If you really must offend someone, wait until they are lying down: people handle anger differently when they’re lying on their backs, compared with sitting upright.

University students who heard personal insults while seated exhibited brain activity linked to so-called “approach motivation” – the desire to approach and explore something. This potential urge disappeared when students took their insults lying down, despite their anger remaining.

“In the upright or leaning forward state one might be more likely to attack,” says Eddie Harmon-Jones, a cognitive scientist at Texas A&M University in College Station, who led the study. “Maybe in the reclining state you’re more likely to brood.”

Harmon-Jones worries that MRI studies performed on subjects lying on their backs – which is practically all of them – could miss the neural signatures of certain emotions.


Seeing red

It isn’t every study that requires researchers to infuriate their volunteers, and Harmon-Jones and his colleagues have honed their technique over more than decade.

Students are not told that they are participating in an anger study. The researchers instead ask them to pick a hot-button issue, such as abortion or public smoking, and write a brief essay on their stance. Next, they are hooked to an electroencephalograph, which measures electrical pulses created by firing neurons, and told that a person in an adjacent room will evaluate the essay.

This is a ruse, and Harmon-Jones’s team play a voice recording of someone disparaging the intelligence, likeability and logical skills of the essayist. “People get angry in response to this kind of feedback,” he says.

Chilled out

Volunteers who heard these insults while on their backs felt as angry as volunteers who were seated. But EEG recordings showed that, for the upright volunteers, a brain region called the left prefrontal cortex was more active than its counterpart in the brain’s right hemisphere. Other research has linked this lopsided activation to anger and approach motivation.

Volunteers who received their digs while lying down, however, exhibited EEG patterns no different from subjects who got slightly positive reviews, Harmon-Jones says.

He thinks lying down could affect how the brain handles other emotions, such as desire and happiness. The mental shift provoked by lying down may even be strong enough to affect the results of brain-imaging studies performed on people lying on their backs.

Unnatural circumstances

“It’s unknown how much of an effect this has, but this study suggests that people should start looking to see if body position is affecting processing in other types of experiments,” Harmon-Jones says, noting that most of our decisions are made while we’re upright, not lying down.

Peter Bandettini, a brain imager at the National Institute of Mental Health in Bethesda, Maryland, agrees – to a point. “It never occurred to me that body position might influence behavioural or neuronal activity in the context of aggression – but it makes sense,” he says. “I do think that this is somewhat specialised to things like aggression or anger.”

After all, he says, it’s not as if neuroscientists pretend that massive, tunnel-like MRI scanners are exact replicas of regular human environments. “The scanner noise, closed space, and generally very alien context might influence the results of other studies as well,” Bandettini adds.

Journal reference: Psychological Science (DOI: 10.1111/j.1467-9280.2009.02416.x)