Dr. Kaia Vilberg, a post doctoral researcher who has recently taken up a position at the University of Texas’ Center for Vital Longevity and School of Behavioral and Brain Sciences in Dallas, has published new research in this month’s journal, Neuron, revealing how and why some memories last longer.
With an interest in human cognition and memory, Dr. Vilberg, working with Dr L. Davachi, an associate Professor at the Department of Psychology and Center for Neural Science, New York University, performed studies to examine how memories are formed. They asked study volunteers to undergo a series of experiments over a three-day period in which they were shown a series of images on a screen and were given words to associate with each image.
In this study, participants were presented with new series of images on day one and day two. After a short break on day two, participants were placed in an MRI machine—in order to monitor neural activity—and were shown the same visual-word pairings they saw on days one and two. They were also presented with a new round of visuals paired with words. Participants then completed a memory test of approximately half of the visual-word pairings they’d seen thus far. This allowed the researchers to study and compare two types of memory: the more consolidated, long duration (LD) memories encoded on day one with the less consolidated, short duration (SD) memories encoded on day two. Finally, the volunteers returned to the lab for a memory test on the remaining visuals.
By testing over multiple days, it was observed that the visual-word association memories that were retained were associated with greater coordination between the two parts of the brain linked with memory formation, the hippocampus and left perirhinal cortex (LPRC).
“These findings show the brain strengthens memories by distributing them across networks,” explained Davachi. “However, this process takes time. Day-old memories show greater coordinated brain activity compared to recent ones. This suggests that co-ordinated brain activity increases with time after a memory is initially formed.”
Photo from http://3.bp.blogspot.com