Could telling the truth be as easy as holding a magnet to your head? Researchers at the University of Tartu in Estonia recently published a small study on the effects of transcranial magnetic stimulation (TMS) on the part of the brain known as the dorsolateral prefrontal cortex (DLPFC). TMS uses a pulsing electromagnet to influence the brain. Those studied were asked to tell researchers the color of an object on a computer screen, but they were allowed to lie or tell the truth as they liked. When the left half of the DLPFC was stimulated with TMS, those studied tended to lie slightly more. Stimulating the right half had the opposite effect. Have we discovered the neural secrets to being a big fat liar? Well, don’t throw away your fire-proof pants just yet. The study was small, just 16 people, and even the head researcher of the project has publicly stated he doesn’t want people to leap to conclusions about their results. Still, it looks as though TMS will be another tool in our efforts to use brain scanning technology to battle lying.
The study into TMS’ on the DLPFC and its effect on lying was produced by Talis Bachmann and his PhD student Inga Karton at the University of Tartu and published in the journal Behavioural Brain Research. Both Bachmann and Karton have a history of exploring forensic cognitive neuroscience and the roots of deceptive behavior in the brain. The details of the study aren’t very earth-shattering – just 16 people and the effect seen was slight. People still could lie about what the color of the object they saw on the screen, they just did so less when TMS was applied to the right DLPFC. That hasn’t stopped from the media getting rather hyped with the results. Bachmann saw fit to write a brief piece for Science and Religion Today to help qualify the study. To counter supposition that brain damage of the left DLPFC might kill our ability to lie he points out that:
- “…the effect [they] obtained was statistically significant, but by no means strong. There were only slight changes in percentages of truthful or deceitful reports, and there never was a subject who lost the ability or willingness to lie.”
- It’s unclear if the part of the brain was ‘specialized’ to deception. It’s more likely that a bigger network is involved and it’s unlikely that such a network could be effectively damaged.
- The brain is pretty plastic. Even if you could damage a ‘lying’ part of the brain, it may be able to recover. There may even be deception types (white lies, erroneous beliefs, etc) that would be managed by completely different portions of the brain.
So, yeah, if you’re worried about some government mandating brain damage to keep all of its people truthful, go ahead and take off your tinfoil hat. That’s not what this research shows. Instead, Bachmann and Karton have illuminated the possibility that TMS could help us learn more about how the brain produces information in different ways based on how it intends to share that information. There’s years and years of amazing basic research to be had here.
But if you’re more of an immediate effects kind of person, this small study is just another development in a much larger movement to quantify lying through creative neuroscience. We’ve covered the efforts by legal institutions around the world to incorporate lie-detector tests based on brain scanning technology like fMRI. Research into TMS and the DLPFC could become another facet of that. No one in the US has managed to get brain scans admitted as proof of lying during a court case yet, but India has done so regularly. Other nations around the world may experiment with TMS and scanning technology to improve detection, or even prevention, of lying.
Bachmann makes a point in his editorial to acknowledge that research with such wide-ranging legal implications should be approach carefully by both scientists and society. That’s a sentiment we’ve discussed before – it certainly seems like advances in neuroscience are going to profoundly shape our view of guilt and accountability, not to mention mental health. We should start preparing ourselves for a ever-approaching future where neurologists change our understanding of emotion, free will, and other fundamental parts of being human.
In the meantime, transcranial magnetic stimulation appears to be a technique whose star is certainly on the rise. Now a more accepted research tool, TMS has been used to probe how the DLPFC effects self control (not too far off from lying, perhaps?). We’ve also seen those who believe TMS of different areas of the brain can lead to super-human like feats of mental acrobatics. TMS is even becoming a respected treatment for depression, as you’ll see in this video:
The popularity of TMS makes the cynic in me recall fluoroscopy in the early 20th Century when doctors would casually put their hands in the path of x-rays…and then lose their hands to radiation damage. Still want to pulse magnetic fields into your brain? Actually, TMS research has guidelines to keep it safe, but I digress. My point is that precise research into TMS is relatively new, and while that could be a scary thing, it’s also very hopeful. There’s really no telling what we may learn as scientists carefully probe our brain with magnetic fields, temporarily disrupting portions to determine how we use them. To date TMS has revealed a little about how we lie, make decisions, process information, and keep ourselves mentally stable. Tomorrow it could show us even more.
I hope we can believe what we find.
[image credit: Psychlopedia (modified)]
[source: Behavioural Brain Research, Bachmann Lab]
