Older minds fall prey to distractions
The decline in memory performance complained of by older people has been linked to an inability to ignore irrelevant information when forming memories.
In order to ignore distracting information, the brain should act to suppress its responses to distractions, but it has been shown that in older adults there is in fact an increase in brain activity at those times.
In a study published in an issue of Elsevier’s Cortex researchers at the University of California San Francisco have shown that even prior knowledge of an impending distraction does not help to improve the working memory performance of older adults.
Doctors Theodore Zanto and Adam Gazzaley studied 21 adults aged between 60 and 80 years while they performed a working memory task in which they were shown random sequences of pictures containing faces and scenes. From a given sequence, participants were asked to remember either only the faces (ignoring scenes) or only the scenes (ignoring faces).
In a second round of testing, the participants were given prior information about which specific pictures in the sequence would be relevant and which to ignore. The participants’ brain activity during the tasks was recorded using electroencephalograms (EEGs).
Previous research from this laboratory has indicated that the increase in brain activity in response to distractions occurs very soon (within 200 milliseconds) after the distraction appears.
Since there is only a very short amount of time allotted for the brain to identify an item as irrelevant and suppress any further neural processing, it was suggested that older adults might benefit from prior knowledge of the impending distraction. However, results from the new study have proved that this is not the case.
Interestingly, the researchers found that later stages of neural processing (500-650 milliseconds after item presentation) do show signs of suppression, confirming that the “suppression deficit” is related to early stages of neural processing.
The findings suggest that a working memory decline in older adults is indeed due to an inability to ignore distracting information, which furthermore cannot be improved with preparedness.
How to improve memory and cognitive function in older age
A study published in an edition of Alzheimer’s & Dementia: The Journal of the Alzheimer’s Association suggests that taking docosahexaenoic acid (DHA), an omega-3 fatty acid available as a dietary supplement, may improve memory and learning in older adults with mild cognitive impairments.
The study found that DHA taken for six months improved memory and learning in healthy, older adults with mild memory complaints.
“The results of this study are very encouraging for those consumers concerned about maintaining memory. We know that lower DHA levels are associated with cognitive decline in healthy elderly and Alzheimer’s patients, and higher DHA levels help reduce the risk of Alzheimer’s disease,” said Duffy MacKay, vice president, scientific & regulatory affairs, for the Council for Responsible Nutrition (CRN).
“Memory loss, dementia and the development of Alzheimer’s disease are prominent health concerns for older individuals. The more we learn about the valuable role DHA plays in supporting brain function, the more options aging Americans have towards managing cognitive decline.”
These findings underscore the importance of early DHA intervention.
“This study reinforces the principle that consumers will reap the most benefit from their DHA supplements – and many supplements – when they are taken over time and before a health concern is imminent,” said Dr MacKay.
