Brain Over Binge (15 page)

So it was no coincidence that I typically binged on sweets. In therapy, I was told that craving sweets was symbolic of the need for some sort of emotional comfort or sensual satisfaction, but it was not. Eating sweets was indeed pleasurable, but there was no deep emotional significance there. Just like the rats, I chose sweet food primarily because I was following my instincts. We all have an inborn and instinctual sweet tooth, stronger in some people than others. Babies, who have no prior experience with food or its emotional significance, have a preference for sweets, and nature even made breast milk sweet.

Having said all this about instincts, I must point out again that I was more than just an animal acting on instinct. After all, I am human. I tried to reason myself out of binge eating, I felt strong emotions accompanying my binge eating, I reflected on my behavior afterward, and I felt guilt and pain following a binge. An animal just acts; it does not reflect or think about how it
should
behave. The rats in the studies above were only following their primitive brains—they did not try to fight their cravings, reason with themselves, try to distract themselves from the desire to eat, or regret their decision to overeat. They merely followed the automatic signals from their brains in order to maximize their chances of survival.

Humans, on the other hand, do not have to follow every instinct or automatic signal from their brains. We have the unique capacity to think about what we do and change what we do. But it is difficult to change if we don't know what's going on in our brains, as I found out through all those years of binge eating. I didn't realize that I had the capacity to override the automatic and instinctual functions of my brain.

20
: Why Did I Continue Having Urges to Binge?

Reason 2: Habit

S
o far, I've explained that my urges to binge began and continued because of survival instincts, originating in the animal brain; however, this was not the only factor in the maintenance of my bulimia. Certainly, if survival instincts had been the only reason, those urges would have eventually let up. My body and brain would have eventually received the message that starvation was no longer a threat, especially after I gained almost 55 pounds from binge eating throughout college. What else was keeping my bulimia going? What else made my urges to binge persist month after month and year after year?

As I've said, my therapists said that emotional problems drove my binge eating for all those years; but during my experience on Topamax, and during and after my recovery, I discovered that this was not the case. I had similar emotional problems even while I was on Topamax and my urges temporarily faded, even after I read
Rational Recovery
and learned to resist my urges to binge, even after those urges disappeared completely and my bulimia was just a memory. The emotional problems that did improve were predominantly the ones that resulted from binge eating—like shame, guilt, disgust, isolation, and self-hatred.

While it simply isn't plausible that emotional problems drove my binge eating all those years, survival instincts don't explain the whole picture either. This is because my dieting and the consequent survival instincts only began the binge-purge cycle, setting my bulimia in motion and keeping me binge eating long after it was physically necessary. Then, after I'd binged and purged for a prolonged period of time, survival instincts became less and less the problem and another brain function took over: habit.

When I say the word
habit,
it probably conjures up an image of some annoying behavior, like biting one's fingernails, chewing gum, or thumb sucking. But here, I am talking about much more. Habits aren't only little annoyances; habits are how we survive. The brain has a remarkable ability to create and maintain habits, giving us the ability to easily repeat actions that are necessary for our very existence, but habits also have a dark side.

We create our own habits—good or bad—by repeating behaviors, and those habits—for better or worse—then govern our lives. When we create good habits, it only makes our lives easier, because we can then unconsciously and easily perform the behaviors that are consistent with our goals and identity. On the other hand, when we create bad habits, we can become ensnared by them—performing destructive behaviors automatically, even though we know better and despite our best efforts to change.

Bulimia and BED are but two examples of the dark side of habit formation. There are countless examples of destructive habits, but the worst kind of habits often involve tempting and pleasurable substances. These habits—like drinking to excess, smoking, drug abuse, and binge eating—are sometimes called "addictions" and occur when the body and brain become dependent on and crave the habit. Binge eaters, smokers, drinkers, and others who are ensnared by destructive habits experience powerful urges (akin to the urges I felt to binge) to perform the behavior, to get more of their substance of choice, even when they know they shouldn't.

