Why you shouldn’t cram your brain before an exam


It’s well known that synapses in the brain, the connections between neurons and other cells that allow for the transmission of information, grow when they’re exposed to a stimulus. Now new research from the lab of Carnegie Mellon Associate Professor of Biological Sciences Alison L. Barth has shown that in the short term, synapses get even stronger than previously thought, but then quickly go through a transitional phase where they weaken.

“When you think of learning, you think that it’s cumulative. We thought that synapses started small and then got bigger and bigger. This isn’t the case,” said Barth. “Based on our data, it seems like synapses that have recently been strengthened are peculiarly vulnerable — more stimulation can actually wipe out the effects of learning.”

Psychologists know that for long-lasting memory, spaced training — like studying for your classes after very lecture, all semester long — is superior to cramming all night before the exam. This study shows why. Right after plasticity, synapses are almost fragile — more training during this labile phases is actually counterproductive.

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