July 28, 2010

Payments Bias Viewers’ Art Judgment

You hear it all the time in museums and art galleries: "I don't know much about art, but I know what I like."

As a corollary, neuroscience researchers at Baylor College of Medicine add that money, even if only tangentially related, can influence that opinion. On a more global platform, value judgments of this sort can be altered by such influences or favors, said Dr. P. Read Montague, professor of neuroscience at BCM and the senior author of a report evaluating the effect of a payment on art evaluation that appears in the Journal of Neuroscience.

"We used art because there are no right answers and the fact that someone sponsors the experiment should not matter," said Montague, who is also director of the Brown Human Neuroimaging Laboratory at BCM.

However, when the payment reached $300, it did, said Dr. Ann H. Harvey, the first author of a report on the experiment. She is a postdoctoral associate in neuroscience.
Brains show value judgments affected by sponsorship

"There is no notion that the kinds of paintings you enjoy looking at should be affected by whether or not someone did you a favor," said Harvey. "Nonetheless, in our study we found that your personal preferences can be altered by biasing gestures, notably without any knowledge that you are being influenced. These biasing effects act through regions of the brain previously known to be involved in value judgments and response to reward."

Twenty-nine subjects received $30, 29 received $100 and 29 received $300. They were then put into functional magnetic resonance imaging scanners (fMRI), which use powerful magnets to monitor brain activity. At the beginning of that task, they were shown two company logos and told which one was sponsoring them along with the amount of compensation. The companies were fictitious and the logos associated with them were generated in the laboratory itself to prevent any other kind of bias.

They then saw 60 paintings, each partnered with one of the logos. The participants just looked at the paintings as they were flashed before them.

After the scanning, they were then asked to rate the paintings, which they saw paired with the same logo that they saw in the scanner. While there was a "trend" toward preferring the paintings shown next to the sponsor's logo in the $30 and $100 groups, the preference was only statistically significant in the $300 group.

When Harvey, Montague and their colleagues looked at the brain scans of the subjects in the $300 group, they found that the money did not appear to influence any special set of brain responses but instead affected responses in those parts of the brain that are normally affected when people are asked to make value judgments. This was true when they looked at the ventromedial prefrontal cortex, which encodes preferences across a variety of senses, and other regions of the brain that can respond to such subjective preferences.

In another set of experiments, the researchers found that the mere offer of payment could affect the subject's responses to the paintings.
Subjects unaware of bias

In questionnaires filled out after the experiment, subjects said they did not think that the logo affected their abilities to judge the paintings fairly.

"This suggests that the observed influence is covert and the subjects are not consciously changing their judgment," the researchers wrote.

The finding could have application in many settings where people receive favors or rewards, said the authors.

"Physicians and the pharmaceutical industry, for instance, are under increasing scrutiny for the mounting evidence that gifts to physicians are capable of drastically influencing treatment and prescribing behavior," they wrote. "In our experiment, we show that monetary favors only mildly associated with the stimuli being judged could still influence behavior, suggesting that repeated reciprocal interactions with a company providing gifts could easily influence physicians' valuation mechanisms without their explicit knowledge."

Others who took part in this research include Dr. Ulrich Kirk and George H. Denfield, also of BCM.

Funding for this work came from the National Institute of Neurological Disorders and Stroke, the National Institute on Drug Abuse and the Kane Foundation.

An abstract of the report is available.

Montague holds the Brown Foundation Chair of Human Behavioral Neuroscience.


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