TL;DR Caffeine has several positive effects on your brain, especially in terms of concentration and mental performance. Experts say that the optimal way to maximize these effects is to have caffeine every 48 hours.
What if I tell you that aside from perking you up, caffeine can also help you concentrate and become more productive?
If, during mind-numbing, brain-wracking moments, you want to feel like Popeye going for a whole can of spinach, just reach out for the coffee-maker and you’re likely to feel the same! (For the best java experience, know when’s the best time to drink your coffee here.)
Caffeine can also help you absorb information and remember it more efficiently.
Yep! Our favorite stimulant can boost mental performance in more ways than one. Have a cuppa and you’ll find yourself retaining more information from classes and business meetings, kill it in planning and problem-solving, and finish those day-to-day tasks efficiently.
Without further ado, here are 8 ways caffeine can help us take a step closer to becoming Einstein-genius:
In fact, according to the European Food Safety Authority (EFSA), there’s a direct causal relationship between 75mg of caffeine, which is equivalent to a tall cup of coffee, and a higher level of attention and alertness. 
If you find yourself lacking focus and alertness because you stayed until the wee hours last night, fret not. You can turn to caffeine for an instant rescue.
According to various studies, caffeine can help pull you through extremely sleepy but highly-important-to-stay-awake moments, such as:
Cognitive function refers to our body’s ability to absorb and retain information and knowledge. Specifically, it involves learning, memory, reasoning, attentiveness, and language.
According to a study done by researchers from the Department of Psychiatry and Clinical Psychobiology at the University of Barcelona, caffeinated beverages mixed with sugar (glucose) can “improve cognitive performance in terms of sustained attention and working memory.” 
Studies also show that caffeine helps you learn more efficiently by up to 10%. 
Johns Hopkins researchers have found caffeine to be an effective memory-enhancer. Specifically, a study conducted in 2014 concluded that caffeine can help you remember things for up to 24 hours, even enhancing long-term memory. 
According to Michael Yassa, an assistant professor of psychological and brain sciences at Johns Hopkins and the team lead of said study,
"We've always known that caffeine has cognitive-enhancing effects, but its particular effects on strengthening memories and making them resistant to forgetting has never been examined in detail in humans… We report for the first time a specific effect of caffeine on reducing forgetting over 24 hours.”
A 2005 study conducted at the Medical University at Innsbruck, Austria shows that caffeine promotes higher activity in parts of the brain involved in planning, attention, monitoring, and concentration. 
It may be hard to imagine how caffeine, a stimulant, can be used as a potential treatment to ADHD. But studies have shown that caffeine can help with ADHD, as it:
For more information, check out this article on “Does caffeine help control ADHD?”
A 2008 research conducted by B. Sökmen, L.E.Armstrong and their team found that caffeine boosts cognitive function among athletes, especially when taken before a training exercise. It has been reported to improve concentration especially when the athlete lacks a good night sleep the prior night. 
Related article: How much caffeine is allowed in sports?
With all these brain-wracking benefits of caffeine, one question remains:
How do we make the most of our caffeine fix?
The answer is plain and simple according to this article from QT: For an optimal mental performance, have a cup every 48 hours.
The hack is simple: if you are an average adult, a cup of coffee every 48 hours will do the trick. (Disclosure: I’ve been doing this for more than two years.) A typical cup of coffee contains 80mg of caffeine, which as a non-addict should be enough to give you the mental boost. You can have a double espresso shot too, if you like. The half-life law will ensure that most of it is out of your system in 48 hours. But break the 48-hour-gap law at your own risk.
However, if 48 hours is too much of a wait for you, don’t worry. You can still have your java multiple times a day without getting over-caffeinated. Just keep in mind how much caffeine you should have in a day.
To find out more about how exactly coffee works on your brain, watch this video:
We have good news for lovers of America’s two favorite mood-altering substances, caffeine and marijuana: Caffeine may enhance a pot smoker’s high.
The downside is that caffeine can also increase the chance of becoming addicted to cannabis.
If you often find yourself going to a room in your house only to forget what you’re meant to do, or talking about a movie character you’ve seen so many times but can’t remember the name of, then one thing is going on.
It’s so easy to dismiss these as simple moments of forgetfulness. But if this happens a lot, then it may be your body sending you a signal to do something and beat brain fog.
The writer, Dan Charles, bought a 4-ounce bag of caffeine and said it had as much caffeine as 1,000 tall Starbucks lattes. He said this caffeine was created in coffee beans on a hillside in the tropics. “Slowly and quietly, driven by the energy of sunlight, it formed inside coffee beans hanging on thousands of trees, most likely in Brazil or Vietnam,” Charles wrote.
“Those beans were harvested, loaded on ships bound for the port of Houston, Texas, and ended up at a factory within sight of downtown Houston: Atlantic Coffee Solutions. It’s owned by one of the world’s largest coffee traders, ECOM Agroindustrial Corp., which is based in Switzerland.”