Not all tDCS is used for good. Some applications of noninvasive brain stimulation can be directed toward aless ethical pursuit: helping us lie more convincingly.
A study instructed 44 volunteers to role-play as thieves. Participants had to pretend to steal money and were then interrogated about their misdeeds. This interrogation was conducted via the “Guilty Knowledge Test,” a variation of the polygraph test.
By using tDCS to inhibit the function of the anterior prefrontal cortex—the part of the brain responsible for deception—scientists were able to trigger remarkable improvements in test subjects’ ability to lie. People receiving brain stimulation were quicker at coming up with lies, though no quicker when answering truthfully. Perhaps even more interestingly, these participants were also shown to feel less guilty about lying than the control group.
This indicates that it may be possible to improve somebody’s ability to lie at will, should that be required. Think of the many professionals that could benefit from this type of improved lying ability: spies, undercover cops, soldiers taken prisoner, and campaigning politicians.