Disclosing concealed information on the basis of cortical activations.

Concealed information, which is information only known to oneself is sometimes crucial for criminal investigation. In this study, we examined cortical activations related to incidental responses to concealed information. We found that cortical responses to stimuli related to concealed information were different from those to other stimuli; the bilateral ventrolateral prefrontal (VLPF) areas, left inferior frontal gyrus, right middle frontal gyrus and right inferior parietal lobule were activated, and among those activated areas, the right VLPF was found to be crucial. Furthermore, we examined by discriminant analysis which cortical areas contribute to the determination of whether the subjects had concealed information. On the basis of the activity in the right VLPF, we were able to correctly identify 32 of the 38 subjects (84.21%) as who had concealed information. These results suggest that the right VLPF may play a crucial role in the incidental processing of concealed information, and we were able to determine whether a subject had concealed information without the need for deceptive responses.