What is fear? Most people think of “fear” as the conscious feeling they get when in danger. I feel afraid when I’m standing on top of a mountain ledge. I’m scared when I hear a noise in an old building. Spiders of all sizes are frightening, and uncertainty is terrifying.
The English language boasts over three dozen words for fear and anxiety. And in the study of emotion, scientists generally drop the f-bomb we call fear to describe a number of defensive responses to threat. It’s confusing, not just to scientists, but to journalists and the public as well, claims NYU neuroscientist Joseph LeDoux. In a paper published in the journal PNAS, LeDoux seeks to banish the f-word once and for all and proposes what he considers to be more appropriate language for the sacred halls of research.
The story begins with John Watson, who in 1913 published “Psychology as the Behaviorist Views It,” known more colloquially as “The Behaviorist’s Manifesto.” Before this time, psychologists used a technique called “introspection” to understand human consciousness. But Watson wasn’t having any subjective mumbo jumbo. He believed that for psychology to succeed as a natural science it would have to drop its infatuation with consciousness and focus on something it could control, predict, and measure.
This something was “behavior” — and others caught on to the idea. Seven years later, Watson along with Rosalie Rayner successfully conditioned “fear” in a baby. But by “fear” he meant a behavioral reflex — not the feeling of being afraid. And because fear wasn’t a feeling, he could apply the same principles that guided this behavior to other animals.
By the 1950s behaviorism dominated psychology and it brought a procedure, known as “Pavlovian fear conditioning,” along with it. Scientists use it to study learning, memory, and emotions in animals, usually rodents.
In a typical experiment, a researcher puts a rat in a box and presents a tone that previously meant nothing. He follows the tone with a mild shock and observes the behavioral response — freezing. With just one pairing, he has “conditioned” the animal to the tone — the animal associates the tone and shock, and the tone morphs from a neutral sound to a predictor of threat. And the freezing is a “defensive response” because in a natural setting, it makes predator detection less likely.
Scientists, including LeDoux, have called this learned association “fear” — however, LeDoux calls for a “sharper conceptualization of what is being studied.” Even nonscientists relate to studies of fear because we all know what it’s like to experience a threat. We simply call it fear. But can a rat consciously feel fear?
Maybe a rodent can … however, we cannot prove that it does, and that’s LeDoux’s point. So when a group of scientists acknowledged animal consciousness by signing “The Cambridge Declaration on Consciousness,” LeDoux, like Watson decades before him, wasn’t having it. As he writes:
Terms like “fear conditioning” and “fear system” blur the distinction between processes that give rise to conscious feelings of fear and nonconscious processes that control defense responses elicited by threats. These processes interact but are not the same.
Using terms that respect the distinction will help focus future animal research on brain circuits that detect and respond to threats, and should also help clarify the implications of this work for understanding how normal and pathological feelings of fear come about in the human brain.
Despite the number of f-bombs LeDoux has dropped in the past, he’ll be the first one to tell you, he does not study so-called conscious fear.