New Insight into the Brain’s Timekeeper
Neurobiology and Behavior Professor Michael Yassa has published a new manuscript in the journal, Nature Neuroscience. In the study, led by Professor Yassa’s graduate student Maria Montchal, the research team identified areas of the brain that control how people precisely remember the correct order in which recent events have occurred.
Brain networks involving the entorhinal cortex, a region that surrounds a key memory center known as the hippocampus, have been previously shown to play important roles in memory formation, particularly in the identification and arrangement of objects in the environment. Professor Yassa and collaborators sought to determine if the entorhinal cortex plays a role in recording an object’s temporal information as well.
With the use of a high-powered functional magnetic resonance imaging (fMRI) scanner, the researchers tested the temporal memory of college students by scanning their brains after watching a popular TV show. After viewing the show, while remaining in the fMRI scanner, students were shown still-frames of the episode and asked to indicate on a timeline when the event occurred. They found that when the students had more precise answers to questions about what time certain events occurred, they activated a brain network involving the lateral entorhinal cortex, as well as an associated area known as the perirhinal cortex.
Previous work by Professor Yassa had shown that the lateral entorhinal cortex and the perirhinal cortex are associated with memories of objects, but not their location. The new study shines light on how these two brain regions might process information about an object’s time, adding another clue to the mystery of how a full memory is formed.