What are your first memories?

Memory is one of the most important survival skills of human beings, and it is also an important factor affecting people's character and three views.

However, psychological research has found that most people can't remember anything that happened in infancy, and they don't start to have memories gradually until after the age of 3.

Where did the memories from before the age of 3 go?

Why can't people remember it at all?

The root of all this comes from "childhood amnesia".

　　□ Our reporter Wang Tianyezhen

　　Childhood Amnesia: From Psychoanalysis to Cognitive Neuroscience

　　"The so-called childhood amnesia is that when people recall the events of childhood, they are completely unable to recall any clear and complete details. Psychologists call this phenomenon 'childhood amnesia'." Jiangsu Psychological Society Cognitive Neuroscience Xue Song, secretary-general of the special committee and lecturer at the School of Psychology of Nanjing Normal University, introduced that this phenomenon was first proposed by Sigmund Freud, a famous psychologist and founder of the psychoanalytic school more than 100 years ago. The age boundary is generally between 3-4 years old, and most people can't remember what happened before the age of 3.

　　"Freud believed that our brains do not forget these things, but store these early memories in a place in the brain, which is what we call the subconscious." Xue Song explained, according to Freud Childhood amnesia occurs when children’s gender image of their parents and their own aggressive character during their growth period are suppressed by their parents.

"In adulthood, people can awaken repressed childhood memories through methods such as hypnosis."

　　With the development of cognitive neuroscience, the "immature brain" theory gradually replaced Freud's psychoanalytic theory as the mainstream.

"Before a child is 3 years old, the brain is in the developmental stage. Especially in the hippocampus and prefrontal regions, these brain regions are not yet able to encode, store and retrieve episodic memory well." Li Li, an attending TCM physician at the Encephalopathy Center of Jiangsu Provincial Hospital of TCM Yun Ze explained that the hippocampus and the medial temporal lobe are the key brain regions for memory formation. "Because the brain is immature, infants and young children will have greater physiological barriers whether it is memory formation or memory retrieval."

　　In addition, the carriers of memory, the synapses on nerve cells, undergo a process of sharply increasing and then decreasing after birth.

"The process of human learning and memory is mainly achieved through the establishment of connections between neurons. When a baby is born, there are 100 billion neurons in the brain. At a certain period, the brain will carry out spontaneous synaptic pruning activities, which are not commonly used. Neuron connections will be pruned away, and the memories stored in them will disappear." Li Yunze said that a lot of information in the brain is lost in the process of synapse reduction.

　　There are also studies suggesting that the reason why people have no memory before the age of 3 is because of the increase in the number of brain nerve cells.

During this process, the number of cells in the hippocampus of the brain increased particularly significantly.

"In the first few years of life, the growth and growth rate of these cells is the fastest, and they will continue to decline with age. It is these brain cells that continue to grow after birth to replace the original cells. , leading to the disappearance of human memory before the age of 3." Xue Song explained.

　　The source of memory - self-consciousness and the objective world

　　Remembering "what I've been through before" requires at least developing the concept of "self" and the sense of time "before", which are not innate.

　　"What we call memory has a great relationship with our consciousness, and in philosophy, consciousness is the subjective reflection of the brain on the objective world." Xue Song explained that consciousness is people's understanding of the objective world, and there is no objective thing. The human brain will not produce consciousness, let alone memory.

Therefore, people without the objective world will not have self-awareness, nor will they have relevant memories, which shows that human consciousness is inseparable from the activities of the brain and the stimulation of the external environment.

　　So, is there any unique connection between human beings' inability to remember things before the age of 3 and consciousness?

Studies have shown that humans can't remember things before the age of 3, which may be because the self-awareness in the brain has not yet appeared, so it does not remember some objective environments.

　　Humans before 18 months have no self-awareness. Scientists have made the famous "mirror experiment" to confirm this argument.

Scientists found some animals and let them appear in front of the mirror. If they could know that the object in the mirror was themselves, it showed that they had a certain degree of self-awareness. As a result, a small number of animals passed the test.

　　But what if the target of the trial was an infant under 18 months of age?

　　The experimenter first made a mark on the place where the baby could see (such as applying a color block on the face), and then put the baby in front of the mirror every other day. If the baby intentionally looked for the mark on himself according to the mark in the mirror, It means that you have begun to have self-awareness.

"As a result, the infants did not look for their own markers according to this, and this experiment also shows that infants and young children before 18 months are not self-aware, so they naturally do not remember the various environments they are in."

　　And why did those animals that passed the mirror test fail to develop into higher species?

This is because they lack the primary means of dissemination of information, which is the concept of language and time.

For adults, normal memory is encoded, recorded, and stored deep in the brain in the form of language.

"Children before the age of 3 can't speak yet, and have no complete form of language expression. The memory form stored deep in the brain is basically infancy language." Xue Song said that after the child gradually learned to speak and the correct way of expression, the language As the form of expression changes, the form of memory also changes.

　　"Therefore, it is difficult to retrieve memories from infancy through existing memory forms." That is to say, when human beings did not receive systematic training in the early days, they did not have relatively perfect language ability and time concept, and naturally they could not compare them. If you fully understand the surrounding environment, you will not be able to remember the surrounding environment.

　　The original memory does not disappear, it just exists in another form

　　"Although people will forget most things before the age of 3, people will still have some impressions of major events or deep impressions, such as moving house or being seriously injured." Li Yunze gave an example.

In addition, before children can read and speak, their brains are more sensitive to pictures, colors, and smells, so memories related to colors, pictures, and smells may be retained.

　　A 2016 study published in "Nature Neuroscience" showed that our initial memories are actually traceable, "This study shows that the brain has no problem with memory storage, it just can't retrieve those memories correctly, But it can be re-extracted only by appropriate stimulation." Li Yunze said.

Mechanical and programmed movements such as standing, walking, running, and hugging, once formed in memory, can be performed spontaneously, without conscious effort, and will not be forgotten for a lifetime.

And strong receptive memories such as extreme warmth, extreme happiness, extreme fear, extreme sadness... Things involving strong emotions are more likely to be remembered by children.

　　"Among them, the emotion of fear tends to be stronger than pleasure. The study found that children in distress had reduced functional connectivity in the anterior hippocampal network, and the strength of functional connectivity in the anterior hippocampal network was positively correlated with visual memory ability. Childhood adversity experiences reduced the anterior hippocampal network. Therefore, Li Yunze believes that it is very important for infants and young children to establish trust in the world and a sense of inner security, which requires responding to the needs of children.

"During the first few months of life, babies need the gentle voice of their parents, the smell of their mother's hug, and even the touch of their skin to create a sense of familiarity and pleasure."

　　Although explicit memories may be completely forgotten over time, implicit memories that cannot be retrieved remain in the brain.

　　The basic survival skills that children learn in infancy will not be forgotten. The hugs and comforts parents give to their children when they cry, and the encouragement and acceptance from the outside world will profoundly affect the formation of children's character and personality.

"They will remember that the world is warm and worth exploring, and the care of parents is unconditional and trustworthy." Xue Song said that infancy is a critical period for the formation of a person's character, and children who grow up in this way, I will definitely retain all the warm traces given by the outside world in my childhood, and grow into an optimistic, tenacious and calm adult.

　　It turns out that calmness, curiosity, optimism, and tenacity in us are not born like this.

And the ability to laugh with friends and be intimate with your partner is in part due to the memories of those first days.

Even if we can't tell the original story, our neural circuits still remember it.

In that time that was forgotten by us, someone once, loved us deeply.