Can Just a Little Meditation Change Brain Structure?

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

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

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

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).

Join the Conversation


Twitter Search Feed: @scireltoday