Powerful magnets hamper our ability to lie

06 September 2011
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YOU will tell the truth. Applying a magnetic field to the brain seems to hamper our ability to tell lies.

Lying is thought to involve inhibiting our normal propensity to truth-telling, so Talis Bachmann's team at the University of Tartu in Estonia reasoned that dampening brain activity in the dorsolateral prefrontal cortex (DLPFC) - which is involved in cognitive control - might alter the likelihood of lying.

The researchers asked 16 volunteers to name the colour of a disc on a computer screen after receiving transcranial magnetic stimulation (TMS) to dampen activity in their DLPFC. They were given the option to lie or answer honestly. The task was then repeated following TMS of the parietal cortex - a part of the brain unassociated with cognitive control. The volunteers gave significantly fewer truthful answers after TMS of the left DLPFC - but suppressing the right DLPFC increased the number of true responses (Behavioural Brain Research, DOI: 10.1016/j.bbr.2011.07.028).

"DLPFC seems to be involved in deception, but its exact role remains unclear," says Bruno Verschuere at the University of Amsterdam in the Netherlands. He says it is difficult to draw firm conclusions from a small sample.

Source: http://www.newscientist.com/article/mg21128284.400-powerful-magnets-hamper-our-ability-to-lie.html?DCMP=OTC-rss&nsref=online-news

Transcranial magnetic stimulation (TMS) is a noninvasive method to cause depolarization or hyperpolarization in the neurons of the brain. TMS uses electromagnetic induction to induce weak electric currents using a rapidly changing magnetic field; this can cause activity in specific or general parts of the brain with minimal discomfort, allowing the functioning and interconnections of the brain to be studied. A variant of TMS, repetitive transcranial magnetic stimulation (rTMS), has been tested as a treatment tool depression and auditory hallucinations.

http://en.wikipedia.org/wiki/Transcranial_magnetic_stimulation