Intense and unwanted urges to perform a behavior are primarily tied to bad habits, even though there are certainly urges to perform good behaviors as well. For example, if you get in the good habit of exercising every day, you will automatically crave daily physical activity; or if you create a good habit of flossing every night, you will have involuntary urges to floss nightly—especially if you try to go to sleep without doing it. The cravings and urges in the case of good habits are not problematic but instead very fruitful, in that just a small amount of craving convinces you to perform a beneficial behavior, and you are always glad you did. But in the case of bad habits, the cravings and urges are extremely problematic in that they drive you to perform a harmful behavior you regret.

My destructive habit was nothing more than my body and brain becoming conditioned to expect and demand binges. I have identified three possible habit types to describe my binge eating—termed the "habit of excess," the "habit of pleasure," and the "habit of impulsivity"—all of which have a physical basis in the brain. I believe my binge eating was at least one (and most likely a combination) of those three habits, discussed in detail below. But first, a fuller discussion of the concept of habits is necessary so that I can explain how my binge eating became a destructive habit.

THE NEUROSCIENCE OF HABITS SIMPLIFIED

Habit formation is a simple, yet remarkable, process in the brain. A habit works like this: When we repeat a behavior many times, it causes physical changes in the brain—changes that make that behavior easier to repeat. Soon, we become so adept at performing the behavior that we can do it without much conscious thought. This is when the behavior becomes habit. Habits are unthinking and automatic, but most habits are adaptive, healthy, and necessary for our existence. To explain habits properly in terms of the brain, I'll delve here into a bit of simple neuroscience.

Our brains have billions of cells called neurons. All of our physical functions, thoughts, feelings, sensations, perceptions, moods, memories, and actions are the results of signals passing through the neurons. Neurons form connections with one another known as synapses. When a neuron fires, it transmits its electrical signal across a synapse to the next neuron, which must fire to continue transmitting the signal.

No single neuron works alone, but with the coordinated activity of many others. In order to perform any physical or mental task—from the simple act of taking a step to the more complex one of throwing a curve-ball; from saying hello to a friend to solving a complex math equation; from recalling an elaborate memory to simply feeling sad or glad—neurons have to fire in a coordinated way. "Each experience and each memory are composed of a multitude of neurons firing together at different levels of the brain and in diverse areas."
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When patterns of neurons fire simultaneously many times, the synapses become stronger and better able to transmit signals. As one neuroscience maxim has it: "Cells that fire together, wire together,"
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meaning that patterns of neurons that are used repeatedly to perform any function become connected in such a way that makes that function easier to repeat. This is a testament to the amazing efficiency of our brains.

Patterns of neurons that are strongly connected form neural pathways. We have virtually unlimited numbers of neural pathways in our brains that are responsible for our behaviors, thoughts, memories, perceptions, and, most importantly for the purposes of this book, our habits. Habits are nothing more than efficient neural pathways, created when patterns of neurons fire together repeatedly, forming powerful bonds. The habit, whether productive or unproductive, becomes easier and easier to repeat as connections between the neurons in the pathway become stronger and stronger.

The formation of habits in the brain is "analogous to the way that traveling the same dirt road over and over leaves ruts that make it easier to stay in the track on subsequent trips."
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Neurons become so well connected that the habit becomes automatic, which is advantageous when the habit is a good one, but harmful when the habit is a destructive one, like my binge eating. Once the pattern of bingeing became established, the neurons involved in it became coordinated, organized, and strong, so that I felt compelled to continue the behavior. In a real physical way, my brain became hooked on binge eating.

My habit didn't begin as a conscious choice, like many productive habits do. In stark contrast to someone who consciously practices a skill—such as playing a musical instrument, solving algebra problems, or learning to type—I felt propelled into my habit by some force beyond my control. That force was my survival instincts. What began as a survival reaction to food deprivation turned into a terrible habit because, by binge eating many times, I programmed my brain to become dependent on binge eating.

