Cramming: Quick Fix or Cognitive Disaster?

It’s the night before a test. You haven’t reviewed any of your notes, and the clock is ticking. So, like millions of students, you cram information, hoping a marathon study session will save the day. But while cramming might help you scrape tomorrow’s exam, it could come at a cost to your memory, performance, and mental health.

To understand these harmful side effects, we must look at how memory works. Memories are formed in the hippocampus, which is located within a larger structure in the brain known as the temporal lobes. There are two main forms of memory. Short-term or “working” memory, handled by the prefrontal cortex, is used by your body to quickly organize, process, and use information. However, this kind of memory is limited and fragile and thus can be easily overwhelmed. Long-term memory, on the other hand, requires deeper processing and involves a network of brain regions, including the basal ganglia, cerebellum, neocortex, striatum, and amygdala. Regions like the hippocampus organize and store new facts, working together with other regions like the cerebellum, which is crucial for procedural memory, to create long-lasting neural connections. 

One reason why cramming fails is because the brain forgets information over time. This pattern, called the Forgetting Curve, was discovered by psychologist Hermann Ebbinghaus. His research showed that memory retention drops steeply after learning, with up to 70 percent of new information being forgotten within 24 hours if not reviewed. This is because when we recall information, specific groups of neurons located in these parts of the brain, called ensembles, are reactivated. The more often an ensemble is activated, the stronger those memories become. Since you only reactivate these ensembles a few times during a cramming session, the information only fills short-term memory.

So, if cramming fills short-term memory, why is it harmful? For one, cramming causes a rush of adrenaline and cortisol, heightening alertness and facilitating learning. However, this stress can also lead to dendritic atrophy, meaning neurons’ connections with other neurons shrink, losing complexity. Dendritic atrophy is associated with volume and neuronal density decrease in the hippocampus, impairing cognitive functions like attention, memory, and problem-solving.

Furthermore, cramming can be detrimental to one’s health. When cramming, students often rely on excessive amounts of caffeine or other mental stimulants. Caffeine’s effects are frequently underestimated because of its everyday use, but it works by blocking adenosine receptors, which disrupt natural sleep signals and can alter neurotransmitter activity. While it boosts attentiveness in small doses, excessive consumption may impair memory, increase anxiety, and lead to dependency.

Cramming can also lead to overconfidence. While you may think you are familiar with the material, that is not the same as being able to recall it under pressure, a phenomenon that’s referred to as an illusion of competence. Ultimately, relying on cramming forms a cycle of procrastination, panic, and poor academic performance.

Studies, including those published in the Journal of Neuroscience, have shown that spaced, consistent study schedules consistently outperform cramming in both retention and understanding. In fact, students who used spaced practice remember up to two or three times more information over time compared to those who crammed. Spaced studying involves breaking material into manageable chunks and reviewing it regularly over days or weeks. This gives your brain time to reinforce neural pathways and create lasting memories through a process called long-term potentiation, making the memories more stable and retrievable.

So, is cramming ever useful? It can be, but in limited situations. Cramming can be effective when you need to refresh already learned material or learn a few isolated facts just before a quiz. When used sparingly and strategically, it can help you get through a sketchy scenario, but for long-term information retention, slow and steady wins the race.