[How exactly do horror games work on the brains of players? In this new feature, neuroscientist Maral Tajerian, of Thwacke! Consulting, unpacks the mechanism behind the scares in Amnesia, Dead Space and Silent Hill, among others.]

Fear is one of the most primitive instincts in humans. Although it has been particularly useful in keeping us alive in dangerous situations, it has also helped the entertainment industry capitalize on our sheer joy of being scared. The video game industry has done a good amount of scaring by taking advantage of these emotions and employing them in gameplay narrative and design.

This practice is best exemplified by putting the player in a vulnerable situation with limited resources to confront enemies. With proper execution, the genre can make your heart race, palms sweat and make you go to sleep with nightmares. However, when executed poorly, players feel as if they're simply "going through the motions".

Over the last two decades, several games (ranging from the early Resident Evil series to the more recent Amnesia: The Dark Descent) have defined the survival horror genre by successfully engaging fear and anxiety in players.

Although successful iterations of these games offer different enemies, gameplay mechanics and plot, they all share similar ways of handling the human psyche. This article will discuss how fear as an emotion has been employed in the gaming industry and discuss how the balance between scares and gameplay can lead to success or failure.

The Science of Terror

Anxiety. Next to fear, anxiety is perhaps the most prominent feeling experienced in video games. Unlike fear, which is a response to an imminent threat, anxiety is a response to a future potential threat.

When perceptual systems are taxed, research has shown that a looming threat results in anxiety that heightens attention and increases sensitivity to potential dangers. This implies that solving a puzzle the character is presented with in the game does not take away from the experience of fear and danger. In fact, according to many gamers, solving the puzzles under dangerous circumstances only increases the feelings of fear. Consider how riddles and puzzles in Silent Hill excel in this respect.

An example of a puzzle from Silent Hill 2 that needs to be solved in a dark and dilapidated room.

While games like first person shooters are notorious for desensitizing players to violence, games that raise the player's anxiety actually sensitize them to danger. This is simply how animals behave, and it's a highly adaptive behavior, since it keeps individuals on their toes in anxiety-causing environments. Raising the levels of anxiety in a video game will therefore ensure that the player is sensitized to the danger in the game. In a game like Amnesia, the entire experience teeters on anxiety created up to confrontation with an enemy since the player has absolutely no means to defend himself.

Helplessness. As mentioned earlier, players in the survival horror genre are often faced with terrifying and inescapable circumstances, with little means of self-defense. In other words, they are truly and utterly helpless.

In Amnesia, some may remember locking themselves in a closet, or hiding in a corner staring at a blank wall for several minutes, because you're convinced that if you move, even an inch, a certain and horrible death will soon ensue. Furthermore, elements like rigid camera angles, awkward control schemes (Silent Hill, and Early Resident Evil titles), lighting (Alan Wake, Dead Space), etc. all serve to obliterate what little control the player might have thought she possessed.

Helplessness is truly a powerful feeling. Studies have shown that animals that are faced with situations where they're helpless develop strong feelings of fear and anxiety. This is also true in the case of humans. You may remember this feeling from your last visit to the dentist. Whenever you experience feelings of helpless and loss of control, you are bound to feel more anxious and fearful. The same stays true in video games.

Priming. In psychology, priming is defined as the effect in which the response to a stimulus is influenced by the exposure to a previous stimulus.

Consider the word-stem completion task, for example. Here, a test subject is exposed to certain words, one of which is the word "lettuce". He is then asked to complete the following word: "let----". The effect of priming can be seen when the subject fills the blank with "tuce" due to the fact that he was exposed to that word earlier in the experiment.

Several games rely heavily on creating anxiety using this strategy, by using sounds that remind the player of an encroaching yet unseen enemy. In Amnesia, visits to various torture chambers (where he actually "hears" victims in an iron maiden, a brazing bull, etc.) leads up to being locked in a cell. The fact that such priming took place (being exposed to the torture scenes) clearly influences the way the player feels when he himself is locked up and dreading the possibility of similar tortures.

