[In this in-depth analysis, Neils Clark examines the intimate bond between psychology and play, and how games might tap into the recesses of the ancient human brain in order to reach new levels of immersion.]

What many works heretofore miss about immersion is the physiological. Specific senses have specific effects.

When the reds, greens, and blues of television images careen in through your retinas, and then bang back and forth between your amygdala and your prefrontal cortex, you're having a certain type of experience. When sounds, smells, or even tastes hit varied sensory receptors, you're having other types of experience.

The nature of such input, as well as how it's processed, has an effect on the final product. As games could hypothetically throw together near every other traditional method for presenting media experiences -- from poetry to painting -- it makes sense for developers to understand a great deal about how we sense and perceive them.

Topics like "flow", "theories of fun", culture (online and off), the psychology of identity, operant conditioning, and self-actualization -- more the culture and psychology of media experience -- relate to its physiology as light relates to dark in the Tao; each is fundamentally reliant on the other.

What follows, then, is a mega-abbreviated exploration of how the game experience slaps together a patchwork of elements, in the senses and in the mind, thereby forging something desirable. Something that the brain takes as a convincing-enough pastiche. Something that's still a medium, but which, while in its clutches, the mind might be forgiven for mistaking as real.

Sound and Vision

Scholars in the field of visual communication, combining theories in fields ranging from evolutionary psychology to neurobiology (Nobel Laureate-types -- not fringe wackos) write that visual media cannot help but be both immediate and convincing.

Much of our visual learning is "prewired by evolution to detect and respond to danger," writes Anne Marie Barry, Associate Professor of Communication at Boston College, saying that while that wiring hasn't changed in millions of years, visual media has.

"For the brain's perceptual system, visual experience in the form of the fine arts, mass media, virtual reality, or even video games is merely a new stimulus we have inherited as part of our brain potential and is processed in the same way." While it doesn't take 18 WIS to know that a television is a television, the implication here is that our visual system taps the forgotten Congo of the brain.

Those ancient, reptilian areas have no physical way of recognizing the difference between everyday experience and the flashing phosphor of a screen. Considering this, Barry suggests that visual media aren't some event. A kid playing violent games, let alone an adult, won't have some Mysterious Black Switch of Menace flipped in their brains. Rather, the brain's visual system files it as one apparently real experience among the many that we might have as we learn and grow.

And yet, visual media may flip a different kind of switch. These theories suggest that convincing visuals draw in a TV watcher, or a gamer, by virtue of simply being visual. Before we can think about our sight, we feel and respond. Optical impulses sent through the "quick and dirty" thalamo-amygdala pathway rush to the amygdala, where they're quickly matched against low-resolution images from this ancient emotional center.

By the time a more fulsome image can be sent down the cortical pathway for conscious, thoughtful awareness, we've already had some type of response. Visual experience that constantly yanks on these visceral puppet-strings, engaging old responses for (for instance) danger or mating, may keep players deeply engaged without their full mental awareness.

Distraction, visual, aural or otherwise, likely also lowers our physical awareness of outside stimuli while gaming. Of course, 'gaming' encompasses a wide variety of designs and experiences. Harry Potter Scene It! is meant to be a wholly different experience than Lego Harry Potter. Paying only physical attention to a board game (not the people, the snacks, or the spilled beer) would be a bit ridiculous. On the flip side, full solitary adhesion to a console game when you're home alone -- that's the ideal.

We want to find an interest-worthy world inside. As we may not even cognitively process inputs that occur while attending especially attractive stimuli, it's possible that some gamers forget near all of what's happened in their apartment during gaming (if it was even processed). They may also forget much of what flew at them in a game (if the game offers too many stimuli to process).

In that sense, though games may be designed as somewhat different than any common experience we're having in everyday life, how we process the gaming experience is physically no different than how our senses process any other experience in day-to-day life.

The human brain has no inborn mechanism separating photorealistic visuals on a screen from the visuals in reality. Sound and vision hold human attention within that frame of experience. In neither case has our fundamental processing changed simply because we've sat down for a little gaming. Physiologically, our Stone Age brains seem helpless but to fall into worlds. Does this imply that in passive media showing realistic scenes, that the barrier for passive immersion is almost zero? What, then, would be the barrier to interactive immersion?