Memory and the Brain (page 2)
Prior to addressing a conference for educators and administrators in sub-Saharan Africa a year ago, the absolutely profound beauty of non-Western thinking had never been quite so obvious to me. In several regions of Southern Africa, a single word exists for both "teaching" and "learning." In the Western mindset, we have separated the two, as if they were distinct functions unto themselves. We often hear educators lament, "I taught it; they just didn't learn it!" However, within the insightful African context, when learning does not take place, then the instructor has not yet completed the important "teaching component," rendering the learning equation fragmented and unfinished.
From tribal elders to master tradesmen to university professors to kindergarten teachers, all "teachers" have noticed that learning often depends as much on certain attributes of the learner, as it does on the nature of the knowledge at stake. It is also clear that some teachers are very good at tapping into these learner attributes to assure effective understanding, while others struggle despite their own knowledge of a given subject.
The primary function of the human brain is to encode, process, dissect, distribute, store, retrieve, and use information for survival or emotional fulfillment. For most of the mid-20th Century, under the influence of psychologist B.F. Skinner and other behaviorists dominating the field of psychology at the time, we oversimplified these complex brain functions. Whether the spotlight was on pigeons depressing a lever to receive food pellets or on multifaceted issues, such as the elaborate process of language acquisition, the deliberations were commonly forced to fit into Skinner's Stimulus -› Response model. Conversations about teaching were also frequently reduced to this same model. Such oversimplification became almost unavoidable, considering that behaviorists influenced most views on thinking and learning during those decades. However, we now recognize a host of additional factors that undeniably influence the outcome of human learning and/or behavior.
Student history has consistently recorded evidence that learners don't obediently "respond" to new information simply because they have been exposed to it. Formal education, to say nothing about parenting, has never been characterized as such an effortless venture met with instantaneous success implied by the Stimulus -› Response model. According to distinguished educator Art Costa, teaching is considered to be among the most demanding professions in the world because of the innumerable variables that are not captured in a simplistic Stimulus -› Response framework (see "Factors Governing Learning and Behavior" above). Instead, the challenges facing educators are found in the intermittent and sometimes permanent brain-based obstacles that stand firmly between one's dedicated teaching efforts and the sometimes unpredictable student outcomes.
Prior to entering kindergarten, a child's personality and temperament are well established. That child's ability to learn will be a function of the following factors:
- Whether the child is a male or female;
- His/her access to proper nutrition during prenatal development;
- Genetic deficiencies and assets;
- The amount of postnatal care given to the child's health concerns. (This would include, among other things, simple hearing tests to detect early central auditory processing disorders, which can lead to early language problems.); and
- His/her emotional development and current emotional state. Emotions, in many ways, dictate whether the child has any interest in the subject at hand, and is even willing to pay attention. They also determine whether or not a child can remain focused on the subject and not be easily distracted by other personal and emotional intrusions. With the more extreme emotional states, such as living in a highly stressful environment, children are frequently more prone to focus on any perceived threat -- be they physical, emotional, psychological, or intellectual -- rather than on the less significant academic focus of the day. (For a more detailed discussion of emotions and learning, see "Where Is God in the Brain?" Independent School, Winter 2002.)
These considerations extend our understanding (beyond the artificial parameters presented by the simple Stimulus -› Response equation) of the relationship between learning and the myriad factors that affect it -- whether in the classroom, the home, or the workplace.
Biology figures prominently in the final outcome of the human brain and how it processes information. In the gender factor alone, we find numerous gender-specific patterns in learning styles, behavior, information processing, and even in problem solving. When learning-style preferences exist, we often find some of them to be strategies preferred by young girls than by comparably aged boys, and vice versa.
All brains start out as female brains in utero. However, once the TDF (the testosterone determining factor) kicks in, boy brains become distinctly male. We often regard the result as the creation of a "doer" brain because it gets wired for higher levels of activity. The "gray matter" inside the cerebral cortex refers to the densely packed neurons, which are largely responsible for processing thoughts and incoming information. By contrast, the "white matter" refers to the axons, which are the signal-sending portion of brain cells that transmit command signals from the brain to the body. Boys and men have considerably more white matter and typically less gray matter than girls and women.