A diagram in the Strappado torture room in Amnesia: The Dark Descent.

In addition to this priming, certain events characterized by unexpected novelty can, very efficiently, startle a player. For example, events that can lead a player through a relatively safe part of a level may lower our guard to new threats when revisiting the same environment (i.e.: consider the first 30 minutes of Doom 3 or the hubs in the Silent Hill and Dead Space series).

These choices will often save time in level design while still maintaining progress and the required ambience to startle and terrify.

Mirror Neurons. Mirror neurons are neurons in certain regions of the brain that are active when an animal performs an action, or observes another individual performing that same action.

Discovered a few decades ago, these neurons are argued to be the key in understanding other individuals' intentions and feelings, empathy, and even imitating the actions of others. It is very possible that mirror neurons play an important role interfacing our experiences with a virtual avatar.

PET studies highlighting similar clusters in the brain that activate between individuals who are watching an action (listening to music) or partaking in an action (playing music).

In most video games, moving in a three dimensional space is likely to trigger spatial orientation mirror neurons. In the Silent Hill series, similar mechanisms would elicit anxiety and disgust when players are given the choice to stick their hand into a hole in a wall or to take something out of a toilet.

James Sunderland from Silent Hill 2 asked to stick his hand in a dirty toilet, likely eliciting disgust in the player, who mirrors this experience in her own brain and, to some extent, "experiences" it herself.

Similarly the same can be said in Dead Space 2, where players are given the choice to crawl in very confined spaces (where the right camera angle make the entire difference) or guide a needle into the eye of Isaac Clarke.

And what's best is that the developers of these games are increasingly aware of these facts and capitalize on it. As Thomas Grip of Frictional Games (Amnesia: The Dark Descent) himself said at the Games Colloquium at Concordia University last year, the involvement of mirror neurons is important when the empathy factor is high. In other words, you can't help but put yourself in the protagonist's shoes.

Context and Environment. Naturally, our environment plays a large role in the perception of fear and potentiating startle responses. In the right context and environment, our baseline startle reflex shows gradual elevation over the course of aversive conditioning (antagonizing the player).

This works both inside and outside the game. Out of the game, mood plays a large role in getting the most out of the experience (consider the importance of playing in a dark room, adjusting the gamma, and wearing headphones). Creating the right environment inside of the game is equally important and capitalizes off of our own neurobiology. For example, our fear of the dark stems from our evolved circadian rhythms that revolve around a diurnal (day-night) cycle making us vulnerable at night. Similarly nocturnal animals like rats exhibit very similar startle responses, only in the light.

The use of light has always created a sense of helplessness and a shrouded and mysterious environment creating ambience in the survival horror genre. Alan Wake (top) and Dead Space 2 (bottom).

It should be noted that the appropriate context can also elicit fear in not so dangerous objects or cues. Fear conditioning with auditory cues can still cause anxiety, with the auditory cue and no immediate aversive stimuli.

An example of this is best exemplified by F.E.A.R.'s antagonist Alma, a little girl who can do rather terrible things. Additionally the unpredictability of aversive stimuli (such as a little girl vs. a man with a chainsaw) increases our perceived anxiety and fear.

In the case of F.E.A.R., game designer Craig Hubbard said that "...a guy in a mask chasing co-eds with a meat cleaver can be scary, but on some level you're thinking to yourself, you could probably kick his ass if you got the drop on him... But when a spooky little girl takes out an entire Delta Force squad, how are you supposed to deal with that?"

Integrating Terror into Gameplay

Achieving scares and interactivity in the horror genre is no easy feat. Whereas other games challenge the player's ability to solve a puzzle or take down an array of enemies, the survival horror genre challenges a hardwired and highly adaptive response to threats. To establish one good startle, you need to take into account the ability for your design to establish a baseline of expectations with your environment and the purpose of your character in that environment, build anxiety, connect with the character, and remove any control the player may have (consider the importance of the first 10-15 minutes of Dead Space and the player's first encounter with an enemy).

