The beautiful life of your brain

At this very moment, the twin Voyager spacecrafts, launched in 1977, are carrying precious cargo on their journey beyond the solar system: among other things, a Mozart aria, greetings in 55 languages and the brainwaves of a young woman newly in love.

Astronomer Carl Sagan led the Golden Record project, intended to introduce the people of Earth to any beings the spacecrafts might encounter. As part of the contents, Sagan’s teammate Ann Druyan had her brainwaves measured with an EEG test, which was then compressed into one minute of sound. Two days before, Sagan and Druyan had realised they were in love—an overwhelming sensation flooding Druyan’s mind during the EEG. Today, 18 years after Druyan became Sagan’s widow, that song of a brain in love (it sounds like exploding fireworks) is still soaring into the vastness of space.

To distill the essence of the human race, Sagan and his team chose to reveal a hint of our brain’s inner workings. To many scientists, the answer to the question of what makes us human lies in the mystery of our brain. “On a physical level, there’s just a bunch of atoms sloshing around,” says Christof Koch, scientific officer of the Allen Institute for Brain Science in Seattle. “But there’s a magical jump where this activity turns into feelings of anger or the memory of your first kiss.”

Advances in technology, such as fMRI scanning, allow us to see how regions of the brain function. Experts hope new research efforts will advance the fight against autism, Alzheimer’s and depression, as well as shed light on questions about how we fall in love or make a tough decision, says Dr Thomas Insel, director of the National Institute of Mental Health.

“To understand the brain is the ultimate journey to find out who we are.”

This organ has been evolving for millions of years through a process similar to adding ice-cream scoops to a cone, says David Linden, a Johns Hopkins University neuroscientist. “Lower parts like the cerebellum and hypothalamus, which handle survival-oriented behaviour such as sex drive and eating, haven’t evolved as much, so what a lizard has and what we have aren’t that different,” he says, describing the first evolutionary scoop. “Higher centres involved in emotional processing, such as the hippocampus and amygdala, are a lot more elaborate in mice than in lizards,” he says of the second scoop. “Then as you move further up, humans have a giant, complex cortex,” he says of the top scoop. This is home to our uniquely human thoughts and language.

Here’s another way to look at how our brains evolved. “Say someone asked you to build a racing boat, but they gave you a wooden rowboat and said you could only add things to make it into the racing boat,” says Linden. “That’s evolution: you can only subtly tweak what was there before and can’t change the basic plan.” The interaction between these older and newer brain regions makes us who we are today.

“Both people and mice can feel pleasure from eating and making babies, which both need to survive and pass down their genes. But only a human can take pleasure in fasting or abstaining from sex, which has no evolutionary advantage. The miracle of human thinking is that our ancient pleasure circuitry can be activated by higher, more complicated parts of our brain,” Linden explains.

“That we can take pleasure from things that are utterly arbitrary is what enriches so much of our lives.”

Human evolution is a glacial process, but we can directly affect our personal “evolution” in our lifetime. “There’s a well-known saying, ‘Neurons that fire together, wire together’,” says neuropsychologist Rick Hanson, meaning that repeated patterns of thoughts and feelings change our brain structure. Here’s how our brain operates during seven situations; we can use these insights to flex our mental muscle.

Think back to your last performance review. “Your boss starts by saying 19 positive things,” says Hanson. “But if there’s one piece of criticism at the end, that’s what you remember. What sticks is the negative 20th.”
 

That overreaction—called negativity bias in psychology circles—helped keep ancient humans alive.

“Ancestors had to ‘get carrots’, meaning food and mates, and ‘avoid sticks’, such as predators,” Hanson explains. “If you don’t get a carrot today, you’ll have another chance tomorrow. But if you fail to avoid a predator? Game over! Our brains became wired to focus on bad news. It’s like Velcro for bad experiences but Teflon for good ones.”

Fortunately, simple practices can help counteract this bias. “Negativity quickly becomes neural structure,” he says. “But positive experiences can take more time to encode. Intentionally feeling positive experiences longer helps them sink in, which can help you become happier and more resilient.” Savour receiving a compliment. Be mindful during happy moments; note details so they’re easier to remember.

When you put off a pressing project, you avoid negative emotions caused by an unpleasant task because you want to feel good now. But all you’re doing is giving the problem to your future self. “So the question neurologically becomes, ‘Why do we treat Future Self like that?’” says Timothy Pychyl, an associate professor of psychology at Carleton University in Ottawa, Canada. One study used fMRI to see what parts of the brain were active when subjects thought about their present selves and their future selves, and found that the brain thinks about the future self more similarly to the way it thinks about a stranger.
 

Procrastination is also the struggle between two different brain systems.

The limbic system, responsible for our basic emotions, is an old part of our brain (in the second scoop). It’s a fast automated system that responds nonconsciously. It wants to feel good now. Then there’s the newer prefrontal cortex (the third scoop), home of executive function, which involves planning and impulse control. It’s a slower process you have to kick consciously into gear.

When you contemplate doing your taxes, the limbic system first activates with its urgent goal of feeling better now, accomplished by avoiding this dreaded task. Lagging behind is the more responsible prefrontal cortex, which you need to engage to think about the benefits of completing your tax return on time.

