Neurorealism: Impressed by pretty pictures of the brain
In a recent visit to Deric Bownd’s excellent cognitive science blog, MindBlog, I discovered this interesting finding: people are more impressed by cognitive science findings if these findings include neuroimaging. Should they be?
Bownd reports that
“A paper published online in September by the journal Cognition shows that assertions about psychology — even implausible ones like “watching television improved math skills” — seem much more believable to laypeople when accompanied by images from brain scans. And a paper accepted for publication by The Journal of Cognitive Neuroscience demonstrates that adding even an extraneous reference to the brain to a bad explanation of human behavior makes the explanation seem much more satisfying to nonexperts.”
Should people really be more impressed by cognitive science research if it presents neural scans (e.g., functional magnetic resonance imaging, fMRI) indicating differential activation patterns in different experimental conditions? As is discussed in Bownd’s post, these brains scans in many cases do not seem to add any additional information when it comes to evaluating the validity and value of findings. If you want to find out if a person finds chocolate enjoyable, do you really need to see if the pleasure centres in the brain are activated? Do you really need to see changes in dopamine activity to answer this question? Can’t we just ask the person if they’re enjoying their chocolate? And if they say “yes”, wouldn’t it be safe to assume that certain centres in the brain are behaving differently during the chocolate experience than before it? The notion that brain states change with changing phenomenological states is not exactly news. This has been a pillar of cognitive skcience for a quite a while now.
And if you want to find out if watching television is beneficial to math skills, can’t we just do simple experiments in which television viewership is controlled across groups and math tests are administered? If there is a difference between the groups, do we really need to see differential activation patterns to prove this? We already have as much proof as is going to be gained in one study: a positive finding.
The finding that people are more impressed by cognitive science findings accompanied by neural imagery seems to be a clear case of understandable ignorance of cognitive science—understandable because not everyone is well-versed in the field, nor should they be expected to be—combined with peripheral route information processing. We’ll consider the latter factor first.
A few decades ago psychologists Richard Petty and John Cacioppo developed the Elaboration Likelihood Model (ELM) of argument evaluation or persuasion. According to this model, individuals being presented with an argument tend to engage in one of two modes of processing to varying degrees. The first is the central route. When one is engaging in central route information processing, they are critically examining the content of the argument for its validity. They are persuaded by arguments that arguments that stand up to their honest and thoughtful rational scrutiny, and remain dubious of those that do not. The second type of information processing is referred to as the peripheral route. Humans do not always carefully scrutinize every argument that they are presented with. When the meteorologist says it’s gonna be sunny tomorrow, I don’t call up the TV station to demand evidence for the bold claim. People are more impressed by a new abdominal trainer if it is endorsed by a medical doctor as opposed to a fire fighter. People are often more credulous when a speaker is attractive, confident, provides many different arguments, and conveys authority in their speech. These points are all demonstrations of peripheral route processing. In each of these cases we are persuaded by virtue of cues peripheral to the actual content of the message. Such cues include the attractiveness of the speaker, their confidence, the authority we attribute to them (e.g., medical doctors are ascribed authority with regard to issues of health and the body), the number of arguments made, how much one likes the speaker, whether one agrees with the speaker on other things, and so forth. When we are tired, uninterested or preoccupied, we use these peripheral cues as heuristics, or short cuts, in information processing, rather than slogging through a drawn out analysis.
Neurorealism, the phenomenon in which people find CogSci findings more impressive and real if they include neural imagery, seems to be a product of peripheral route processing in conjunction with understandable ignorance—or temporary forgetfulness—of some tenets of cognitive neuroscience. It’s no secret that the average person has more respect for the more materialistic hard sciences (biology, chemistry and physics) than the “soft” sciences (e.g., psychology). Thus, when cognitive scientists are able to tie their very real behavioural findings to specific neurological centres many people are more impressed than if the findings were exclusively behavioural. If the individual were knowledgeable about and mindful of how cognitive science works and were engaging exclusively in central route processing, assessing the argument on its merits, they should not be more impressed by these brain scans. They should be impressed on the basis of tightly controlled and orchestrated procedures, rationally sound analysis, and the fact that the study had survived the gauntlet of expert peer review. They should only be additionally convinced by the brain scans if 1) they had engaged in peripheral route processing, and were positively influenced by the tying of psychological findings to hard neuroscience, and/or 2) they are unaware or forgetful of the facts that i) it is wellknown that behavioural changes correlated with brain activation changes, so this is to be expected, and ii) the brain scans are of secondary importance; when considering if a particular treatment or stimulus has a particular consequence for behaviour/performance, all that matters is that a well-designed and soundly-analyzed study produced a real behavioural difference.