How do lie detectors work?

Experts explain how lie detectors work, what happens in the brain when we tell lies and how accurate polygraph tests are.

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  • In a 2002 study, 60 percent of people were found to lie at least once during a 10-minute conversation, with most people telling an average of two or three lies. The polygraph, invented in the early 1920s, detects physiological responses to lying (such as elevated heart and respiratory rates as well as spikes in blood pressure.
  • Three main areas of the brain are stimulated during deception: the frontal lobe, the limbic system, and the temporal lobe.
  • According to the American Polygraph Association, the estimated accuracy of a polygraph can be up to 87 percent.
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Humans are still evolving, and maybe faster now than ever

The sudden prevalence of an artery in the forearm is evidence that we're still very much a work in progress.

  • Australian scientists see signs of accelerating human evolution.
  • Exhibit A is the rapid rise in the prevalence of the median artery in adults.
  • Other emerging traits, like shorter baby jaws, support their finding.
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A buried ancient Roman city uncovered using radar technology

Ground-penetrating radar allows the non-invasive virtual excavation of Falerii Novi.

Image source: L. Verdonck/University of Cambridge
  • Using ground-penetrating radar, layers of an ordinary field in Italy are pulled back to reveal a lost Roman town.
  • Without disturbing a single artifact, an incredible level of detail is uncovered.
  • The buried town, Falerii Novi, has been quietly awaiting discovery since it was abandoned at the start of medieval age.
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Urine survey reveals Europe’s favorite drugs

Coke, meth, ecstasy, amphetamines: each drug has a different 'capital'

  • A large-scale survey of wastewater across Europe shows which illicit drugs are popular.
  • The use of four main drugs was up across the board last year, but regional variation persists.
  • Cocaine is popular in the west and south, meth in the east and north.
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‘An evil I’ve never seen before’: Doctors scramble to understand vaping-related lung disease

Thousands of people are experiencing severe pulmonary issues from vaping, and some are dying.

Image source: Aliaksandr Barouski/Shutterstock
  • Scientists now believe that the primary culprit in this health crisis is vitamin E acetate, though research continues for other toxic factors.
  • Vitamin E is a gooey thickener often used in black-market cannabis-based vaping products.
  • Vapers who feel like they may have pneumonia should consult a physician immediately.
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