We are brain hobbyists who attend Learning and the Brain Conferences on a regular basis to keep up to date with the latest neuroscience research about learning and memory. As former teachers we were always interested in brain growth and development to help us understand how to better present lessons to our students so they would remember what they had been taught. Despite being mindful of trying to teach for recall, former students I have met over the year seldom remember what course I taught, much less specific detail. Some of that may be explained by the fact that I taught history. I can not tell you how often, upon learning I was a history teacher, adults tell me how much they disliked history classes but now that they are older they love reading about the past.
That is an important aspect of learning, you must first be interested if you are to remember. Although that seems obvious, but to understand why that is true one must know that learning and memory are two parts of a whole process. Neuroscientists who investigate these things say that memory is dependent upon more than electrical interactions between sodium and calcium, it is emotional and personal driven by both nature and nurture. Neuroscientist are exploring the cognitive, psychomotor, and affective domains to help them understand how brains remember. Their discoveries provide a wide variety of methods for teachers to enhance student learning, but more importantly these methods can help a person to live a healthier life by developing strategies to strengthen their brain's learning/remembering systems.
The first step to understanding memory is to know how brain cells or neurons transmit information. Neurons are composed of dendrites and a cell body (the soma) where information can be received and a tube shaped axon which connects to the dendrites of another neuron. Communication takes place within the neuron and between neurons. The communication within the neuron is electrical and between neurons chemical.
A sensory stimulus (ouch) sends an electrical impulse to a neuron and that signal travels quickly along the axon of that cell until it reaches the synaptic gap, a tiny opening between cells. This is where the electrical potential triggers a chemical reaction that releasing hormones that cross the gap to the adjoining cell’s feathery dendrites. Thus beginning a process that can form thousands of links with other neurons giving a typical brain well over 100 trillion synapses.
The movement continues until the stimulus has created a neural network categorized by function that was created by the stimulus and neurotransmitters. This network is a pathway that shares itself with the hippocampus where the axons in the neural network are strengthened through the process of myelin ( white matter or glial cells) building up on the axon. If the axons do not get strengthened appropriately the network fades away from the brain.
Learning is the act of making and strengthening the neurons forming the network and memory is the ability to reconstruct or reactivate the previously made networks. It is important to remember that networks that fire together wire together. When another similar stimulus (ouch) is received the old networks light up saying hey there is more about that over here. And that in turn mylenates the axons.
So what can we do to strengthen our memories to remember what we have done or even who we are? John Medina, a neuroscientist from Harvard, advocates first of all a healthy brain. The brain is one of the most amazing organs in the human body. It controls our central nervous system, keeping us walking, talking, breathing and thinking. The brain is also incredibly complex, comprising around 100 billion neurons which are each connected to a thousand more. Thinking and remembering occur because of the integrated action of these neurons. Every thought and action is controlled by the brain. The brain uses more energy than any other human organ, accounting for up to 20 percent of the body's total use. There are over one hundred thousand miles of vessels and capillaries intertwined with the brain to supply the oxygen needed to fire neurons, for cell maintenance and to produce the proteins needed for synaptic transfer.
All of this convinces me that John Medina is right. He recommends a healthy diet, exercise, adequate sleep and stress reduction as some of the ways to maintain a brain that will remember, even in old age. This is a life long process and commitment that each person has to decide to make in order to live a full and healthy life.
My father contracted congestive heart failure when he was in his late 80s. The lack of blood flow caused his brain to change. He lost his immediate memory and was unable to create new memories. He was able to recall many events and details from his early life, childhood and his young adult life. He remembered chemistry, his major in college and some family events if he was primed. He could, however, talk in detail about his experiences in WWII as a bomber pilot and he could remember some things about his career as an Air Force officer. But, he couldn’t recall what we had just discussed minutes before. It pointed out to me the importance of a healthy brain. You have to keep the blood flowing and insure your body can produce the elements needed to keep your nervous system and brain firing.
If you don’t sleep well your brain can not consolidate the neurons into networks to give you plenty of points of recall for the things you have recently learned. It is obvious that exercise causes the blood to flow and carry oxygen to the brain. A healthy diet impacts your total health, obesity, for instance, causes changes in the brain that impair memory. Stress is the most toxic of memory disrupters. It releases cortisol, a chemical that inhibits the information processing system. The impact of not following a lifestyle to have a healthy brain and body may take a while to impact a person, but eventually your memory will exhibit symptoms of poor care and maintenance if you don’t.
