Functional near-infrared (fNIR) neuroimaging is used to assess credibility, detect deception, and implement a query methodology for determining deception via neuroimaging. Oxygenation levels of portions of the brain are imaged via fNIR spectroscopy and utilized to determine if the subject is telling a lie or a truth. In an example configuration, oxygenation levels in the inferior and/or middle prefrontal cortical areas of the brain, such as the bilateral dorsolateral prefrontal and/or inferior frontal cortex, are measured to determine if a subject is lying relative to telling the truth. An example system includes a portable, flexible, belt like sensing device that is positioned proximate the subjects scalp. Sensed neural activity is transmitted either through wired or wireless means, to a processor for analysis of the sensed neural activity. The query methodology utilizes an attestation assertion that mitigates variance in brain responses due to the length or form of a question.