Researchers Rethink Basis of Faulty Memory
Researchers at UC Irvine said this week that they have evidence faulty memory can result less from forgetting things than from not “getting” them in the first place.
The discovery could have a major impact on the way doctors treat patients with memory disorders such as Alzheimer’s, said Dr. Mike Alkire, who teaches anesthesiology at the UCI School of Medicine.
“We’ve always thought that if you can’t remember something it’s a problem of retrieving the information,” Alkire said. “What we found is that the problem [could] be that it was never stored.”
That conclusion stemmed from a study Alkire and several colleagues conducted in which they recited a list of nonemotional words such as “accept,” “garden,” “spot,” and “blanket” to eight UCI students while simultaneously scanning their brains. Then, 24 hours later, the students were asked to recall as many of the words as they could.
In every case, Alkire said, those who remembered the greatest number of words had also registered the highest degree of electrical activity in a part of their brains called the para-hippocampal gyrus during the actual recitation. .
This demonstrates two things, Alkire said. First, it confirms studies showing that unemotional memories are stored in the para-hippocampla gyrus, as opposed to more emotional memories stored in another part of the brain, the amygdala. Alkire’s work extended the earlier studies to include longer-term memories.
Finally, Alkire said, the study suggested that some patients with memory loss may be better treated by medications aimed at improving their initial memory “imprints” rather than their ability to retrieve those memories later.
“By understanding how the memory circuits work,” Alkire said, doctors can begin unraveling how to improve them. Among other things, he said, the study may point the way toward future techniques of evoking the power of the amygdala, associated with emotional memories, to improve the retention of the more mundane memories associated with the para-hippocampla gyrus.
Alkire’s findings, part of an ongoing study begun in 1994, were published in this week’s edition of Proceedings of the National Academy of Sciences, a scientific journal.
The doctor said he got interested in the physiology of memory after observing how some patients retain memories of surgical procedures taking place after they had ostensibly been put to sleep. The next step, he said, is to monitor the effects of various hormones on long-term memory.
