With our first glance at the trench-coated stranger passing our classroom door, our limbic system
— interconnected anatomical structures nearly encircling the brain stem — orchestrates a “startle response,” led by the amygdala. This can occur so spontaneously that the body is responding (sweating and/or running) before the brain is consciously aware of the threatening stimulus — occasionally generating an irrational false alarm, under the “better safe than sorry” principle. Cortical processing in the more sophisticated regions of the brain has to play catch-up in its appraisal of the precise type of threat, the degree of threat and our history with that type of threat, based on incoming information now being evaluated by the slower-processing cerebral cortex.
There are multiple attention-getting elements in the environment, all simultaneously competing for the limited amount of attentional resources in the brain. Like a motorist permitted to drive in the fast lane of a freeway, fear is a high-priority customer and the highest-ranking traveler on the neural superhighway, with unrivaled authority to sprint past reason and other more thoughtful responses at any time. Human survival did not allow our ancestors the luxury of weighing each environmental variable cautiously prior to taking action. Eons later, in contemporary humans, our first reaction is still to freeze and (assuming that time permits) scrutinize the situation, during which time we can plan our next move, which may be to flee or, if we absolutely must, to fight. Physiological changes to our body rise to promote peak performance levels, preparing us for the fastest getaway or the best defense we can muster. When these systems work collectively and effectively to ward off danger, we call that an “adaptive response.”
Fear often prompts the “freeze, flight, fight, and fright” repertoire of reactions, typically in that order. in addition to the immediate release of stress-related hormones and neurotransmitters, once a threat has been registered, all nonessential systems and the body’s “long-term building projects” (growth, T-cell production, ovulation, sperm-cell count, etc.) reduce their operations significantly or shut down completely. Women who worry about their prospective pregnancy or their subsequent medical treatments (and their exorbitant costs) are less likely to become pregnant in the first place.
It is under these conditions that the hypothalamus triggers the pituitary gland and the nervous system to prepare the major organ systems for quick action, assault, and/or a possible shutdown (hopefully, only temporarily). The amygdala signals an “all systems alert,” triggering the anterior cingulate and the hypothalamus to turn on the autonomic nervous system and to prepare the motor system, the bodily functions and vital organs to anticipate adjustments.
The pituitary gland produces adrenocorticotropin and thyrotropin, activating the adrenal system. The heart muscles contract, causing heart rate and blood pressure to rise quickly, sending “fuel” to the body. The blood vessels constrict, promoting sweating. Hairs stand on end. The spleen contracts and begins the quick production of white blood cells and platelets, to prevent excessive blood loss in the event of a physical injury. Blood vessels in the stomach, the gastrointestinal tract and the kidneys constrict to divert blood to the large muscle groups. The digestive system shuts itself off and the bladder and colon get ready to spill their contents, if necessary. Our salivary glands shut down saliva production, prompting “cotton mouth.”
Recall and rational thinking are compromised as the carotid artery reduces cerebral blood flow in order to send more blood to the muscles. The adrenal medulla flushes the bloodstream with adrenaline and noradrenaline, which increase blood sugar and constrict the blood vessels. Pupils in the eyes dilate, sharpening our visual acuity and sending more information to the visual thalamus. Bronchioles in our lungs dilate to increase oxygen intake. Glycogen is broken down in the liver to increase the availability of instant energy. Finally, the hippocampus stores this event and our response to it as a permanent memory to be used in the future. Regrettably, these threat-response processes do not reverse themselves on command. The changes to body chemistry do not dissipate quickly, making it difficult for us to settle down after an emotionally upsetting event.
Some body systems shut off for emergencies, while others turn on. Once the threat has subsided, we return to a state of homeostasis, the tendency toward a relatively stable equilibrium between interdependent physiological processes. Frequently, the only way to resume homeostatic balance is for us to separate ourselves from the associated source of danger.
With extended periods of stress, the body-brain systems establish a new baseline for operating, through the process of allostasis; however, when the threat-response systems do not shut down occasionally for rest and repair, long-term damage can occur to both the body and brain systems — for example, post-traumatic stress disorder (PTSD).
