Emotions and Physiology

In the human brain, learning, memory and emotions are housed in the limbic system surrounding the brainstem. Within the limbic system, emotional impulses originate in the amygdala, an almond-shaped structure that triggers the physiological reactions associated with emotions. The amygdala is also responsible for imprinting emotions onto memories by releasing some of the same neurochemicals when an event is recalled as when it occurred.

A network of neural pathways connect the amygdala to the neocortex, the "thinking brain," allowing us to reflect on our feelings and to think before acting. In times of perceived crisis, however, those pathways are bypassed and impulse overrides reason. When the man succumbs to road rage and yells at his wife over an innocent remark, he is experiencing what Goleman dubbed "an emotional hijacking," in which the amygdala takes over the brain.

Sometimes, emotions and their physiological effects can seem indistinguishable. Intuitive "gut feelings," or somatic markers, develop simultaneously in the limbic system and the body. These steer us toward one course of action or another, whether it be avoiding danger or seizing opportunity.

Each emotion sparks a distinctive physiological reaction, the body's program for dealing with the different situations that arise in our emotional lives. Happiness cues the brain to suppress worrisome or negative feelings and increases the body's energy level. Sadness does the opposite, slowing down its metabolism, and manifests itself most visibly in tears. Research has substantiated the age-old theory that crying releases harmful toxins by showing that tears of sadness have a different chemical composition than tears of joy or those caused by irritants. Cardiologists have also found that crying can reduce stress and the harmful physiological reactions associated with it.

Anger floods the brain with catecholamines hormones that prime the body for action and stimulates the nervous system, putting it on a general state of alert. This explains why someone who is already in a foul mood will remain edgy and more easily aroused to anger than someone who is not.

*Stress and *anxiety set off the nervous system's "flight-or-fight" response, a chain of physiological events in which the blood pressure rises and muscles contract. In chronic cases, they can lead to *headaches, *cramps and *insomnia, as well as to more serious ailments, such as *heart disease, *colitis and gastrointestinal disorders. According to the American Medical Association, stress contributes to 75 per cent of all cases of illness in the United States.

People can also engage in certain behaviours to induce the release of neurotransmitters, causing them to have the sensation of an emotional experience without having to identify and process their feelings.

On the surface, this might seem like a good strategy for dealing with difficult situations. But such behaviours can quickly become addictive and serve as false substitutes for true emotional wellness. Moreover, like most addictions, their potency gradually wears off as the body's tolerance level increases, forcing the people who resort to them to seek ever-greater levels of stimulation.

Ultimately, it is less the physiological effects of emotions than how we deal with them that affects our overall health. A decade-long study by Ohio State University researchers tracked both men and women who had been diagnosed with *depression, but appeared free from cardiac problems. Over the course of the study, 46 per cent of the men eventually died from heart disease, compared to only 16 per cent of the women. The researchers theorized that the male tendency to bury feelings and avoid examining or expressing them might have led to the difference in mortality rates. So the man's wife is probably right: it does help to talk.

*Mood swings rapid fluctuation from one emotion to another can also wreak havoc on the body. A 1999 study conducted at Duke University Medical Center found that people prone to moodiness were four times more likely to develop ischemia, a condition that reduces the flow of blood to the heart, than those whose emotional highs and lows tended to stay stable.

Neurotransmitters

Neurotransmitters are chemicals that send messages within the brain to regulate our mental and bodily functions. Emotions or emotional behaviour can trigger their release. Among the most important neurotransmitters are:

Acetylcholine (ACTH): Important for memory. It also lowers blood pressure and reduces cholesterol. Stress reduces the enzyme that converts choline to acetylcholine.

Vitamin B₅ is needed to convert choline to acetylcholine. Lecithin is also used to make choline. Food sources include soybeans, fish, seaweed, oatmeal, brown rice, peas, lentils, cabbage and kale. Mothers' milk is high in acetylcholine.

Dopamine: Gives us our sense of pleasure and motivation by regulating the release of endorphins. It improves mood, sex drive and memory. People with low levels of dopamine often try to compensate through caffeine, sugary foods, cigarettes, alcohol and other drugs, which also induce the release of endorphins, or activities like gambling, work or exercise.

Without Vitamin B₆ the body may not produce dopamine, endorphins, and serotonin, norepinephrine.
Endorphins: Natural pain killers released by exercise. Several studies have shown that they can also be released when we listen to music with a strong beat.

GABA: Needed for sleep and relaxation, as well as enabling us to withstand craving. People with low levels of GABA, including alcoholics and other addicts, can be tense, anxious and aroused to anger with little provocation.

Glutamate: Facilitates long-term learning and retention. It also plays a role in our tolerance for pain. GABA balances glutatamate's effects in the brain.

Norepinephrine: A hormone that acts like a neurotransmitter and is released in response to low blood pressure. It enhances our memory, makes us more alert and gives us a sense of power and control. Noradrenaline is the commercial form of norepinephrine.

Serotonin: The body's natural tranquilizer, it relaxes us, regulates body temperature and appetite, sets our internal clock for sleep, and makes us feel peaceful and contented. It also acts as a natural counterbalance to dopamine. People with low levels of serotonin tend to act rashly and aggressively and to become easily depressed.