Monday, 31 March 2008

The power of blobs on the brain

The media love those colourful brain images - the ones adorned by blobs purportedly showing which areas are most active when the experimental participant is thinking about something specific like cheese on toast. Now researchers in America have shown just how persuasive these images can be.

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.

A final study used a real-life news story taken from the BBC: "Brain scans can detect criminals". This time the students were more likely to agree with the conclusions of the news report when it was accompanied by a picture of the brain.

McCabe and Castel said their results show people have a "natural affinity for reductionistic explanations of cognitive phenomena, such that physical representations of cognitive processes, like brain images, are more satisfying, or more credible, than more abstract representations, like tables or bar graphs."

These new results come after earlier research showing that the mere mention of cognitive neuroscience data leads people to judge scientific findings to be of higher quality.

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

Post written by Christian Jarrett (@psych_writer) for the BPS Research Digest.

1 comment:

Silas Barta said...

The results sound persuasive and all, but I can't quite be sure of the validity of their claims until I see some kind of brain scan showing what's going on in the subjects' heads...

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