Brain limits explored
By Melissa Healy
By Melissa Healy
Los Angeles Times
(MCT) — The human brain is a marvel of power and flexibility, and a pair of new studies demonstrate that when it runs up against the limits of its capacity to take in and store information, the brain often relies on its agility to fill the gap. In the process, however, information can be lost.
Two unrelated research studies published Monday in the journal Proceedings of the National Academy of Sciences explore how people visually process and remember information about a panorama of similar and dissimilar objects. The new research supports the idea that our brains use different sites in the visual cortex to interpret different categories of visual stimuli — suggesting that, when confronted with too much of the same thing, those circuits can be overloaded. And it tells us that when we upload such groupings for long-term storage, we leave by the wayside objects that our experience tells us don't really fit into the picture. Although efficient, such selective memory can be wrong.
Immediately after seeing the group of pictures, the researchers found, subjects were more accurate at recalling all the images when the four images had been a mix of two types of things than when all four images came from the same category. This study was led by Michael A. Cohen of Harvard University's psychology department.
"Automatic retrieval occurs constantly in the background, pruning invalid memories without burdening our conscious mind" with a yes-or-no decision about allotting precious memory space to them, the study's authors wrote.