Science and Religion Today » Neuroscience

Can Just a Little Meditation Change Brain Structure?

Heather Wax — Mon, 24 Jan 2011 16:22:54 +0000

According to a new study by researchers at Massachusetts General Hospital, the structure of a person’s brain can change after just eight weeks of practicing mindfulness meditation for about half an hour a day. They took brain images of people before and after they participated in a mindfulness meditation training program—learning to be aware of their feelings and sensations without judgment—and according to a write-up of the research:

The analysis of MR images, which focused on areas where meditation-associated differences were seen in earlier studies, found increased gray-matter density in the hippocampus, known to be important for learning and memory, and in structures associated with self-awareness, compassion and introspection. Participant-reported reductions in stress also were correlated with decreased gray-matter density in the amygdala, which is known to play an important role in anxiety and stress. Although no change was seen in a self-awareness-associated structure called the insula, which had been identified in earlier studies, the authors suggest that longer-term meditation practice might be needed to produce changes in that area.

What Happens in the Brain When We’re Courageous

Heather Wax — Thu, 24 Jun 2010 15:22:03 +0000

What neural mechanisms are associated with courage?
A team of researchers led by Yadin Dudai of the Weizmann Institute of Science decided to find out by looking at how people who are scared of snakes respond to them. Volunteers were put in an fMRI scanner and then told to bring a live snake as close to their head as they could. The volunteers could choose whether they brought the snake closer, step by step or—succumbing to their fear—moved it farther away.
Those who acted courageously—moving the snake closer even though they were intensely afraid of it—showed more activity in a part of the brain called the subgenual anterior cingulate cortex (sgACC) as their degree of fear went up. Volunteers who gave into their fear and moved the snake away didn’t show the same correlation; activity in the sgACC went down as fear went up. The researchers also found that activity in some temporal lobe structures decreased as the level of fear went up in people who chose to overcome it.
As the researchers explain in their paper:

Our results thus propose an account for brain processes and mechanisms supporting an intriguing aspect of human behavior, i.e., the ability to carry out a voluntary action, namely courage, opposed to an action promoted by ongoing fear. Specifically, our results delineate the importance of maintaining high sgACC activity in successful efforts to overcome ongoing fear. They hence point to the possibility of manipulating sgACC activity in therapeutic intervention in disorders involving a failure to overcome fear. Such interventions may range from training in meditation techniques that lead to greater activity in this region to transcranial magnetic stimulation (TMS) similar to that attempted to alleviate depression.

Agreeing With Others Is Rewarding

Heather Wax — Mon, 21 Jun 2010 13:45:08 +0000

According to a team of researchers, we tend to change our opinions so that they’re in line with what experts think—and by looking at the brain, they have some idea why. They found that the ventral striatum, an area of the brain linked to receiving rewards, is activated when we agree with others about the value of something. And how much we value that thing can also change based on what other people think of them.
The researchers asked volunteers to pick 20 songs they liked but didn’t own and then to rate how much they wanted the song on a scale of 1 to 10. Then, the volunteers were put in an fMRI machine and asked to decide between two songs, one that they had said they wanted and an unknown song. After they chose, they were told which of the songs two experts had preferred.
Those who picked the same song as an expert showed activity in the ventral striatum, and the activity was strongest when both experts chose the same song as the volunteer. This suggests there’s satisfaction in finding common ground with others—and it can be as satisfying as receiving more tangible rewards.
What happened when the volunteers were again asked to rate how much they wanted their 20 songs, this time after hearing the experts’ opinions? While a quarter of them lowered their rating of a song if the experts liked it, the majority raised the rating of songs the experts preferred—and for this group, getting the songs the experts liked produced more activity in the ventral striatum than getting the other songs did.
As Chris Frith, who worked on the study, notes in a write-up:

It seems that not only are some people more influenced by the opinions of others, but by looking at activity in the brain, we can tell who those people are.

