obtained through the senses. It begins to develop before birth, as it doesn’t require verbalization. Two-year-old Adam, for example, listens to a lot of music with his family. “He started humming at 16 months,” says Adam’s dad, Clériston. “He doesn’t sing the words, but he starts to hum as soon as he hears the first notes of certain songs.”

Procedural memory

Procedural memory also begins to develop at a very young age. This is the memory of gestures, which helps a child develop skills such as walking, swimming, using a spoon, riding a bike, or tying shoelaces. Once a child has gotten the hang of them, the series of actions associated with these skills become second nature. Remembering them no longer requires a conscious effort.

Semantic memory

Semantic memory is how children acquire knowledge with each new experience. It can be thought of as a continually expanding bank of information used to store everything from colours, smells, and the meanings of words to numbers, important dates, and the appearance and purpose of different objects.

Episodic memory

When your child tells you what she ate for lunch or about a birthday party she went to, she is drawing upon her episodic memory. “This type of memory is used to recall details about past events,” says Marion Noulhiane, a researcher at the NeuroSpin neuroimaging research centre in France and a professor at Paris Descartes University. Episodic memory plays a minor role before the age of 2, developing mainly between the ages of 2 and 7, and peaking after the 5-year mark.

Since their brains are still developing, however, children forget recent events—sometimes even things they did earlier the same day. “Childcare educators will often remind kids of the activities they’ve done,” says Lippé. “At lunchtime, for example, they might ask which park the class went to and what game they played. Then they’ll ask the same questions again while the children are eating their snacks. Doing this gives them a better chance of being able to answer when their parents ask about their day.”

Memory training

Your child’s memory will develop naturally, but there are ways you can help it along. Memory games, for example, where you flip over cards to find the matching images can give your child’s visual memory a workout.

For Geneviève Cadoret, a professor and member of the Qualité des contextes éducatifs de la petite enfance (Quality of early childhood educational contexts) research team at UQAM, these exercises are all well and good, but the other four senses are just as important for memory development. Memories of sounds, smells, tastes, and touch “all work in concert to help children better understand their environment,” Cadoret explains. “It’s by using all of their senses that children learn to associate Daddy’s voice with his face, an animal with its cry, a food with its taste, and so on.”

Here are a few memory-stimulating games that test the senses:

• Guessing the objects in a bag based on touch
• Identifying different smells while blindfolded
• Matching sounds with images (e.g., a revving engine with a truck, meowing with a cat)
• Learning a nursery rhyme or basic dance moves

Childhood memories

All parents want to create happy childhood memories for their children. But what makes some memories stick while others eventually fade?

Five-year-old Luiza visited her mom’s side of the family in Morocco when she was 3. She spent no more than a few hours with her grandpa, but she can tell you all about what they did. “She remembers him giving her candy and cookies and the two of them playing a game together,” says her mom, Maria.

Luiza also recalls being shoved on the school bus two years ago. “She has no recollection of the day camp she went to, but she still talks about what happened on the bus!” Maria says, shaking her head.

When children experience something unusual or emotional, it tends to stay in their memories longer. This is what happened with Luiza, and the same can be said about 4year-old Émile, who saw a show featuring a pirate a year ago. “He got so excited and hasn’t stopped talking about it since,” says his mom, Elizabeth.

Keep in mind that what you consider memorable won’t always have the same impact on your child. Take the birth of a little brother or sister, for example. “Parents just assume their children will remember a big event like that,” says Geneviève Cadoret, a professor at UQAM whose research focuses on memory. “But that’s not always what happens. They might have stronger feelings about a special trip to the park!”

At other times, children will forget everything about an activity apart from one seemingly trivial detail. For instance, Émile’s parents took their son to the museum when he was 2 years old. “We saw a dog as we were leaving, and that was all he would talk about for days,” says his mom, laughing.

Naturally, children have an easier time remembering things that interest them. But their inability to retain much about any given activity also has to do with their brains being at a developmental stage, explains Sarah Lippé, a neuropsychologist and professor at the Université de Montréal. “Getting the full picture requires processing a lot of information at once—more than what a young brain is ready to handle,” she says.

Childhood amnesia

Most adults can trace their earliest memories back to when they were 3 or 4 years old. Everything before then remains a blur. This is known as childhood amnesia. Although babies are capable of forming memories by the age of 8 months, children often have no recollection of their first birthday party—or, for that matter, anything that happened before they turned 2. Memories from these early years are quickly forgotten, including those formed before age 3.

Although science has solved much of the mystery surrounding this phenomenon, many questions remain. In children under the age of 2, the part of the brain called the hippocampus is not yet mature enough to properly store and recall memories. Moreover, the brain is busy replacing neurons with new and improved ones.

“The purpose of these new neurons is to accommodate the child’s new knowledge,” explains Marion Noulhiane, a neuroscience researcher at the NeuroSpin research centre in France. “To make room for what a child needs to learn, the brain has to get rid of information that’s no longer useful. That explains why certain memories disappear.”

Childhood amnesia is also due in part to the fact that toddlers are still learning to speak. It’s easier to remember events after talking about them, but children who haven’t yet mastered language are unable to share their memories.

Do past experiences, even those that have been forgotten, affect a child later on in life? Possibly. “If a child is mistreated, certain parts of the brain can retain traces of the emotions he felt,” Noulhiane says. “Even if the child no longer remembers what happened, it can affect his personality and behaviour.”

Helping your child remember

Elizabeth often talks to her son Émile about her favourite moments with him. This is a great idea! While you may not be able to pick and choose what your child remembers, you can still have an influence.

By routinely talking to your child about what you’ve done together and encouraging her to share things from her point of view, you’re helping her mentally relive events and become better at structuring stories. According to Cadoret, this increases the chances of your little one remembering her experiences longer. It’s a more effective approach than simply asking questions to get your child to talk on her own.

As for photos, the camera can lead to false memories. As Noulhiane notes, “It’s hard to tell the difference between something you experienced and actually remember from when you were 2 and something that you know only from photos.”

Source: Naître et grandir magazine, October 2017 Research and copywriting: Nathalie Vallerand Scientific review: Miriam Beauchamp, director of the ABCs Developmental Neuropsychology Lab, Université de Montréal and Sainte-Justine Hospital Research Centre

Photos : (in order) GettyImages/Freemixer, Maxim Morin, Maxim Morin, GettyImages/Sidekick