1. A method for detecting deception, the method comprising: receiving near-infrared optical energy indicative of an oxygenation level in a blood supply of a cortex of a brain of a subject; comparing the oxygenation level indicated by the received near-infrared optical energy with a baseline oxygenation level; and if the oxygenation level indicated by the received near-infrared optical energy differs from the baseline oxygenation level, determining that the subject conducted deception.