The Development of the Brain
To truly understand autism, one must begin with a clear understanding of how the brain develops. Research during the 1990's clarified this process in a way that we had never realized before. The most important factor that we must take into consideration is that the brain is not complete at birth, but continues to develop throughout our lifespan. The majority of this development happens to us between the ages of birth and 6 years.
At birth, a baby’s brain contains 100 billion neurons, virtually all the nerve cells it will ever have. It also contains a trillion glial cells, which form a kind of honeycomb which protects and nourishes these neurons. However, the stabilization of the pattern of wiring between the neurons in the brain has yet to occur for most of these cells. The brain has laid out a network of what is required for the basic operation of the body’s organs so that the infant will survive. It is neural activity, driven by a flood of sensory experiences coming directly to the child from the environment, which takes this rough blueprint and progressively refines it.
During the first years of life, the brain undergoes a series of extraordinary changes based directly on experience from the environment. When a baby is born, it can see, hear, smell and respond to touch, but only dimly. The wiring for vital life functions such as heart rhythm and breathing are in place in the brain stem, but all of the other connections between neurons in the brain are limited. Within the first few months of life, the brain’s higher centers create millions of new synapses. By the age of two, a child’s brain contains twice as many synapses and consumes as much energy as the brain of a normal adult. These synapses are all formed through sensory input.
Each time a child listens to a sound, looks at an object or reaches out to touch something, tiny bursts of electricity shoot through the brain, knitting the neurons into circuits. The specific genetic code and the experiences the child has already had come into play. When we combine our knowledge that sensory stimulation from the environment is the method through which our brain is wired after birth with the fact that the level of sensitivity to sensory stimulation from one child to the next is going to differ due to their genetic make-up and to the assaults their body has experienced to date, we open a whole new concept in our understanding of the development of autism in a child. The specific sensory input that each infant is exposed to from birth on will affect the wiring of his/her brain. The specific genetic code of that particular child will determine the level of response to the sensory stimulation, which will also determine the wiring of the brain. The assaults which the foetus experienced in the womb, perhaps a virus, may have set the sensory system on alert, thus heightening the sensory response and in turn affecting the specific wiring of the brain. Assaults, such as the long term effects of vaccinations and antibiotics, that happen after birth will also set the sensory system on alert, raising the level of sensory response and creating a different level of synapses in the brain. This means that every brain will have its own unique wiring. This process of wiring the brain continues on through the preschool years of the child. Everything that happens to this child during that time will have an impact on the actual make-up of his/her brain.
So we have a child who is born into a home in which he is held and cuddled by his mother most of his waking hours. His brain will develop differently from that of the child who is left in her crib, baby seat or baby swing to entertain her self when awake. Whether the holding and cuddling is a positive experience or not will be determined by the level of sensory response of that particular infant in that particular moment. Some children may feel constrained in the arms of their mothers because their tactile and/or olfactory response is higher than that of another child who may experience only comfort and love. The child who is on the extreme end of the sensitivity response may scream and become rigid every time that anyone tries to hold them because the experience is so overwhelming it becomes unbearable. Their mother’s arms are not a safe haven because of their genetic code and the assaults that their body has already experienced. The differences in these children’s responses has nothing at all to do with the mother’s actions or reactions, but rather is based directly on their own biological reality. However, the choices that we make as parents to provide sensory stimulation and to respect the response that we get back from our infants will play a major role in the final brain that is produced.
Experience is the chief architect of the brain. Deprivation of any kind for a child, whether it be of nutrition or stimulation, means that the actual brain suffers. Typical children who are not touched or who do not play produce brains that are 20% to 30% smaller than those normal for their age (Perry,1995). Children who are abused or experience high levels of trauma early in life develop brains which are tuned to danger (Schwarz & Perry, 1994). At the slightest threat their hearts race, stress hormones surge, and they anxiously track the nonverbal cues that might signal the next attack. Children born to mothers who suffer from depression show markedly reduced activity in their left frontal lobe, which serves as the center for joy and other light hearted emotions (Dawson, Hessl & Frey, 1994). Infants who are exposed to early pain and stress react more strongly to pain as toddlers, while premature infants who were exposed to multiple painful stimuli in neonatal intensive care units exhibit hyperaglesic responses to subsequent pain, an increased level of sensitivity that outlasts the initial pain by hours and even days (Porter, Grunau & Anand, 1999).
