Tempest 2000: Perception

Probably because of what I’ve been reading lately, I keep thinking of Tempest 2000 as some kind of experiment into human visual perception. There’s always a lot going on, only some of which is visible at any given moment. In extreme cases, you can lose a life to something that hasn’t even been displayed yet.

This isn’t even just because of particle effects covering things up, like I described before. Unlike the original Tempest, the camera moves around a little to follow the player, but doesn’t move as quickly. Sometimes part of the web is offscreen. Some of the webs are crinkly, with segments folded tightly around each other, so that, depending on the camera placement, some segments will be hidden from view. In either case, you can actually be on part of the screen that’s not being shown. On the other hand, when you get killed without expecting it, it’s hard to tell exactly why. Maybe it was something that was hidden from view by a crinkle, maybe it was hidden by an explosion, maybe it wasn’t hidden from view at all and you simply failed to notice it.

So, you basically never have complete visual information. On the other hand, that’s true anyway. The human eye isn’t nearly as perceptive as it seems; only a small region of the retina, covering about 6 degrees of arc, has the acuity we associate with normal vision. We get the illusion of a larger visual field from involuntary movements of the eye. The brain is really good at piecing together the fragmentary data obtained this way, and at extrapolating from it. If it weren’t, playing this game would be pretty much impossible. Tracking things you can’t currently see is a big part of the game, and I suspect that with enough practice, one might learn to see important objects in the game even when they’re completely obscured.

On the other hand, the same phenomena work against the player too. The reason that the brain is good at filling in the gaps is that the eye doesn’t see everything even under normal circumstances. I think the most striking experiment I’ve heard of in this regard is one that involved a system that tracked a person’s eye movements as they looked at words on a computer screen. Whenever the subject’s eye was moving, the words would change. To anyone else observing, the screen was in a constant state of flux, but to the subject, it looked completely stable, just like the words you’re reading right now. Now, think about what this means for a fast-paced game with incomplete information. Obviously the screen isn’t tracking your eye movements, and appears far from stable, but given how much is happening, and how fast, some of it is bound to occur in ways that simply slip past conscious experience, even for a well-trained player.

But that’s what extra lives are for, and the game is pretty generous with them. It’s like Robotron in that respect, only less cerebral.

2 Comments so far

  1. paul on 15 Sep 2008

    ok, so what are you reading?

  2. Carl Muckenhoupt on 22 Sep 2008

    Consciousness Explained, Daniel Dennett.

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