This post is based on Chapter 1, “I Remember Being Born” in “THE MEMORY ILLUSION” a book by the psychologist Julia Shaw, Ph.D. Many millions of people remember being a baby. Fewer people, but still in the millions remember being born, and even fewer people, but still in the millions remember being in the womb. These people are wrong as “research has long established that as adults we cannot accurately retrieve memories from our infancy and early childhood. To put it simply, the brains of babies are not yet physiologically capable of forming and storing long-term memories. People have these misconceptions about remembering due to the creative component of memory that strives to make meaning of the world.
The estimated average age at which we can begin to form memories that last into adulthood is 3.5 years of age, but according to some such as Qi Wang of Cornell University this figure is likely to depend on the individual and can be anywhere between 2 and 5 years of age.
The parts of the brain responsible for long-term memory, including part of the frontal lobe and the hippocampus, begin to grow at around eight or nine months. According to Harvard professor Jerome Kagan, one clue that children start to develop memory at about nine months is that this is typically when they become less willing to leave their parents. Being able to miss their mothers is taken as a sign that the infants have a memory of their mother having just been present, and notice when she leaves. “If you’re five months old, it’s out of sight, out of mind. You’re less likely to cry because you just forgot that you mother was ever there, so it’s not as frightening.”
Long-term memory capabilities develop quickly as we age, both in duration and complexity. We increasingly understand how the world around us works and what we should consider important. The basic functions of long-term autobiographical memory are established within the first fews years of life. But the main structures involved in memory (the hippocampus and related cognitive structures) actually continue to mature well into early adulthood. This finding has contributed to the notion of an ‘extended adolescence’ that lasts all the way to the age of 25, since the brain continues substantial maturation until at least this age.
The baby brain at two to four weeks of age is about 36% of the final adult volume, 72% at one year of age, and 83% of the final adult volume by two years. By the age of 9 the brain reaches about 95% of the adult volume, and it is not until about the age of 13 that our brains reach their full adult size.
While the baby brains undergo rapid growth they also undergo massive neuronal pruning. That is. individual neurons disappear. This process begins almost from birth, and finishes by the time we hit puberty. According to Maja Abitz and her team, adults actually have a whopping 41% fewer neurons than newborn babies in important parts of the brain that play a role in memory and thinking, such as the mediodorsal nucleus of the thalamus.
There is also an overproduction of synaptic connections in infancy followed by persistence of high levels of synaptic density into late childhood or adolescence. As we enter late childhood, our brains start to become better at knowing what connections we need to keep and which are superfluous. From there on until mid-adolescence our brains undergo a short of spring-cleaning. So perhaps “when you were five years old you could list all of the dinosaurs, but did you really need all that information? Probably not, says your brain and erases the connections and neurons responsible for much of this knowledge.” “So, due to structural insufficiencies, as well as organizational and linguistic deficits, memories of early childhood events cannot last into childhood.
This research does not suggest that just because we cannot remember them, that early childhood events are unimportant. According to a 2012 review of the long-term repercussions of adversity experience in early life by medical doctor Jack Shonkoff and his colleagues experiencing adversity, even at an age before we can consciously remember it as adult, can have lasting effects. “Early experiences and environmental influences can leave a lasting signature of the genetic predisposition that affect emerging brain architecture and long-term health.”
To read more about the negative effects in early childhood read the healthy memory blog post,”Turning on Genes in the Brain.” The single best predictor of the healthy growth of a baby is to ask its mother, “Did you want this child?” In 2005 scientists at the University of Wisconsin-Madison designed a study showing what can happen to children whose parents answer “no” to this question. The researchers studied children who were “reared in extremely aberrant social environments where they were deprived of the kind of caregiving typical for our species.” This meant that for seven to forty-two months after their birth, the twelve girls and six boys had lived in Russian or Romanian orphanages that the World Health Organization described as poor to appalling. These environments were generally void of stimulation and human interaction. The children seldom experienced the love and caring of adults who recognized and responded to their needs.These children were adopted by American families. Within a year, most of their medical problems—ear infections and stomach problems, malnutrition and delayed growth—vanished. Nevertheless, due to their legacy of neglect many of the children were diagnosed with attachment disorders, an inability to form emotional bonds to those closest to them
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