Empathy and Racial Identity

Heather Wax — Wed, 28 Apr 2010 15:09:10 +0000

Does how much empathy we feel for other people depend on their race?
A team of Canadian researchers recently decided to look at how our brains respond to racial differences and found that white men show less activity in the motor-cortex area of their brains when they watch men of other races (blacks, South Asians, and East Asians) sip a glass of water than when they watch white men do the same.
Typically, certain cells in the brain, called “mirror neurons,” are activated not only when we perform a certain action, but also when we watch another person perform that same action. Researchers believe that this ability to mentally mimic the actions of others is how we understand their intentions and emotions—and ultimately empathize with them. But it appears we’re less likely to mimic the actions of someone of another race than someone who shares our racial background. In some cases, when the white men watched nonwhite men perform the drinking action, they showed as little activity in their motor cortex as when they watched a blank screen.
Michael Inzlicht, a psychologist at the University of Toronto Scarborough who worked on the study, says he doesn’t expect the results to be different with men of other races since past studies that looked at people’s brains while they watched another person express an emotion found:

When that someone else belonged to a different group, they didn’t simulate those emotions and that was true if you were white and you were observing someone black or if you were South Asian and you were observing someone East Asian (Canwest News Service).

But could there be a difference in the degree of racial bias? In another new study, researchers at Northwestern University used functional magnetic resonance imaging to look at the brains of people viewing images of both black and white people in the middle of a natural disaster (like Hurricane Katrina) or at an outdoor picnic. They found something really fascinating: Blacks showed greater empathy for other black people in pain than white people did for other whites. (The researchers had expected either both groups or neither to show a strong in-group bias.) Perhaps less surprisingly, the more a black person identified with his race, the more likely he was to show greater empathy for his fellow blacks. Maybe blacks associate with their race more than whites do? It’s interesting to speculate.
The researchers conclude that how much we’re able to feel the pain of others and how much we’re willing to help them depends on how similar we are to them and how much we identify with them. As psychologist Joan Chiao, who worked on the study, explains:

We found that everybody reported empathy and showed increased neural response within brain regions associated with empathy toward the Hurricane Katrina victims. But African-Americans additionally showed greater empathic response to other African-Americans in emotional pain. And this enhanced or extraordinary empathy and altruistic motivation for in-group members was associated with increased neural activity within a brain region called the medial prefrontal cortex (Northwestern University).

Neuroscientist Pledge

Heather Wax — Thu, 11 Feb 2010 17:28:58 +0000

Neuroscientist Curtis Bell is calling on his fellow brain scientists to sign a pledge in which they promise not to participate in applying neuroscience to violate basic human rights and international law:

The pledge gives neuroscience the opportunity to join with other professions in moving away from militarism and violence toward a culture of peace and respect for human life. Professionals and their organizations have a special responsibility in this regard, because they are members of a respected elite with knowledge and influence.
Our goal as neuroscientists and human beings should be to create a culture that encourages applications that enhance human life while discouraging those that damage it. If you are a neuroscientist and you agree, sign the pledge.

Whether neuroscientists choose to take this specific pledge or not, the National Core for Neuroethics at the University of British Columbia hopes the document will start a conversation about the neuroethics of war.

Sam Harris v. Raymond Tallis on Neurotheology

Heather Wax — Thu, 28 Jan 2010 14:58:16 +0000

In his latest piece in the New Humanist, Raymond Tallis criticizes the way neuroscience is being used to reduce religious thought to brain function, calling out a recent study on the neural correlates of religious and nonreligious belief by Sam Harris:

The subjects were scanned as they evaluated the truth and falsity of religious propositions such as “The Biblical God really exists” and nonreligious propositions such as “Santa Claus is a myth.” In both believers and nonbelievers, and in both categories of stimuli, belief was associated with a greater signal in the ventromedial cortex. … However, religious thinking was more strongly associated with brain regions that govern … emotion, self-representation, and cognitive conflict. Thinking about ordinary facts, by contrast, is more reliant on memory retrieval networks.
According to Harris , this study “furthers our understanding of how the brain accepts statements of all kinds to be valid descriptions of the world”. … It confirms what the anthropologist Pascal Boyer has asserted, namely that religious thoughts and behavior survive because they are byproducts of ordinary brain function. It is not because they have relaxed their standards of rationality that people accept implausible religious doctrines but simply because this doctrine fits their “inference machinery.” Religion is a spin-off of a more general trait to draw inferences beyond what experience tells us and to seek a coherent explanation of what is around us.

Harris has responded, telling Tallis he has got the conclusion wrong:

For instance, we do not think our results confirm that the brain has a “God spot,” or that religion has been selected for by evolution. On the contrary, our data lends some support to the idea that belief is belief is belief. After all, we found that the difference between belief and disbelief, in both religious and nonreligious subjects, was essentially the same, regardless of what was thought about. Bizarrely, Tallis considers this finding of belief’s content-independence to be a terrible defect: “since they are unable to show a profound difference between religious beliefs and nonreligious beliefs, they tell us nothing about the former.” Unless, of course, no “profound difference” exists.

