Direct Evidence of Role of Sleep in Memory Formation is Uncovered

September 16, 2009

Science Daily/Rutgers University

A research team has pinpointed for the first time the mechanism that takes place during sleep that causes learning and memory formation to occur. The team has determined that short transient brain events, called “sharp wave ripples,” are responsible for consolidating memory and transferring the learned information from the hippocampus to the neocortex, where long-term memories are stored.

A Rutgers University, Newark and Collége de France, Paris research team has pinpointed for the first time the mechanism that takes place during sleep that causes learning and memory formation to occur.

It’s been known for more than a century that sleep somehow is important for learning and memory. Sigmund Freud further suspected that what we learned during the day was “rehearsed” by the brain during dreaming, allowing memories to form. And while much recent research has focused on the correlative links between the hippocampus and memory consolidation, what had not been identified was the specific processes that cause long-term memories to form.

“This is the first example that if a well-defined pattern of activity in the brain is reliably and selectively eliminated, it results in memory deficit; a demonstration that this specific brain pattern is the cause behind long-term memory formation,” says Buzsaki.

The research also represents a move toward a new direction in neuroscience research. While previous research largely has focused on correlating behavior with specific brain events through electroencephalogram, neuronal spiking and functional magnetic resonance imaging studies, increasingly researchers are challenging those correlations as they seek to identify the specific process or processes that cause certain events and behaviors to take place.

http://www.sciencedaily.com/releases/2009/09/090915174506.htm