The Treasure Trove in Ageing Minds

"There might also be treasure in the clutter. The clutter of irrelevant information might interfere with target memory retrieval in one context, but might also provide surprising advantages in other tasks or contexts that benefit from extraneous knowledge. In these latter situations, the term 'enriched' might be a more appropriate descriptor of older adults' representations than 'cluttered'."

"Evidence suggests that older adults show preserved, and at times enhanced, creativity as a function of enriched memories."

"In sum, although excessive information in older adults' memory representations can interfere with the retrieval of specific target information and hurt performance, it can also provide an advantage on more open-ended tasks that benefit from extraneous knowledge."

Research Paper, journal Trends in Cognitive Sciences

Researchers believe "clutter" — in which the brains of older people have more information to filter — could be linked to memory issues.   IvanJekic / Getty Images

Well perhaps it is an apt analogy to compare an ageing brain to an old computer whose RAM is faltering, becoming feeble and retrieval of data hampered simply because there's too much that has been absorbed and the effect has been a dynamic slowdown. Attitudes of memory retrieval failures in the elderly have been notorious in the understanding that an older brain becomes fogged and less functional as its owner ages. Perhaps the full story is only just now being revealed, however.

 

A new review published in the journal Trends in Cognitive Sciences saw researchers at Harvard, Columbia and Toronto universities collaborate on analyzing recent neuroimaging and behavioural studies of people aged between 65 and 80. An analysis that led them to a new hypothesis where they propose that brains of older adults allocate increasing space to knowledge accumulated over their lifetimes and as a result there is more to navigate around when retrieving a memory.

 

When a younger person retrieves a memory, there is far less neural accumulation to sift through slowing down the process, suggests neuroimagining. On the other hand, it takes longer for older people to sift through acquired baggage representing information packed away over a lifetime, since each memory has a link to more information and the mind search is akin to searching out a single book in a vast library holding similar literature.

 

While the researchers focus primarily on the difficulties that these cluttered memories may pose, they also highlight a few situations in which these crowded memoryscapes may be useful. Image is in the public domain

For older people, a struggle ensues to suppress information no longer  relevant and this may explain why ageing often brings the re-emergence of decades-old memories whose resurfacing surprises a person of age, never imagining they might recall the distant memory. What it means is that when searching for a specific memory often other, irrelevant memories are retrieved, explaining why it takes longer to carry out cognitive operations; wading through previous knowledge.

 

Younger people, on the other hand, can be effective at shutting out information not usefully related to the current task. The ability of the brain to draw on a lifetime of experience does have advantages; even though a wealth of prior knowledge renders memory retrieval a sometimes randomly successful enterprise. The process, more complex as it is, encourages people to become more creative, improving skills at problem=solving and decision-making.

Older adults, according to studies, tend to shine on alternative-uses tasks, when asked to think up as many novel functions as possible for an object, suggesting prior knowledge is critical to good performance. Memory loss in older age happens as a result of the brain struggling to produce links, according to previous studies; a process dubbed the 'associative deficit hypothesis'. The study's authors declare both young and old people have a tendency to score similarly on associate deficit tests.

According to other researchers, as people age they 'outsource' memory to external factors in the environment, which results in retrieval becoming more difficult. The new theory, on the other hand, suggests that memory differences in old and young people are likely to be linked to the inability to control excessive information.

"There's this prevalent idea that older adults' memories are kind of impoverished, or they have weak memories that do not contain a lot of information."

"But based on a lot of evidence, we're actually arguing the opposite. Older adults store too much information, so in a sense they have a harder time focusing their attention on one piece of target information and exclude all sorts of other distractions."

Tarek Amer,  postdoctoral research fellow, Columbia and Harvard, lead author, paper in Trends in Cognitive Sciences