Public Release: 

How memories are made, and recalled

UCLA and Israel researchers record single cells as they recall a memory

University of California - Los Angeles



Fried made use of the same electrodes to record neuron activity as memories were being formed. The patients watched several video clips of short duration--including such things as landmarks and people, along with other clips of Homer Simpson, Jerry Seinfeld, Tom Cruise and others. As the patients watched, the researchers recorded the activity of many neurons in the hippocampus and a nearby region called the entorhinal cortex, that responded strongly to individual clips. A few minutes later, after performing an intervening task, the patients were asked to recall whatever clips came to mind. "They were not prompted to recall any specific clips," said Fried, "but to use 'free recall;' that is, whatever popped into their heads." The researchers found that the same neurons that had responded earlier to a specific clip fired strongly a second or two before the subject reported what he had recalled (but did not fire when other clips were recalled). Ultimately, it was possible for the researchers to know what clips the patients recalled before they even said it.



