It’s that time of year again when students flock to the library and the exam period fear can be seen in our eyes. All of the current Antisense Science team are 3rd year students on the brink of graduation, but with the finals mountain to climb first, an obvious change can be seen in students in the grip of revision. Apart from looking like zombies and having an all-time high risk of mental-meltdown at any moment, what changes actually occur within our bodies during these periods of intense studying?
Naturally our brains must change, right?
You would suspect that if any changes occurred in the body of a student it would be in the organ that is needed for learning and memorising facts. A study looking at changes in the brain of a group of medical students studying for a set of exams showed that grey matter “increased significantly in the posterior and lateral parietal cortex”. Grey matter contains most of the brains neuronal cell bodies, as opposed to white matter which consists mainly of long-range axons that relay information but don’t actually control any bodily functions. This finding suggests that “use-dependent” increase in synaptic strength is involved in memory storage, so, rather encouragingly, all that information is sticking somewhere (even if it doesn’t feel like it!). The same students were also tested 3 months after the exams to see if there were any long term effects on brain structures – interestingly, grey matter levels were higher in the hippocampus after the exams then during the revision period. It was suggested that this could be due to stress experienced by the students before the exams, as stress has been shown to reduce hippocampal volume and reduce plasticity. However the hippocampus is very important in learning in memory, so try not to stress… if you can. So, your brain can not only take on all the information you feed it but also it can change its structure to adapt to the period of intense learning. Pretty nifty!
The brain is also known to be a large consumer of ATP (the body’s form of energy), accounting for around 20% of the resting metabolism. This is due to the energy used in synaptic transmission (the mechanism of sending information around the brain amd body) and also in forming memories. So in a period of intense learning are you therefore using more energy? One study that evaluated the amount of energy that this signalling uses found that “an increase in mean firing rate of 1 Hz increases ATP consumption (in rodents) by 6.5 μmol ATP/g/min” so your brain does actually use more energy if there is an increase in signalling, which is unsurprising. The brain does have other mechanisms to deal with the increase in firing such as using differential firing methods so that energy is used more efficiently and the increase in ATP consumption is moderate. Maybe not enough to justify that 5th bar of chocolate, but….
Feeding Your Brain Doesn’t Just Involve Reading
Research into high calorie food cravings has shown that refraining from giving into these urges can actually impair your working memory. When subjected to food-cues participants in the study made more errors and had longer reaction times in a series of test, especially when exposed to images of high calorie foods. If your mind is on chocolate or whatever it is you crave, for the sake of your exams it might be best to succumb to the sweets!
Revision cramming is definitely a strange time for a student and it can lead to very unproductive behaviour: “all-nighters” and nights of excess alcohol indulgence (when it all gets a little too much!) are just a couple of signs you’re nearing the breaking point! However, activities like these have been shown to have detrimental effects on hippocampal function and memory formation. Stress can also cause changes in the body that if sustained can lead to dangerous effects and even an increased risk of stress related death. Unfortunately, it looks like science is saying that the “keep calm and carry on” attitude to revision might actually be the most effective.
Like the Antisense Team have come to realise, revision is simply unavoidable. But at least you might have broken up the boredom a little by reading about some of its interesting effects on your body and brain – just try and work with it and not against it!
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Meule A, Skirde AK, Freund R, Vögele C, & Kübler A (2012). High-calorie food-cues impair working memory performance in high and low food cravers. Appetite, 59 (2), 264-9 PMID: 22613059
Attwell D, & Laughlin SB (2001). An energy budget for signaling in the grey matter of the brain. Journal of cerebral blood flow and metabolism : official journal of the International Society of Cerebral Blood Flow and Metabolism, 21 (10), 1133-45 PMID: 11598490
Draganski B, Gaser C, Kempermann G, Kuhn HG, Winkler J, Büchel C, & May A (2006). Temporal and spatial dynamics of brain structure changes during extensive learning. The Journal of neuroscience : the official journal of the Society for Neuroscience, 26 (23), 6314-7 PMID: 16763039