How the Brain Copes With Multi Tasking Alters With Age

Jan. 18, 2013 — The pattern of blood flow in the prefrontal cortex in the brains alters with age during multi-tasking, finds a new study in BioMed Central’s open access journal BMC Neuroscience. Increased blood volume, measured using oxygenated haemoglobin (Oxy-Hb) increased at the start of multitasking in all age groups. But to perform the same tasks, healthy older people had a higher and more sustained increase in Oxy-Hb than younger people.

Age related changes to the brain occur earliest in the prefrontal cortex, the area of the brain associated with memory, emotion, and higher decision making functions. It is changes to this area of the brain that are also associated with dementia, depression and other neuropsychiatric disorders. Some studies have shown that regular physical activity and cognitive training can prevent cognitive decline (use it or lose it!) but to establish what occurs in a healthy aging brain researchers from Japan and USA have compared brain activity during single and dual tasks for young (aged 21 to 25) and older (over 65) people.

Near infrared spectroscopy (NIRS) measurements of Oxy-Hb showed that blood flow to the prefrontal cortex was not affected by the physical task for either age group but was affected by the mental task. For both the young and the over 65s the start of the calculation task  coincided with an increase in blood volume which reduced to baseline once the task was completed.

The main difference between the groups was only seen when performing the physical and mental tasks at the same time – older people had a higher prefrontal cortex response which lasted longer than the younger group.

Hironori Ohsugi, from Seirei Christopher University, and one of the team who performed this research explained “From our observations during the dual task it seems that the older people turn their attention to the calculation at the expense of the physical task, while younger people are able to maintain concentration on both. Since our subjects were all healthy it seems that this requirement for increased activation of the prefrontal cortex is part of normal decrease in brain function associated with aging. Further study will show whether or not dual task training can be used to maintain a more youthful brain.”


 

Story Source:

The above story is reprinted from materials provided byBioMed Central Limited.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.


Journal Reference:

  1. Hironori Ohsugi, Shohei Ohgi, Kenta Shigemori, Eric B Schneider. Differences in dual-task performance and prefrontal cortex activation between younger and older adultsBMC Neuroscience, 2013; 14 (1): 10 DOI:10.1186/1471-2202-14-10
BioMed Central Limited (2013, January 18). How the brain copes with multi tasking alters with age. ScienceDaily. Retrieved January 27, 2013, from http://www.sciencedaily.com/releases/2013/01/130117230026.htm
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Brain Imaging Can Predict How Intelligent You Are: ‘Global Brain Connectivity’ Explains 10 Percent of Variance in Individual Intelligence

ScienceDaily (Aug. 1, 2012) — When it comes to intelligence, what factors distinguish the brains of exceptionally smart humans from those of average humans?

New research suggests as much as 10 percent of individual variances in human intelligence can be predicted based on the strength of neural connections between the lateral prefrontal cortex and other regions of the brain. (Credit: WUSTL Image / Michael Cole)


As science has long suspected, overall brain size matters somewhat, accounting for about 6.7 percent of individual variation in intelligence. More recent research has pinpointed the brain’s lateral prefrontal cortex, a region just behind the temple, as a critical hub for high-level mental processing, with activity levels there predicting another 5 percent of variation in individual intelligence.

Now, new research from Washington University in St. Louis suggests that another 10 percent of individual differences in intelligence can be explained by the strength of neural pathways connecting the left lateral prefrontal cortex to the rest of the brain.

Published in the Journal of Neuroscience, the findings establish “global brain connectivity” as a new approach for understanding human intelligence.

“Our research shows that connectivity with a particular part of the prefrontal cortex can predict how intelligent someone is,” suggests lead author Michael W. Cole, PhD, a postdoctoral research fellow in cognitive neuroscience at Washington University.

The study is the first to provide compelling evidence that neural connections between the lateral prefrontal cortex and the rest of the brain make a unique and powerful contribution to the cognitive processing underlying human intelligence, says Cole, whose research focuses on discovering the cognitive and neural mechanisms that make human behavior uniquely flexible and intelligent.

“This study suggests that part of what it means to be intelligent is having a lateral prefrontal cortex that does its job well; and part of what that means is that it can effectively communicate with the rest of the brain,” says study co-author Todd Braver, PhD, professor of psychology in Arts & Sciences and of neuroscience and radiology in the School of Medicine. Braver is a co-director of the Cognitive Control and Psychopathology Lab at Washington University, in which the research was conducted.

One possible explanation of the findings, the research team suggests, is that the lateral prefrontal region is a “flexible hub” that uses its extensive brain-wide connectivity to monitor and influence other brain regions in a goal-directed manner.

“There is evidence that the lateral prefrontal cortex is the brain region that ‘remembers’ (maintains) the goals and instructions that help you keep doing what is needed when you’re working on a task,” Cole says. “So it makes sense that having this region communicating effectively with other regions (the ‘perceivers’ and ‘doers’ of the brain) would help you to accomplish tasks intelligently.”

While other regions of the brain make their own special contribution to cognitive processing, it is the lateral prefrontal cortex that helps coordinate these processes and maintain focus on the task at hand, in much the same way that the conductor of a symphony monitors and tweaks the real-time performance of an orchestra.

“We’re suggesting that the lateral prefrontal cortex functions like a feedback control system that is used often in engineering, that it helps implement cognitive control (which supports fluid intelligence), and that it doesn’t do this alone,” Cole says.

The findings are based on an analysis of functional magnetic resonance brain images captured as study participants rested passively and also when they were engaged in a series of mentally challenging tasks associated with fluid intelligence, such as indicating whether a currently displayed image was the same as one displayed three images ago.

Previous findings relating lateral prefrontal cortex activity to challenging task performance were supported. Connectivity was then assessed while participants rested, and their performance on additional tests of fluid intelligence and cognitive control collected outside the brain scanner was associated with the estimated connectivity.

Results indicate that levels of global brain connectivity with a part of the left lateral prefrontal cortex serve as a strong predictor of both fluid intelligence and cognitive control abilities.

Although much remains to be learned about how these neural connections contribute to fluid intelligence, new models of brain function suggested by this research could have important implications for the future understanding — and perhaps augmentation — of human intelligence.

The findings also may offer new avenues for understanding how breakdowns in global brain connectivity contribute to the profound cognitive control deficits seen in schizophrenia and other mental illnesses, Cole suggests.

Other co-authors include Tal Yarkoni, PhD, a postdoctoral fellow in the Department of Psychology and Neuroscience at the University of Colorado at Boulder; Grega Repovs, PhD, professor of psychology at the University of Ljubljana, Slovenia; and Alan Anticevic, an associate research scientist in psychiatry at Yale University School of Medicine.

Funding from the National Institute of Mental Health supported the study (National Institutes of Health grants MH66088, NR012081, MH66078, MH66078-06A1W1, and 1K99MH096801).

 

Link:

http://news.wustl.edu/news/Pages/24068.aspx

Journal Reference:

  1. M. W. Cole, T. Yarkoni, G. Repovs, A. Anticevic, T. S. Braver. Global Connectivity of Prefrontal Cortex Predicts Cognitive Control and Intelligence. Journal of Neuroscience, 2012; 32 (26): 8988 DOI: 10.1523/JNEUROSCI.0536-12.2012

Citation:

Washington University in St. Louis (2012, August 1). Brain imaging can predict how intelligent you are: ‘Global brain connectivity’ explains 10 percent of variance in individual intelligence. ScienceDaily. Retrieved August 3, 2012, from http://www.sciencedaily.com­ /releases/2012/08/120801154716.htm