Neuroscientists at Stanford and Harvard have been able to show that neural activity in certain brain regions predicts what experiences will be remembered later. The study at Stanford involved memory for scenic photos while the study at Harvard involved memory for words. Both are reported in the Aug. 21 issue of the journal Science, along with a commentary article about them. Scientists have long suspected that people remember some things better than others partly because of differences in the way the initial experience is encoded into the brain. These are the first studies to show which parts of the brain determine whether a specific, current experience is fated to be remembered or forgotten.
Both studies took advantage of new developments in functional magnetic resonance imaging to obtain measures of the neural activity of volunteers as they viewed words or photographs, one at a time. (Only recently has the temporal resolution of imaging been sufficient to allow brain activity to be measured separately for each picture or word.) Previous studies had indicated more neural activity when volunteers were presented with novel photos than when they were presented repeatedly with the same ones, but the earlier work had not determined the quality of their later memories for the photos.
The research at Stanford was conducted by James Brewer, a graduate student in neurosciences and in medicine; associate psychology Professor John Gabrieli; radiology Professor Gary Glover; and research associates Zuo Zhao and John Desmond.
Gabrieli said that people with memory difficulties as a result of brain injuries or diseases like Alzheimer often have vivid memories for events early in their lives but do not remember recent experiences.
"This gives us the tool to ask whether such selective problems in memory for
recent events occurs due to poor initial encoding -- the memory is never formed
in the first place -- or later difficulties of storing or using the memories," he
Contact: Kathleen O'Toole