In the Baycrest study, 12 younger adults (average age 26) and 12 older adults (average age 70) took part in a face recognition task that involved having their brains scanned with fMRI while they were shown pictures of faces and later again when trying to recall whether they'd seen each face before. Researchers found that when younger and older adults had difficulty encoding a new memory (certain face), this was marked by decreased activity in brain regions important for encoding, such as the hippocampus. The researchers weren't surprised by this based on an abundance of scientific evidence indicating the importance of hippocampus for making memories.
But the older brains showed additional increased activation in certain regions during memory encoding failure that was not found in younger brains!
"The older brains showed increased activation in certain regions that normally should be quieter or tuned down," said Dale Stevens, who led the study as a psychology graduate at Baycrest's Rotman Research Institute, with senior scientists Drs. Cheryl Grady and Lynn Hasher, both of whom are distinguished researchers in aging, memory, attention and distraction.
"The auditory cortex and prefrontal cortex, which are associated with external environmental monitoring, were idling too high. The older brains were processing too much irrelevant information from their external environment – basically the scanner noise," said Dr. Stevens, who is now a post-doctoral fellow in the Department of Psychology and Cognitive Neuroscience at Harvard University. The younger brains did not show this abnormal high idling during their failed memory encoding.
The practical take-home lesson here: As you get older cut back on environmental distractions when you need to concentrate.
Another take-home lesson for employers: Cubicles are especially productivity draining for older employees. The noise and distractions of unwalled workplaces exact a greater cost in lost productivity as your employees age. Put up some sound-deadening walls and increase profits.
The better solution we need: brain rejuvenation therapies. We need remyelination to restore the neuron insulation which deteriorates with age.
|Share |||Randall Parker, 2008 November 26 09:30 AM Brain Aging|