Featured Research

from universities, journals, and other organizations

Trouble coping with the unfamiliar as you age? Blame your white matter

Date:
April 11, 2012
Source:
Vanderbilt University
Summary:
A brain-mapping study has found that people's ability to make decisions in novel situations decreases with age and is associated with a reduction in the integrity of two specific white-matter pathways.

Brain scans showing the white-matter pathways involved in everyday learning: Top, the pathway shown in red connects the medial prefrontal cortex to the ventral striatum and, bottom, the pathway shown in blue connects the medial prefrontal cortex to the thalamus.
Credit: Gregory Samanez-Larkin

If you are an aging baby boomer and you've noticed it's a bit harder to drive to unfamiliar locations or to pick a new brand of olive oil at the supermarket, you can blame it on the white matter in your brain.

Related Articles


A brain-mapping study, published in the Apr. 11 issue of The Journal of Neuroscience, has found that people's ability to make decisions in novel situations decreases with age and is associated with a reduction in the integrity of two specific white-matter pathways that connect an area in the cerebral cortex called the medial prefrontal cortex with two other areas deeper in the brain.

Grey matter is the part of the brain that contains the bodies of the neurons while white matter contains the cable-like axons that carry signals from one part of the brain to another. In the past, most brain-imaging research has concentrated on the grey matter. Recently, however, neuroscientists have begun looking more closely at white matter. It has been linked to the brain's processing speed and attention span, among other things, but this is the first study to link white matter to learning and decision making.

"The evidence that this decline in decision-making is associated with white-matter integrity suggests that there may be effective ways to intervene," said Gregory R. Samanez-Larkin, the post-doctoral fellow in Vanderbilt's psychology department and Institute of Imaging Science, who is the study's first author. "Several studies have shown that white-matter connections can be strengthened by specific forms of cognitive training."

The critical white-matter connections that the experiment identified run from the thalamus, a highly connected relay center in the brain, to the medial prefrontal cortex, an area of the brain involved with decision making, and from the medial prefrontal cortex to the ventral striatum, which is associated with the emotional and motivational aspects of behavior.

The study involved 25 adults ranging from 21 to 85 years of age. They were asked to perform a monetary learning task. The task was designed to elicit what psychologists call probabilistic reward learning. "This is a common type of decision making that we use every day," said Samanez-Larkin. "Whenever we try to choose the best alternative based on previous experience and are uncertain of the outcome, we are relying on probabilistic reward learning."

On the same day, the participant's brains were scanned using a relatively new MRI technique called diffusion tensor imaging (DTI). In the last 20 years, most brain imaging research has been done with fMRI, an imaging method that measures variations in the oxygen consumption in different areas of the grey matter, which correspond to variations in neuron activity levels. By contrast, DTI detects the water trapped by the myelin sheaths that surround the axons in white-matter regions and produces a signal related to the density, diameter and amount of myelination of the axons (a combination the researchers call 'integrity').

"The protocols for DTI have improved substantially," said Samanez-Larkin, "In future studies we'd really like to combine fMRI and DTI to better characterize age differences in these neural circuits and examine how training might improve both structure and function."

Samanez-Larkin performed this research while he was a graduate student at Stanford University. His co-authors are Brian Knutson, Robert Dougherty and Michael Perry from Stanford and Sara Levens from Carnegie Mellon University. The research was funded by the Financial Industry Regulatory Authority Investor Education Foundation and the National Institute on Aging.


Story Source:

The above story is based on materials provided by Vanderbilt University. Note: Materials may be edited for content and length.


Journal Reference:

  1. G. R. Samanez-Larkin, S. M. Levens, L. M. Perry, R. F. Dougherty, B. Knutson. Frontostriatal White Matter Integrity Mediates Adult Age Differences in Probabilistic Reward Learning. Journal of Neuroscience, 2012; 32 (15): 5333 DOI: 10.1523/JNEUROSCI.5756-11.2012

Cite This Page:

Vanderbilt University. "Trouble coping with the unfamiliar as you age? Blame your white matter." ScienceDaily. ScienceDaily, 11 April 2012. <www.sciencedaily.com/releases/2012/04/120411131917.htm>.
Vanderbilt University. (2012, April 11). Trouble coping with the unfamiliar as you age? Blame your white matter. ScienceDaily. Retrieved December 20, 2014 from www.sciencedaily.com/releases/2012/04/120411131917.htm
Vanderbilt University. "Trouble coping with the unfamiliar as you age? Blame your white matter." ScienceDaily. www.sciencedaily.com/releases/2012/04/120411131917.htm (accessed December 20, 2014).

Share This


More From ScienceDaily



More Health & Medicine News

Saturday, December 20, 2014

Featured Research

from universities, journals, and other organizations


Featured Videos

from AP, Reuters, AFP, and other news services

The Best Tips to Curb Holiday Carbs

The Best Tips to Curb Holiday Carbs

Buzz60 (Dec. 19, 2014) It's hard to resist those delicious but fattening carbs we all crave during the winter months, but there are some ways to stay satisfied without consuming the extra calories. Vanessa Freeman (@VanessaFreeTV) has the details. Video provided by Buzz60
Powered by NewsLook.com
Sierra Leone Bikers Spread the Message to Fight Ebola

Sierra Leone Bikers Spread the Message to Fight Ebola

AFP (Dec. 19, 2014) More than 100 motorcyclists hit the road to spread awareness messages about Ebola. Nearly 7,000 people have now died from the virus, almost all of them in west Africa, according to the World Health Organization. Video provided by AFP
Powered by NewsLook.com
Researchers Test Colombian Village With High Alzheimer's Rates

Researchers Test Colombian Village With High Alzheimer's Rates

AFP (Dec. 19, 2014) In Yarumal, a village in N. Colombia, Alzheimer's has ravaged a disproportionately large number of families. A genetic "curse" that may pave the way for research on how to treat the disease that claims a new victim every four seconds. Duration: 02:42 Video provided by AFP
Powered by NewsLook.com
Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Double-Amputee Becomes First To Move Two Prosthetic Arms With His Mind

Buzz60 (Dec. 19, 2014) A double-amputee makes history by becoming the first person to wear and operate two prosthetic arms using only his mind. Jen Markham has the story. Video provided by Buzz60
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:

Strange & Offbeat Stories


Health & Medicine

Mind & Brain

Living & Well

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