Posts Tagged ‘accessibility’

Senior Moments

July 15, 2020

“The Myth of Cognitive Decline: Non-Linear Dynamics of Lifelong Learning”1 is certainly one of the most important scientific articles HM has read in recent years. Contrary to the commonly accepted notion that cognitive information processing capabilities decline across adulthood, the article makes a compelling argument that older adults’ changing performance reflects memory search demands, which increase as experience grows.

This argument is based on a series of simulations that show how the performance patterns observed across adulthood emerge naturally in learning models as additional knowledge is acquired. The simulations identify greater variation in the cognitive performance of older adults, and also predict that older adults show greater sensitivity to fine-grained differences in the properties of test stimuli than younger adults. In other words, the results indicate that older adults’ performance on cognitive tests reflects the predictable consequences of learning on information processing and not cognitive decline.

Simply put, the more information we have as we age can slow down the retrieval of information and make it more difficult to distinguish differences among items in memory. Here it is wise to revisit the distinction between information availability and information accessibility. Information can be available in memory, but we simply cannot access it. Many times we know we know something, but simply cannot recall it. These are the cases when information is available but not accessible. Frequently, HM tries to recall some piece of information, say an actor’s name, but just can’t seem to locate it. Sometimes he will challenge his wife and see if she remembers. Sometimes she does, and sometimes she doesn’t. Sometimes she will come up with a partial cue that leads to the desired memory. HM tries to resist the temptation to Googling it in these situations as he thinks these attempts at retrieval aid keeping the memory healthy.  They force us to revisit infrequently visited memory circuits. What is interesting is that long after he has consciously given up the search and resisted Googling it, the desired memory will suddenly pop into mind. This might occur the next day, perhaps even several days later. This is a good example of how a long latency might be mistakenly interpreted as a memory loss.

One might argue that these conclusions are based on simulations rather than on human experiments. Research into this topic is currently underway using humans. The problem with using human participants to research this problem is that it is difficult to control or estimate important variables. In these cases, simulations can actually provide more accurate answers.
There is the observation that cognitive decline really kicks in around 60 or 70. What is the basis for this observation? How can it be explained? Here is the explanation taken directly from the Ramscar article on p. 34: “If a common environmental change like retirement was to systematically reduce the variety of contexts people encounter in their lives, learning theory predicts that the amount of contextual information they learn will drop further, as the background rates of cues in the remaining contexts rise (Kruschke,2 Ramscar et al3). It follows from this that if people were to increasingly spend time in environments where any cues have high background rates already (family homes), any effects arising from their cumulative experience of learning to ignore task irrelevant contextual (background) cues will be exacerbated. In other words because discriminative learning by its very nature reduces sensitivity to everyday context, retirement is likely to make memories harder to individuate and more confusable, absent any “cognitive declines,” simply because retirement is likely to decrease contextual variety at exactly the time when the organization of older adults’ memories needs it most.”

In other words, as you have read in previous healthymemory blog posts, retirement can foster cognitive decline. So retirements need to be active, so that people can continue to grow cognitively and have social engagements in varying contexts. Obviously HM is biased, but he thinks that reading the healthymemory blog and following some of its practices provide a good start.

So, if you are a senior, and are slow in or having difficulty recalling. Although this is a senior moment, this senior moment is caused by all the additional information available in memory. Although this information is available it is not accessible at the moment. Actually we are to be congratulated for these senior moments as the reflect the extremely large amounts of information available in memory and, hopefully, wisdom.

It is certainly true that there can be pathologies that cause cognitive decline. Unfortunately, what is the normal performance of what are truly healthy memories can be misinterpreted as cognitive decline.

1Ramscar, M., Hendrix, P., Shaoul, C., Milin, P., & Bayan, H. (2014). Topics in Cognitive Science, 6, 5-42.
2Krushke, J.J. (1996). Base Rates in Category Learning. Journal of Experimental Psychology: Learning, Memory, & Cognition. 22, 3-26 .
3Ramscar, M., Dye, M., & Klein, J. (2013). Children value informativity over logic in word learning, Psychological Science, 24, 1017-1023.

Let Me Think It Over

August 19, 2015

“Let me think it over”  is something we should say to any proposition other than the most trivial.  Included here are conversations with ourselves.  If we have an idea we should think it over before acting on it.  Whenever we read, hear. or think of something we are only accessing an extremely small portion of our memory.  Our conscious awareness is quite limited and the vast majority of cognition occurs below our level of awareness (See the healthy memory blog post, “Strangers to Ourselves”).  Moreover, the amount of information we are able to access at any given time is quite limited.  Trying to recall something or thinking about something at a different time should yield some new information.

Think of your brain as a large corporation.  You are the CEO at its executive headquarters.  Most of this corporation is below your level of consciousness.  So not only is information stored, but information is also processed at this nonconsciousness level.  After you have finished your initial consideration of a topic, other parts of this corporation will continuing processing.  Allowing time to think something over allows this nonconscious processing to occur.  Perhaps the best example of this nonconscious processing occurs after you have tried, but failed, to remember something.  Some time later, perhaps the next day even, what you were trying to remember pops into your conscious awareness.

Memory theorists speak of accessible memory, which is information we can easily remember.  Then there is information which we cannot access at a particular time, which is nevertheless available in memory.  It might become accessible during another recall attempt, or after detailed search and processing by your unconscious memory.   This is called available memory.

Then there is also transactive memory.  Transactive memory is memory that is not stored in our own brains, but exists in the brains of fellow humans or technology.  So we can speak of accessible transactive memory which is information we cannot recall but we know how to look it up or whom to ask.  Available  transactive  memory is information that we know exists, but that we need to conduct some research to find it.

I have lost money because I failed to think something over.  Had I just done some quick research on the internet i would not have spent money on unnecessary repairs.  I fear this has happened more than once.  I have suffered undesirable consequences from failing to ask someone making a proposal, or from failing to adequately think over my own ideas.

© Douglas Griffith and, 2015. Unauthorized use and/or duplication of this material without express and written permission from this blog’s author and/or owner is strictly prohibited. Excerpts and links may be used, provided that full and clear credit is given to Douglas Griffith and with appropriate and specific direction to the original content.