Scientists find key to improved memory
Their findings show that the better the coordination between hippocampus and left perirhinal cortex (LPRC) - two parts of the brain previously linked with memory formation - the less likely we are to forget newly obtained information.
"When memories are supported by greater coordination between different parts of the brain, it's a sign that they are going to last longer," said Lila Davachi, an associate professor in New York University's Department of Psychology and Center for Neural Science.
It is commonly understood that the key to memory consolidation - the cementing of an experience or information in our brain - is signalling from the brain's hippocampus across different cortical areas, researchers said.
Davachi and Kaia Vilberg, a postdoctoral researcher at the University of Texas, examined how memories are formed at their earliest stages through a series of experiments over a three-day period.
The researchers aimed to encode, or create, new memories among the study's subjects. They showed participants a series of images - objects and outdoor scenes, both of which were paired with words.
Subjects were asked to form an association between the word and image presented on the screen.
On day two, the subjects returned to the lab and completed another round of encoding tasks using new sets of visuals and words.
This allowed the researchers to 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.
Participants were placed in an MRI machine - in order to monitor neural activity - and viewed the same visual-word pairings they saw on days one and two as well as a new round of visuals paired with words.
They then completed a memory test of approximately half of the visual-word pairings they'd seen thus far. On day three, they returned to the lab for a memory test on the remaining visuals.
By testing over multiple days, the researchers were able to isolate memories that declined or were preserved over time and, with it, better understand the neurological factors that contribute to memory preservation.
Their results showed that memories (ie, the visual-word associations) that were not forgotten were associated with greater coordination between the hippocampus and LPR.
By contrast, there was notably less connectivity between these regions for visual - word associations that the study's subjects tended to forget. The study was published in the journal Neuron.