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Can Drugs Unlock Hidden Secrets? The Neuroscience of Truth Serum · Understanding the Brain

• 0:01
  Speaker 1: Truth theorem. We've seen it a lot on TV shows.
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  Speaker 1: But can someone be forced to tell the truth? In
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  Speaker 1: Marvel's Ant-Man and the Wasp, there's a particularly funny interrogation
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  Speaker 1: scene involving the characters insist it's truth theorem. The criminals
• 0:18
  Speaker 1: administering the injection believe their chemical cocktail would force their
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  Speaker 1: prisoner to reveal everything. The idea isn't unique to Marvel, though.
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  Speaker 1: It's been around for decades. In True Lies, Schwarzenegger's character
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  Speaker 1: receives an injection intended to make him talk Television thrillers
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  Speaker 1: such as Alias have also explored chemical interrogation, and I
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  Speaker 1: even believe The Americans, the spy show from years ago.
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  Speaker 1: But can it? The answer is actually no. At least
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  Speaker 1: no drug has ever been scientifically demonstrated to reliably distinguish
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  Speaker 1: truth from deception or compel someone to provide accurate information.
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  Speaker 1: One substance historically associated with truth serum is sodium thiopental,
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  Speaker 1: or also called sodium pentothal. Thiopental belongs to a class
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  Speaker 1: of drugs known as barbiturates. The medications enhance the activity
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  Speaker 1: of GABA, or the brain's primary inhibitory neurotransmitter. Essentially, GABA
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  Speaker 1: helps reduce neuronal activity. When thiopental increases GABA's inhibitory effects,
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  Speaker 1: the brain becomes less alert. Judgment deteriorates, anxiety may decrease,
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  Speaker 1: and the person can become less inhibited. At higher doses,
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  Speaker 1: the medication produces unconsciousness. It was only wildly used to
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  Speaker 1: induce general anesthesia. But at lower doses, individuals may become
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  Speaker 1: unusually talkative. This observation is what established the myth of
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  Speaker 1: truth serum. Unfortunately, reduced inhibition doesn't guarantee honesty. A person
• 1:42
  Speaker 1: under the influence of phenylpentol might review genuine information, or
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  Speaker 1: they may fabricate a story, or describe something that never
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  Speaker 1: happened and unknown to them. Another drug investigated for similar
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  Speaker 1: purposes was scopolamine. Unlike thiopental, scopolamine interferes with acetylcholine, a
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  Speaker 1: neurotransmitter essential for memory and attention. By blocking the muscarinic
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  Speaker 1: acetylcholine receptors, scopolamine can produce confusion, disorientation, and impaired memory formation,
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  Speaker 1: and that creates a major scientific problem. How can investigators
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  Speaker 1: trust someone's answers when the substance they're administering may interfere
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  Speaker 1: with the person's ability to remember correctly? This is where
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  Speaker 1: Hollywood science intersects with actual intelligence history. During the Cold War,
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  Speaker 1: the CIA launched a secret research program known as MKUltra.
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  Speaker 1: Beginning in 1953, the program investigated whether drugs, hypnosis, or
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  Speaker 1: other techniques could influence behavior. Researchers experimented with substances, of course,
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  Speaker 1: like LSD, often through profoundly unethical methods involving people who
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  Speaker 1: had never given consent. The CIA was interested in questions
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  Speaker 1: remarkably similar to those presented in fictional spy thrillers. But
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  Speaker 1: could chemicals lower resistance to questioning? Could they disrupt a
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  Speaker 1: person's judgment? But the program never demonstrated the existence of
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  Speaker 1: a reliable truth serum, and there's another reason. Human memory
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  Speaker 1: is not a recording device. Memories are reconstructed through complex
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  Speaker 1: interactions involving the hippocampus, cerebral cortex, and other systems. Sedatives
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  Speaker 1: and psychoactive substances can disrupt attention, encoding, retrieval, and the
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  Speaker 1: ability to distinguish actual experiences from imagined ones. A chemically
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  Speaker 1: impaired individual might sound confident while providing completely inaccurate information.
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  Speaker 1: The CIA director in 1973 ordered the destruction of many
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  Speaker 1: MKUltra records, leaving important gaps in the historical record. Congressional
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  Speaker 1: investigations later exposed portions of the program. Those missing records
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  Speaker 1: have also helped fuel decades of speculation and conspiracy theories.
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  Speaker 1: But the documented experiments are disturbing enough without inventing more claims.
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  Speaker 1: That brings us all the way back to Ant-Man. The
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  Speaker 1: fictional truth serum works because the screenplay requires it. In reality, though,
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  Speaker 1: chemicals can alter consciousness, reduce inhibition, and impair memory. What
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  Speaker 1: they cannot do is distinguish a truthful statement from a
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  Speaker 1: false one.