Kinda sorta definition
Multitasking is never really concretely defined in any of my reading, but the definitions all seem to revolve around the idea of a person or thing performing more than one action at a given time. I'll go a step further, saying that there are two categories of actions that people and things can do: mental and physical. I really don't think this is cheating the definition as a person's center of thought, the brain, is generally in control of both mental and physical action in humans. The part of the first definition I have a hard time getting my head around is with regards to the time that passes between two actions taken. I find it really minimizes how much we can discuss as multitask-able actions if a second, millisecond, or frame is the window humans actually have to do two things simultaneously. I also believe that most research around this topic revolves around scenarios where people do more than one thing over a period of time. So...for purposes of keeping pace in this post, we'll define multitasking as follows:
The ability of one person to perform more than one action, mental or physical, over the course of a given period of time.
At the end of the post I'll have a neat twist on this, as well, so bear with me.
Games tend to force people into scenarios requiring multitasking
Be it for better or worse, video games put players in scenarios that fit that definition constantly. To cite a pretty recent example that I was having a lot of fun with:
To get to my citation, this quest wants you to set yourself on fire, launch off the jump pad, and butt slam onto the tiny hoop on the opposite side of the basketball court (I won't delve into how one gets to this quest, it's actually quite funny, but irrelevant). This may sound like a sequence of events, and to be fair, the setting yourself on fire portion is achieved before entering the execution of the slam dunk. After being set aflame, you launch off the jump pad for a single attempt at this action. This jump pad is less reliable than others in the game, forcing you to adjust your movement in midair, both by looking with the mouse and adjusting player location with the WASD keys. There are cameras constantly flashing, intentionally distracting the player, all the while the fire effect is disrupting the player's UI. The mind is effectively purposefully ignoring extraneous sensual input, keeping the mouse moving to keep a constant eye on the hoop, slightly tapping four other keys to adjust positioning while judging when the right point to hold down the crouch button is. That is a lot of processing going on!
The first time I did this quest I think I was at it for about fifteen minutes. I was still new to the new aerial controls and I'm not terribly great with first-person shooter controls to begin with. This felt like a nightmare trying to coordinate my mind to do all of the things necessary up until the final push of the crouch button. This screenshot was taken on a second play-through where I was much more comfortable with the controls, and it still took multiple tries, yet far from an autonomous response at a player perspective. Games do this kind of thing all the time, and while seemingly frustrating, they're still quite fun. It's cool to challenge yourself physically and mentally in these scenarios, which I'm certain are well thought out while being designed. They're intentionally expecting players to attempt multitasking to accomplish goals like these.
Apparently this is bad for you
This kind of activity is supposedly bad for the human brain. Studies have shown that prolonged multitasking can show regression in the mind to the point of displaying up to 15-point drops in IQ. It's something that was always thought to be recoverable, similar to a brain drain after pulling an all-nighter, but MRIs performed on individuals that multitask show lower brain density in regions controlling cognitive and emotional control.
This seems a little scary after accepting that players enjoy being put into physically and mentally challenging situations that encourage attempts at multitasking. These studies are actually a little inconclusive as to if multitasking is the cause of brain damage or if existing brain damage is amplified by it. In either case, there is plenty of research taking place that is doing a pretty decent job at showing that multitasking has negative effects on temporary, and potentially long-term, human cognitive ability.
But wait...gamers are benefiting from this exposure
If games, some of which employ the need to multitask a lot, do this, why are players so efficient? The U.S. Government went through big phases wondering if virtual training sessions were effective for dealing with real-world scenarios. Turns out their research goes even further than just their virtual training exercises.
Studies show that video game players perform 10-20% higher in areas of perception and cognitive processing than non-game players. It's also proven that players exhibit greater short-term memory, can focus for longer periods of time, and have a larger field of vision. This may not directly contradict the studies that say multitasking is bad for brains, but in an environment where that type of activity is commonplace, the brain actually grows.
