Our subconscious mind: Who's really in charge?

Who’s Minding the Mind?

By BENEDICT CAREY
From the NY Times

In a recent experiment, psychologists at Yale altered people’s judgments of a stranger by handing them a cup of coffee.

The study participants, college students, had no idea that their social instincts were being deliberately manipulated. On the way to the laboratory, they had bumped into a laboratory assistant, who was holding textbooks, a clipboard, papers and a cup of hot or iced coffee — and asked for a hand with the cup.
That was all it took: The students who held a cup of iced coffee rated a hypothetical person they later read about as being much colder, less social and more selfish than did their fellow students, who had momentarily held a cup of hot java.

Findings like this one, as improbable as they seem, have poured forth in psychological research over the last few years. New studies have found that people tidy up more thoroughly when there’s a faint tang of cleaning liquid in the air; they become more competitive if there’s a briefcase in sight, or more cooperative if they glimpse words like “dependable” and “support” — all without being aware of the change, or what prompted it.

Psychologists say that “priming” people in this way is not some form of hypnotism, or even subliminal seduction; rather, it’s a demonstration of how everyday sights, smells and sounds can selectively activate goals or motives that people already have.

More fundamentally, the new studies reveal a subconscious brain that is far more active, purposeful and independent than previously known. Goals, whether to eat, mate or devour an iced latte, are like neural software programs that can only be run one at a time, and the unconscious is perfectly capable of running the program it chooses.

The give and take between these unconscious choices and our rational, conscious aims can help explain some of the more mystifying realities of behavior, like how we can be generous one moment and petty the next, or act rudely at a dinner party when convinced we are emanating charm.

“When it comes to our behavior from moment to moment, the big question is, ‘What to do next?’ ” said John A. Bargh, a professor of psychology at Yale and a co-author, with Lawrence Williams, of the coffee study, which was presented at a recent psychology conference. “Well, we’re finding that we have these unconscious behavioral guidance systems that are continually furnishing suggestions through the day about what to do next, and the brain is considering and often acting on those, all before conscious awareness.”
Dr. Bargh added: “Sometimes those goals are in line with our conscious intentions and purposes, and sometimes they’re not.”

Priming the Unconscious

The idea of subliminal influence has a mixed reputation among scientists because of a history of advertising hype and apparent fraud. In 1957, an ad man named James Vicary claimed to have increased sales of Coca-Cola and popcorn at a movie theater in Fort Lee, N.J., by secretly flashing the words “Eat popcorn” and “Drink Coke” during the film, too quickly to be consciously noticed. But advertisers and regulators doubted his story from the beginning, and in a 1962 interview, Mr. Vicary acknowledged that he had trumped up the findings to gain attention for his business.

Later studies of products promising subliminal improvement, for things like memory and self-esteem, found no effect.

Some scientists also caution against overstating the implications of the latest research on priming unconscious goals. The new research “doesn’t prove that consciousness never does anything,” wrote Roy Baumeister, a professor of psychology at Florida State University, in an e-mail message. “It’s rather like showing you can hot-wire a car to start the ignition without keys. That’s important and potentially useful information, but it doesn’t prove that keys don’t exist or that keys are useless.”

Yet he and most in the field now agree that the evidence for psychological hot-wiring has become overwhelming. In one 2004 experiment, psychologists led by Aaron Kay, then at Stanford University and now at the University of Waterloo, had students take part in a one-on-one investment game with another, unseen player.

Half the students played while sitting at a large table, at the other end of which was a briefcase and a black leather portfolio. These students were far stingier with their money than the others, who played in an identical room, but with a backpack on the table instead.

The mere presence of the briefcase, noticed but not consciously registered, generated business-related associations and expectations, the authors argue, leading the brain to run the most appropriate goal program: compete. The students had no sense of whether they had acted selfishly or generously.
In another experiment, published in 2005, Dutch psychologists had undergraduates sit in a cubicle and fill out a questionnaire. Hidden in the room was a bucket of water with a splash of citrus-scented cleaning fluid, giving off a faint odor. After completing the questionnaire, the young men and women had a snack, a crumbly biscuit provided by laboratory staff members.

The researchers covertly filmed the snack time and found that these students cleared away crumbs three times more often than a comparison group, who had taken the same questionnaire in a room with no cleaning scent. “That is a very big effect, and they really had no idea they were doing it,” said Henk Aarts, a psychologist at Utrecht University and the senior author of the study.

