give life and color to our experiences. But where do they come from? What caused the fear and terror I experienced during the fire? In order to answer these questions, we need to go a little deeper into another structure of the brain, the limbic system—the site of emotions.
Limbic System
The limbic system is the site from which positive and negative emotions emanate; it is also the site of learning and memory. It consists of several structures. The major ones include the hippocampus, thalamus, hypothalamus, septum, and amygdala.
The hippocampus is located in the temporal lobe of the brain and is involved with learning and memory.
The thalamus is located on top of the brainstem and acts like a relay station that receives, processes, and sends information to various parts of the brain, especially the higher levels of brain activity.
The hypothalamus is located under the thalamus; it has many functions, but for limbic purposes it involves the regulation of hormones and the autonomic nervous system.
The septum, located in the midline of the brain, is involved in mood, pleasure, sexual gratification, and rage.
These structures are involved in other roles as well as limbic functions; however, it is the amygdala, another limbic structure, whose key role is emotional reactions (Sapolsky, 2007).
The amygdala is a small, almond-sized structure—one in each hemisphere of the brain—located deep within the temporal lobes. It acts like a storage site for emotional responses, especially those related to fear. It is involved in the fight and flight response. This little structure reminds me of a fire truck speeding down the road, with lights flashing and alarms blaring. This visceral response can be so loud that it’s deafening, and all other controls in the brain appear to be on mute. The amygdala is a wonderful built-in feature to have if the house is on fire, as was the case when our house caught on fire. I was sounding the alarm at the top of my voice. My emotions were appropriately excessive. I was running around the house like Speedy Gonzales, yelling, “The house is on fire! The house is on fire!” Even though the fire was out, I continued to run and sound the alarm, until my father caught me and sat me down. It was then that my frontal lobe, the site of reasoning and judgment, could look at the facts and analyze the situation, which was the fire is now out.
This built-in system is very effective in the face of any danger, such as running from an intruder or jumping to safety. In these situations it’s a true lifesaver. But the amygdala can also get us into trouble. There are many individuals who regret their impulsive emotional response to someone else’s behavior. For instance, a teacher in Houston was caught on tape beating her student unmercifully for his bad behavior. She had obviously lost touch with her frontal lobe, and her amygdala was out of control.
Our emotions are registered in the amygdala before we are conscious of the situation. Think about the last time you were incensed about something; that emotion began so quickly you were not even aware that it was happening. A positive emotion, such as a smile from a baby or loved one, generates an automatic smile in most cases, unless you are Mr. Grump. Studies indicate that an emotional feeling occurs within milliseconds, and it takes 10-15 seconds before it begins to subside (Ekman, 2003).
Psychologist Paul Ekman, author of Emotions Revealed, has traveled internationally and in the United States studying emotions for over 40 years. He states “emotions are universal across cultures” (p. 58). He indicates that there are seven basic emotions: sadness, anger, surprise, fear, disgust, contempt, and happiness. Ekman goes on to say that these emotions are experienced in anticipation of something sensed to be either right or wrong (2003).
In response to each emotion, we have a specific chemical reaction that corresponds to that feeling. For example, we have different types of tears—tears of sadness and tears of joy. We also have tears that come from irritants like onions and tears that moisten our eyes. Dr. William Frey, a biochemist at the St. Paul-Ramsey Medical Center in Minnesota, performed studies analyzing tears. He and his team looked at emotional tears from a negatively charged stressful encounter and compared them to tears from irritants. His findings revealed that emotional tears contained a higher concentration of protein-based hormones: prolactin (lactating hormone), adrenocorticotropic hormone (stress hormone), and leucine enkephalin (natural painkiller) (Skorucak, 2010). Other studies show that tears that moisten the eyes contain lysozyme, a chemical which washes away bacteria. Tears not only relieve pain and stress, but also kill little critters.
The body produces many other types of chemicals and hormones. Many of us are familiar with the runner’s high, that feeling of euphoria after exercising. This is produced by the natural chemicals called endorphins. Or perhaps you’ve sprained your ankle and are in pain; the body produces natural painkillers known as enkephalin, which are similar to the narcotic morphine—working on the nervous system to inhibit pain.
We produce many hormones and neurotransmitters which communicate how we are feeling: chemicals such as serotonin, which regulates mood; epinephrine, a form of adrenaline which involves the stress response; dopamine, which causes pleasure; glutamate, which excites nerve cells to fire; and GABA, which inhibits the nerve cells. Scientists have identified approximately 70 chemicals that the body manufactures, and they believe that there are many more waiting to be discovered (Norden, 2007d).
Thoughts
We have looked at our nerve cells and have seen that we have 100 billion trees making 100 trillion connections. These are the building blocks for the brain. It is here on these trees that electrical impulses are produced and chemicals are made which cause thoughts to become permanent, store memories, and produce emotions that can be relived.
But what about our thoughts; where do they come from? What generates that initial thought? You know the kind of thought that comes out of the blue when you are just relaxing and something just pops into your head. You may have had an ingenious thought that moved your career into a new and exciting direction. And you wonder: where did that come from? Well, where does it come from? In search of the answer to this question, I spoke with three leading neuroscientists, and the answer to this question was quick and short. “We don’t know!” Science has not been able to figure this one out. But what we do know is that information comes from the outside world through our five senses, which give us cues and activate previous memories. However, that initial thought, which just appears in the mind, we don’t know.
Trying to answer this question is like trying to discuss how God created the universe. We see the evidence, but we don’t know how He did it, except that He said, “Let there be” and of course there it was. Science cannot explain the origin of our thoughts; however, Scripture gives us a little insight. In Deuteronomy 29:29, God says: “The secret things belong unto the LORD our God.” This just sums it up. Some things we will never know this side of heaven. However, we do have hints.
Throughout Scripture we see information regarding the mind, what it does, and its capacities. For instance in Proverbs 23:7, we read: “For as a man thinketh in his heart, so is he.” The word “heart” has several connotations—the mind, emotions, and the physical heart (Strong, 1995). This text is referring to the thinking part of the brain (frontal lobe), the emotions aspect (limbic system), and the physical heart. It is our thoughts and feelings that make us who we are.
When we look back at the anatomy of the nerve cell, we see a biological process, electrical current, and chemical reactions. It has only been within the last few decades that science has been able to demonstrate what Scripture said thousands of years ago. We now have scientific proof that by beholding and thinking we become changed. When we think, information travels on our nerve cells, and then branches out to other cells. Thoughts dwelled upon leave indelible impressions that become memories and are stored in the mind. What an incredible and awesome gift!
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