In response to a recent post on spindle cells in which I referred to that neuronal cell type as a transmitter of social emotions, I received a very astute comment:
This doesn't as a statement make any sense "their antenna-like cell body is able to convey our social emotions across the entire brain". Neurons fire action potentials and the best they can conduct is patterns of firing or epsps/ipsps. They can't convey something as complex as 'social emotions'! That sounds like very sloppy thinking, even if they conduct something, some pattern, some information, to other brain regions its not 'saturating other brain regions with the same feeling'.
The comment, of course, is true. Neurons traffic in electricity and neurotransmitter. A squirt of dopamine isn't a feeling; it's just a squirt of dopamine. Jake made a similar point a few months back, criticizing an article that was also about spindle cells (they are clearly a tricky cell type to describe):
Sometimes, science journalism makes me crazy.First of all, neither parts of the brain nor neurons themselves are not associated with emotion or social behavior or consciousness. Neurons release neurotransmitters and participate in neural circuits. These neural circuits are located in particular parts of the brain and are responsible for complex behaviors. You cannot reify either a cell or a part of the brain into a complex behavior because the action of a circuit is not separable from the whole.
And yet, I'm also not planning on abandoning my "reification" of brain cells anytime soon. I still think it's acceptable to refer to spindle cells as conveyors of social emotion, or to allude to dopamine neurons as representing feelings of pleasure. Although no subjective experience - like a feeling - can be literally reduced into a discrete neural circuit, I think such writerly approximations are acceptable. The amygdala doesn't actually secrete fear - it just secretes electrical impulses - but those impulses are endowed with a consistent functional meaning (at least according to a 1001 fMRI experiments), so I think writers should be allowed to refer to the amygdala as a source of fear, anxiety, etc. It's a necessary inaccuracy, a way of collapsing different levels of scientific description.
Besides, what's the alternative? Our neuroscientific sentences would get pretty cluttered if, every time we decided to describe some sort of neural activity, we were forced to remind our readers that cells just fire action potentials, and that our descriptions of function are actually metaphors. And then, of course, we would constantly be butting our heads against the real mystery, which is where, exactly, all these electrical impulses acquire their meaning? If the amygdala doesn't generate aversive emotions, then what does? If our neurons just convey a binary code, then how does that binary code become consciousness?
I think we ascribe an inaccurate amount of meaning to discrete bits of the brain because otherwise all our descriptions of the brain would be unbearably meaningless. They would be devoid of anything resembling our actual experience. The mind and the brain would seem hopelessly disconnected, as the mind would contain all these vivid feelings and sensations but the brain would just be a few pounds of meat trafficking in minor voltages.
As a science writer with a background in neuroscience, I'm well aware that my sentences are imperfect. But I also think that one of the tasks of a science writer is to translate the details of data into something understandable to the-man-on-the-street. My job is to show people how these strange electrical cells actually embody their being. I have to connect the material facts of the brain with the immateriality of our experience. That process of translation inevitably results in bad metaphors and sloppy oversimplifications, but it's the best way we have of bridging the mysterious divide between mind and body.
Comments (18)
Or, conversely, people complain about such descriptions because they still like to think of conscious perception/mind as something ineffable/emergent/transcendent, or simply not-fully understood. (And insofar as those functions aren't fully understood, some kind of slightly distancing weasel-wording --associated with, perceived as, blah blah -- can be wise.)
It may be interesting to see how people handle similar issues for computers -- arguably objects analogous to brains in some ways. Computers don't traffic in text or pictures or numbers, or even bits and bytes. They traffic in electrons and holes (or occasionally patterns of light, phonons or fluid flow). But no one complains when someone says that a particular register in a CPU holds a floating-point number, or that the circuitry signals a divide-by-zero error. Perhaps because we believe that someone somewhere actually designed the damn things and understands exactly how they (are supposed to) work.
Posted by: paul | March 15, 2007 11:16 AM