Negative emotions in the classroom or at home are incompatible with student learning and achievement. The stress hormones and neurotransmitters required for fight-or-flight response characteristically prepare the body-brain for escape rather than for learning. Parents who believe they are helping their child with homework but who spend the vast majority of this time frustrated, angry and shouting instead may notice that memory and content-learning take considerably longer, if they occur at all. To be truly helpful, parents should take the child for a walk, during which time the target concept can be explored and visualized, with the parent filling in the conceptual blank spaces for the young learner.
When a teacher or parent uses aggressive body language coupled with a raised voice, children shift their attention away from the learn this quickly intention to Mother Nature’s imperative to leave quickly, you are in danger! For a child or an adult, being trapped by a seemingly inescapable threat takes a toll on learning, and, eventually, toxic stress impacts one’s physical health. Deep breathing, exercise, walking and yoga can serve as anxiety-reducing strategies that can bring us back from the emotional extremes (either 10 on the emotional number line). An “emotional hijacking” (a phrase coined by Dr. Daniel Goleman in his bestselling book, “Emotional Intelligence”) of the brain takes place in milliseconds. Once it subsides, learning is again possible, but not while the emotional takeover is underway.
It is no wonder that when parents and teachers resign from “helping” in frustration, minutes later, the child jumps up, joyfully shouting, “I got it!” Reducing the tension was critical to any learning taking place. Unfortunately, the adult thinks that he or she was a light along the path to learning, but they were more accurately an obstacle. An upset parent or teacher should extricate themselves from that highly emotional situation completely until he or she can get a better handle on their own emotional instability. Learning is never enhanced by increasing the level of fear for learners.
There is truly a joy to long-term learning, as a child experiences the emotional fulfillment derived from achievement and public recognition for his or her academic successes. When students ask, “Can we do today what we did yesterday?” they are telling us that “Yesterday, you weren’t just teaching me, you were reaching me in an emotionally gratifying way that I would hope to experience again today.” When students are in what psychologist Dr. Mihaly Csikszentmihalyi calls “flow,” they become so engrossed in learning and discovery that they tend to forget about the passage of time. Emotional engagement is one of the essential keys to cognition.
In an interview with Shannon Brownlee for U.S. News & World Report (“The Biology of Soul Murder”), Dr. Bruce D. Perry, a child psychiatrist at Children’s Hospital and at Baylor College of Medicine, states, “Children who are aroused [from fear] can’t take in cognitive information. They’re too busy watching the teacher for threatening gestures, and not listening to what she’s saying.” Brownlee writes, “Such behavior makes sense given the constant threats in the child’s world. His brain has become exquisitely tuned to emotional and physical cues from other people. At the same time, he may be failing to develop problem-solving and language skills.” The child’s primary goal becomes to extricate himself from the stressful conditions, not to learn content information. In such children, Perry found that the cerebral cortex is approximately 20 percent smaller on average than in children of comparable age and size.
Not only will the growth of an individual’s brain be reduced under stressful conditions, but the critical operations of his immune system, the body’s otherwise highly effective internal pharmacy, also shuts down. Prolonged stress in Romanian orphans, reported famously in the late 1980s following the collapse of the communist government, caused decreased glucose metabolism, high levels of cortisol and increases in other symptoms of stress, which resulted in decreased functioning of the amygdala, the temporal lobe, the orbital frontal cortex, the orbital gyrus, the prefrontal infralimbic cortex, the lateral temporal cortex, the medial temporal cortex and brainstem.
While shrinkage in cortex may be a predictable expectation, a vastly diminished view of oneself is an unexpected casualty of living under the stress of constant fear, according to Perry. Children from troubled homes and rough neighborhoods were asked, “What do you want to be when you grow up?” Sadly, their answers consistently began with the phrase, “If I grow up,” rather than “When I grow up.” For these children, threats of, I will give you a poor grade at the end of the semester! have virtually no bearing whatsoever on increasing standardized test scores for the No Child Left Behind Act of 2001 data collection, or for long-term learning. For these children, tomorrow is considered a dicey proposition, let alone the end of the semester.
