Memory (among other things) is impaired when you are sleep-deprived, and having a full night of sleep (around eight hours, depending on the person) maximizes the potential for accurate memory retrieval. It’s not yet clear as to why this happens, but there is no denying the immense research behind these findings. In the first study to show an interaction between hippocampal-cortical regions and long-term memory, research from New York University now suggests that rest — even while awake — is important for memory as well. So when it comes to studying, relax!
Published in the Jan. 28, 2010 issue of the journal Neuron, the study was headed by Arielle Tambini, an NYU graduate student. Researchers scanned participants in a functional magnetic resonance imaging (fMRI) machine before the experiment began to measure their neural activity while in a relaxed state. The researchers then showed participants numerous picture-pairs, one a human face and the other an object, and told them to imagine that the person in the face-picture is interacting with the object in the object-picture. Participants were told to rest and think about anything they wanted to for a few minutes and were subsequently scanned via fMRI. The procedure was repeated with new picture-pairs. Finally, researchers gave a pop quiz to see if participants could recognize whether or not a face and an object had been paired together.
The fMRI scans were used to compare neural activity during rest with neural activity both before and after the visual tasks. The experimenters scanned two brain regions associated with memory: the first was the hippocampus, which is associated with episodic memories (e.g., emotional or vivid memories about events), and second, the visual cortex, which is associated with vision. They found that the correlation of the two brain regions’ activity predicted how well each participant performed on the memory test, suggesting that whatever was happening during rest was actually facilitating memory-consolidation. As memory expert Barry Gordon from Johns Hopkins University said, “The brain is trying to weave ideas together even when you don’t think you are thinking of anything.”
For students, this is another good reason to manage your time effectively and take breaks, instead of trying to learn too many things at once. Memory involves three processes: encoding, storage and retrieval. So after you read something (encoding), you should rest to allow your brain to make connections about your newly acquired information (storage) in order to increase your potential for remembering it (retrieval). However, you must keep in mind that this research entirely involved pictures, and it was a recognition task (i.e., multiple-choice), not a recall task (i.e., fill-in-the-blanks.) So far, there is no official research to support that taking breaks improves memory of text-based activities, like reading a textbook.
Maurizio Corbetta and others from Washington University published a paper in Proceedings of the National Academy of Sciences in August 2009, indicating that two separate regions in the cerebral cortex were correlated after a visual task, but not before. This suggests that rest was the key factor that led to improved memory. Dale Stevens of Harvard University published a paper in December 2009 in the journal Cerebral Cortex on brain activity of participants remembering landscapes vs. faces. He believes that his research shows that there is a distinct memory-consolidation event that occurs when we rest. These studies are bound to have an impact on cognitive psychology research in the future.
Just imagine the implications of what it would mean if rest truly solidifies memory. If you take two people who are — for the purpose of this argument — in all ways equal and you have them study for a test for four hours, the student who takes some breaks (which, in effect, means they end up studying less) might actually perform better on a subsequent exam. This is not a newly-observed phenomenon, but now there is a neurological explanation for it. So for any anxious students out there, instead of trying to cram for exams, it may be more beneficial if you take breaks and let your brain do the rest (no pun intended.)
