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.
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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.
Or as aligned domains on hard drives.
The issue, I think, is that we have different levels of emergent behavior which needs description. It would be impossible to explain the complete workings of a computer on the levels of currents and voltages.
The lower level descriptions are difficult because of the needed detail. (In this example, it isn't enough to describe the currents to understand what is happening, we need the voltages and the physical design as well.) The upper level descriptions are difficult because of the complexity. (In this example, the software objects, inputs and execution threads.)
The one thing I would object to is that it can be sloppy thinking if there is no assurance of a real referent to the description. Then it becomes another "just so" story.
But this can also be used to be nitpicky. For example, suppose some emotion needs hormones to be expressed. Then it seems to me slightly wrong to say that the neurons are transmitting said emotion, while signaling or processing it seems fully correct. I'm not sure the difference is much to argue about.
Well, this kind of speech usage reminds me too much of instances where intentionality is implied in some setting in which it doesn't really belong. For example, cold viruses give us respiratory symptoms so that they can spread to other hosts. Now, this is a ubiquitous speech device, and I realize that people generally know that a virus or neuron or whatever other thing or process that is being discussed doesn't possess intentions. The real, but more subtle, problem is that the implied direction of causality is usually backwards when we do this.
While it's fine for everyday speech, I think it's worth the extra linguistic gymnastics it takes to avoid this kind of usage when talking or writing about science.
I agree (as a scientist and science writer) that it is hard to walk the tightrope between being too analytical and reductionist and objective, on the one side, and being too reified/synthetic and subjective on the other. If I may comment with a sonnet:
The Sun Breaks
by
Jonathan Vos Post
The sun breaks into many suns
where the wave breaks into many waves.
The year breaks into many days,
and the rocks become sand.
The jungle breaks into many trees,
the palm tree breaks into many fronds,
the shadow lies broken on the ground
and moves in fragments of the wind.
My life breaks into memories,
my family broken into many lives.
The wise are mostly underground.
The young are scattered by the wind.
Old songs are broken into many notes.
Old grief into innumerable tears.
I much prefer erring in the direction of giving the trees too much credit for the forest than to make neuroscience as abstract as cognitive psychology. Someone recently called me on my saying that if the mind is completely explained by the brain then even abstract thoughts are merely physical processes. Of course a philosopher might say that even when neuroscience can show that some pattern of neuronal firing equals the word "firing", maybe one as written, another as heard, and still another for its semantic meaning, there still is that conscious experience that might require something more as well as a concept that is beyond however I think about "firing". Well, fine, what I hear in that is the ambiguity of language, which is always present. All words are imperfect reflections of reality, maybe oversimplifications of reality, maybe mixing up a number of different things as the same concept and multiple concepts as the same word. If I could write in equations and express anything I wanted, I would. But we're stuck with words.
As least with our habit of speaking simplistically or symbolically, people can talk about how they get different meanings out of the same sentence. If you worry too much about being perfectly precise, people either won't understand you at all or there won't be that much to understand.
And you haven't even mentioned the problems we science journalists have: inadequate space to explain much of anything and editors who push us constantly to both simplify and dramatize for the sake of grabbing readers. Blogs are a great luxury. They are a functionally endless tablet on which to ramble endlessly. Furthermore, bloggers suffer no editors demanding brevity and hype, to hell with precision.
And I haven't even mentioned deadlines.....
What you're struggling with, though, what all of us who write about neuroscience struggle with, is the good old-fashioned mind-body problem so beloved of philosophers.
There is no way to dispense with that struggle until somebody somewhere figures out exactly how spindle cells do, somehow, generate/communicate those near-indescribable emotions. Coming up with that explanation is, I suppose, the great task of neuroscience. Are we there yet?
Science writers can't begin to explain this stuff simply until scientists can explain it at all. Until then, we're stuck with trying to sneak terms like "emergent properties" into news stories. Lots o' luck with that, my friend.
Thanks for the poem, Jonathan Vos Post. I like it.
