Imagine that Tom is analysing a work of literature – The Grapes of Wrath, say. He looks at the plot, characterisation, historical context, and uses the various tools of literary analysis. But now Tom takes the study further, and begins to examine the type of paper that the book was printed on. Next, he looks at the ink used, employing gas chromatography to elucidate the chemical makeup of its ingredients. What if at some point Tom insists that the book can be fully understood through this latter, scientific methodology, and that The Grapes is nothing more than the sum of its parts – the molecular interactions between ink droplets and the cellulose in the paper?
Science has made great progress in the last three centuries by pressing the cause of reductionism. The idea is that underneath complex phenomena and entities are simpler, more fundamental layers that can be studied in order to fully elucidate the complex conglomerate. For example, biology has benefited by exploiting the reductionist tools of biochemistry – reducing complex biological phenomena to the level of chemistry. But, as in our example above, the process can go haywire, as when claims are made that human beings are no more than a collection of biochemical responses to stimuli and neuronal interactions. [Chris Mooney’s The Republican Brain: the Science of Why They Deny Science – and Reality (2012) disavows “reductionism” yet encourages readers to treat people with whom they disagree more as pathological specimens of brain biology than as rational interlocutors.]
Informed consumers of science need to be aware of reductio ad absurdum in the realm of brain scans. The idea that a neurological explanation could exhaust the meaning of experience was already being mocked as “medical materialism” by the psychologist William James a century ago. And in The Invisible Gorilla (2010), Christopher Chabris and Daniel Simons advise readers to be wary of such “brain porn”. But popular magazines, science websites and books are frenzied consumers of- and proselytisers for these scans. “This is your brain on music”, announces a caption to a set of fMRI images, and we are invited to conclude that we now understand more about the experience of listening to music. The genre is inexhaustible: “This is your brain on poker”, “This is your brain on metaphor”, “This is your brain on diet soda”, “This is your brain on God” and so on. The attempt to explain, through snazzy brain-imaging studies, not only how thoughts and emotions function, but how politics and religion work, and what the correct answers are to age-old philosophical controversies is nothing less than an intellectual pestilence, a plague of neuroscientism, also known as neurobabkes. For years, the uninformed public has been deluged by references to innumerable studies that “explain” the most complex, subtle and ethereal phenomena on the basis of some colour-drenched picture of a sliced brain. The accompanying report, which purports to explain why human beings love, or envy, or believe in God, or prefer Coke to Pepsi, is heavy on neuro-babble. This is reductionist science run amok. The ubiquity of headlines containing phrases like brain scans show is matched only by the confusion they create in the minds of the public, uninformed about science as it is. So let’s revise some basics.
The human brain is, so far as we know, the most complex object in the universe. That a part of it “lights up” on a functional magnetic resonance imaging (fMRI) scan does not mean that the rest is inactive; it means that certain areas in the brain have an elevated oxygen consumption when a subject performs a task such as reading or reacting to stimuli such as pictures or sounds. The significance of this is not necessarily obvious. Technicolor brain scans are not anything remotely like photographs of the brain in action in real time. Scientists cannot “read” minds. Paul Fletcher, Professor of health neuroscience at Cambridge University, says that he gets “exasperated” by much popular coverage of neuroimaging research, which assumes that “activity in a brain region is the answer to some profound question about psychological processes. This is very hard to justify given how little we currently know about what different regions of the brain actually do.” Too often, he says, a popular writer will “opt for some sort of neuro-flapdoodle in which a highly simplistic and questionable point is accompanied by a suitably grand-sounding neural term and thus acquires a weightiness that it really doesn’t deserve. In my view, this is no different to some mountebank selling quacksalve by talking about the physics of water molecules’ memories, or a beautician talking about action liposomes.”
In fact, a new branch of the neuroscience-explains-everything genre may be created at any time by simply attaching the prefix “neuro” to whatever. So “neuroeconomics” is the latest in a line of rhetorical attempts to sell the dismal science as a hard one; “molecular gastronomy” has now been trumped in the gluttony stakes by “neurogastronomy”; students of Republican and Democratic brains are doing “neuropolitics”; literature academics practise “neurocriticism”, and there is “neurotheology”, “neuromarketing” and other assorted neurononsense.