The neurons that "fired together," driving me to binge eat those first few times, eventually became "wired together," ensuring the persistence of my urges to binge. What began as a way of dealing with the threat of starvation became physically stamped into my brain, so my brain kept urging me to binge even after the threat of starvation was long gone and even after all of my weight gain. I continued to binge because I was caught up in a destructive habit—the expression of something physical going on in my brain. I didn't know that each time I followed my urges and binged, I only strengthened the neural pathways involved, making the habit stronger and making it more and more difficult to quit.

This brings me to a very important concept for understanding my eating disorder, the concept of
neuroplasticity.

NEUROPLASTICITY AND MY BINGE-CREATED BRAIN-WIRING PROBLEM

In simple terms, neuroplasticity refers to the brain's ability to rewire itself.
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Neurons are not fixed, but instead have the ability to "forge new connections, to blaze new paths through the cortex, even to assume new roles."
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Only a little more than twenty years ago, neuroscientists thought that only brains of infants and young children were plastic and that the adult brain could not change. However, we now know that the adult brain can be altered too; it retains some of its plasticity throughout life.
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It is said that the brain "learns as it plays,"
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physically changing based on one's experience. The following passage from Sharon Begley's
Train the Mind, Change the Brain
gives a telling explanation of neuroplasticity:

The actions we take can literally expand or contract different regions of the brain, pour more juice into quiet circuits and damp down activity in buzzing ones. The brain devotes more cortical real estate to functions that its owner uses more frequently and shrinks the space devoted to activities rarely performed. That's why the brains of violinists devote more space to the region that controls the digits of the fingering hand. In response to the actions and experiences of its owner, a brain forges stronger connections in circuits that underlie one behavior or thought and weakens the connections in others. Most of this happens because of what we do and what we experience of the outside world. In this sense, the very structure of our brain—the relative size of different regions, the strength of connections between one area and another—reflects the lives we have led. Like sand on a beach, the brain bears the footprints of the decisions we have made, the skills we have learned, the actions we have taken.
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The importance of this concept in understanding my eating disorder and recovery cannot be underestimated, so I will include another explanation here—this from neuropsychiatrist Jeffrey Schwartz in
The Mind and the Brain:

[T]he brain's ensembles of neurons change over time, forming new connections that become stronger with use, and letting unused synapses weaken until they are able to carry signals no better than a frayed string between two tin cans in the old game of telephone. The neurons that pack our brain at the moment of birth continue to weave themselves into circuits throughout our lives. The real estate that the brain devotes to this activity rather than that one, to this part of the body rather than that one, even to this mental habit rather than that one, is as mutable as a map of congressional districts in the hands of gerrymanderers. The life we lead, in other words, leaves its mark in the form of enduring changes in the complex circuitry of the brain—footprints of the experiences we have had, the actions we have taken. This is neuroplasticity.
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So, where we focus our attention and the actions we take physically change our brains. For example, if I concentrated on learning a musical instrument, and practiced consistently, more neurons in my brain would be allocated to that task. Neurons would form new connections as I—the musician—became more proficient, and the connections would grow stronger and more efficient with practice. It was the same with my bulimia. The more I binged due to survival instincts, the more my brain changed to accommodate the behavior. As I focused attention on food and followed my urges to binge, my brain devoted more and more neurons to my habit and strengthened the connections between those neurons. Indeed, "habits are behavioral expressions of plastic changes in the physical substrate of our minds."
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Sports coaches often say that "practice makes permanent." They use this saying in contrast to the cliché "practice makes perfect" to illustrate that practice doesn't make perfect if you are practicing incorrectly. If, for instance, a tennis player practices serving with incorrect form over and over again, the incorrect form becomes permanent. "Practice makes permanent" has a real biological basis in the brain. By practicing incorrectly, the tennis player trains groups of neurons in his brain to send incorrect signals to his muscles. The incorrect serve becomes wired into his brain as a habit.