Normal human brains are lopsided. The left hemisphere is generally larger and more active than its right counterpart. Paula Tallal, of Rutgers University, and others have noted that whenever the two sides more closely approximate symmetry, the left hemisphere is usually somewhat underpowered. This neurophysiological downside is suspected as a leading cause in incidences of language disorders. In females, the left hemisphere is noticeably larger than the right. However, the male brain appears slightly more symmetrical because the average male brain comes equipped with a larger right hemisphere than would be typically found in females. In addition, females average approximately 11 percent more brain cells than males, giving them a distinct neurological advantage in language-related abilities.
It is no coincidence that more than 80 percent of the cases of developmental language delays -- dyslexia, stuttering, and other language-related problems -- afflict boys. Travel anywhere in the United States and one finds that nearly 80 percent or more of the children enrolled in remedial reading classes in the elementary grades are boys. In middle and high schools, the figure climbs to slightly above 90 percent. More than three-quarters of the men in America's prisons have a severe language, reading, learning, or hearing problem, or some combination thereof. Over the course of 12 years of formal education, a 1.7-year gap in language fluency typically separates boys from girls, along with a three-year performance gap in written language.
Memory is a biological event involving the activation of several brain systems. Our memories are not situated in only one brain structure or in a single place inside the brain. For any memory to be created, it is necessary that neurons form new connections via synaptic linkages with other neurons. Combined, these neurons will represent the elements of an experience or idea. In order for information to be remembered, it must be encoded and processed by the neurons.
Physiologically, we cannot store and recall ("remember") information that has not been properly attended to and encoded by specific regions of the cerebral cortex. The brain translates incoming data into the digestible fragments needed to reconstruct a mental representation. The manner in which one encodes and records information will govern precisely what is later remembered and how the information will be recalled, if it can be consciously recalled at all. A student will remember information best if he or she can use the same techniques in retrieving the information that he or she used initially to encode it, and if he or she has a personal/ emotional connection with the target information.
|The highest rated school activity for American children is none other than "show and tell," during which children get to feel and touch something that has high emotional connections to a classmate, the perfect equation for attention-getting and subsequent learning.|
Poor memories are often the product of ineffective initial encoding, which usually occurs because little attention is paid during the initial encoding and processing phases, where no personal/emotional linkages are established. When asked to identify the only accurate picture of a U.S. penny on a page with nine other choices, very few people can make the correct selection from the sheet with nine imposters. Although most adults have likely seen and held over 10,000 pennies during their lives, few can pick the correct picture. The reason for this is simple: We don't really care enough to memorize what an exact reproduction of a penny looks like since a penny has such little personal value. With over ten thousand exposures to the stimulus, the response is still inaccurate without a personally motivating linkage to details in the coin. There are two groups of people who can make an accurate identification of the penny. They are either professional coin collectors or penny-pinchers. When there are emotional "hooks" planted for the learner, the probability of subsequent recall increases dramatically.
When one broadens the mixture of the modalities by which information is encoded, more neural avenues for retrieving it are simultaneously created. All memories are aided by the introduction of multiple methods available for their retrieval. This is why teaching a concept several different ways (do it, touch it, say it, hear it, write it, and read what others have written about it) is vitally important for satisfactory student recall. Doing so might require additional instructional time, but it constitutes a wise investment of teaching time. "Shortcuts" in teaching -- such as straight lectures -- can actually take longer when teachers find themselves going over material again and again, frustrated by the fact that students don't seem to be able to remember much.
The mental constructs derived from first-hand experience later serve as the foundational basis for hypothetical constructs ("what if" questions) leading to the highest levels of cognition.
Whether we actually ever forget anything or whether learned material simply becomes increasingly more difficult to access from our neural networks is still the subject of spirited debate. What we do know is that, as we age, retrieval of information becomes more difficult. We also know that, in the absence of any personal/emotional hook, the likelihood of "forgetting" rises. It is also interesting to note that, within the first two days of an incident, we typically have difficulty recalling more than 20 percent of what was learned. This is because the brain will process and even learn a great deal more than it can retain for long periods of time (thus, we use notepads, audio recorders, computer disk drives, palm pilots, etc., to assist us with our heavily-taxed memory systems). We forget things quickest shortly after we learn them, which is why we must download that information to maintain it.
Some faulty memories are attributable to faulty "wiring," which can often be a consequence of damaged nerve cells from trauma (an injury to the brain), high fever, disease, etc. -- each of which can disrupt a previously functional brain circuitry. Damage to the myelin sheath (the insulation/covering on the exterior of an axon found on a typical neuron) can disrupt the electrical signal, thereby interrupting the entire system of networks containing the memory. The demyelinating diseases, such as multiple sclerosis, will accelerate the destruction of the neural circuitry necessary for appropriate brain functioning.
