Absolutely certain you鈥檝e seen that person鈥檚 face before? Now there is a tool to help you weed out the real memories from the false ones. Roberto Cabeza at Duke University Medical Center in Durham, North Carolina, and Hogkeun Kim at Daegu University in South Korea asked 11 volunteers to view 82 related-word lists, each with a theme 鈥� like 鈥渇arm animals鈥�.
Immediately afterwards, they were given more lists and asked which ones they had seen before and how confident they were about their answer. All of this was done inside an MRI scanner, which measures brain activity.
They found that when volunteers confidently remembered true memories, there was more activation in the medial temporal lobe (MTL) 鈥� a region of the brain known for storage and consolidation of long-term memory. When volunteers were confident but wrong, they were more likely to activate the frontal parietal network 鈥� implicated in familiarity and gist (, DOI: 10.1523/jneurosci.3408_07.2007). Differences were less stark when memories were recalled without confidence.
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The finding could help to explain why we are more likely to misremember things as we get older, says Cabeza, since as people age they lose the ability to recall specifics faster than more general impressions. 鈥淭rue memory is likely to have detail,鈥� he says.
By contrast, Alzheimer鈥檚 patients lose both types of memory simultaneously, so these types of brain scan could prove a useful detection tool in future.
The Human Brain 鈥� With one hundred billion nerve cells, the complexity is mind-boggling. Learn more in our cutting edge special report.
