Written by Tatjana Djakovic, Staff Writer. Study attempts to explain the common idea of mental decline in old age may be an oversimplification of a process related to learning in the elderly.
People are now living longer than ever before and world’s population is growing at an increasing rate. In fact, by 2030 there will be 72 million American aged 65 and older (1). It is generally believed that cognitive abilities decline with age.
The authors of the recent article designed a study in which they showed that cognitive tests are often misleading for the elderly. They suggest that the way in which older adults respond to test questions is due to the basic principles of learning (2).
The experiment was designed in such a way that computers were trained to accumulate knowledge at a rate of an average human being. They were trained to read a certain amount each day, and to learn new information(2).The results of the computer generated data were consistent to that of a study in which 30 younger adults (mean age 21.1) and 30 older adults (mean age 76.3) were recruited to be involved in a lexical decision test. The stimuli were displayed on a computer screen, which consisted of 2,906 words ranging from 2 to 8 letters in length and the participants were asked to decipher between a word and a non-word. The time for their response was measured to the nearest millisecond (3).
The researchers compared the word frequencies (the number of times a certain word appears within the total of 2,906 words that were assigned) and the difference between the time in milliseconds between the old and the young to answer. They found that correct responses were the same for the young and the old when it came to words that appeared commonly in the test such as the word “where”. The response time was the same for the young and the elderly. However, for words that appeared more rarely, such as the word “whelp”, resulted in slower reaction times from the elderly. The words that appeared 10 times had an approximately 80 millisecond slower reaction time among the elderly, while the words that appeared 16 times, there was no difference between the young and the old (2).
It is reasoned that younger adults are more insensitive to the words that are rare. Meanwhile, older adults are more sensitive to the words that appear at lower frequency because they associate the rare word with another rare word that they have encountered in their lifetime. In a smaller vocabulary of younger people, rare words have higher values, but as the experiences grow, these rare words become vulnerable to competition and are not as easily recognizable (2).
The researchers give the example of people having to remember birthdays. They are usually reminded of birthdays of family members on an annual basis so they are quite good at remembering them. However, as they move through life they learn many other birthdays and the task of recalling a particular birthday becomes more complex (2).
The results of this study possibly suggests that the performance of older adults on cognitive tests is indicative of predictable ways in which information is processed during the learning and not cognitive decline. In order to come to a more definitive conclusion, it would be helpful to perform a variety of cognitive versus information processing tests in the elderly versus the young.
Source: Ramscar, Michael, Peter Hendrix, Cyrus Shaoul, Petar Milin, and Harald Baayen. “The myth of cognitive decline: Non‐linear dynamics of lifelong learning.” Topics in cognitive science 6, no. 1 (2014): 5-42.
© 2013 Cognitive Science Society, Inc. All rights reserved.
Posted March 4, 2014.
References:
- Watkins, K., et al. (2005). International cooperation at a crossroads-aid. UN Development Programme: Trade and Security in an Unequal World.
- Ramscar, Michael, et al. “The Myth of Cognitive Decline: Non-Linear Dynamics of Lifelong Learning.” Topics in cognitive science 6.1 (2014): 5-42.
- Balota, D. A., & Spieler, D. H. (1998). The utility of item level analyses in model evaluation. Psychological Science, 9, 238–240.
