[The image features Mrs. Birdie Nebel, a receptionist and switch operator. This image, taken in 1961, shows Mrs. Nebel at her desk surrounded by a typewriter and switchboard equipment. She holds a black telephone to her ear as she flips a switch. She wears a white blouse and has short, curly hair and glasses. Source: Cover Girl Advertising Oral History and Documentation Project, Archives Center, National Museum of American History]

A few days ago, a series of popular science sources reported that scientists had just discovered the brain’s “off switch” or “lightswitch” for consciousness. The titles to these articles are remarkably similar:

• Scientists Have Located the Brain’s On/Off Switch for Consciousness (Gizmodo)
• Consciousness On-off Switch Discovered Deep in Brain (New Scientist)
• Researchers May Have Discovered The Consciousness On/Off Switch (IFLScience – and glad to see the modifier “may” in this one)
• Scientists Accidentally Discover The Brain’s Consciousness “Off Switch” (i09)
• Neurosurgeons find small brain region that turns consciousness on and off, like the key in a car’s ignition (Research Digest)

There are more, but you get the idea.

These articles all report on a brief communication, published in the journal Epilepsy and Behavior, by researchers from George Washington University, Mohamad Koubeissi et al. The article in question, titled “Electrical Stimulation of a Small Brain Area Reversibly Disrupts Consciousness,” [DOI: 10.1016/j.yebeh.2014.05.027] does not use the switch or lightswitch metaphor. In the article, the researchers describe how stimulating one region of a woman’s brain, an area between the left claustrum and anterior-dorsal-insula, caused her to lose consciousness. The researchers hypothesize that this region may act as a “gate” toward consciousness, thereby introducing a different metaphor that implies not a simple on/off, but more of a pathway through a network.

The authors also quote another metaphor, this one from Francis Crick and Kristof Koch, who called the claustrum “a conductor coordinating a group of players in the orchestra.” The full quote, from the original continues: “Without the conductor, the players can still play but they fall increasingly out of synchrony with each other. The result is a cacophony of sounds.”

And Crick and Koch also introduce (but then discard) another metaphor: “the highly networked nature of the claustrum raises the question of whether it acts as a sort of ‘Cartesian theatre” (1276).

Why so many metaphors? What work are metaphors doing for neuroscientists–and for popularizers? Metaphors are useful for scientists, and for popularizers. For popularizers, they help to concretize abstract phenomena in terms we can understand. But for scientists, they do more–they serve as prompts for theorizing about science. Each new metaphor can lead to new insights and new lines of inquiry.

So what is the problem with these metaphors? The drawback for any metaphor is that it can easily obscure or distort information, often by oversimplifying or, in the case of neuroscience, by making an abstract phenomenon or function “uncritically real,” as Eric Racine, Ofek Bar-Ilan, and Judy Illes explain in their article, “fMRI in the Public Eye.” This constitutes “neurorealism.”

“Neurorealism” is easily seen in the article titles above. Clearly, the claustrum may function in some ways akin to an on/off switch, or the key in a car’s ignition, but it is NOT an on/off switch, or a lightswitch. Metaphors, then, are fundamental strategies for neurorealism: they make things seem concrete and real, even when they are not.

Yet, this neurorealism appears not only in the popular texts but in the scientific articles quoted above. Both Koubeissi et al. and Crick and Koch resort to metaphors to try to understand the claustrum and its functions. Using these metaphors, scientists act as though the claustrum IS a gate (or an orchestra conductor) and then proceed along that line of thought in order to determine what that metaphor can illuminate. The gate metaphor Koubeissi et al. use allows them to think about the claustrum as a key point in a pathway, while the conductor metaphor allows Crick and Koch to think about the claustrum as though it were more of a coordinator among a number of regions or functions.

So neurorealism is not a simply a fallacy to be avoided–it is crucial for scientific practice. We see similar kinds of realism operating in genetic research, where the metaphor of the “gene” itself has done important work for scientists, as Elizabeth Parthenia Shea explains in How the Gene Got Its Groove. But, as in neuroscience, popularized metaphors of the gene as “the book of life,” as a “blueprint,” or as a “code,” can also mislead public audiences. And they can mislead scientists, too, since sometimes the attendant characteristics from a metaphor get carried into scientific theories in ways that can lead them on the wrong track.

Notice, also, that the metaphors we choose are always culturally dependent. The lightswitch, gate, and orchestra conductor metaphors all draw upon culturally available ideas. Notice that no one compared this area of the brain to the switch operator, a Mrs. Birdie Nebel, pictured above in an image from 1961.

What is needed then, is not a crusade against metaphors, but perhaps greater awareness of metaphors, both among scientists and public audiences–of their limitations as well as their important functions in all kinds of discourse.