Q. What do vegan zombies eat?
If that joke made you groan like the undead, thank your bilateral processing abilities. Researchers studying the neuroscience of puns say that understanding them, even the bad ones, requires cooperation between both sides of the brain. They published their research in the journal Laterality: Asymmetries of Body, Brain and Cognition.
Humor has a reputation for being transgressive, but all that boundary-pushing is only possible thanks to a system of internal rules. From knock-knock jokes to digs on someone’s mama, each class has its own standardized scaffolding. Some philosophers argue that humor itself depends on a formula: taking something familiar and giving it an unexpected—but not upsetting—twist.
This “benign violation” setup is also at the heart of the pun. The joke up top takes a reader’s familiarity with the cliché of the lurching, brain-craving zombie, then uses a rhyme to add a surprising shade of meaning. Yes, we know that dissecting jokes isn’t funny. We’re done now.
Neuroscientists at the University of Windsor wondered how our brains would parse the two-step process of understanding puns. They were specifically curious to find out how the work was divvied up between the brain’s left and right hemispheres.
To find out, they brought volunteers into the lab and sat them down in front of computers, which proceeded to display a series of easy, cheesy puns. (Ex.: “They replaced the baseball with an orange to add some zest to the game.”) Some of the puns showed up on the left side of the screen, where they would be processed first by the right side of the brain. The rest showed up on the right. The participants were timed to see how long it took them to get each joke, such as it was.
The results showed that participants were quicker on the uptake when their puns appeared on the right side of the screen—that is, starting with the left side of their brains. This makes sense, co-author Lori Buchanan told Scientific American: “The left hemisphere is the linguistic hemisphere, so it’s the one that processes most of the language aspects of the pun, with the right hemisphere kicking in a bit later.”
Understanding a pun, they found, requires input from both hemispheres. The left side introduces the standard, linguistic part of the sentence or joke—essentially setting up the setup—while the right side analyzes the punchline’s double meaning.
That's probably more thought than most puns deserve.