You're welcome, fullerenedream. The contrast between poetry and science writing illustrates some of your points:
(1) inadequate space -- poetry deal with this by brevitas, highly compressed language, connotation, metaphor, and implicit parallelism;
(2) editors -- significant for long poetry (consider Pound helping Eliot with "The Wasteland") but mostly hands-off for shorter verse;
(3) simplify -- poetry need not explain fully and persuade logically but can use Metonym;
(4) dramatize -- by persona, other techniques;
(5) deadlines -- different inspiration/perspiration ratio for poetry and science writing.
Yes, I do agree with you and the other commenters here that being that precise runs the risk of being boring and even ill understood. And while Kurt is right that this similar to the kind of problem that arises when intentionality is attributed to organisms, it's, I think, just a bit different.
For instance, spindle cells might merely carry information on the valence of a particular stimulus. The kinds of firing evoked by fear or joy might not be different. It could get in the way of figuring out what information precisely is being transferred. Which would be why I would think of it as sloppy thinking rather than writing.
My other reason for feeling this way is precisely that I headbutt a lot. "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?"
Tabitha mentions some very good reasons why I should withhold (most) of my critical comments about science writers, since they have to contend with:
-inadequate space
-editors who push to simplify
-deadlines
However, I agree with this statement...
Blogs are a great luxury. They are a functionally endless tablet on which to ramble endlessly. Furthermore, bloggers suffer no editors demanding brevity and hype...
...so I think that making pronouncements such as "spindle neurons convey our social emotions across the entire brain" and "spindle cells use their cellular velocity - they transmit electrical signals faster than any other neuron - to make sure that the rest of the cortex is also saturated in that specific feeling" without any scientific evidence is sloppy writing.
I think there's a significant and growing body of evidence suggesting that our spindle neurons are involved in the transmission of social emotion and social intuition. The evidence is indirect but very suggestive. Here's Allman, et.al. from a 2005 Trends in Cognitive Science paper:
"As of yet, we do not know the mechanisms responsible for the differentiation of the complex social emotions that activate FI and ACC, but we do know that the VENs are a recently evolved population that probably serves to relay output of the processing within FI and ACC to other brain structures. Their large size suggests that the VENs may relay a fast intuitive assessment of complex social situations to allow the rapid adjustment of behavior in quickly changing social situations. They can thus be seen as an adaptation supporting the increased complexity of hominoid and especially human social networks. This is reflected in evidence that the capacity for empathy
is better developed in chimpanzees than in monkeys. We hypothesize that the VENs and associated circuitry enable us to reduce complex social and cultural dimensions of decision-making into a single dimension that facilitates the rapid execution of decisions. Other animals are not encumbered by such elaborate social and cultural
contingencies to their decision-making and thus do not require such a system for rapid intuitive choice.
Your critics pick up on a spectrum of points. You can't say that a single neuron is any more responsible for conveying an emotion than an engine is for driving a car. An engine itself, sans fuel, sans drive shaft, sans wheels, can't run a car. Ditto for the neuron. At the same time, saying that the neuron doesn't convey the emotion, that the engine doesn't drive the car, that it's just the marvelous whiffly-woof of "the mind" or "the car" isn't quite correct either.
On a nit-picky side note, fMRI doesn't show neuronal activity, it shows relative change in blood oxygenation across the brain which is correlated with neuronal activity- areas which are typically larger than the active region itself.
If an automotive writer had to explain the performance of a particular sports car by describing every detail of the internal combustion process and suspension mechanics, the story would be tedious indeed.
-Roger
Based on the cited comments from Allman et al. (2005), I can see why you might think that spindle neurons transmit social emotions. However, their Trends in Cognitive Sciences article was categorized under the "Opinion" section with the title, "Intuition and autism: a possible role for Von Economo neurons" [my emphasis]. The article is highly speculative. No neurophysiological studies of spindle cells have ever been conducted, for obvious reasons (no single-unit recording in chimps or humans or humpback whales). So nothing is known about their physiological properties. Nothing is even known about their target projection sites (Allman et al., 2005): "However, it is not known where the VENs ultimately project."