The luckiest among us relate to not only the romantic love Ann Druyan experienced when she first fell for Carl Sagan, but also the long-lasting bond that linked the couple until Sagan’s death 19 years later. Those two distinct types of love arise from different brain regions, says Helen Fisher, a member of the Centre for Human Evolutionary Studies at Rutgers University.

“Love originates in the ventral tegmental area in the oldest part of the brain near centres that govern thirst and hunger”

Fisher explains, “It’s a basic drive that focuses our energy on winning a mating partner.”

A primary brain region linked with attachment, however, is the ventral pallidum, which is more modern (in the third scoop). “Intense, romantic attraction is a more primitive response than feelings of attachment, which are more recent,” she says. This circuitry is linked to lifelong love.

“People in love long-term show activity in the ventral medial prefrontal cortex, which is linked with ‘positive illusion’—the ability to overlook cons,” Fisher says. “People in long-lasting relationships say things like, ‘It annoys me when he doesn’t pick up his socks, but I love his sense of humour’. ”

This mindset is a huge factor in making relationships last, as it helps to nurture loving feelings long after the honeymoon period has ended.

When another driver cuts you up on the road, you assume that person is an idiot, and that makes you angry.

Our brains were built to overreact to a perceived threat.
 

“The same neuronal machinery that protected our ancestors from charging lions is primed when we encounter stresses such as traffic,” says neuropsychologist Rick Hanson. Your body releases the hormone cortisol; this sets off the brain’s alarm by stimulating the emotionally charged amygdala while damaging neurons in the hippocampus, which shrinks the calming part of the brain.

To bring this stress response under control, we can use our newer brain regions, like the prefrontal cortex, to regulate our older ones. When you feel angry behind the wheel, forcing yourself to refocus—say, by thinking, I’ll be only 15 minutes late—may help.

A participant came to a dream study with a dilemma. He couldn’t decide between two graduate programmes near his Massachusetts home and two further west. Then he dreamed he was in a plane flying over a map. The pilot said they were having engine trouble and needed to land. The student suggested Massachusetts, but the pilot said Massachusetts was “very dangerous”. The student woke up realising the right choice was away from home.

By conducting such studies, Deirdre Barrett, assistant clinical professor of psychology at Harvard University, has been exploring the workings of the brain’s sleep circuitry.

After you conk out your brain becomes quiet, but after 90 minutes it reactivates with rapid eye movement (REM) sleep, becoming as active as when you’re awake.

But that activity comes from a different distribution of regions.

While the primary visual cortex, which receives light input from your eyes, is less active while you’re sleeping, the secondary visual cortex, which is involved when you imagine something, is most active during REM sleep. The motor cortex turns on, firing off movement commands that are countered by another area that paralyses muscles during sleep. Also, the “censoring” prefrontal cortex, which helps ensure you behave in conventional ways, becomes less active while you snooze.

Not only does this distribution of activity match the features of dreams—rich environments where events take bizarre twists—but it also makes dreams fertile ground for solving the problems of your waking life.

To maximise dreaming’s problem-solving benefits, Barrett suggests that at bedtime, you phrase your concern in a succinct way by writing it or repeating it to yourself. Then come up with a visual image representing the issue, and tell yourself you want to dream an answer. And write it down as soon as you wake up. “This transfers them to long-term memory,” says Barrett.

Imagine you’re in line for coffee and a catchy song comes on the radio. The resulting cascade of mental activity it takes to process the music “touches on all the most advanced aspects of human cognition”, says Robert Zatorre, professor of neuroscience at the Montreal Neurological Institute and Hospital at McGill University.

First, the sound hits your ear, activating a series of structures from the cochlea (where vibrations are turned into electrical impulses) to the brain’s cortex. When you recognise the tune—its name or where you last heard it—your auditory cortex is connecting with regions that handle memory retrieval. Then, if you start tapping your foot, you’ve activated the motor cortex in a particular way because you’re tapping to the exact beat of the song.
 

If it has you feeling happy, the song has turned on your brain’s reward system—ancient, powerful circuitry triggered by essentials for survival such as eating and sex.
 

Why does music engage that life-promoting system? Scientists are still trying to work that out, but what happens to your brain may provide a clue. “Music increases cross talk between brain structures in old reward centres that handle pleasure and newer areas of the cortex that handle prediction and anticipation,” says Zatorre. In one study, he found that the brain released dopamine, a chemical linked to pleasure, in anticipation of a subject’s favourite part of the song. So it may be that music fuels your brain’s desire to detect patterns and solve problems.

Meditation may be a powerful way to build our brains. The practice can grow brain tissue, improving our moods and making us more resilient.

“It engages the entire brain,” says Hanson, accessing sensory and emotional experiences, wants and drives, and ancient substrates of consciousness.

“Meditation seems to engage the most modern parts of the brain as well as the most ancient ones.”

One study showed that eight weeks of mindfulness meditation boosted grey-matter density in several regions, including the hippocampus (learning and memory), and decreased grey-matter density in the amygdala (which plays a role in generating the feeling of stress).

“Sitting down, focusing on breathing and relaxing every day is actually going to build brain structure?” Says Hanson: “That’s pretty cool!”

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