The seductive allure of neuroscience scans

An article by Farah & Hook (2013) examined the much discussed idea that attaching fMRI scans to an article (even if they are unrelated or totally meaningless) makes said article appear more “scientific” and that they “overwhelm critical consideration” (Uttal, 2011). This is obviously not a good thing, as it could lend undue credibility to “bad science”. The evidence to support these claims about the unstoppable power of fMRI scans comes from two articles: McCabe & Castel (2008) and Weisberg et al. (2008).

The McCabe & Castel (2008) study looked at how credible made up studies were rated when they had either functional brain images, bar charts, topographical maps of scalp-recorded EEG (electroencephalogram) or no image attached. When comparing the credibility of studies with either the bar charts or the fMRI scans, they found the fMRI scan condition studies were rated as more credible. However it is not a fair comparison between the two different types of information: the fMRI scans vividly displayed the location and shape of the activity within the temporal lobe, whilst the bar charts merely showed total activity levels within the temporal lobe. The “study” was based on comparing activity between brain areas to see differences, so the fact you could “see” the brain activity meant it would be more likely to be persuasive than just a description of the total brain activity. They are not “informationally equivalent” aka the fMRI images give more information to the reader than the bar charts so are more likely to be persuasive. They also compared the fMRI scans to EEG readings and whilst the EEG readings are more specific (as to the location of the brain activity) than the bar graph, they are still not as specific as the fMRI scans (low temporal resolution is one of the biggest problems with measuring electrical activity in the brain).


The Weisberg et al. (2008) study didn’t actually examine the impact neuroscience IMAGES have on people’s ratings of an article’s credibility, it looked at how neuroscience INFORMATION affected the perceived quality of information about psychological phenomena (and no images were used).


A huge-scale replication of McCabe & Castel’s original study showed a brain image had almost no effect on how persuasive the article was (Micheal et al., 2013). There is another failed replication of McCabe & Castel’s study by Hook & Farah (2013).


The idea that fMRI scans are intrinsically influential is relatively widespread yet there appears to be a lack of evidence to support this claim, so I feel declaring neuroscience images to be overwhelming a bit premature. 


References: 

Farah, M.J. & Hook, C.J. (2013). The seductive allure of “seductive allure”. Perspectives on Psychological Science, 8 (1), 88-90.
Hook, C.J. & Farah, M.J. (2013). Look again: effects of brain images and mind-brain dualism on lay evaluations of research. Journal of Cognitive Neuroscience, 25 (9), 1397-1405.
McCabe, D.P. & Castel, A.D. (2008). Seeing is believing: the effects of brain images on judgments of scientific reasoning. Cognition, 107 (1), 343-352.
Michael, R.B.; Newman, E.J.; Vuorre, M.; Cumming, G. & Garry, M. (2013). On the (non)persuasive power of a brain image. Psychonomic Bulletin and Review. 20 (4), 720-725.
Uttal, W.R. (2011). Mind and Brain: A Critical Appraisal of Cognitive Neuroscience. London: The MIT Press.
Weisberg, D.S.; Keil, F.C.; Goodstein, J.; Rawson, E. & Gray, J.R. (2008). The Seductive Allure of Neuroscience Explanations. Journal of Cognitive Neuroscience, 20 (3), 470-477. (function(i,s,o,g,r,a,m){i[‘GoogleAnalyticsObject’]=r;i[r]=i[r]||function(){ (i[r].q=i[r].q||[]).push(arguments)},i[r].l=1*new Date();a=s.createElement(o), m=s.getElementsByTagName(o)[0];a.async=1;a.src=g;m.parentNode.insertBefore(a,m) })(window,document,’script’,’//www.google-analytics.com/analytics.js’,’ga’); ga(‘create’, ‘UA-63654510-1’, ‘auto’); ga(‘send’, ‘pageview’);