The mid to lower part of your brain (the limbic region), which houses the amygdala, runs from the brain stem, at the top of your neck, to about the level of the bridge of your nose. Although it’s already well developed at birth, it’s sometimes referred to as primitive, because it’s responsible for regulating basic functions like breathing, heart rate, digestion, and wake and sleep cycles. It’s ready at a moment’s notice to activate the body’s fight, flight, or freeze response. This part of the brain allows you to act before you think. It’s responsible for strong emotions, impulses, and instincts, like the intense fear you feel and your quick reaction when your toddler runs out into a busy street, or the panic that sets in when you see a coyote cross your front lawn and you frantically search for your cat. This part of the brain is the source of our reactivity, and while it’s lifesaving at times, it can also get us into trouble.
The upstairs part of your brain comes online later in development. This outer layer, called the cortex, runs from your forehead to the back of your head, covering the lower brain, and it doesn’t reach full maturity until we’re in our mid-twenties. The cortex, and more specifically an area called the prefrontal cortex, is part of our self-regulation system, and it depends on properly working connections and input from lower parts of the brain. This area of the brain is responsible for cognitive, emotional, and relational skills: it helps you regulate your emotions, observe your thoughts, take in insight, adjust your behaviors, learn from your mistakes, stay flexible and adaptive, make wise decisions and plans, and feel empathy and compassion for yourself and others.
This part of the brain allows you to think before you act and to evaluate emotionally driven impulses — like the urge to eat more than a couple of slices of pizza or buy an entire cheesecake sampler. With normal development and sufficient early nurturance, integrative circuits grow and strengthen between our upstairs and downstairs brain regions. We gradually develop the ability to apply mature, top-down control strategies that help us regulate our behaviors. When the downstairs part of the brain sends out signals to grab the pizza and the cheesecake, the upstairs part might remind us about an upcoming social event and the outfit we want to fit into. It might help us access a nurturing, limit-setting adult voice that reminds us we can have pizza and cheesecake if we like, but it’s best to buy single servings. This area of the brain can become compromised, however, by insufficient, stressful, or adverse early experiences with caregivers. It may feel inaccessible when we are experiencing intense emotions and stress, especially if we are fatigued or sleep deprived.
Self-regulation, or the ability to manage our emotions, moods, thoughts, impulses, and behaviors, is a developmental achievement. Life experiences activate certain pathways in and between different regions of the brain, strengthening existing connections and creating new ones. Developing and connecting, or integrating, the proper brain circuitry for self-regulation requires certain conditions. In his book The Developing Mind, Daniel Siegel states that “optimal relationships are likely to stimulate the growth of integrative fibers in the brain, whereas neglectful and abusive relationships specifically inhibit the healthy growth of neural integration in the young child. Experience early in life may be especially crucial in organizing the way the basic regulatory structures of the brain develop.”
In order to curb our emotional reactivity and wayward impulses and make wise decisions about food, we need the upstairs brain to step in and perform its duties as the captain of the ship. When our self-regulation circuitry is working well and all parts of the brain have open communication, we find ourselves less dependent on external supports, such as food or chemicals, to calm us down, lift us up, or get us going.
The Triune Brain
This simple model of the brain describes the three areas of the brain that are designed to process information separately and to function as a whole. (Triune means “three in one.”)
The brain stem regulates basic processes like heart rate and respiration, as well as states of arousal. This area receives input from the body and communicates with the areas above it.
The limbic region is the emotional brain, responsible for our basic drives and emotions, and it is home to the emotional-processing amygdala and the hippocampus, which is responsible for converting our feelings and experiences into words and memory.
The cortex is the thinking brain, responsible for higher-level cognitive functions and relational skills and helping to coordinate the connections among all brain regions.
Left Brain, Right Brain
The brain is organized into lateral as well as vertical regions. Like the upstairs and downstairs regions of the brain, the left and right sides of the brain need open channels of communication. The right side develops earlier than the left and communicates more directly with the lower brain areas and the body. This side of the brain receives emotional information: it is home to our emotions, intuition, gut feelings, imagery, nonverbal communication, and autobiographical memory. As very young children, we’re right-brain dominant: we live completely in the moment and have little concern for concepts like right and wrong or following the rules. Our left brain, responsible for logic, language, and linear thinking, develops a bit later.
Generally, the two sides of the brain work together fairly smoothly, even in people who seem to favor one side over the other. However, traumatic memories appear to activate the right hemisphere and deactivate the left. One of the results of this imbalance is that when something reminds us of a traumatic event, we can feel as though the event were happening in the present, not the past. Unable to access our rational left brain, we may feel flooded and overwhelmed by our feelings. At times like these, there’s a high probability that our emotional response will be bigger than the crime and that we’ll resort to a maladaptive coping behavior in an attempt to stop the emotional overload and restore tranquility. We may grab our favorite comfort foods and overeat. We might ignore the alarm messages from our emotional brain, even though our bodies are registering the threat, and deny the existence of our feelings. But the right side of the brain keeps working, as stress hormones signal the muscles to prepare for fight, flight, or freeze. Eventually, the physical effects on the body will demand attention.
Similarly, when we function predominantly from our left brain, we cannot harness the full potential of both sides working together. Cut off from our emotions and intuition and the richness and creativity they offer, our lives can feel dull and unsatisfying. We may find that delectable foods offer the excitement and bliss our left-brained lives seem to be missing.
Brain Chemistry and Overeating
Consistent and sufficient parental nurturing in infancy and childhood plays a major role not only in the normal development of the structure of the brain regions and circuits, but in the brain’s chemical communication systems as well. Brain chemicals, called neurotransmitters, allow messages to pass from one cell to the next and are essential for communication between brain cells. Brain chemicals regulate our mood and mental energy, alertness, focus, and calmness. The quality of our lives is highly determined by our brain chemistry.
There is a specific area of the upstairs brain, called the orbitofrontal cortex, that is heavily involved in our ability to regulate our emotions, impulses, and behaviors. This area has a dense network of connections to the lower brain structures, where our most primitive emotions, like rage and fear, are generated, and the brain stem, where our physiological body states are managed. This area of the brain is at the center of our reward and motivation system, and it contains a large supply of the reward chemicals — endorphins and dopamine — associated with soothing, calm, joy, and pleasure.
Endorphins: Molecules of Emotion
Endorphins alleviate physical and emotional pain and facilitate emotional bonding. If you’ve ever had a serious injury and didn’t feel