Speaking of secrets and lies: the contribution of ventrolateral prefrontal cortex to vocal deception

Behavioural and functional anatomical responses exhibited by humans support the hypothesis that deception involves the prefrontal executive. Functional neuroimaging studies have demonstrated that ventrolateral prefrontal cortex (among other areas) is activated during lying, compared with telling the truth. However, despite some consistencies discernible across studies, problems remain concerning experimental validity, e.g., the expediencies of experimenter-sanctioned cued-deception (i.e., subjects being told when to lie); such 'lies' may not have comprised adequate proxies for 'real-life' deception. In this experiment, we attempted to address such confounding issues by designing an fMRI paradigm in which subjects chose when to lie (thereby minimising cue-dependency), using spoken words, concerning intimate material, which they regarded as 'embarrassing'; and where further control conditions required them to 'comply' with their examiners or to 'defy' them (by withholding pre-specified responses). The main effect of lying revealed significant activation of ventrolateral prefrontal cortices. These results replicate and extend our previous findings to those circumstances under which subjects are allowed to choose when to deceive.