It's the end of the day, you have no idea where the day went, and you still have a day's worth of work to do. If only you could get more done in the day--if only your brain worked faster! We've all had these thoughts. In fact, people's desire to accelerate and improve our cognitive function is common enough that, in recent years, several companies have built brain-training products that promise to help. One app, Lumosity, gained over 50 million users in seven years. Other apps, like Posit Science, CogniFit, and Memoranda, have raised millions of dollars from investors.

While these games might make us feel like our brains are becoming faster and smarter, this might not actually be the case. Earlier this year, Luminosity paid the Federal Trade Commission $2 million in settlement fees after being charged for making deceptive claims about the effectiveness of its product. The company had promised users that its games would help people perform better at work and school and even help prevent future cognitive impairments. The FTC said, "Lumosity simply did not have the science to back up its ads."

So if the games that are intentionally engineered to accelerate our cognitive function don't actually work, is there anything that does?

People generally turn to brain-training games to help improve their brain's capacity in a variety of ways, including memory, focus, creativity, and speed. While there may not be one single golden bullet to improve all of these, psychology provides us with unique ways in which we can work to improve individual skills.

To improve your memory, learn something new and exciting.

In a 2014 study, researchers at the University of Texas found that when people engaged themselves in learning something new over a period of time, it enhanced their memory function. The key here was that people had to be learning something that was intellectually stimulating and demanding (in this case, it was quilting and/or digital photography). Instead of repeating the same memory tricks and games, find something that excites you and get deep into learning it. This new craft could be work-related (for example, learning how to code or run a campaign) or something you find personally fascinating (like learning how to play a musical instrument or woodworking).

To be more focused, cue up your favorite tunes.

In a study published in Scientific Reports, it was found that listening to our preferred music (be it Beethoven or Beyoncé) activated neural circuits that are important for internally-focused thoughts. Participants hearing music that they liked were able to better tune out their surroundings and focus internally. When it's time to focus, it may not be necessary to sit in silence, and it may also be OK that everyone on your team doesn't agree on the same "work tunes." Simply put on your headphones and listen to whatever music you like best.

When you want to be creative, tire yourself out.

Though you probably want your brain at its sharpest for an important presentation, tiring it out may be a better way to go when you're aiming for creativity. We are most creative when we let our minds wander, going into seemingly irrelevant spaces where we can make non-obvious connections. This effect was demonstrated in one study where people were better at solving analytic problems during their optimal time of day (e.g., in the morning, if they were morning larks), while they were more successful at coming up with creative insights during their non-optimal time of day (e.g., at night, if they were morning larks). Figure out when you work best, then test your creativity at the opposite end of the day.

To speed up your mind, eat healthy snacks.

Fluctuation of insulin levels can slow down your brain's response times and prevent you from performing at the best of your abilities. When your insulin is too high--or too low--it can negatively impact your brain function. In one study conducted at Brown University, researchers found that rats whose bodies were not efficiently processing insulin had trouble making their way through a maze. The takeaway here is to keep yourself nourished throughout the day. Even when things are crazy, try not to skip meals or binge. Instead, have healthy snacks throughout the day to keep your brain moving at the speed you need.

Though there may not be some special pill or magic game you can play to improve your cognitive function, there are several simple ways you can set yourself up to perform at an optimal level for your task at hand. And when it doubt, remember: mind over matter.