Stimulating a certain brain region can influence our tendency to lie or tell the truth, a new study shows.
People who receive transcranial magnetic stimulation (TMS) to their left dorsolateral prefrontal cortex (DLPFC) tend to lie more often, while people who receive TMS to their right DLPFC are more likely to tell the truth. Stimulation of other brain regions doesn’t seem to have any particular effect on people’s truthfulness.
As the journal Behavioural Brain Research reports, a team led by Inga Karton and Talis Bachmann1 at Estonia’s BachmannLab stimulated 16 volunteers with TMS, which sends magnetic pulses through targeted brain areas. TMS doesn’t directly stimulate nervous activity in the regions it targets, though – instead, it interferes with normal activity, which can produce some bizarre effects on processes like memory and speech.
For this study, the researchers targeted the DLPFC, because it’s known to be involved in complex cognitive functions like considering outcomes and conjuring deceptions. The team also added a unique variation on previous studies of lying behavior:
Combined brain imaging and stimulation research has been concerned mostly with deceptive behaviour in the contexts of mock thefts and/or denial of recognition of critical objects. Spontaneous, “criminally decontextuated” propensity to lying and its dependence on the activity of selected brain structures has remained unexplored. The purpose of this work is to test whether spontaneous propensity to lying can be changed by brain stimulation.
In other words, they aimed to test whether TMS could affect a person’s tendency to lie or tell the truth specifically when no consequences were involved – when the choice was essentially spontaneous.
The researchers simply asked the volunteers to name the colors of a series of objects, explaining that they were free to tell the truth or not. They found that TMS definitely affects those spontaneous decisions:
The tendency to stick to truthful answers can be manipulated by stimulation targeted at dorsolateral prefrontal cortex. Right hemisphere stimulation decreases lying, left hemisphere stimulation increases lying. Spontaneous choice to lie more or less can be influenced by brain stimulation.
I don’t have to tell you that this is a Damned Interesting Finding – if it doesn’t cast the whole of human morality in a strange new light, it certainly lends some novel shades to the moral spectrum.
Though I won’t step too far into philosophical territory, I will say this: many of our moment-to-moment decisions aren’t based on absolute black-and-white certainty, but on our intuitive perception of the likely outcomes of certain actions. In short, we all spend a lot of our time leaning one way or the other on moral decisions. This experiment shows that it’s fairly easy for artificial stimulation to mess with those leanings – easier, maybe, than we’d like to think.
And by the way, my award for “Best Title for an Article About This Study” goes to i09.com for their piece, “Scientists Can Make You Lie Using Magnets.” I mean, that pretty much just handed Nicholas Cage his next movie premise: “The maaagnets!”
1. As soon as I saw the name “Talis Bachmann,” this video was the first thing I thought of. Coincidence? You decide.