By Jen Benepe
The new study stops short of confirming the idea that the limited amount of storage in short term brain memory leads to the perception that memory declines as we age. But it does confirm many aspects of that idea.
Albert Einstein was known to have six suits of the exact same color and style hanging in his closet so he didn’t have to use precious brain power to decide what to wear that day. He also famously said, “Never memorize what you can look up in books.”
The new study does confirm however that as you grow older you have more material in your memory and this makes accessing the information take longer. The difference in sheer quantity of knowledge accounted for 75 percent of the processing differences, said the scientists.
In their paper published in Topics in Cognitive Science, a team of linguistic researchers from the University of Tübingen in Germany used advanced learning models to search enormous databases of words and phrases.
They also found a difference between the types of brain processes in younger and older brains. “Fluid intelligence,” which includes short term memory, analytical reasoning and the ability to shut out distractions, was greater in younger people, and “crystallized intelligence” which represents accumulated knowledge, vocabulary and expertise, was greater in older people.
But what scientists led by Dr. Matthew Ramscar argue is that an increase in crystallized intelligence can account for a decrease in fluid intelligence.
Writes Benedict Carey for the NY Times, “In essence, what Ramscar’s group is arguing is that an increase in crystallized intelligence can account for a decrease in fluid intelligence,” said Zach Hambrick, a psychologist at Michigan State University.”
Dr. Hambrick and Timothy A. Salthouse of the University of Virginia have shown that crystallized knowledge climbs sharply between ages 20 and 50 and then plateaus, even as the fluid kind (like analytical reasoning) is dropping steadily — by more than 50 percent between ages 20 and 70 in some studies.
“To know for sure whether the one affects the other, ideally we’d need to see it in human studies over time,” Dr. Hambrick said.
Read the whole story at the NY Times website.