How Your Brain Decides Without You
Rich Hua stashed this in Psychology
Wait, is that a rabbit or a duck?
But while everyone, at some point, can be made to see duck-rabbit, there is one thing that no one can see: You cannot, no matter how hard you try, see both duck and rabbit at once.
In a world full of ambiguity, we see what we want to see.
We form our beliefs based on what comes to us from the world through the window of perception, but then those beliefs act like a lens, focusing on what they want to see.
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.”
This connection between sensory input on the one hand, and prediction and belief formation on the other hand, has been observed in the laboratory. In a study published in Neuropsychologia, when people were asked to think about whether a statement linking an object and a color—the banana is yellow is one example—was true, similar regions of the brain were activated when they simply were asked to perceive colors. As if thinking about the banana as yellow was the same as actually seeing yellow—a kind of re-perception, as is known to happen in memory recall (though the researchers also cautioned that “perception and knowledge representation are not the same phenomena”).
We form our beliefs based on what comes to us from the world through the window of perception, but then those beliefs act like a lens, focusing on what they want to see. In a New York University psychology laboratory earlier this year, a group of subjects watched a 45-second video clip of a violent struggle between a police officer and an unarmed civilian.3 It was ambiguous as to whether the officer, in trying to handcuff the person resisting arrest, behaved improperly. Before seeing the video, the subjects were asked to express how much identification they felt with police officers as a group. The subjects, whose eye movements were being discretely monitored, were then asked to assign culpability. Not surprisingly, people who identified less strongly with police were more likely to call for stronger punishment. But that was only for people who often looked at the police officer during the video. For those who did not look as much at the officer, their punishment decision was the same whether they identified with police or not.