Ordinarily, we do not forget something in its entirety. Instead, memories go through a "graceful degradation." As many people over 40 will attest, there is a decrease in memory performance -- known formally as age-associated memory impairment (AAMI) -- that accompanies more than four decades of processing and storing information. Memory is still retained; it just takes more time recovering the sought-after memories, its details, or related facts, as we must sort through the massive number of other mental files and neural connections representing our 40 or 50 years of accumulated information. Processing rates are also part of an overall slowdown in functioning and age-related responsiveness. We don't run as swiftly. We don't jump as high. We move more slowly, and recollections take more time to reconstruct than they once did. These are all normal parts of the benign course of aging.
Octogenarians, who can remember every detail of their wedding day or high school graduation, often cannot remember whether they took their medications that very morning. We can vividly remember the name, face, voice, and kindness of a teacher who took a true interest in us back in elementary school, but we can't remember where we parked our own car at the shopping mall one hour ago. This is because it is the emotional connections that determine what we choose to remember and what we elect to disregard. The noticeable challenges to one's recall have more to do with confusion and stress than they do with "senior moments." Children in elementary grades often forget their coat at school or their homework on the kitchen table. No one ever blames these events on "elementary moments." Various levels of MCI (mild cognitive impairment) are evident at all brain stages and ages.
Capitalizing on the human senses to promote learning
We know today that, during infancy, the processes by which young children begin their acquisition of the earliest forms of knowledge are rather similar. Children, as well as other mammals, begin their earliest learning through exploration and play. Psychologist Jean Piaget described play as the serious business of childhood learning. Youngsters also learn via a genetically predetermined sequence of skills that are mastered based on how and when different structures composing the human brain go "online." Once born, the young human brain is so responsive to external stimuli that we can now safely say that nearly all early experiences contribute in shaping a child's growing brain. These sensitive developmental processes transform and "tailor-make" one's neuroanatomy. They also eventually determine the regional functioning capabilities in an individual's brain.
When new learning occurs, the brain changes physically. The very architecture of each human brain is altered as a result of all newly acquired skills. The unfolding events one experiences in life largely decide how much cortical growth will take place, in what regions that growth will take place, and when, if, and where subsequent development will occur (or not) in a blossoming young brain.
Many new competencies are often accompanied by a series of "brain spurts" that are fixed primarily by genetic programs (see "The Seven Brain Spurts" on p. 86) in which parts of the brain mature and a greater amount of myelination takes place in the maturing regions. Initially, a child's brain has twice as many neural connections as the brain of an adult. Recognizing that early exposure to a wide range of learning experiences has a positive impact on brain development, we are now taking a closer look at the critical role that early cognitive development should play in preschool and day-care programs. These years are not just the "developmental years." They constitute the optimal incubation periods for developing the fundamental skills needed for successful kindergarten through college-level learning.
|With the momentum that the field of neuroscience is currently enjoying -- particularly given its far reaching implications to learning -- education and nearly every other aspect of our human existence can be enhanced. The broad field of education will be among the first and greatest beneficiaries of this research.|
Multisensory experiences further extend these precious and plentiful connections throughout the cerebral cortex. Since it often takes six exposures (hearing, saying, touching, seeing, etc.) before new information enters into long-term memory for permanent cortical storage, combining multisensory with multimodal approaches will reach nearly any student's learning preference or cognitive learning style.
Increases in both the size and the weight of the brain are among the many expected neocortical results of learning and memory formation. The more frequently a given network of neurons fires together, the greater the likelihood it will later become permanently hardwired. Conversely, diminishing one's learning opportunities will reduce the quantity of neural networks, which will often permanently decrease one's ability to learn. However, the human brain is more than capable of developing trillions of interrelated neural networks rendering our capacity to learn virtually limitless -- if we choose to continue stimulating and challenging the mind.
Reprinted with the permission of the National Association of Independent Schools. © 1997-2008. All rights reserved.
Washington Virtual Academies
Tuition-free online school for Washington students.
- Kindergarten Sight Words List
- Coats and Car Seats: A Lethal Combination?
- Signs Your Child Might Have Asperger's Syndrome
- Child Development Theories
- The Homework Debate
- Social Cognitive Theory
- GED Math Practice Test 1
- 10 Fun Activities for Children with Autism
- Why is Play Important? Social and Emotional Development, Physical Development, Creative Development
- First Grade Sight Words List