The Same Brain Circuits

The real-world evidence for these unconscious effects is clear to anyone who has ever run out to the car to avoid the rain and ended up driving too fast, or rushed off to pick up dry cleaning and returned with wine and cigarettes — but no pressed slacks.

The brain appears to use the very same neural circuits to execute an unconscious act as it does a conscious one. In a study that appeared in the journal Science in May, a team of English and French neuroscientists performed brain imaging on 18 men and women who were playing a computer game for money. The players held a handgrip and were told that the tighter they squeezed when an image of money flashed on the screen, the more of the loot they could keep.

As expected, the players squeezed harder when the image of a British pound flashed by than when the image of a penny did — regardless of whether they consciously perceived the pictures, many of which flew by subliminally. But the circuits activated in their brains were similar as well: an area called the ventral pallidum was particularly active whenever the participants responded.

“This area is located in what used to be called the reptilian brain, well below the conscious areas of the brain,” said the study’s senior author, Chris Frith, a professor in neuropsychology at University College London who wrote the book “Making Up The Mind: How the Brain Creates our Mental World.”

The results suggest a “bottom-up” decision-making process, in which the ventral pallidum is part of a circuit that first weighs the reward and decides, then interacts with the higher-level, conscious regions later, if at all, Dr. Frith said.

Scientists have spent years trying to pinpoint the exact neural regions that support conscious awareness, so far in vain. But there’s little doubt it involves the prefrontal cortex, the thin outer layer of brain tissue behind the forehead, and experiments like this one show that it can be one of the last neural areas to know when a decision is made.

This bottom-up order makes sense from an evolutionary perspective. The subcortical areas of the brain evolved first and would have had to help individuals fight, flee and scavenge well before conscious, distinctly human layers were added later in evolutionary history. In this sense, Dr. Bargh argues, unconscious goals can be seen as open-ended, adaptive agents acting on behalf of the broad, genetically encoded aims — automatic survival systems.

In several studies, researchers have also shown that, once covertly activated, an unconscious goal persists with the same determination that is evident in our conscious pursuits. Study participants primed to be cooperative are assiduous in their teamwork, for instance, helping others and sharing resources in games that last 20 minutes or longer. Ditto for those set up to be aggressive.

This may help explain how someone can show up at a party in good spirits and then for some unknown reason — the host’s loafers? the family portrait on the wall? some political comment? — turn a little sour, without realizing the change until later, when a friend remarks on it. “I was rude? Really? When?”

Mark Schaller, a psychologist at the University of British Columbia, in Vancouver, has done research showing that when self-protective instincts are primed — simply by turning down the lights in a room, for instance — white people who are normally tolerant become unconsciously more likely to detect hostility in the faces of black men with neutral expressions.

“Sometimes nonconscious effects can be bigger in sheer magnitude than conscious ones,” Dr. Schaller said, “because we can’t moderate stuff we don’t have conscious access to, and the goal stays active.”

Until it is satisfied, that is, when the program is subsequently suppressed, research suggests. In one 2006 study, for instance, researchers had Northwestern University undergraduates recall an unethical deed from their past, like betraying a friend, or a virtuous one, like returning lost property. Afterward, the students had their choice of a gift, an antiseptic wipe or a pencil; and those who had recalled bad behavior were twice as likely as the others to take the wipe. They had been primed to psychologically “cleanse” their consciences.

Once their hands were wiped, the students became less likely to agree to volunteer their time to help with a graduate school project. Their hands were clean: the unconscious goal had been satisfied and now was being suppressed, the findings suggest.

What You Don’t Know

Using subtle cues for self-improvement is something like trying to tickle yourself, Dr. Bargh said: priming doesn’t work if you’re aware of it. Manipulating others, while possible, is dicey. “We know that as soon as people feel they’re being manipulated, they do the opposite; it backfires,” he said.
And researchers do not yet know how or when, exactly, unconscious drives may suddenly become conscious; or under which circumstances people are able to override hidden urges by force of will. Millions have quit smoking, for instance, and uncounted numbers have resisted darker urges to misbehave that they don’t even fully understand.

