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Mental animation: Inferring motion from static diagrams of mechanical systems.

Hegarty, M. (1992). Mental animation: Inferring motion from static diagrams of mechanical systems. Journal of Experimental Psychology: Learning, Memory and Cognition, 18(5) 1084-1102

Reaction-time and eye-fixation data are analyzed to investigate how people infer the kinematics of simple mechanical systems (pulley systems) from diagrams showing their static configuration. It is proposed that this mental animation process involves decomposing the representation of a pulley system into smaller units corresponding to the machine components and animating these components in a sequence corresponding to the causal sequence of events in the machine's operation. Although it is possible for people to make inferences against the chain of causality in the machine, these inferences are more difficult, and people have a preference for inferences in the direction of causality. The mental animation process reflects both capacity limitations and limitations of mechanical knowledge.

Following the theme of yesterday's post this is another non-PL research paper that explores cognitive factors that might be relevant to programming language design.

The research in the paper nicely illustrates how different accounts of the cognitive processes involved in reasoning about the behavior of a mechanical system or model can be compared experimentally. The results suggest the types of inferences that are involved in mental animation of the type requested from the subjects, and how they are orchestrated.

The first section of the paper provides the general framework, and explains the notion of mental animation. A discussion of the generality of the results can be found at the end of the paper.

Those who find my last two posts too far removed from PL issues need not worry; I am not going to post more research of this type soon. Those who are intrigued by this research will be happy to know that a lot more is available where this came from.

By Ehud Lamm at 2009-06-18 00:59 | General | other blogs | 2776 reads

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if there is a problem

If there is a problem with PL's, maybe its that language designers haven't been able to incorporate research of this type. I think the machine side is is much better understood than the person side, so there is at least an outside chance the next good big idea targets the brain rather than the code. This is great stuff, thanks.

By debreuil at Thu, 2009-06-18 05:27 | login or register to post comments

Ramble Alert

I think it is really interesting to contrast such a technical paper to a similar idea in the arts. Scott McCloud, in his "Understanding Comics", noted that the primary mechanic that makes comics work is the "gutter" -- that is the space between the panels.

McCloud didn't user the same words as Hegarty, but "mental animation" is really what it all comes down to.

In more recent art forms such as motion pictures and video games, this "mental animation" is the only thing that gives form to both static pictures -- 256x240 intensities of light representing a woman-- and dynamic pictures -- at a fast enough rate, say thirty different images per second, a set of similar pictures viewed one at a time seems to "come to life".

I am starting to think this kind of model building is intrinsic to all humans. Is there anyone who can't synthesize pixels into an image, images into an animation?

Look at the frontiers of game design -- the procedural animations of Chris Hecker's Spore or the shadowing of John Carmack's Rage -- these are but models of a model, approximations to physics which are themselves approximations of reality.

In my opinion, video games are a mixture of set design and animation that I call "co-animation". The living room doesn't have to be real, it only has to convince the audience it is real. "Mental animation" will fill in the rest. Light and gravity don't have to be accurate, they only have to convince the player they are accurate. "Mental animation" fills in the rest. Given a model, the player is now free to bring it to life -- that is, to build their own model on top of it.

Anyways, what really gets me is how much the traditional animators at Disney and Pixar study acting. How much further from the properties of bismuth telluride can you get? :)

Thanks for the post.

By Nicholas Ralabate at Wed, 2009-06-24 22:08 | login or register to post comments