Hot on the heals of a recent study that found that neuroscience jargon made unlikely scientific claims more believable, comes a new study, covered by the BPS Research Digest, that found that simply showing a picture of a brain scan made bogus science more convincing.
David McCabe and Alan Castel presented university students with 300-word news stories about fictional cognitive research findings that were based on flawed scientific reasoning. For example, one story claimed that watching TV was linked to maths ability, based on the fact that both TV viewing and maths activate the temporal lobe. Crucially, students rated these stories to be more scientifically sound when they were accompanied by a brain image, compared with when the equivalent data were presented in a bar chart, or when there was no graphical illustration at all.
McCabe and Castel repeated the experiment with a control condition featuring a topographical activation map – it’s just as visually complex as a brain image but it doesn’t look like a brain. These stories were rated as more credible when accompanied by a brain image compared with a topographical map, showing that the allure of brain images is not merely down to their complexity.
Most of these sorts of reasoning errors are due to the fact that the public at large still thinks about the mind and brain as separate, loosely connected systems.
The influence of ‘placebo science-a-likes’ isn’t a problem restricted to neuroscience, of course. I suspect adding the language of genetics will have a similar confidence-boosting effect, regardless of the actual claim being made.
If you want to know the nitty gritty about how fMRI brain scans can mislead, I highly recommend the sardonic guide, How to Lie with fMRI Statistics.