A small Estonian study is offering some hints that our brains could be even weirder than we'd imagined. Researchers found that magnetic pulses directed at a certain part of the frontal cortex affected whether people were more willing to fib, or more likely to tell the truth. Only 16 people were involved in the study, so these results are more something potentially cool to follow up on than a definitive declaration about brain function. There's a good chance this could turn out to be a statistical fluke. But it is worth researching further. If the effect is real, it could have some really interesting ethical, legal, and neurobiological implications.
Say it with me now: "F***ing magnets, how do they work?" Mo Costandi explains:
Inga Karton and Talis Bachmann of the University of Tartu adopted a different and novel approach, by examining the natural propensity to lie spontaneously during situations in which deception has no consequences. They recruited 16 volunteers, and showed them red and blue discs, which were presented randomly on a computer screen. The participants were asked to name the colour of each disc, and that they could do so correctly or incorrectly at their free will.
The researchers used a technique called transcranial magnetic stimulation (TMS) to disrupt the participants' brain activity during the task. TMS is a non-invasive technique in which pulses of electromagnetic radiation are targeted to a specific brain region, inducing weak electrical currents that can either inhibit or enhance activity in that area.
They split the participants into two groups of eight for the experiment. Half of the participants in one group received magnetic pulses to the dorsolateral prefrontal cortex (DLPFC) in the left hemisphere of the brain, while half in the other received them to the DLPFC on the right side. The rest of the participants acted as controls, and TMS was targeted to either the left or the right parietal cortex.
Statistical analysis of the results revealed that magnetic stimulation directed at the left DLPFC slightly increased the participants' tendency to lie about the colour of the discs, whereas stimulation of the right DLPFC slightly reduced it. By contrast, stimulation of the left or right parietal cortex had no effect on the participants' propensity to lie.
Costandi has actually made his full interview with the primary researcher in this study available online. In it, he gets a bit more into the nuance of what happens when you turn up a result as odd as this one, why scientists conduct such small studies, and what they do with the results of those studies.