When the media conjure up stories with titles like “Brain Scans Show Vegetarians and Vegans More Empathic than Omnivores”, the content is almost entirely fictitious. It would be hilarious if not for the fact that the masses out there take this as Science – magisterial, peremptory, authoritative. Examples of this pop-science abound. Marketing consultant Martin Lindstrom tells us that people “love” their iPhones. This conclusion is based on the fact that brain scans of telephone users listening to their personal ring tones showed a “flurry of activation” in the insula, a prune-sized area of the brain. But researchers at UCLA claimed that photos of former presidential candidate John Edwards provoked feelings of “disgust” in subjects because they “lit up” the… insula. Is dopamine “the molecule of intuition”, as Jonah Lehrer suggested in The Decisive Moment (2009), or is it the basis of “the neural highway that’s responsible for generating the pleasurable emotions”, as he wrote in Imagine (2012)? Susan Cain’s Quiet: the Power of Introverts in a World That Can’t Stop Talking (2012), meanwhile, calls dopamine the “reward chemical” and postulates that extroverts are more responsive to it. Other stars of the pop literature are the hormone oxytocin (the “love chemical”) and mirror neurons, which allegedly explain empathy.
Informed consumers of science are aware that just about any conclusion in science – but especially in psychiatry, neurology and psychology – is possible, if you pick your evidence carefully. “Having outlined your theory,” says Professor Fletcher, “you can then cite a finding from a neuroimaging study identifying, for example, activity in a brain region such as the insula… You then select from among the many theories of insula function, choosing the one that best fits with your overall hypothesis, but neglecting to mention that nobody really knows what the insula does or that there are many ideas about its possible function.” The insula plays a role in a broad range of psychological experiences, including empathy and disgust, but also sudden insight, uncertainty, and the awareness of bodily sensations, such as pain, hunger, and thirst. With such a broad physiological portfolio, it is no surprise that the insula is activated in many fMRI studies.
Even more versatile than the insula is the infamous amygdala. Invariably described as “primitive” or even “reptilian”, the amygdala shows increased activation when one experiences fear, but it also springs to life when one encounters novel or unexpected stimuli. The multi-functionality of most brain areas renders reasoning backwards from neural activation depicted by a scan to the subjective experience of the brain’s owner a dubious strategy. This approach – formally referred to as “reverse inference,” – is nothing but a high-tech and expensive Rorschach test, inviting interpreters to read whatever they wish into ambiguous findings. There is strong evidence for the amygdala’s role in fear, but then fear is one of the most heavily studied emotions; popularisers downplay or ignore the amygdala’s associations with the cuddlier emotions and memory. (In The Republican Brain, Mooney suggests that “conservatives and authoritarians” might be the nasty way they are because they have a “more active amygdala”.)
Brain imaging is ubiquitous in pop science mostly because the images are mediagenic. The technology lulls the hoi-polloi into thinking that the most complex entities and phenomena are reducible to simple images on a screen, a perfect fit for a generation hooked on iGadgets. Pretty pictures of the brain can seduce us into drawing simplistic conclusions, leading us to ask more of these images than they can possibly deliver. And the pictures inspire uncritical devotion: a 2008 study, notes Fletcher, showed that “people – even neuroscience undergrads – are more likely to believe a brain scan than a bar graph”.
Even if brain scans were reliable indicators of brain activity, it is not straightforward to infer general lessons about life from experiments conducted under highly artificial conditions. Furthermore, let’s remember that we do not have the faintest clue about the biggest mystery of all – how a lump of grey matter produces the conscious experience we take for granted.
Brain scams are not the only area where scientists and science reporters overreach. The same is true of gene studies that purport to pin down the most intricate human characteristics and behaviours to this or that gene, reducing human beings to nothing but a collection of amino acids.
And the same is true of evolutionary biology, which purports to reduce human beings to the sum total of random mutations. Any claim about diffuse phenomena that is made on the basis of reductionism should be treated with suspicion.
See the following two articles:
Retrieved 3rd June 2013.
Retrieved 3rd June 2013.