Older news items (pre-2010) brought over from the old website
More evidence the aging brain is easily distracted
Here’s another study demonstrating that older adults aren't able to filter out distracting information as well as younger adults. The imaging study compared face recognition performance in younger adults (average age 26) and older (average age 70). It was found that, for both groups, difficulties encoding a new face were marked by decreased activity in the hippocampus. But older brains also showed increased activation in the auditory cortex, left prefrontal cortex and medial parietal cortex, showing that they were processing too much irrelevant information from their external environment – the notoriously loud noise of the scanner. Apart from confirming the distractibility of the older brain, the finding also raises questions about imaging studies in general, for older adults. It’s likely that older adults’ cognitive performance have been systematically underestimated.
[520] Stevens, D. W., Hasher L., Chiew K. S., & Grady C. L.
(2008). A Neural Mechanism Underlying Memory Failure in Older Adults.
J. Neurosci.. 28(48), 12820 - 12824.
http://www.eurekalert.org/pub_releases/2008-11/bcfg-sfm112408.php
Age-related memory loss tied to slip in filtering information quickly
Increasing research in recent years has concluded that one of the problems for the aging brain is a diminished ability to ignore irrelevant information. In fact, many believe it is the major problem for the healthy aging brain. Others believe, more traditionally, that the main problem is a decline in processing speed. A new study shows that both of these happen — in tandem. The difficulty in suppressing irrelevant information occurs because the processing of that irrelevant information has slowed down. This slowdown, at least in visual memory, seems to occur only in the first 200 milliseconds of visual processing, and the difficulty in suppressing irrelevant information occurs only during this period. This suppression failure is thought to impact on working memory.
[553] Gazzaley, A., Clapp W., Kelley J., McEvoy K., Knight R. T., & D'Esposito M.
(2008). Age-related top-down suppression deficit in the early stages of cortical visual memory processing.
Proceedings of the National Academy of Sciences. 105(35), 13122 - 13126.
http://www.eurekalert.org/pub_releases/2008-09/uoc--aml090208.php
More on why older adults are more distractible
A number of recent studies have made it clear that as we age, we find it harder to block out unwanted distractions. A new study used a new brain imaging technique known as EROS to determine whether this is due to faster sensory memory decay or to inefficient filtering of irrelevant sensory information. The study involved 16 young and 16 older participants who read a book of their choice while distracting tones played in the background. The volume of the tones was adjusted so that all the participants heard them at the same level, and the tones were emitted in groups of fives. The young participants showed brain activity in the auditory cortex in response to the first tone in each sequence only, but the older adults' brains responded to all five. The finding supports the view that the growing difficulty at blocking out distractions is due to inefficient filtering of irrelevant sensory information , not faster sensory memory decay.
[1380] Fabiani, M., Low K. A., Wee E., Sable J. J., & Gratton G.
(2006). Reduced Suppression or Labile Memory? Mechanisms of Inefficient Filtering of Irrelevant Information in Older Adults.
Journal of Cognitive Neuroscience. 18(4), 637 - 650.
http://www.sciencentral.com/articles/view.htm3?article_id=218392783
Why older adults more vulnerable to distraction from irrelevant information
We know older adults find it harder to filter out irrelevant information. Now a study looking at brain function in young, middle-aged and older adults has identified changes in brain activity that begin gradually in middle age which may explain why. In younger adults, activity in the dorsolateral prefrontal cortex (associated with tasks that require concentration, such as reading) normally increases during the task, while activity in the medial frontal and parietal regions (associated with non-task related activity in a resting state, such as thinking about yourself, what you did last night, monitoring what's going on around you) normally decreases. In middle age (40-60 years), this pattern begins to break down during performance of memory tasks, although performance is not affected (but most of the participants were fairly well educated, so the finding of brain changes without accompanying behavioural changes in the middle-aged group may reflect the "protective effect" of education). Activity in the medial frontal and parietal regions stays turned on while activity in the dorsolateral prefrontal cortex decreases. The imbalance becomes more pronounced in older adults (65+), suggesting there is a gradual, age-related reduction in the ability to suspend non-task-related or "default-mode" activity and engage areas for carrying out memory tasks.
[759] Grady, C. L., Springer M. V., Hongwanishkul D., McIntosh A. R., & Winocur G.
(2006). Age-related Changes in Brain Activity across the Adult Lifespan.
Journal of Cognitive Neuroscience. 18(2), 227 - 241.
http://www.eurekalert.org/pub_releases/2006-02/b-oam013006.php
Changes in brain, not age, determine one's ability to focus on task
It’s been established that one of the reasons why older adults may do less well on cognitive tasks is because they have greater difficulty in ignoring distractions, which impairs their concentration. But not all older people are afflicted by this. Some are as focused as young adults. An imaging study has now revealed a difference between the brains of those people who are good at focusing, and those who are poor. Those who have difficulty screening out distractions have less white matter in the frontal lobes. They activated neurons in the left frontal lobe as well as the right. Young people and high-functioning older adults tended to use only the right frontal lobe.
[1117] Colcombe, S. J., Kramer A. F., Erickson K. I., & Scalf P.
(2005). The implications of cortical recruitment and brain morphology for individual differences in inhibitory function in aging humans.
Psychology and Aging. 20(3), 363 - 375.
http://www.eurekalert.org/pub_releases/2005-10/uoia-cib102605.php
Memory loss in older adults due to distractions, not inability to focus
We know that older adults often have short-term memory problems, and this has been linked to problems with attention. An imaging study now provides evidence that these short-term memory problems are associated with an inability to filter out surrounding distractions, rather than problems with focusing attention. It’s been suggested that an inability to ignore distracting information may indeed be at the heart of many of the cognitive problems that accompany aging. It should be noted that this is not an inevitable effect of age — in the study, 6 of the 16 older adults involved had no problems with short-term memory or attention.
[383] Gazzaley, A., Cooney J. W., Rissman J., & D'Esposito M.
(2005). Top-down suppression deficit underlies working memory impairment in normal aging.
Nat Neurosci. 8(10), 1298 - 1300.
http://www.eurekalert.org/pub_releases/2005-09/uoc--mli090805.php