How Thinking affects brain chemistry
It’s been proven over and over again that just thinking about something causes your brain to release neurotransmitters, chemical messengers that allow it to communicate with parts of itself and your nervous system. Neurotransmitters control virtually all of your body’s functions, from hormones to digestion to feeling happy, sad, or stressed.
Studies have shown that thoughts alone can improve vision, fitness, and strength. The placebo effect, as observed with fake operations and sham drugs for example, works because of the power of thought. Expectancies and learned associations have been shown to change brain chemistry and circuitry which results in real physiological and cognitive outcomes, such as less fatigue, lower immune system reaction, elevated hormone levels, and reduced anxiety.
According to Rick Hanson, Ph.D., a neuropsychologist, founder of the Wellspring Institute for Neuroscience and Contemplative Wisdom, humans are evolutionarily wired with a negativity bias. In other words, our minds naturally focus on the bad and discard the good. This is because it was much more important for our ancestors to avoid threats than to collect rewards: An individual who successfully avoided a threat would wake up the next morning and have another opportunity to collect a reward, but an individual who didn’t avoid the threat would have no such opportunity.
Thus, the human brain evolved to focus on threats. Millennials are no stranger to stress and depression, especially when it’s work related—a recent study reported that around 20 percent of Millennials sought out help or advice in the workplace for depression—a higher percentage than any other generation. According to the Status of Women in the States report from the Institute for Women’s Policy Research, Millennial women ages 18-34 report an average of 4.9 days of poor mental health per month, while Millennial men report an average of 3.6 poor mental health days. Our brains are highly attuned to stress, even when such stress is of the mundane variety and not at all life threatening.
“Negative stimuli produce more neural activity than do equally intense (e.g., loud, bright) positive ones, Hanson writes on his website. “They are also perceived more easily and quickly. For example, people in studies can identify angry faces faster than happy ones; even if they are shown these images so quickly (just a tenth of a second or so) that they cannot have any conscious recognition of them, the ancient fight-or-flight limbic system of the brain will still get activated by the angry faces.”
Hanson describes the brain as like “Velcro for negative experiences and Teflon for positive ones.” While some individuals may be inherently more optimistic than others, it’s generally true that in order for positive experiences to “stick” in our brains as well as negative ones do, these positive experiences need to be held in our consciousness for a longer period of time.
“The alarm bell of your brain — the amygdala (you’ve got two of these little almond-shaped regions, one on either side of your head) — uses about two-thirds of its neurons to look for bad news: it’s primed to go negative,” writes Hanson. “Once it sounds the alarm, negative events and experiences get quickly stored in memory — in contrast to positive events and experiences, which usually need to be held in awareness for a dozen or more seconds to transfer from short-term memory buffers to long-term storage.”
How negative thinking changes the brain
The more that an individual’s thought patterns trend negative and slip into rumination—continually turning over a situation in one’s mind and focusing on its negative aspects—the easier it becomes to return automatically to these thought patterns.
That’s not so great for our health. According to a blog post on Psychology Today, ruminating can damage the neural structures that regulate emotions, memory, and feelings. Even when our stress and worry is completely hypothetical and not based on any real or current situation, the amygdala and the thalamus (which helps communicate sensory and motor signals) aren’t able to differentiate this hypothetical stress from the kind that actually needs to be listened to.
Cortisol, a stress hormone, breaks down the hippocampus, the part of the brain that helps form new memories. Most people experience a peak of cortisol in the morning, but it can also spike throughout the day in response to stress. The more cortisol that’s released in response to negative experiences and thoughts, the more difficult it can become, over time, to form new positive memories.
In neuroscience, the expression “neurons that fire together, wire together” describes “experience-dependent neuroplasticity”—essentially, the concept that our brains are shaped by our thoughts and experiences. According to Hanson, the synapses in our brains that fire frequently become more sensitive. Our experiences and thoughts can lead to the growth of new synapses and even change our genes, altering the very structure of our brain. Or, as Hanson writes, “the brain takes its shape from what the mind rests upon.”
If you’re prone to negative thinking, this might seem disheartening. It’s easy to assume that we have no control over our thoughts. After all, they often pop up out of nowhere, and when rumination takes hold, it can be difficult to break its grip (I would know, I’m an accomplished ruminator). But the good news—and the basis of much of Hanson’s work—is that it ispossible to change our thought patterns and even “hardwire happiness” into our brains (which is the title of Hanson’s 2013 book).
If I were to put you into an MRI scanner—a huge donut-shaped magnet that can take a video of the neural changes happening in your brain—and flash the word “NO” for less than one second, you’d see a sudden release of dozens of stress-producing hormones and neurotransmitters. These chemicals immediately interrupt the normal functioning of your brain, impairing logic, reason, language processing, and communication.
In fact, just seeing a list of negative words for a few seconds will make a highly anxious or depressed person feel worse, and the more you ruminate on them, the more you can actually damage key structures that regulate your memory, feelings, and emotions. You’ll disrupt your sleep, your appetite, and your ability to experience long-termhappiness and satisfaction.
If you vocalize your negativity, or even slightly frown when you say “no,” more stress chemicals will be released, not only in your brain, but in the listener’s brain as well. The listener will experience increased anxiety and irritability, thus undermining cooperation and trust. In fact, just hanging around negative people will make you more prejudiced toward others!
Any form of negative rumination—for example, worrying about your financial future or health—will stimulate the release of destructive neurochemicals. And the same holds true for children: the more negative thoughts they have, the more likely they are to experience emotional turmoil. But if you teach them to think positively, you can turn their lives around.
Negative thinking is also self perpetuating, and the more you engage in negative dialogue—at home or at work—the more difficult it becomes to stop. But negative words, spoken with anger, do even more damage. They send alarm messages through the brain, interfering with the decision making centers in the frontal lobe, and this increases a person’s propensity to act irrationally.
Fear-provoking words—like poverty, illness, and death—also stimulate the brain in negative ways. And even if these fearful thoughts are not real, other parts of your brain (like the thalamus and amygdala) react to negative fantasies as though they were actual threats occurring in the outside world. Curiously, we seem to be hardwired to worry—perhaps an artifact of old memories carried over from ancestral times when there were countless threats to our survival.
In order to interrupt this natural propensity to worry, several steps can be taken. First, ask yourself this question: “Is the situation really a threat to my personal survival?” Usually it isn’t, and the faster you can interrupt the amygdala’s reaction to an imagined threat, the quicker you can take action to solve the problem. You’ll also reduce the possibility of burning a permanent negative memory into our brain.
After you have identified the negative thought (which often operates just below the level of everyday consciousness), your can reframe it by choosing to focus on positive words and images. The result: anxiety and depression decreases and the number of unconscious negative thoughts decline.
Making the association between thoughts and our brain chemistry is crucial in understanding the link between our thinking and our physical and mental health. Thinking rationally and trying to look for positives has far more benefits that many of us realise, or even really understand.