It's Not Memory Loss - Older Minds May Just Be Fuller of Information

Hugh Pickens DOT Com writes: "Benedict Carey writes in the NYT that the idea that the brain slows with age is one of the strongest in all of psychology. But a new paper suggests that older adults' performance on cognitive tests reflects the predictable consequences of learning on information-processing, and not cognitive decline. A team of linguistic researchers from the University of Tübingen in Germany used advanced learning models to search enormous databases of words and phrases. Since educated older people generally know more words than younger people, simply by virtue of having been around longer, the experiment simulates what an older brain has to do to retrieve a word. When the researchers incorporated that difference into the models, the aging 'deficits' largely disappeared. That is to say, the larger the library you have in your head, the longer it usually takes to find a particular word (or pair). 'What shocked me, to be honest, is that for the first half of the time we were doing this project, I totally bought into the idea of age-related cognitive decline in healthy adults,' says lead author Michael Ramscar but the simulations 'fit so well to human data that it slowly forced me to entertain this idea that I didn't need to invoke decline at all.' The new report will very likely add to a growing skepticism about how steep age-related decline really is. Scientists who study thinking and memory often make a broad distinction between 'fluid' and 'crystallized' intelligence. The former includes short-term memory, like holding a phone number in mind, analytical reasoning, and the ability to tune out distractions, like ambient conversation. The latter is accumulated knowledge, vocabulary and expertise. 'In essence, what Ramscar's group is arguing is that an increase in crystallized intelligence can account for a decrease in fluid intelligence,' says Zach Hambrick, In the meantime the new digital-era challenge to 'cognitive decline' can serve as a ready-made explanation for blank moments, whether senior or otherwise (PDF). 'It's not that you're slow,' says Carey. 'It's that you know so much.'"