Whatever reason you enjoy playing videogames, there is one specific part of the brain that lies behind it.

For some time, game designers have known how to apply the work of the behaviourist B.F. Skinner to videogame design, creating reward schedules (such as levelling mechanics in computer RPGs) that will hook players in and keep them addicted while they play, or setting up short and medium term challenges to overcome in order to produce the same kind of pattern. These reward schedules work because when we win or attain something, the pleasure centre in the brain (the nucleus accumbens) releases a neurotransmitter called dopamine, which is chemically similar to cocaine.

But recent research into cognitive functions using functional magnetic resonance imaging has shown that these are not the only ways to trip the pleasure centre – and in fact, it's starting to look suspiciously as if whichever aspect of videogames you enjoy, the pleasure centre lies behind your enjoyment.

Suppose you are one of those players who hates the grinding for reward that cRPGs and MMORPGs expect their players to follow, much like the rats in Skinner's experiments, and you instead enjoy seeing incredible landscapes and finding wondrous things in games. Brain researchers Irving Biederman and Edward Vessel conducted fMRI scans of people viewing various different scenes and discovered a neurological mechanism for interest (or curiosity) involving the visual cortex, a part of the brain where memory is co-ordinated known as the association area (hippocampus) and a neurotransmitter called endomorphin, which is chemically similar to opium. Surprisingly, their research discovered that this interest mechanism also relied upon the pleasure centre for its sense of reward – if you are motivated by exploration and curiosity, your experience of enjoyment comes from the release of dopamine – just as it does with the grinding in cRPGs.

In all, there are at least six different ways in which a player can trip the pleasure centre and derive enjoyment from a game, the first of which is that related to Skinner's research, and which also matches what Richard Bartle has called the Achiever player in his MMO typing system. The reward of achievement is the release of dopamine from the pleasure centre – this is the most basic way to enjoy a game, and many videogame players respond to this pattern strongly, while others can enjoy it provided the game is also meeting their play needs in other ways.

Then there is the interest mechanism studied by Biederman and Vessel, which in videogames relates to why people remain interested in exploration and other expressions of curiosity, something Nicole Lazzaro has termed Easy Fun, and which relates in part to Richard Bartle's Explorers. The ultimate payoff of this kind of play is wonder – the feeling of slack-jawed amazement when you see something unexpected or utterly incredible. Although as yet the experimental evidence doesn't prove it, wonder is likely to be a large hit of endomorphin, which in turn means a large hit from the pleasure centre.

The classic “hardcore” way of playing videogames is to come up against incredibly challenging and difficult challenges and foes, and strive to overcome them. In our earlier studies we have termed players who enjoy this struggle for victory, Conquerors, while Nicole Lazzaro calls this kind of play Hard Fun. Characteristic of this play style is the emotional hit a player gets when they finally achieve victory (which in Italian is known as fiero). You know this feeling well – it's what makes you punch the air, or raise your arms suddenly, or shout out when you finally get the win. This is your body responding to a large hit of dopamine from the pleasure centre, under specific conditions set up by the gruelling battle you have fought to achieve there – the “fight” in the “fight or flight” mechanism, which is driven by frustration and anger. While gamer hobbyists often value this kind of play highly (1 in 5 gamers report anger increases their enjoyment of play) most hate it – 42% of those players surveyed in the last International Hobo player survey reported that they didn't enjoy feeling angry, and avoided games that made them feel that way.

Another traditional way that videogames can bring about enjoyment is by inciting excitement (the release of adrenalin, known these days as epinephrine), which relates to Lazzaro's Serious Fun. I have called games which have this focus rushgames, and identified many different types including those focussed upon high speeds (Burnout, Need for Speed), vertigo (Super Mario and other platform games), time pressure (Tetris, Diner Dash), linking chains (DDR, Guitar Hero), fear and survival (Resident Evil, Silent Hill), and mischief (Grand Theft Auto, Burnout 2's crash mode). These games represent the "flight" in the "fight or flight" mechanism, which is connected with what I call the fear centre (the amygdala). Not only is feeling excited something most people enjoy (8 out of 10 players surveyed gave it high marks), it enhances the feeling of success (winning, escaping or carnage) thus causing the pleasure centre to give a greater sense or reward, although not as strong a hit as that which comes from beating difficult challenges.

Another way to trip the pleasure centre is related to the games of difficult challenge, namely devising strategies and solving puzzles. There is a part of the frontal cortex of the brain which I have termed the decision centre (the orbito-frontal cortex) which transpires to be closely linked to the pleasure centre. Our brains are wired up in a particular way such that making good decisions is especially rewarding, and much as with extremely difficult play, the harder the puzzle, the bigger the reward. It seems that the pleasure centre will give a greater payoff for what is perceived as a bigger achievement, hence games that ask the player to solve difficult puzzles can be intensely rewarding for the players with the skills (and often, the patience!) to overcome them. However, such players are no longer the majority in the videogame audience, hence the decline of the adventure game genre.

Finally, enjoyment can also be derived in games from playing with people we trust – our friends, or even strangers whom we have formed a temporary bond with, as with parties in MMORPGs. These kinds of game activate a part of the brain I have termed the social centre (the hypothalamus), which releases a neurotransmitter called oxytocin. Everyone in principle enjoys the warm feelings this produces, but some introverted (or especially grumpy!) people struggle to overcome their fear or dislike of other people to get to this. A group of researchers at the University of Cagliari have shown that oxytocin (the “trust hormone”) and dopamine (the reward chemical) are closely interlinked. It seems that players who enjoy interacting with other players, such as those MMO players Richard Bartle has described as Socialisers, are also getting their enjoyment ultimately from the pleasure centre.

These six different mechanisms represent essentially all the different ways that players can find enjoyment in videogames – all ultimately triggering the pleasure centre. Three of these patterns – the Achiever-style pursuit of successive rewards, the Conqueror-style triumph over adversity, and the related solving of difficult puzzles – produce very great releases of dopamine from the pleasure centre and are thus highly addictive, but this addiction is tempered by an aspect of the play in question which certain players find off-putting. Achievement is offset by the tedium of grinding, conquering is offset by frustration and anger, and puzzle-solving is offset by bewilderment or boredom. The other three mechanisms all pair dopamine with another brain chemicals and are generally less addictive but equally engaging for the players who enjoy the relevant style of play.

So we can say, with some simplification, that the pleasure centre is the reason why you enjoy videogames, in biological terms at least – but we can't know without asking how you like to play videogames (your play style) nor which videogames you enjoy, which depends upon many other factors such as what kinds of settings, stories and art styles you enjoy. Every player is different – but every player's enjoyment rests, at the neurological level, upon triggering the pleasure centre in the brain.

You can also learn more about the biology and psychology of play in our new book Beyond Game Design: Nine Steps Toward Creating Better Videogames (with Richard Bartle, Noah Falstein, Michelle Hinn, Katherine Isbister, Nicole Lazzaro, Sheri Graner Ray, and Joseph Saulter), which will be published on March 16th but can be pre-ordered now from Amazon and all good book stores.

I would like to extend my grateful thanks to Ben Cowley for alerting me to Biederman and Vessel's work, to Corvus for creating the image of the limbic system of the brain used above, to Becca Lowenhaupt for her statistical number crunching, and to everyone who participated in the Ultimate Game Player Survey and other DGD2 research efforts, without whom this piece could not have been written.