Recent experiments by CSU and UCLA psychologists show that brain scan images can make even the silliest scientific claims believable to readers.
In three experiments, beginning psychology students were given a supposedly scientific article to read, then asked to rate the credibility of the article’s claims. Students were more likely to agree with the conclusions of an article illustrated by brain scan images than they were to agree with the same article illustrated by a bar graph or without images.
In two of the experiments, readers were presented with clearly flawed scientific reasoning, said Dr. David McCabe, a CSU psychology professor led the study along with Dr. Alan Castel of UCLA.
“We made up really terrible arguments,” McCabe said. In one of the articles, “the implication was that watching TV would improve your math skills because similar areas in the brain lit up. Which is a ridiculous claim because watching TV is usually associated with poorer academic performance.”
However, the picture of the brain is alluring. After looking at the three different versions of the math skills/TV watching article, Jessica Weinberg chose the version with the brain scan as the most convincing.
“It seems a little more scientific,” Weinberg, a junior majoring in human development and family studies, said. “The brain is so complex, it can do so many things.”
People seem to believe that if the same region of the brain is activated by two activities, they must be correlated, McCabe said.
“Which isn’t necessarily true, all different sorts of things could light up the same area of the brain. It doesn’t mean that you’re doing the same thing. It doesn’t mean that you can draw some sort of cause/effect relationship based on those data,” he said.
In another experiment, readers received a real article from a BBC Web site, titled “Brain Scans Can Detect Criminals.” They were more likely to believe that brain imaging could be used as a lie detector if the article was illustrated with a functional magnetic resonance imaging (fmri) picture of a brain, McCabe and Castel said.
This study may indicate that the graphic that accompanies scientific text affects people’s confidence in their understanding of the material, Dr. Castel said, meaning it has “implications for how people learn science.” This could also affect how science writers in the popular media choose the pictures to illustrate their stories, Castel said.
Science is often oversimplified and sensationalized in the media, particularly if intriguing technologies like brain scans are involved, McCabe said.
McCabe cited as a prime example the God spot, referring to a 1997 University of California San Diego study in which brain scans of religious people being shown words associated with their religion displayed activity in one area in the frontal lobe, an area promptly dubbed the God spot by some in the media. “God spot” arose again in 2006 when a group of Carmelite nuns were scanned as they attempted to relive spiritual experiences.
The data and conclusions of the two studies were used to speculate that spirituality is a physical function of the brain, or to support claims that all people have the physical capacity to believe in God.
McCabe found the claims overreaching.
“This is the area that’s related to believing in God or thinking about God, and perhaps that’s true,” he said. “It’s sort of ridiculous to reduce someone’s belief in God to the activation of a particular brain area.”
As to why people are more convinced by brain scan images, Dr. Castel speculates that “the general public doesn’t have as much experience with interpreting the brain, but they have one. Where as a bar graph . they’re not as connected to it.”
McCabe thinks that perhaps the pictures let people reduce the mind to a “physical thing rather than an ephemeral, mental thing. That’s attractive to people, almost seductive. People see that and say ‘wow, that’s incredible, we’re looking at the mind.'”
Though not everyone liked the brain images best.
Matthew Tullis, a sophomore political science and criminology major, chose a different version of the false TV-watching-boosts-math-skills article.
“The one with the bar graph, definitely,” Tullis said.
Staff writer Beth Malmskog can be reached at firstname.lastname@example.org.