The brain functions that are associated with learning depend on communication with between neurons, which is mediated by neurotransmitters. Many chemicals are known to function as neurotransmitters, and also many chemicals are known to influence the functioning of neurotransmitters. Further, cognitive scientists have identified several environmental factors that are associated with the production and function of neurotransmitters and the neurons they connect. All of these factors influence how the brain perceives the world, cognates, and responds to the world; so they affect how humans interact socially and learn.
Several examples illustrate the effect neurotransmitters have on brain function. Glutamate is a neurotransmitter that crosses the synapses when two neurons first communicate, so it is essential in initial learning. Serotonin is associated with moods and emotions; abnormal levels of this neurotransmitter are associated with depression, anxiety, and similar conditions that can be debilitating. Drugs to control the level of serotonin reduce the symptoms of these conditions in many individuals. Norepinephrine is associated with levels of attention and motivation; too much or too little of this neurotransmitter can interfere with one’s ability to pay attention to important parts of the environment. Dopamine is a neurotransmitter associated with one’s perception of reward and with learning. Many addictions can be explained by the release of dopamine when the addict engages in the addictive behavior.
In addition to the role of many neurotransmitters that influence brain function, cognitive scientists have elucidated the role of structures in the brain that function in the control of humans’ social interactions. The amgydala is associated with emotional responses to situations, and it “decides” if incoming information is important. Meaningful information is passed along to the hippocampus, which “decides” how to sort and store the information. In reality, all of the processes are far more complex, but even when oversimplified, educators have a more accurate and sophisticated understanding of human learning if they recognize that emotion and the environment affects brains.
Lieberman (2013) reported several findings that illustrate the modular organization of the brain and the adaptions of the brain for social interaction. When we engage in cognitive tasks, lateral (outer) sections of the cortex tend to be more active. When we engage in social activities, the medial (middle) sections become active. Scientists can increase lateral activity in the brain by asking a subject to perform a task; itself this is not very interesting. What is interesting is that when the brain stops the focusing on the task, it reverts to a pattern consistent with social interaction. It appears the default mode for human brains is to be socially active; when a brain is not otherwise engaged it is primed to attend to social interaction. Further, the same parts of the brain that are active when we feel physical pain are active when we feel social pain.
Several discoveries about the environment and brain function have particular relevance to educators designing exemplary practices for 21st century curriculum and instruction. First, moderate levels of exercise are good for brain function (Ratey 2008). Moderate is a difficult quantity to define, and the data are not yet conclusive, but it appears that the physician who recommends aerobic exercise that raises your heart rate to 80% of maximum for 20 minutes three times per week is recommending too little exercise. Fit bodies deliver food, water, and oxygen to brain cells and those are all necessary for proper function; fitness is also associated with greater levels of chemicals to build and support synapses. From this we can conclude that educational structures and organizations restricting students’ opportunities to move around can interfere with healthy brain function, thus limit students ability to learn.
These findings support the inclusion of fitness-based physical education programs in the curriculum and these findings refute policies restricting participation in extracurricular athletics for academic reasons. Further, these findings suggest that decisions to reduce physical education classes to allow for enhanced academic instruction as a strategy for improving test performance are likely to result in the opposite effect. Students who are restricted from athletics are likely to have greater academic difficulties despite the increased time for academic activities.
Second, enriched environments are good for brains. This conclusion was first supported by research in which rodents were kept in two different environments; those kept alone and in cages without structures on which to climb or other toys had brains with fewer connections than were found in the brains of the mice kept together with other rodents in cages that contained complex toys and structures. This research has been criticized, as it was not clear the changes in the brains were the result of brains atrophying in stark conditions, brains in stark conditions failing to develop properly, or brains growing abnormally complex in the enriched environments. The implications for educators are identical regardless of the causes of the changes: enriched environments are associated with richer connections in brains and more connected brains are indicative of those that have learned more and that are capable of learning more.
Third, stress can be either good for brains or bad for brains, the effect depends on the level of stress that is experienced. What is true for physical stress (exercise) is true of psychological stress: none is bad, some is good, but too much is bad. Stress results in the release of a chemical called cortisol into the blood. Although not a neurotransmitter itself, cortisol does influence the release of the neurotransmitter norepinephrine, which causes the fight-or-flight response with its characteristic increase heart rate and more focused attention. In moderate levels, cortisol is associated with normal and healthy building of new connections between neurons and the brain functions necessary for social interaction. Too much cortisol can interfere with the normal building of connections and brain function. Exposure to excessive levels of cortisol for an extended time (for example when individuals experience chronic stress) is associated with degraded brain function.
We can conclude that modern cognitive science is creating a model of the human brain that is more accurate and more detailed than ever available to educators. This situation is not unlike the changes in medicine that followed the discovery and elucidation of germ theory. Once scientists discovered germs and understood their role in disease, doctors began to take steps to minimize the spread of germs; for example, they started washing their hands frequently. It is anticipated that educators who ignore the effects of their classroom environments on brains will be viewed with as much suspicion as doctors who ignore the advice to wash regularly.
References
Lieberman, Matthew D. 2013. Social: Why Our Brains Are Wired to Connect. Crown Publishers.
Ratey, John. 2008. Spark: The Revolutionary New Science of Exercise and the Brain. Little, Brown and Company.