This design often leads to the scripted scare (i.e. Pyramid Head's non-confrontational spooky/disturbing appearances scattered throughout Silent Hill 2), which can remind us of the linearity of gameplay and a lack of a personalized experience/choice and replay value.

Top: Dead Space's first/scripted encounter with a necromorph does not give the player a chance to fight back, but removes control and increases anxiety. Bottom: Scripted moment with Pyramid Head omniously staring at James Sunderland through impenetrable bars.

This raises the additional challenge of creating unpredictable moments while playing. For example, in a game like Silent Hill: Shattered Memories, certain events can cue an "ice-world transition", prepping the player to run in order to avoid danger.

The first time, such an event can create anxiety but not as much after the third or fourth. This does not mean that these events fail to create anxiety in the player, but they do not achieve it to the same degree due to our own learning of what a player must do in order to play/win.

Similarly in Dead Space, some players can plan their confrontations by prepping themselves to orient their attack to nearby vents or gratings. In fact, once they do, their experience with the game is not one of fear, but of confrontation and seizing power.

Top: Necromorph whack-a-mole in Dead Space. Bottom: Ice transitions in Silent Hill: Shattered Memories = run.

It seems that with the growing tendency of video games to move towards more visceral action/gore (Dead Space 2 vs Dead Space, or Resident Evil 4 and 5 vs Resident Evil 1 to 3) signals that it is easier to design an action game based off of a terror franchise instead of a true horror game that can succeed in the aforementioned principles of animal behavior.

Conclusions

As a neuroscientist, it is very rewarding for me to see science being used so elegantly in video games, and I can easily see this trend continue to appeal to an increasingly smart gaming audience. So, what can we learn from games like Amnesia, Silent Hill, F.E.A.R., etc.? And in more general terms, how can we implement basic principles of neuroscience into video games?

Clearly, the first step is to stay informed. Research in the sciences is extremely fast-paced, and most of the findings don't reach the general audience until at least a decade later when they're published in textbooks. The recent revolution in information exchange does not completely solve the problem and is a double-edged sword. It helps spread knowledge faster, but is often unreliable.

The second step is to be bold enough to experiment with new genres. Every now and then, a game comes along that creates a completely new way of thinking about video games. Although this is a risky approach, it is much needed in an industry that boasts literally hundreds of games that follow the exact same recipe.

Finally, it is important to form a solid emotional bond between the game (or the main character) and the player. RPGs do this beautifully by blurring the line between the gamer and his avatar. For non-RPGs, the task is less straightforward.

One of the ways to establish/strengthen the bond is to elicit very strong emotions in the gamer. Games in the survival horror do this using fear, which can be very effective. However, it is not the only way. We have recently seen an onslaught of different games that capitalize on a range of different emotions such as grief (Graveyard, Tale of Tales), love and loss (Dear Esther, Thechineseroom), etc. It is clearly evident that the era of "one size fits all" video games is long gone.

At the end of the day, it's important to know your audience before you can sell them a product. With the abundance of game studios, whether it's the triple-A industry or the budding indie games, no developer can risk making a game that will flop. Understanding what humans find engaging/stimulating/addictive is necessary in making a given video game a success.

References

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Fikretoglu D, Brunet A, Best SR, Metzler TJ, Delucchi K, Weiss DS, Fagan J, Liberman A, Marmar CR (2007) Peritraumatic fear, helplessness and horror and peritraumatic dissociation: do physical and cognitive symptoms of panic mediate the relationship between the two? Behaviour research and therapy 45:39-47.

Harris JC (1989) Experimental animal modeling of depression and anxiety. The Psychiatric clinics of North America 12:815-836.

Gewirtz JC, McNish KA, Davis M (1998) Lesions of the bed nucleus of the stria terminalis block sensitization of the acoustic startle reflex produced by repeated stress, but not fear-potentiated startle. Progress in neuro-psychopharmacology & biological psychiatry 22:625-648.