Yet the new research on priming makes it clear that we are not alone in our own consciousness. We have company, an invisible partner who has strong reactions about the world that don’t always agree with our own, but whose instincts, these studies clearly show, are at least as likely to be helpful, and attentive to others, as they are to be disruptive.

Exercise and the Mind

Lobes of Steel
By GRETCHEN REYNOLDS
August 19, 2007

The Morris water maze is the rodent equivalent of an I.Q. test: mice are placed in a tank filled with water dyed an opaque color. Beneath a small area of the surface is a platform, which the mice can’t see. Despite what you’ve heard about rodents and sinking ships, mice hate water; those that blunder upon the platform climb onto it immediately. Scientists have long agreed that a mouse’s spatial memory can be inferred by how quickly the animal finds its way in subsequent dunkings. A “smart” mouse remembers the platform and swims right to it.

In the late 1990s, one group of mice at the Salk Institute for Biological Studies, near San Diego, blew away the others in the Morris maze. The difference between the smart mice and those that floundered? Exercise. The brainy mice had running wheels in their cages, and the others didn’t.
Scientists have suspected for decades that exercise, particularly regular aerobic exercise, can affect the brain. But they could only speculate as to how. Now an expanding body of research shows that exercise can improve the performance of the brain by boosting memory and cognitive processing speed. Exercise can, in fact, create a stronger, faster brain.

This theory emerged from those mouse studies at the Salk Institute. After conducting maze tests, the neuroscientist Fred H. Gage and his colleagues examined brain samples from the mice. Conventional wisdom had long held that animal (and human) brains weren’t malleable: after a brief window early in life, the brain could no longer grow or renew itself. The supply of neurons — the brain cells that enable us to think — was believed to be fixed almost from birth. As the cells died through aging, mental function declined. The damage couldn’t be staved off or repaired.

Gage’s mice proved otherwise. Before being euthanized, the animals had been injected with a chemical compound that incorporates itself into actively dividing cells. During autopsy, those cells could be identified by using a dye. Gage and his team presumed they wouldn’t find such cells in the mice’s brain tissue, but to their astonishment, they did. Up until the point of death, the mice were creating fresh neurons. Their brains were regenerating themselves.
All of the mice showed this vivid proof of what’s known as “neurogenesis,” or the creation of new neurons. But the brains of the athletic mice in particular showed many more. These mice, the ones that scampered on running wheels, were producing two to three times as many new neurons as the mice that didn’t exercise.

But did neurogenesis also happen in the human brain? To find out, Gage and his colleagues had obtained brain tissue from deceased cancer patients who had donated their bodies to research. While still living, these people were injected with the same type of compound used on Gage’s mice. (Pathologists were hoping to learn more about how quickly the patients’ tumor cells were growing.) When Gage dyed their brain samples, he again saw new neurons. Like the mice, the humans showed evidence of neurogenesis.

Gage’s discovery hit the world of neurological research like a thunderclap. Since then, scientists have been finding more evidence that the human brain is not only capable of renewing itself but that exercise speeds the process.
“We’ve always known that our brains control our behavior,” Gage says, “but not that our behavior could control and change the structure of our brains.”
The human brain is extremely difficult to study, especially when a person is still alive. Without euthanizing their subjects, the closest that researchers can get to seeing what goes on in there is through a functional M.R.I. machine, which measures the size and shape of the brain and, unlike a standard M.R.I. machine, tracks blood flow and electrical activity.

This spring, neuroscientists at Columbia University in New York City published a study in which a group of men and women, ranging in age from 21 to 45, began working out for one hour four times a week. After 12 weeks, the test subjects, predictably, became more fit. Their VO2 max, the standard measure of how much oxygen a person takes in while exercising, rose significantly.
But something else happened as a result of all those workouts: blood flowed at a much higher volume to a part of the brain responsible for neurogenesis. Functional M.R.I.’s showed that a portion of each person’s hippocampus received almost twice the blood volume as it did before. Scientists suspect that the blood pumping into that part of the brain was helping to produce fresh neurons.

The hippocampus plays a large role in how mammals create and process memories; it also plays a role in cognition. If your hippocampus is damaged, you most likely have trouble learning facts and forming new memories. Age plays a factor, too. As you get older, your brain gets smaller, and one of the areas most prone to this shrinkage is the hippocampus. (This can start depressingly early, in your 30’s.) Many neurologists believe that the loss of neurons in the hippocampus may be a primary cause of the cognitive decay associated with aging. A number of studies have shown that people with Alzheimer’s and other forms of dementia tend to have smaller-than-normal hippocampi.

