1. A method comprising: measuring near-infrared optical energy indicative of oxygenation levels in a blood supply of a cortex of a brain of a subject to obtain a plurality of neural responses of the subject each time the subject answers a question of a respective plurality of questions, wherein at least one of the plurality of questions is repeated a plurality of times; measuring near-infrared optical energy indicative of oxygenation levels in the blood supply of the cortex of the brain of the subject to obtain a neural response of the subject associated with the subject's response to a visual cue of an affirmation attestation, wherein the affirmation attestation is indicative of a query as to the truthfulness of a response to a previous one of the plurality of questions; comparing the oxygenation levels indicated by the measured near-infrared optical energy with a baseline oxygenation level, wherein the baseline oxygenation level is indicative of one of a known truthful response or a known false response; and if the oxygenation levels indicated by the measured near-infrared optical energy differs from the baseline oxygenation level, determining that the subject conducted at least one of deception in response to a question or malingered in response to a question.