Neuroanatomical data suggest that the dendritic structure of VENs (von Economo neurons) makes them "computationally simple compared with pyramidal neurons" (Watson et al., 2006), as least for their inputs.
Finally, humpback whales have many spindle cells (Hof et al., 2006), but they're largely solitary creatures (Valsecchi et al., 2002):
These findings suggest that, if any social organization does exist, it is formed transiently when needed rather than being a constant feature of the population, and hence is more likely based on reciprocal altruism than kin selection.
Based on the cited comments from Allman et al. (2005), I can see why you might think that spindle neurons transmit social emotions. However, their Trends in Cognitive Sciences article was categorized under the "Opinion" section with the title, "Intuition and autism: a possible role for Von Economo neurons" [my emphasis]. The article is highly speculative. No neurophysiological studies of spindle cells have ever been conducted, for obvious reasons (no single-unit recording in chimps or humans or humpback whales). So nothing is known about their physiological properties. Nothing is even known about their target projection sites (Allman et al., 2005): "However, it is not known where the VENs ultimately project."
Neuroanatomical data suggest that the dendritic structure of VENs (von Economo neurons) makes them "computationally simple compared with pyramidal neurons" (Watson et al., 2006), as least for their inputs.
Finally, humpback whales have many spindle cells (Hof et al., 2006), but they're largely solitary creatures (Valsecchi et al., 2002):
"These findings suggest that, if any social organization does exist, it is formed transiently when needed rather than being a constant feature of the population, and hence is more likely based on reciprocal altruism than kin selection."
Based on the cited comments from Allman et al. (2005), I can see why you might think that spindle neurons transmit social emotions. However, their Trends in Cognitive Sciences article was categorized under the "Opinion" section with the title, "Intuition and autism: a possible role for Von Economo neurons" [my emphasis]. The article is highly speculative. No neurophysiological studies of spindle cells have ever been conducted, for obvious reasons (no single-unit recording in chimps or humans or humpback whales). So nothing is known about their physiological properties. Nothing is even known about their target projection sites (Allman et al., 2005): "However, it is not known where the VENs ultimately project."
Neuroanatomical data suggest that the dendritic structure of VENs (von Economo neurons) makes them "computationally simple compared with pyramidal neurons" (Watson et al., 2006), as least for their inputs.
Finally, humpback whales have many spindle cells (Hof et al., 2006), but they're largely solitary creatures (Valsecchi et al., 2002):
These findings suggest that, if any social organization does exist, it is formed transiently when needed rather than being a constant feature of the population, and hence is more likely based on reciprocal altruism than kin selection.
Roger: on the other hand, a good automotive writer may use details of spark timing, of the mixing pattern of fuel and air in the cylinder, the relative masses and movements of the suspension components to draw a beautifully evocative picture of what it's like to ride a particular sports car.
Part of what this discussion seems to be missing is a solid understanding of the intended readers of a particular piece. One writes neuroscience very differently for people who already know neuroscience than for those who don't (and I'm not talking journal article vs popularization). Sometimes you can be looser when addressing an audience that already knows all of the qualifications, caveats and possible corrections to what you're saying than you can to a less knowledgeable audience. Sometimes not.
Back when I was a fulltime science writer, we tried to simplify things only in ways that wouldn't give an actively misleading impression of what was "really" going on -- so that the people who knew we'd left stuff out would also know that the stuff being left out didn't change the ultimate picture. Of course we failed regularly, but that's the way it goes, like death and taxes -- you compress beyond a certain point, you lose information.
"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?"
But this is, or should be a central point of your science writing about neuroscience! These are metaphors, only! So, your sentences might get 'cluttered'. Better that, than to actually mis-inform. The cell fire action potentials. The amygdala does NOT generate emotions-The mystery IS how do these impulses becomes consciousness. Presently, all the exciting research is useful, but to compress and simplify, is actually doing a disservice, by merely avoiding what still remains the mystery.
Go ahead, report the findings- muse about the implications, but yeah, remind your readers about the mystery and the metaphors.
mk