The Columbia study suggests that shrinkage to parts of the hippocampus can be slowed via exercise. The subjects showed significant improvements in memory, as measured by a word-recall test. Those with the biggest increases in VO2 max had the best scores of all.

“It’s reasonable to infer, though we’re not yet certain, that neurogenesis was happening in the people’s hippocampi,” says Scott A. Small, an associate professor of neurology at Columbia and the senior author of the study, “and that working out was driving the neurogenesis.”

Other recent studies support this theory. At the University of Illinois at Urbana- Champaign, a group of elderly sedentary people were assigned to either an aerobic exercise program or a regimen of stretching. (The aerobic group walked for at least one hour three times a week.) After six months, their brains were scanned using an M.R.I. Those who had been doing aerobic exercise showed significant growth in several areas of the brain. These results raise the hope that the human brain has the capacity not only to produce new cells but also to add new blood vessels and strengthen neural connections, allowing young neurons to integrate themselves into the wider neural network. “The current findings are the first, to our knowledge, to confirm the benefits of exercise training on brain volume in aging humans,” the authors concluded.

And the benefits aren’t limited to adults. Other University of Illinois scientists have studied school-age children and found that those who have a higher level of aerobic fitness processed information more efficiently; they were quicker on a battery of computerized flashcard tests. The researchers also found that higher levels of aerobic fitness corresponded to better standardized test scores among a set of Illinois public school students. The scientists next plan to study how students’ scores change as their fitness improves.

What is it about exercise that prompts the brain to remake itself? Different scientists have pet theories. One popular hypothesis credits insulin-like growth factor 1, a protein that circulates in the blood and is produced in greater amounts in response to exercise. IGF-1 has trouble entering the brain — it stops at what’s called the “blood-brain barrier” — but exercise is thought to help it to do so, possibly sparking neurogenesis.

Other researchers are looking at the role of serotonin, a hormone that influences mood. Exercise speeds the brain’s production of serotonin, which could, in turn, prompt new neurons to grow. Abnormally low levels of serotonin have been associated with clinical depression, as has a strikingly shrunken hippocampus. Many antidepressant medications, like Prozac, increase the effectiveness of serotonin. Interestingly, these drugs take three to four weeks to begin working — about the same time required for new neurons to form and mature. Part of the reason these drugs are effective, then, could be that they’re increasing neurogenesis. “Just as exercise does,”Gage says.

Gage, by the way, exercises just about every day, as do most colleagues in his field. Scott Small at Columbia, for instance , likes nothing better than a strenuous game of tennis. “As a neurologist,” he explains, “I constantly get asked at cocktail parties what someone can do to protect their mental functioning. I tell them, ‘Put down that glass and go for a run.’ ” .


This Is Your Brain on Something Other Than Exercise
The human brain undergoes neurogenesis — the creation of new cells — throughout a person’s life, although the amount depends on a variety of factors, not just exercise.

MARIJUANA: We just report the data; we don’t endorse it. A 2005 study on rats found that stimulation of the brain’s receptors for marijuana increased neurogenesis.

ALCOHOL: A 2005 study found that mice that swallowed a moderate amount of ethanol showed more neurogenesis than teetotalers. Other studies on mice have suggested that heavier drinking can be damaging to the brain.

SOCIABILITY: One study suggests that rats that live alone and have access to a run ning wheel experience less neurogenesis than those that have access to a running wheel and live in group housing. So go ahead and join that singles running club you’ve been avoiding.

DIET: A diet high in saturated fat and sugar sharply diminishes the brain’s production of the proteins and nerve-growth factors necessary for neurogenesis. Exercise may mitigate that effect somewhat.

STRESS: Mice that are subjected to uncontrollable stress (like electric shock) suffer substantial deterioration in their ability to produce new neurons.

CHOCOLATE: In a study published this year, an ingredient in cocoa,
epicatechin, was shown to improve spatial memory in mice, especially among those that exercised. Epicatechin can also be found in grapes, blueberries and black tea. “I plan to start ingesting more epicatechin,” says Henriette van Praag, a neuroscientist at the Salk Institute, “as soon as I can’t find my car keys anymore.” G.R.