Reconsidering the Role of Brain Images on Judgements of Scientific Reasoning Jeanette Akuamoah

The Seductive Allure of Neuroscience Neuroscience research has made many important contributions to the study of the brain and behavior. Perhaps because of these contributions the general public seems to be easily seduced by neuroscientific explanations. Meaning that when a scientific article is paired with a brain image, the information within the article is automatically believed to be more credible The purpose of my summer project was to examine how neuroscientific explanations influence how people evaluation scientific information.

Previous Research The presence of brain images increased perceptions of scientific reasoning (McCabe & Castel; 2008) For lay people, neuroscientific explanations are particular persuasive for weak arguments (Weisberg et al; 2008) Brain images have a small meta-analytic effect on judgements of scientific reasoning (Michael et al., 2013)

Why might this effect be so reliably small? The previous studies asked participants to read and evaluate relatively innocuous scientific information None of the topics are explicitly relevant or consequential to participants. Brain images may produce a larger effect on judgements of scientific reasoning when participants are asked to evaluate articles which are explicitly relevant and consequential to them.

Method 954 participants were recruited via Amazon’s Mechanical Turk All participants read an article allegedly from the BBC, titled “Is caffeine good for your brain?” This article suggest that drinking 3 or more caffeinated beverages per daily effects cognition and brain health. Participants were randomly assigned to read a version of the article suggest that either good or bad for brain health Randomly assigned to read this article in the presence of a brain image + ne(or not) Self-relevance was quantified as participants average daily caffeine intake. High self-relevance = those who drink 3 or more caffeinated beverages per day. Moderate self-relevance = those who drink 2 caffeinated beverages per day. Low self-relevance - those who drink 1 or less caffeinated beverages per day.

Perceptions of Article Quality 6-item measure of article quality What is your opinion of the quality of writing in the article? Did the scientific reasoning in this article make sense? How satisfying are the explanations within the article? Did you enjoy reading this article? How important do you think it is for others to be aware of the information within this article? I would be interested in sharing the information in this article with a friend. Total scores (α = .87) ranged from 6 (low quality) to 42 (high quality) We examined these hypotheses in a 3 (Self-Relevance: high vs. moderate vs. low) × 2 (article valence: positive vs. negative) × 2 (brain images: present vs. absent) between-subjects ANOVA. We added the participant’s responses on each of these items to get a total score.

Hypotheses Hypothesis #1: Brain images will enhance judgements of article quality. Hypothesis #2: When the article is self-relevant the positive article will be rated more positively than the negative article. Hypothesis #3: The hypothesized effects of self-relevance will be larger when brain images are present.

Brain Images Enhance Judgments of Article Quality F (1, 945) = 9.45, p = .002, d = .20 Note: Error bars represent S.E. of the mean

Self-relevance Accentuates a Confirmation Bias Self-relevance × Article Valence Interaction: F (2, 945) = 6.29, p = .002 Note: Error bars represent S.E. of the mean

Brain Images do not Enhance Confirmation Bias Brain Images Present Brain Images Absent As you see in these graphs the patterns observed on the previous slide appear quite similar when brain images are present compared to when they are absent. Self-relevance × Article Valence × Brain Imaging Interaction: F (1, 945) = 0.42, p = .66

Discussion Brain images have a small effect on judgments of scientific reasoning, replicating past research (hypothesis 1) Self-relevance accentuated differences in judgments of scientific reasoning between the positive and negative article (hypothesis 2). However, the presence of brain images did not magnify this effect. Thus we did not find support for hypothesis 3.

Future Directions All the articles participants read purportedly came form the BBC which is a highly reputable news outlet in the US Independent of any other factors, participants likely rate news from a highly reputable outlet more favorably because it is so reputable instead of challenging the article Future studies which use less reputable outlets may show more pronounced effects of brain images on scientific reasoning

Acknowledgments Brian Posner and the Posner Fellowship Program Valerie Kilman and the Neuroscience Program Dr. Robin Nusslock Dr. Nicholas Kelley