Your Frontal Lobes Don’t Think You’re So Great

Heather Wax — Thu, 14 Jan 2010 15:57:22 +0000

People who think they have better personalities than their peers use their brain’s orbitofrontal cortex less than other people, according to new research from Jennifer Beer, a psychologist at the University of Texas at Austin, that shows how brain activity is linked to self-perception. The orbitofrontal cortex is a part of the frontal lobe that is associated with reasoning, decision making, and problem solving.
According to the findings, some people who viewed themselves in an extremely positive light showed four times less activity in their frontal lobes than did others who had an accurate view of themselves. Beer also found that people tend to think their abilities are above average when they’re asked to evaluate themselves quickly, suggesting that having more time in which we can engage our frontal lobes lets us more deliberately process information and come to more accurate judgments.

Predicting Thoughts With Fairly Good Accuracy

Heather Wax — Thu, 23 Jul 2009 18:24:14 +0000

This week, the Proceedings of the National Academy of Sciences published a new paper by a couple of Harvard University psychologists, Joshua Greene and Joe Paxton, who looked at what happens in our brains when we decide to be dishonest. Among other cool things, they discovered that they could use the brain scans to predict how often certain people in their experiment would lie , with about 80 percent accuracy.
There’s another interesting brain-scanning experiment from a team of researchers at Rutgers University and UCLA. They scanned the brains of volunteers doing eight simple mental tasks, such as reading aloud or counting sounds. Then they looked at the scans and tried to figure out the different brain patterns associated with each task. If people’s brains work similarly, the researchers should be able to look for these patterns in another person’s brain scan and tell which task that person was doing.
The finding? As Russ Poldrack, a psychologist at UCLA who worked on the study, explains:

It turns out that we can predict quite well which of these eight tasks they are doing. If we were just guessing, we would get it right about 13 percent of the time. We get it right about 80 percent of the time with our statistical tool. It’s not perfect, but it is quite good—but not nearly good enough to be admissible in court, for example.
Our study suggests that the kinds of things that some people have talked about in terms of mind reading are probably still pretty far off. If we are only 80 percent accurate with eight very different thoughts and we want to figure out what you’re thinking out of millions of possible thoughts, we’re still very far away from achieving that.

What You Can Tell About a Face in 0.1 Seconds

Heather Wax — Wed, 17 Jun 2009 15:06:00 +0000

A team of Spanish and Brazilian researchers has looked at how well—and how quickly—we can recognize the facial expressions of others. Correctly recognizing the emotions behind these expressions is important because they act as signals, and we make judgments and deductions about other people based on what we see. “These inferences can strongly influence election results or the sentences given in trials, and have been studied before in fields such as criminology and the pseudoscience of physiognomy, ” explains University of Barcelona psychologist Jose Antonio Aznar Casanova, who worked on the study.
When the researchers gave a group of psychology students 0.1 seconds to look at a face, they found that they could detect happiness better and faster than sadness. “Positive expressions, or expressions of approach, are perceived more quickly and more precisely than negative, or withdrawal, ones,” Aznar Casanova says. “So happiness and surprise are processed faster than sadness and fear.”

We See More When We’re in a Good Mood

Heather Wax — Mon, 08 Jun 2009 15:53:00 +0000

Our mood really changes the way we see the world, according to a new study from a team at the University of Toronto. “Good and bad moods literally change the way our visual cortex operates,” explains Adam Anderson, a psychologist who worked on the research. When we’re in a good mood, “our visual cortex takes in more information,” he says, “while negative moods result in tunnel vision.”
The researchers showed volunteers a composite image (pictured here) that had a face in the center and a house in the background, and they focused the volunteers’ attention on the face by asking them to identify the gender. Participants who were primed to be in a bad mood did fine on that task, but didn’t process the surrounding image of the house. Those who were in a good mood took in more information and processed more of the picture—both the face and the background.
As Taylor Schmitz, a U of T graduate students and the study’s lead author, notes:

Good moods enhance the literal size of the window through which we see the world. The upside of this is that we can see things from a more global, or integrative perspective. The downside is that this can lead to distraction on critical tasks that require narrow focus, such as operating dangerous machinery or airport screening of passenger baggage. Bad moods, on the other hand, may keep us more narrowly focused, preventing us from integrating information outside of our direct attentional focus.

The study appears in The Journal of Neuroscience. —Heather Wax