Posted by Maria/MDHealthForum.com Team

It’s a common notion that the younger generation learn faster than people of advanced age. Some older adults even point out that they are too old to remember how to use computers, mobile phones or digital cameras. A close relative of mine, in her mid 50’s, would make a good example. She’s been using her mobile phone for at least half-a-year, but until now she panics whenever she presses the wrong key- this means that she panics every time she holds her phone. Then she would always say “ah, I never remember the right key to press”.. Use of new gadgets may also be complicated for the young ones sometimes, but how come learning new things is not always a walk in the park for older people? According to researchers at The Rotman Research Institute at Baycrest and the University of Toronto, it could be due to the difficulty of older adults to concentrate in busy environments and filter out irrelevant information. The findings of this research suggest that this can be attributed to changes in brain activity that transpire gradually in middle age.

This study was conducted in 2006. The investigators observed the brain activity of healthy middle-aged adults, as well as young and old adults using a functional magnetic resonance imaging scanner. The participants were given a series of memory tasks. Activities in the dorsolateral prefrontal cortex and the brain’s frontal and parietal regions were observed during the study. The dorsolateral prefrontal cortex is involved in tasks that require concentration, it also plays a role in working memory. The medial frontal and parietal regions are associated with non-task based activity in a resting state, examples of these are thoughts about yourself, monitoring what’s going on around you and your activities during the previous day.

While performing memory tasks, the scan revealed that in younger adults, the activity in the dorsolateral prefrontal cortex normally increases while activity in the medial frontal and parietal regions normally decreases. However, in participants aged 40-60 years, investigators noted a different pattern: the activity in the medial frontal and parietal regions remains turned on, while activity in the dorsolateral prefrontal cortex decreases. The imbalance becomes more apparent in older adults (65+), according to the researchers, this could explain their reduced ability to ignore distractions or irrelevant information. Dr. Cheryl Grady, the lead author of this study suggested that older adults should try to lessen distractions in their environment and devote efforts on one attentional task at a time. She cited turning down the radio while reading as an example.

Recently, the researchers from Rotman found more evidence supporting the vulnerability of older people to distractions. They discovered that in older brains, the exposure to annoying noise produce unique brain activity underlying memory encoding failure. For this study there were two groups of participants: younger adults (average age 26) and older adults (average age 70). They took part in a face recognition task while they brains are scanned with fMRI. The scan revealed that when younger and older adults had difficulty encoding a new memory (certain face), there was decreased activity in brain regions such as the such as the hippocampus which is responsible for encoding. The researchers didn’t find this unusual because there is a great deal of evidence stating how valuable the hippocampus is in relation to memory. However, they noted that in older participants the auditory cortex and prefrontal cortex, idled too high while memory encoding failure is taking place, such brain activity was not observed in younger adults. The auditory cortex and prefrontal complex allow us to keep track of our external environment. Normally, the activity in these regions is calm or decreased while performing a task. Doctor Dale Stevens, who lead the study, said that it was the scanner’s noise that distracted the older adults. The older participants cannot tune out the noise in their environment and this affected their performance in the face-recognition task.

What do these studies imply about the aging process? These are pieces of evidence showing us how unforgiving it could be. The age-related changes that take place in older people’s brains are beyond their control. It wouldn’t hurt if we would try to decrease the distractions in their environment especially when there’s a need for them to concentrate on something. So better switch the radio off while your older relative is reading an instruction manual.

Sources:
Baycrest (2006, February 7). Older Adults More Vulnerable To Distraction From Irrelevant Information.

Emmanuel Procyk and Patricia S Goldman-Rakic: Modulation of Dorsolateral Prefrontal Delay Activity during Self-Organized Behavior, J. Neurosci. 2006 26: 11313-11323.

Baycrest Centre for Geriatric Care (2008, December 7). More Evidence The Aging Brain Is Easily Distracted

Photo credit: Hindrik Sijens

Tags: aging, geriatrics, memory