Neural correlates of the judgment of lying: A functional magnetic resonance imaging study

Lie judgment is an estimation of the speaker's intention to deceive inevitably accompanied by moral judgment. To depict their neural substrates, we conducted a functional magnetic resonance imaging study. Eighteen subjects read short stories and made judgments in three different tasks: a control gender judgment task, a moral judgment task, and a lie judgment task. Compared with the control task, both the moral and lie judgment tasks activated the left temporal lobe, the medial prefrontal cortex, the lateral orbitofrontal cortex extending to the dorsolateral prefrontal cortex, the caudate nucleus, the left temporo-parietal junction (TPJ), and the right cerebellum. Neural activations were greater in the left middle frontal gyrus, the bilateral TPJ, and the right superior temporal sulcus in the lie judgment condition than in the moral judgment condition. In addition, the left TPJ showed greater activation when a protagonist told lies for anti-social rather than pro-social purposes. These data suggest that the judgment of lies is mediated by the neural substrates of moral judgment (conventionality) and those involved in detecting the intent to deceive (intentionality), and that the left TPJ might play a key role in processing both the conventional and the intentional information involved in the judgment of lying.