You're probably familiar with the rabbit-duck illusion. Like other "ambiguous images," this illusion can tell psychologists a lot about how we perceive our surroundings. The implications are as clear as they are unsettling: When confronted with ambiguity, we often see what our brains want us to see.

How our brains deal with ambiguity is one of the central questions in apiece by Tom Vanderbilt currently running at Nautilus. The essay is about the subconscious decisions that we make when we become spectators to situations that lend themselves to more than one interpretation – sporting events, political debates, police arrest footage. Things like that.

Throughout his piece, Vanderbilt speaks with researchers and points to studies that help illustrate the rabbit-duck metaphor's application to real-world scenarios. I found this response from Northeastern University psychologist Lisa Feldman Barrett to be especially illuminating:

When I put the question of whether we were living in a kind of metaphorical duck-rabbit world to Lisa Feldman Barrett, who heads the Interdisciplinary Affective Science Laboratory at Northeastern University, her answer was quick: "I don't even think it's necessarily metaphorical." The structure of the brain, she notes, is such that there are many more intrinsic connections between neurons than there are connections that bring sensory information from the world. From that incomplete picture, she says, the brain is "filling in the details, making sense out of ambiguous sensory input." The brain, she says, is an "inference generating organ." She describes an increasingly well-supported working hypothesis called predictive coding, according to which perceptions are driven by your own brain and corrected by input from the world. There would otherwise simple be too much sensory input to take in. "It's not efficient," she says. "The brain has to find other ways to work." So it constantly predicts. When "the sensory information that comes in does not match your prediction," she says, "you either change your prediction—or you change the sensory information that you receive."


Pieces like Vanderbilt's serve to remind us that our minds have developed all manner of schemas, strategies, and shortcuts for sifting through the information that surrounds us.

It's important to remember that your brain is always working – even when you're not looking.

Read Vanderbilt's essay in its entirety at Nautilus.