Featured Research

from universities, journals, and other organizations

Stress, anxiety both boon and bane to brain

Date:
January 21, 2011
Source:
University of Wisconsin-Madison
Summary:
The sensitivity to your surroundings felt in the presence of a threat can interfere with the ability to do more complex thinking, according to a new study.

A cold dose of fear lends an edge to the here-and-now -- say, when things go bump in the night.

"That edge sounds good. It sounds adaptive. It sounds like perception is enhanced and that it can keep you safe in the face of danger," says Alexander Shackman, a researcher at the University of Wisconsin-Madison.

But it sounds like there's also a catch, one that Shackman and his coauthors -- including Richard Davidson, UW-Madison psychology and psychiatry professor -- described in the Jan. 19 Journal of Neuroscience.

"It makes us more sensitive to our external surroundings as a way of learning where or what a threat may be, but interferes with our ability to do more complex thinking," Davidson says.

Faced with the possibility of receiving an unpleasant electric shock, the study's subjects showed enhanced activity in brain circuits responsible for taking in visual information, but a muted signal in circuitry responsible for evaluating that information. Remove the threat of shock (and thus the stress and anxiety) and the effect is reversed: less power for vigilance, more power for strategic decision-making.

The shift in electrical activity in the brain, captured by a dense mesh of sensors placed on the scalp, may be the first biological description of a paradox in experimental psychology.

It has long been known that imminent danger can enhance the ability to detect faint stimuli in the environment, such as the crackle of a leaf signaling the approach of a predator. But it is equally clear that the stress and anxiety aroused by a threat can profoundly disrupt the ability to think clearly and perform more complex "executive" tasks.

"In the last few years, theorists have hypothesized that this paradox might reflect several systems working in conjunction: one responsible for the rapid detection of external stimuli, the other responsible for the slower, more reflective evaluation of that incoming information," Shackman says. "Stress upsets the balance of those systems."

In fact, as the senses go into overdrive, they are probably confounding the rest of the brain all the more.

"Your ability to do more complex tasks is disrupted just as the amount of information you're receiving through your eyes and ears is enhanced," Shackman says. "You're having trouble focusing on the information coming in, but your brain is taking in more and more potentially irrelevant information. You can have a viscous feedback loop, a sort of double-whammy effect."

The resulting confusion favors quick, reflexive actions, the "survival instincts" often mentioned by trauma survivors -- Noise? RUN! -- in a way that was likely adaptive in the dangerous environments in which the ancestors to modern humans evolved.

"In our evolutionary past, the dangers we faced were really survival-threatening," Davidson says. "That's not so much the case now. Because of the nature of our brains, we can use our neural capacity to create our own internal danger. We can worry about the future and ruminate about the past."

Either one is likely to present a real hurdle to effective decision-making under stress.

"This is part of a growing body of evidence showing that stress does have important consequences for the brain, not just something that arouses the body -- tension in your muscles or butterflies in the stomach," says Davidson, who studies the effects of meditation as director of UW-Madison's Center for Investigating Healthy minds.

"One of the things we would expect is that if we use an antidote like systematic meditation training to learn to control stress it would not just calm the body, but improve our ability to engage in complex analytical activity," he says.

Jeffrey S. Maxwell of the U.S. Army Research Laboratory joined Shackman as lead author of the study, which was funded by the Department of Defense, National Institutes for Health and National Science Foundation.


Story Source:

The above story is based on materials provided by University of Wisconsin-Madison. The original article was written by Chris Barncard. Note: Materials may be edited for content and length.


Journal Reference:

  1. A. J. Shackman, J. S. Maxwell, B. W. McMenamin, L. L. Greischar, R. J. Davidson. Stress Potentiates Early and Attenuates Late Stages of Visual Processing. Journal of Neuroscience, 2011; 31 (3): 1156 DOI: 10.1523/JNEUROSCI.3384-10.2011

Cite This Page:

University of Wisconsin-Madison. "Stress, anxiety both boon and bane to brain." ScienceDaily. ScienceDaily, 21 January 2011. <www.sciencedaily.com/releases/2011/01/110119102750.htm>.
University of Wisconsin-Madison. (2011, January 21). Stress, anxiety both boon and bane to brain. ScienceDaily. Retrieved April 18, 2014 from www.sciencedaily.com/releases/2011/01/110119102750.htm
University of Wisconsin-Madison. "Stress, anxiety both boon and bane to brain." ScienceDaily. www.sciencedaily.com/releases/2011/01/110119102750.htm (accessed April 18, 2014).

Share This



More Mind & Brain News

Friday, April 18, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

Study On Artists' Brain Shows They're 'Structurally Unique'

Study On Artists' Brain Shows They're 'Structurally Unique'

Newsy (Apr. 17, 2014) The brains of artists aren't really left-brain or right-brain, but rather have extra neural matter in visual and motor control areas. Video provided by Newsy
Powered by NewsLook.com
Is Apathy A Sign Of A Shrinking Brain?

Is Apathy A Sign Of A Shrinking Brain?

Newsy (Apr. 17, 2014) A recent study links apathetic feelings to a smaller brain. Researchers say the results indicate a need for apathy screening for at-risk seniors. Video provided by Newsy
Powered by NewsLook.com
Are School Dress Codes Too Strict?

Are School Dress Codes Too Strict?

AP (Apr. 16, 2014) Pushing the limits on style and self-expression is a rite of passage for teens and even younger kids. How far should schools go with their dress codes? The courts have sided with schools in an era when school safety is paramount. (April 16) Video provided by AP
Powered by NewsLook.com
Could Even Casual Marijuana Use Alter Your Brain?

Could Even Casual Marijuana Use Alter Your Brain?

Newsy (Apr. 16, 2014) A new study conducted by researchers at Northwestern and Harvard suggests even casual marijuana use can alter your brain. Video provided by Newsy
Powered by NewsLook.com

Search ScienceDaily

Number of stories in archives: 140,361

Find with keyword(s):
Enter a keyword or phrase to search ScienceDaily for related topics and research stories.

Save/Print:
Share:

Breaking News:
from the past week

In Other News

... from NewsDaily.com

Science News

Health News

Environment News

Technology News



Save/Print:
Share:

Free Subscriptions


Get the latest science news with ScienceDaily's free email newsletters, updated daily and weekly. Or view hourly updated newsfeeds in your RSS reader:

Get Social & Mobile


Keep up to date with the latest news from ScienceDaily via social networks and mobile apps:

Have Feedback?


Tell us what you think of ScienceDaily -- we welcome both positive and negative comments. Have any problems using the site? Questions?
Mobile: iPhone Android Web
Follow: Facebook Twitter Google+
Subscribe: RSS Feeds Email Newsletters
Latest Headlines Health & Medicine Mind & Brain Space & Time Matter & Energy Computers & Math Plants & Animals Earth & Climate Fossils & Ruins