Have you ever been convinced that you remember being a baby? A moment in a cradle or the taste of a first birthday cake?
There is a good chance that these memories are not real. Decades of research suggest that most people do not remember personal experiences of the first years of life.
However, even if we do not remember having been a baby, a new study has found new evidence that babies take in the world around them and can also start to form memories much earlier than once.
How did the study work and what did he find?
A study published this month in Science by researchers from Yale and Columbia Universities revealed that babies as young as 12 months can train memories via the hippocampus – part of the brain which also stores memories in adults.
To observe this, the researchers used a brain analysis specially adapted for infants for a single session. This allowed them to look at how babies’ brains responded while they were awake and looking at images of faces and objects. Parents remained close to their babies, which helped them keep calm and alerts.
In the study, 26 infants aged four to 25 months showed a series of images. It was found that if a baby’s hippocampus was more active the first time they saw a particular image, they looked at the same image longer when he will reappear shortly after, next to a new – suggesting that they recognized him.
“Our results suggest that the brain of babies has the ability to train memories – but the duration of these memories is still an open question,” said Tristan Yates, a postdoctoral researcher in the Psychology Department of Columbia University and the main study of the study.
This is the first time that scientists directly have observed how a memory has started to take shape in the brain of an awakened baby. Previous research was based on indirect observations, as looking at if the babies reacted to something familiar. This time, however, researchers observed a brain activity linked to specific memories as they form in real time.
Most studies of past brain activities were carried out while babies were sleeping, which limited what researchers could learn about the creation of conscious memory.
What does that tell us about the memories of the first life?
The results suggest that episodic memory – the type of memory that helps us remember the specific events and the context in which they took place – begins to develop earlier than scientists before.
Until recently, it was widely believed that this type of memory started to form until well after the first birthday of a baby, generally around 18 to 24 months. Although the results of the scientific study were the strongest in infants over 12 months, the results were also observed in much younger babies.
So at what age are we starting to make memories?
It is now understood that babies are starting to form limited types of memory when they are as young as two or three months. These include implicit memories (such as motor skills) and statistical learning, which helps infants detect models of language, faces and routines.
However, episodic memory, which allows us to recall specific events as well as where and when they have occurred, takes longer to develop and requires the maturation of the hippocampus.
According to Cristina Maria Alberini, professor of neural sciences at New York University, the early childhood period when the hippocampus develops its ability to train and store memories can be “critical”. This window could be important not only for memory, but also “major implications for mental health and memory or cognitive disorders,” she added.
Memories trained in early childhood generally do not last very long, which could explain why we do not remember it later in life. In a study underway at the Max Planck Institute for Human Development in Germany, toddlers of 20 months were able to remember What a toy was in what place to go up to six months, while young children kept the memory for about a month.
Why can’t we remember anything in childhood?
The almost universal inability of humans to recall personal experiences before the age of about three years is a phenomenon called “infantile amnesia”.
For decades, scientists have believed that it happens simply because the brain of babies was too immature to store episodic memories.
But the scientific study has shown that babies are indeed memories. The mystery is Why These memories become inaccessible as we age.
A explanationAccording to scientists, the brains of babies undergo rapid neurogenesis – the rapid creation of new neurons in the brain. This rapid growth could disrupt or “write” existing memories. In animal studies, when scientists have slowed down this process in baby mice, mice have been able to keep memories much longer – similar to adult mice.
There is also a hypothesis that episodic memory requires language to describe them and a “sense of self” to relate to them. Since these skills do not develop completely before about three or four years, the brain may not yet have the tools to organize and recover memories like adults.
Some researchers also think that the process of forgetting could serve a development objective. By abandoning specific early experiences, the brain could be better able to focus on the creation of general knowledge – to understand how the world works, for example – without being distracted by detailed memories that are no longer used.
Can some people remember early childhood events?
Some people say they can remember being a baby, but nothing proves that they describe are real episodic memories.
According to the study by Yale et Columbia, this belief generally stems from a psychological process called “bad attribution of the source”.
People may remember information, as they cried during their first haircut, but not where this information comes from. They could unconsciously attribute the memory to personal experience when it really comes from a photo, family stories or a parent’s story. Over time, the border between “real” and “rebuilt” has blurred.
Research shows that the first family stories, frequent photo views or emphasis on early development can all contribute to this phenomenon.
Yale is currently conducting a new study in which parents will regularly film their babies, either with their inclined phones from the baby’s point of view, or using cameras mounted on the head on toddlers. Later, as children age, researchers will show children these old videos to see if they recognize experiences, mainly by monitoring brain activity, to find out how long the early memories can last, Yates in Al Jazeera told.
Could the first memories be recalled later in life?
There is a debate on the question of whether the memories of the first life are completely erased or have simply become inaccessible and could possibly be recovered.
Yates said that although the last study does not answer this question, the preliminary evidence of other research at the Yale Lab show that memories of little life can be recalled in early childhood, but not later childhood.
“I think that the idea that at least some of our first memories can exist in a form in a form in our brain as adults is fascinating,” she said.
Studies on adult rodents have shown that the first memories can be brought back through approaches such as optogenetics – activating specific brain cells that are supposed to store these memories. This works by identifying the brain cells involved in the formation of a memory, then using light later to reactivate these same cells, which reminds the animal the memory.
Techniques such as optogenetics cannot yet be used in humans, but the study of rodents suggests that the process by which we recover memories is where the problem is located, rather than if the memories exist, according to Paul Frankland, principal scientist at the hospital for the sick children of Toronto.
“There may be natural conditions where these memories of the first life become more accessible,” he added.
Psychoanalysts such as Sigmund Freud thought that the memories of early childhood are not lost but buried deeply in the unconscious, and that psychotherapy could help them put on the surface by changing the mental states.
However, Frankland said it is a “controversial area” as “it is difficult to verify the veracity of recovered memories”.