The doctor who examined my dad after he had experienced rapid deterioration of his memory did not believe Dad had a stroke, although many of the symptoms were similar. They weren’t sure what caused it, but in retrospect he was probably already experiencing symptoms of low blood pressure and his brain lacked the blood flow necessary to provide energy his brain needed to work at full capacity.
Dad had always been really smart, Mensa type of smart. He had been a pilot, a nuclear chemist, and an officer in the Air Force among other attainments. The loss of his memory was hard for me as I recalled what a witty and humorous man he had been and now he read the same story in the newspaper all day long. I could sort of prime Dad’s memory and get him talking about many things from the past and event recent family or world events. His memory pretty much stopped at about the time he had the rapid deterioration.
He hated exercise, it was kind of a joke in the family. He was physically strong but his cardiovascular system was weak. He had smoked when younger, his primary diet for many years centered on foods that are not heart healthy, he had high blood pressure most of his life (stress), and he had sleep apnea for quite a while. So the amazing fact was that he lived to 93, about five years with impeded memory and immobility.
But what he could remember is a testament to memory being personal and emotional. If you want to remember something find a way to make it yours and feel strongly about it. Dad’s most vivid memories were from WWII. He could remember missions, people, places, procedures and policies. He could remember Mom and many things about our family as we moved to where the Air Force sent us. It was astounding the things he could pull out of his mind.
He could also remember things he had learned in school. Especially those subjects he had been curious about and where he studied and prepared for exams. At the last Learning and Brain conference in San Francisco which we attended this year these two techniques had undergone scrutiny by neuroscientists who reported students remembered best if they were tested repeatedly. Not high stakes testing, but repetition of the information. Quizzing yourself would work. My dad could remember quite a bit about chemistry a subject he loved and one he had been tested on throughout his studies and then in the field.
Current research adds some useful information to the concept of repetition. It demonstrates that it is best to pause between those tests or repetitions. Our brains need time to consolidate information in order to build strong networks of neurons. Everyone has experienced that aha moment when you have taken a break from a difficult task and suddenly the answer is upon you. That is a reason sleep is so important, it is during deep sleep that your brain consolidates previous information. If stimulus events do not get put into networks they fade and eventually are forgotten. Even information you work hard to remember can fade over time. That is why my former students have difficulty remembering my class, they did not keep firing the networks I tried to help them develop.
Nothing works to build strong memories if you do not pay attention. You have to attend to the information you are trying to learn. There are a number of ways to enhance attention through the use of media, peer teaching and hands on learning. The value of those methodologies can be negated, however, if the student has a mindset that puts them in opposition to learning or attention can be diminished by multitasking. Using electronics, passing notes, day dreaming and an over stimulative environment can keep information from ever reaching the hippocampus. You might think you can do more than one thing at a time, but it is unusual to do all of these things well. It is better to complete one task before tackling another if you want to be able to remember what you have done.
Even if you are healthy there are many impediments of strong recall. Evolutionary biologist, Robert Trivers from Rutgers University believes that self deception, an evolutionary adaptation, distorts what we remember.
“Our sensory systems are organized to give us a detailed and accurate view of reality,” he says, “but once this information arrives in our brains, it is often distorted and biased to our conscious minds.” We repress painful memories, create false ones, rationalize immoral behavior and jack up our self-esteem. We deny ourselves the truth.”
We are influenced by, as Robert Sapolsky, evolutionary biologist from Stanford, posits a range of nature nurture events. These events shape who we are and contribute to our mindset and begin with evolutionary impacts from prehistory right up to what we are doing when a stimulus is introduced into our sensory system. What we remember is truly a matter of our genetic makeup, the environment in which we have been raised, and our surroundings at the moment of input.
Since there is no way that the brain can pay conscious attention to all sensory data that constantly bombard the body, it filters out that which is not relevant. That means that, according to Pat Wolfe, a brain educator, approximately 99% of all information entering through senses is immediately dropped. That is probably why so many eye witnesses differ with other eye witnesses when describing what happened to whom.
Add to that the idea that every time you remember an event you actually remember the last time you remembered it event. It is a little like the gossip game where nobody can keep a story straight. That is what happens to all of us. That is why Brian Williams and Bill O’Reilly are defending their integrity, it is a human thing. Just like the young marine I recall returning from Vietnam at the same time I did. In the barracks in Danang his stories were creditable. In Okinawa he had become a central character in his stories, by the time we reached the states he was a hero. I think we do this inadvertently to put ourselves at the center of our stories.
There is a way to ensure you will remember. You could use technology to record your life. Maybe there is a government agency that can help you. If you don’t want to do that you will have to live a fully human life coping with your brain’s strengths and weaknesses while trying to stay healthy.
No comments:
Post a Comment