Does caffeine really give you wings or hold you down?
Surely, you are aware of the caveats concerning regular caffeine consumption – increased tolerance and need, interruption of the sleep cycle, possible dehydration, anxiety, headaches, fatigue and depression.
And if you weren’t aware, you are now.
But in spite of these downsides, many students use coffee, tea, or energy drinks in perking themselves up, pulling all-nighters, or pumping out papers at the last minute. Acknowledging this fact, we would be wise to reexamine how this stimulant affects our cognitive functioning.
First off, a review of the chemistry. Caffeine works, chemically, in three different but related ways. It enhances alertness by inhibiting the action of adenosine, the compound which promotes sleep and suppresses arousal. It gives you a physical boost (increases heart rate, blood flow to major organs, and respiration) by increasing the amount of adrenaline in your system. In addition, it contributes to a euphoric state by stimulating the production of dopamine, the chemical which activates the brain’s pleasure centers. In combination, these effects create what we feel as “energy,” which kindles our creativity and awareness, and make us feel as if we are able to perform or study better. But are we really?
Caffeine addiction symptoms can be subtle
There have been innumerable studies done to try to ascertain some set of rules governing caffeine’s effect on our mental performance. Though wildly inconsistent, most of them find a correlation between moderate intake and improved attention, recollection, and reaction time (at least withing the first 30-90 minutes following consumption). Hence, the usual recommendation is that people monitor and moderate their intake based on the hierarchy of caffeine content in order to maximize benefits and minimize adverse effects.
The tasks assessed in these studies are extremely low-level. Some include watching for particular numbers to flash on-screen, trying to memorize and recall a list of twenty words a few minutes after exposure, tapping two piano keys as fast as you can, or assessing the validity of the phrase “dogs have wings”. For a review of studies over the last fifteen years, you can check out this issue of Nutrition Bulletin.
Students have to perform a significant amount of low-level “grunt work”, such as learning new terminology, internalizing new processes, or regurgitating information for evaluation. For increasing alertness to complete these types of simple tasks, a caffeinated beverage might be the perfect companion.
When it comes to higher-level thinking, the jury is still out. Some tests show that arousal from caffeine makes us more easily distracted, others show that it helps us make complex decisions more quickly, but whether or not they are good decisions is difficult to tell.
Caffeine can be an aid and a distraction
A few recent studies do point to a positive effect on working memory (the ability to temporarily store information for the purpose of doing more complicated tasks), but again, the tests are extremely rudimentary (“tell me if this letter is the same or different than the second-last one that I showed you”). These exercises are hardly comparable to things like solving an engineering conundrum, rebutting an attack during a political debate, or critiquing fixed-form poetry.
Probably the most respected opinion on caffeine’s effect on cognitive performance is that of U.S. Army Research Institute psychologist Harris Lieberman:
“Caffeine improves alertness and reaction time in people, whether they’re habitual consumers of caffeine or not, but the effect is clearly limited to the ability to maintain attention. Things like memory or complex reasoning won’t improve.”
It’s clear that caffeine affects different people in radically different ways. For example, some people have a predisposed preference for caffeine, while others do not. Furthermore, there is at least one set of known genes variants that cause sometimes-positive, sometimes-negative impacts on one’s level of anxiety. There are even indications that caffeine has a greater effect on introverts than on extroverts.
The general effect of caffeine on our mental performance is unequivocal; it heightens your senses, your mood, and your overall brain activity. But given the seemingly multi-faceted influence on specific school-related cognitive activities, it is important that you observe how you react personally to different amounts of caffeine, and under what circumstances it works to help you achieve your goals.