Autistic children, with their higher response to sensory input develop larger, denser, and heavier brains than their peers. High levels of magnification reveal that their brains have more minicolumns than a typical brain and that these minicolumns are smaller than normal. The direct result of this construction is that these brains are overwhelmed by information coming in from the environment which would not affect most people. Other brain research has indicated that there is more white matter in their brains, which will also result in a heightened response to sensory input. This reveals a double-edged sword in the midst of brain development. A heightened level of response to sensory input creates a brain that reacts at a higher level to sensory input. Once this brain is constructed, we can do little to change it.
The growth of a child's brain drives children to actively construct their own learning, which in turn, creates further growth. If one takes the time to closely observe our babies, one can see this process in action. Their eyes survey all that a room has to offer. Their hands reach out to grasp anything that is within their reach. Items that can be lifted are brought to their mouths to be further explored. They twist and turn and roll their bodies in an attempt to get as much information in as possible. On the other hand, children who are not safe, whether because of their unique biological make-up, physical pain due to medical difficulties, or unsafe environments, construct a different type of learning, which focuses on developing coping skills which either limit the amount of stimulation that the brain receives or protects them from what is happening in the environment. They may choose to use repetitive behaviours such as rocking or sucking one’s thumb to produce endorphins which block the reactions to sensory input in the brain. Or perhaps they may choose to be quiet so as to not draw attention to oneself so that they are not picked up, or exposed to abuse of any kind. These processes take place automatically, with little acknowledgment on our part. However, each of us will deal with the input from these experiences for the rest of our lives because of the construction process of the brain.
It is repeated experience that strengthens the connections in the child’s brain so that actions and reactions become unconscious, or in other words, done without actual thought. This gives us the opportunity to do without the input of energy that thought requires. We write effortlessly without thinking about the shape of the actual letter or the direction that the pen is going. We type without looking at the keys. We drive without being conscious of what our hands and feet are doing.
Our little ones seem to know that repetition is necessary as they repeat the same actions over and over again until they have them mastered. They are content to listen to the same bedtime story every night for weeks on end, or watch a video repeatedly. They will climb up on the arm of the couch and jump down only to run back to the arm and do it all over again. They ask the same questions over and over again, no matter how many times we give them an identical answer. It’s an incredible process that we each do automatically, on our own, as toddlers. As adults, we experience the power that repetitious action has in our lives as we find ourselves almost at work with no memory of the drive thus far or complete several different tasks simultaneously with our mind on one. It’s only when we do something that is totally new to us that we have to consciously think of each movement. The more we do this new activity, the more unconscious it becomes.
The repetition that people on the autism spectrum engage in different from that of the rest of us because it is not used to learn but to protect. If we want learning to take place we must make the effort to put them into situations that are safe so that they do not need to concentrate their energies on protection. This means we ensure that the environment is NOT overwhelming, that our interactions with them are those of acceptance, understanding and total respect, and that we DO NOT expose their bodies to any more assaults, if at all possible. It's not that difficult a job to do if we make the effort. It will never happen without clear understanding of this whole process.
The impairment in social interaction found in people with autism also develops through this process. As the brain develops, our reactions to each other and to the world are created and stored through the actual experiences we have. We learn how to live, how to interact with each other, how to protect ourselves from pain, and how to define and accept ourselves, by the way that we are treated and through the information that we are given as small children. Much of this information is gathered through the experience of watching our family members interact with one another. More is added through actual experience with our peers. When one's energy is focused on self preservation due to the heightened level of sensory input, most of these lessons will be missed. It may appear to be a problem that is innate, but in reality it is something that develops over time through actual experience.
The title of the book “All I Needed to Know I Learned in Kindergarten” is a good synopsis of the process of brain development because most of the connections in our brain are have been created by the time we reach grade one. This is why early intervention for those on the autism spectrum is so important. However, it is also why we must be extremely careful in the type of learning that we share with these children. Placing them in situations in which they will be traumatized by too much stimulation or by the treatment that they receive is going to have a LONG TERM impact on their brain. The lack of understanding and the drive to "fix" these children can be disastrous We must be very careful.
