Detecting concealed information using functional near-infrared spectroscopy.

The present study focused on the potential application of fNIRS in the detection of concealed information. Participants either committed a mock crime or not and then were presented with a randomized series of probes (crime-related information) and irrelevants (crime-irrelevant information) in a standard concealed information test (CIT). Participants in the guilty group were instructed to conceal crime-related information they obtained from the mock crime, thus making deceptive response to the probes. Meanwhile, their brain activity to probes and irrelevants was recorded by functional near-infrared spectroscopy (fNIRS). At the group level, we found that probe items were associated with longer reaction times and greater activity in bilateral dorsolateral prefrontal cortex and supplementary motor cortex than irrelevant items in the guilty group, but not in the innocent group. These findings provided evidence on neural correlates of recognition during a CIT. Finally, on the basis of the activity in bilateral dorsolateral prefrontal cortex and supplementary motor cortex, the correct classification of guilty versus innocent participants was approximately 75 % and the combination of fNIRS and reaction time measures yielded a better classification rate of 83.3 %. These findings illustrate the feasibility and promise of using fNIRS to detect concealed information.