technologyreview | Time flies like an arrow; fruit flies like a banana.
For
psychologists who study humor, this statement is a classic. It embodies
the ambiguity of language that much humor exploits. In this case, the
words “flies” and “like” have different meanings that come into conflict
in the reader’s mind. The way our cognitive processes resolve this
conflict lies at the heart of the nature of humor, say theorists.
Humor
showcases the speed and flexibility of human cognition at its most
impressive. Clearly, the ability to reproduce this behavior would be
hugely useful in machines that could appreciate humor and generate
laughs.
So psychologists and computer scientists would dearly love
to understand and reproduce the cognitive processes behind humor.
Sadly, progress in this area has been slow, not least because it is hard
to properly model this cognitive conflict.
Today, that changes,
at least in part, thanks to the work of Liane Gabora at the University
of British Columbia in Canada and Kirsty Kitto at the Queensland
University of Technology in Australia. These guys have created a new
model of humor based on the mathematical formalism of quantum theory.
They then apply it to verbal puns and cartoons.
The basic problem
with modeling humor is to find a way to represent a joke at the moment
it is understood. That’s tricky because it requires the ability
to able to handle two or more conflicting interpretations at the same
time.
In the joke above, the brain first assimilates the set-up
statement “time flies like an arrow,” in which flies is verb meaning “to
travel through the air.” It then assimilates the punch line statement
“fruit flies like a banana,” in which flies is a noun describing flying
insects.
By themselves, these phrases are not particularly amusing. The humor
arises when the meaning from the set-up phrase clashes with the meaning
in the punch line. This clash requires the brain to hold both meanings
at the same time.
Gabora and Kitto say the process of holding two
ideas simultaneously in our brains is analogous to the process of
quantum superposition. This is the bizarre quantum phenomenon in which a
single object can exist in two places at the same time. The object’s
position only becomes localized when it is measured and the
superposition collapses.
Similarly, the brain holds two meanings
in mind at the same time and the process of getting a joke resolves this
conflict as the brain settles on one meaning or the other. Gabora and
Kitto’s idea is that the mathematics behind quantum superposition can
also model this kind of double-think.
They are not saying that the
brain relies on quantum processes, only that quantum formalism can be
used to model it. “The quantum approach enables us to naturally
represent the process of ‘getting a joke,’ ” they say.
