Experience, Not Cognitive Decline, Slows Aging Brains
Older brains are slow due to greater experience rather than cognitive decline, according to astudy led by Dr. Michael Ramscar of the University of Tuebingen in Germany and published in the journal Topics in Cognitive Science. The researchers found that aging brains may take longer to process ever increasing amounts of knowledge and that this phenomenon has often been misidentified as declining capacity.
Dr. Ramscar's team used computers programmed “to act as though they were humans”. The computers read a certain amount each day, learning new things along the way. When the researchers let a computer “read” a limited amount, its performance on cognitive tests resembled that of a young adult. However, if the same computer was exposed to data that represented a lifetime of experiences, its performance looked like that of an older adult. Often it was slower, not because its processing capacity had declined, but because increased "experience" had caused the computer's database to grow, giving it more data to process, and that processing takes time.
A release from the publishers quotes Dr. Ramscar as saying, "What does this finding mean for our understanding of our aging minds, for example older adults' increased difficulties with word recall? These are traditionally thought to reveal how our memory for words deteriorates with age, but Big Data adds a twist to this idea. Technology now allows researchers to make quantitative estimates about the number of words an adult can be expected to learn across a lifetime, enabling the team to separate the challenge that increasing knowledge poses to memory from the actual performance of memory itself."
Ramscar added, "Imagine someone who knows two people's birthdays and can recall them almost perfectly. Would you really want to say that person has a better memory than a person who knows the birthdays of 2,000 people, but can 'only' match the right person to the right birthday nine times out of ten?”
Topics in Cognitive ScienceEditors Wayne Gray and Thomas Hills commented that "it is time we rethink what we mean by the aging mind before our false assumptions result in decisions and policies that marginalize the old or waste precious public resources to remediate problems that do not exist."