For the next five to seven years, the brain enters a new phase in which the neural connections are strengthened and consolidated through experience and repetition and in which excess synapses, which are not being used or are damaged, are pruned. During this period the brain also rests as it prepares itself for the next big struggle for the brain is not complete at this point.
At the beginning of puberty (approximately age 11 for girls and 13 for boys) the brain suddenly produces a whole flood of grey brain matter in the frontal cortex, and the process of building neural connections begins all over again. Those who comment that teenagers appear to be brainless at times, aren’t as far from the truth as one would think, except for the fact that it is not that they don’t have a brain, it’s that their brain is not completely connected. Again actual sensory experience is the architect of these new connections, and again the process takes a number of years to complete. In many ways, the level of difficulty and frustration experienced by our toddlers is mirrored during adolescence as the years of 13 for girls and 15 for boys resemble the “terrible twos”. These years are the most difficult to go through, both for the teens themselves and for their parents. By age 15 and 17 respectively this building process draws to a close and the brain begins again to strengthen and consolidate those connections which are used the most often, and prune those that are not needed.
Puberty is a tough time for those on the autism spectrum. When your brain and body are working at an extreme level, the anxiety that you experience is naturally going to be higher than those who have a more typical reaction. Anxiety leads to the need to use more of the protective behaviors. People who don't understand the purpose of these behaviors believe that regression has occurred. It hasn't. It's not what is stored within the brain that is important at this point, it's what the body is dealing with in the moment. Parents and teachers throw up their hands in futility. The group home business begins to boom. Psychiatric drugs are administered and begin to do their own type of damage. Segregation from the regular classroom becomes the norm. The barriers to success as adults are firmly put into place by society that has no understanding of what is going on.
When we realize that the brain is not something that we acquire at birth as a solid entity and cannot change, but is instead an organ which is developed through the actual experience of our lives, the unique differences in each of us become profound. Much of our development happened to us as infants and toddlers of which we have no consciousus memory, and yet was so instrumental in forming our self. As a newborn I was taken home from the hospital to a small house on a farm in Northern Alberta. There I spent my early years with a limited number of people, wide-open fields, and a variety of farm animals. The type and amount of sensory stimulation that I experienced in that rural setting as a toddler was far different from that which was experienced by my grandchildren, who started their lives in large cities during the 1990’s with the television as a constant companion. This means that our brains are wired differently. This development of the brain through actual experience likely explains much of the evolutionary process that mankind has undergone over time.
The world that a child is born into today is a far different world from that of the past. The following set of pictures are a small example of how much things have changed in the last 40 years for our little ones. This is not to say what we are doing is necessarily wrong, but that we are doing things differently and that we are going to have to live with the consequences of these difference. The researchers who pinpointed the differences in minicolumn size and number suggest that these microscopic differences in cell organization may not be a defect at all, but only a step in the evolution of the human brain which enables people to truly focus on complex issues in today's society such as technology and science. Perhaps the increase in the level of sensory stimulation to our babies are affecting all of them.
This is an example of the typical baby walker babies used in the sixties: a bare bones model that allowed the children to be upright and move around the room on their own, but provided little sensory stimulus other than tactile.
On to the typical baby walker of the late seventies and early eighties. A tray has now been added so that the child can have access to toys to play with while in the walker. Mom gets lots of exercise retrieving the toys from the floor and replacing them on the tray.
By 1990 walkers had been banned in Canada because of the number of accidents babies had experienced in them. However, they were still sold in the United States and were becoming more and more complex.
Welcome to the new millennium where the walkers no longer move about the room but rock in one place. The toys are bolted securely to the tray so that the child cannot get away from them They all move and make noises and so on: a constant barrage of sensory input. Baby walkers are only a small part of the different sensory experiences that we give our little ones. Think about all of the other things we share with our little ones on a daily basis that involve sensory information. When you add them all together, it's quite a brave new world out there. This increased level of sensory input may play a major part in the increase the rate of autism, ADD, hyperactivity and so on throughout the world. It's not the whole answer, but it definitely may be part of it. It also may not necessarily be a negative thing, but it certainly isn't something that we can afford to ignore.