You can't deny some things proven are indeed true
So, we come to a little bit of an impasse. One of the most multitask-heavy mediums is showing growth in the same cognitive regions of the brain that studies also show being reduced by multitasking. What makes games have a positive outcome out of all of this activity? Perhaps the problem-solving aspects outweigh the multitasking negatives? But these scenarios players are tasked with solving involve both thinking and acting on something very quickly over a given period of time.
The other side of the coin, how research is carried out regarding multitasking outside of games, is kind of interesting and may shed some light on this anomaly. Whenever I'm reading about multitasking research, humans are generally asked to carry out tasks that have absolutely no relation. Things like read this book and speak this poem, write this paragraph and boil this egg, eat this taco and drink this water; but those are the kinds of things people are asked to do.
But guess what...
Games are applying this differently
Think of just about any wartime first-person shooter. The player is acting as a soldier on a front line of some sort. This is a pretty advanced time setting, so the soldier has their vitals displayed before them. They are receiving mission critical advice from their superior while the map next to their vitals is updated with the location of the next target to reach, all while fending off enemy troops and constantly considering when the opportune time to move and reload is.
Granted, most players don't actually take in all of this at once. But they do take in more than the average person would be taking in doing office work. The mission's success is dependent on being able to survive these scenarios, so as long as game's like these are beaten, players are utilizing a good chunk of this information coming in at them. You might notice that games do this quite often, and after getting used to the style of immersion the game offers, the player is able to comprehend and continue on. What these tasks are doing are working together to aid the player in the execution of said tasks.
Through cooperative cognitive processing
I just made that phrase up, but it sounds about right. Games give players lots of tasks. A good amount of games, and a great deal of mainstream ones, have a lot of tasks being given very quickly. Each of these tasks that the game is asking the player to perform have tells and helpers to assist the player in ultimately reaching the goal. Left thumb to position and right thumb to look, accomplishes the goal of targeting the enemy. Some games will offer a “soft” targeting lock to assist in getting the player there, rewarding them for getting in the ballpark of the zone necessary to complete the goal.
Reaching the next target area is similar in that the player knows they have to go somewhere. Their communications unit just displayed the objective, the goal: reach the extraction point. The map next to their vitals display pulses the general area of the target point while the radar is picking up nearby enemies. They're coming in fast and blocking the best path to the player's goal and a fight breaks out. Their partner communicates alternate paths that the player can take all the while trying to survive the fire fight.
These scenarios put the player into very difficult positions that will require them to fight, move, listen, and plan nearly simultaneously. The player is immersed in these scenarios and ultimately comes out on top. And these kinds of situations are actually increasing the player's cognitive ability. The secret here seems to lie not necessarily in multitasking itself, but in what these tasks are trying to accomplish. When every action a player takes is toward a common goal, the ability to handle multiple tasks becomes both easier and beneficial to cognitive function.
I said there would be a twist by the end, so here it is. Multitasking isn't a real thing. Humans have one brain. One processor. It's not [yet] possible for a human to send off signals to do things in complete simultaneity. Even activities like snapping your fingers together with both hands are just very quick back-to-back electrical signals running across synapses telling your hands to do things simultaneously. While the action is seemingly in sync, the precursor to that, very likely, is not. Human brains are just so fast that it's really hard to catch that there are gaps in action, both mental and physical. What people are actually doing and researching is the ability to swap between actions very quickly.
I don't think this is discouraging, though. Really, all of these signs point to games using this ability in ways that nurture player growth in and out of the game world. Game developers put a lot of thought into how many tasks is too many, and how the game can assist the player in achieving the goal these tasks are meant to reach.
And games aren't the only medium doing action-swapping correctly. Mediums such as music also employ doing things in a multitask-able manner. Think of any drummer you've seen perform. I'm a percussionist so I can tell you that every limb is needing to work on its own accord. But each of those actions performed together allow the drummer to reach a goal: the groove.
I'm not reaching for any real statistics for this one, but people who play games and people who play music tend to be very cognitively efficient. I don't think that's a mistake. I think the way both types of people employ their brain has a high impact on this outcome. As long as developers and composers consider the concept of actions that reach a common goal, multitasking seems to be a fine way to challenge and mold a more efficient human.