Not long ago we discussed work led by Deena Skolnick Weisberg showing that most people are more impressed by neuroscience explanations of psychological phenomena than plain-old psychology explanations. Talking about brains, it seems, is more convincing than simply talking about behavior, even when the neuroscience explanation doesn’t actually add any substantive details.
Now David McCabe and Alan Castel have taken this work on the acceptance of neuroscience to a new level: now they’ve got pictures! They asked 156 students at Colorado State University to read three different newspaper articles about brain imaging studies. The articles were completely fake, and they all discussed brain imaging, but one of the articles included only text, one included a bar graph showing brain-scan results, and one showed pictures of brains. The articles were about three different topics, but an equal number of students saw each article with text only, the graph, or the brain image.
For example, in one of the fake studies, the claim was made that TV-watching is related to math ability. As evidence, students read a text explanation, or saw one of these two figures:
The [fake] claim was that since the same area of the brain is activated while doing arithmetic or watching TV, that the two activities are related. The students then rated this article for whether its scientific reading made sense, on a scale of 1 (strongly disagree) to 4 (strongly agree). Here are the results:
The articles accompanied by brain images were rated significantly higher than the other articles, despite the fact that the fake claim in each article wasn’t actually supported by the fake evidence, in whatever form it was presented.
But maybe people are simply more impressed by the complexity of the brain image. In a second experiment, the researchers repeated the study but instead of using a graph, they used a topographic map of brain activity and a brain scan:
Once again, the article with the brain image was rated higher for scientific reasoning.
But since these studies feature made-up data, maybe they don’t apply to real studies. In a final experiment, McCabe and Castel modified a real write-up of a real brain-imaging study, which argued that brain imaging can be used as a lie detector. Students read one of two different versions of the article. One version contained criticism from a brain researcher who wondered whether the technique would work in the real world, while the other omitted the criticism. These groups were again divided into two groups, one of which saw a brain image accompanying the article, and the other who read the article without any images. Here are the results:
Once again, the agreement with the article’s conclusion was significantly higher when a brain image was presented, even though the same evidence was presented in textual form in the article, making the brain image redundant. Even more striking, while agreement with the conclusion was affected by the presence of the brain image, the presence or absence of substantive criticism had no effect. Criticism did have an effect on whether the students thought the article title (“Brain scans can detect criminals”) was appropriate.
Given the power of the brain image to sway opinion, perhaps it will only be a matter of time before we start seeing brain images in advertising.
MCCABE, D., CASTEL, A. (2008). Seeing is believing: The effect of brain images on judgments of scientific reasoning. Cognition, 107(1), 343-352. DOI: 10.1016/j.cognition.2007.07.017