We really know only a percentage of the complexity of the human brain. It is the center of conscious thought, language processing, imagination, calculation, memory, abstract conceptual thought and an almost infinite number of tasks. The brain is constantly attempting to make sense of stimulus — always processing and categorizing information. The human mind generalizes for it to make sense of otherwise unrelated phenomena. For example, the brain enables us to distinguish a threat in camouflage from a similar background.

   The brain's ability to recognize anomalies increases survivability. Distinguishing a threat amongst non-threats is an example of pattern recognition. This skill is especially beneficial to protective detail members. An emotionally distraught face distinguished from a crowd of a smiling faces might be a clue for agents to anticipate imminent danger.

   Regular exposure to training conditions can massage the subconscious into quickly spotting anomalies. After a few years of service, most officers are capable human lie detectors with remarkable accuracy. Even without formal training, their subconscious recognizes when a person's mannerisms are incongruent with what is coming out of his or her mouth. Recent studies show that about one out of a thousand acquire this talent naturally. The most logical explanation is that they trained themselves, through exposure, to automate their responses.

   Most people can detect overt expressions. What distinguishes human lie detectors is their ability to read micro expressions that flash unnoticeably (sometimes as quickly as 1/25 of a second) to the uninitiated. These are subconscious non verbal communications that reveal another layer of a person. It is theorized that people with uncanny lie detector abilities generally read micro expressions quicker.

   The fact is a person's subconscious, precipitated by training, is infinitely faster than a person's conscious efforts. For example, how does a wide receiver manage to catch a high pass and set two toes in-bounds in a fraction of a second? Training and automation. Why are some people naturally better at this task than others? Automation.

   Training creates an automated response. This is the "muscle memory" misnomer that shooting instructors use. Obviously, muscle does not have memory. If it did, we would all convince our muscles to remember when we were in our 20s.