Forum for Science, Industry and Business

Sponsored by:     3M 
Search our Site:

 

Who’s the liar? Brain MRI stands up to polygraph test

01.02.2006


Traditional polygraph tests to determine whether someone is lying may take a back seat to functional magnetic resonance imaging (fMRI), according to a study appearing in the February issue of Radiology. Researchers from Temple University Hospital in Philadelphia used fMRI to show how specific areas of the brain light up when a person tells a lie.



"We have detected areas of the brain activated by deception and truth-telling by using a method that is verifiable against the current gold standard method of lie detection--the conventional polygraph," said lead author Feroze B. Mohamed, Ph.D., Associate Professor of Radiology at Temple.

Dr. Mohamed explained how the standard polygraph test has failed to produce consistently reliable results, largely because it relies on outward manifestations of certain emotions that people feel when lying. These manifestations, including increased perspiration, changing body positions and subtle facial expressions, while natural, can be suppressed by a large enough number of people that the accuracy and consistency of the polygraph results are compromised.


"Since brain activation is arguably less susceptible to being controlled by an individual, our research will hopefully eliminate the shortcomings of the conventional polygraph test and produce a new method of objective lie detection that can be used reliably in a courtroom or other setting," Dr. Mohamed said.

Dr. Mohamed and colleagues recruited 11 healthy subjects for the study. A mock shooting was staged, in which blank bullets were fired in a testing room. Five volunteers were asked to tell the truth when asked a series of questions about their involvement, and six were asked to deliberately lie. Each volunteer was examined with fMRI to observe brain activation while they answered questions either truthfully or deceptively. They also underwent a conventional polygraph test, where respiration, cardiovascular activity and perspiration responses were monitored. The same questions were asked in both examinations, and results were compared among the groups.

"With fMRI, there were consistently unique areas of the brain, and more of them, that were activated during the deceptive process than during truth-telling," Dr. Mohamed said. In producing a deceptive response, a person must inhibit or conceal the truth, which activates parts of the brain that are not required for truth-telling. Thus, fewer areas of the brain are active when telling the truth.

Fourteen areas of the brain were active during the deceptive process. In contrast, only seven areas lit up when subjects answered truthfully.

By studying the images, investigators were able to develop a better picture of the deception process in the brain. The increased activity in the frontal lobe, especially, indicated how the brain works to inhibit the truth and construct a lie.

Polygraph test results correlated well with actual events when subjects were asked to lie (92 percent accuracy); however, the results were not as conclusive when subjects were asked to tell the truth (70 percent accuracy).

The largest implications for a credible method of lie detection are in the field of crime investigation and prevention, and in the judicial determination of the guilt or innocence of accused individuals. Since the polygraph has not been embraced as a fully credible means of lie detection, the authors hope to provide a more accurate means of determining whether or not someone is telling the truth.

"A more consistent and verifiable method of lie detection could lead to changes in this particular realm of the legal system down the road," Dr. Mohamed said.

Heather Babiar | EurekAlert!
Further information:
http://www.rsna.org

More articles from Health and Medicine:

nachricht Why might reading make myopic?
18.07.2018 | Universitätsklinikum Tübingen

nachricht Unique brain 'fingerprint' can predict drug effectiveness
11.07.2018 | McGill University

All articles from Health and Medicine >>>

The most recent press releases about innovation >>>

Die letzten 5 Focus-News des innovations-reports im Überblick:

Im Focus: First evidence on the source of extragalactic particles

For the first time ever, scientists have determined the cosmic origin of highest-energy neutrinos. A research group led by IceCube scientist Elisa Resconi, spokesperson of the Collaborative Research Center SFB1258 at the Technical University of Munich (TUM), provides an important piece of evidence that the particles detected by the IceCube neutrino telescope at the South Pole originate from a galaxy four billion light-years away from Earth.

To rule out other origins with certainty, the team led by neutrino physicist Elisa Resconi from the Technical University of Munich and multi-wavelength...

Im Focus: Magnetic vortices: Two independent magnetic skyrmion phases discovered in a single material

For the first time a team of researchers have discovered two different phases of magnetic skyrmions in a single material. Physicists of the Technical Universities of Munich and Dresden and the University of Cologne can now better study and understand the properties of these magnetic structures, which are important for both basic research and applications.

Whirlpools are an everyday experience in a bath tub: When the water is drained a circular vortex is formed. Typically, such whirls are rather stable. Similar...

Im Focus: Breaking the bond: To take part or not?

Physicists working with Roland Wester at the University of Innsbruck have investigated if and how chemical reactions can be influenced by targeted vibrational excitation of the reactants. They were able to demonstrate that excitation with a laser beam does not affect the efficiency of a chemical exchange reaction and that the excited molecular group acts only as a spectator in the reaction.

A frequently used reaction in organic chemistry is nucleophilic substitution. It plays, for example, an important role in in the synthesis of new chemical...

Im Focus: New 2D Spectroscopy Methods

Optical spectroscopy allows investigating the energy structure and dynamic properties of complex quantum systems. Researchers from the University of Würzburg present two new approaches of coherent two-dimensional spectroscopy.

"Put an excitation into the system and observe how it evolves." According to physicist Professor Tobias Brixner, this is the credo of optical spectroscopy....

Im Focus: Chemical reactions in the light of ultrashort X-ray pulses from free-electron lasers

Ultra-short, high-intensity X-ray flashes open the door to the foundations of chemical reactions. Free-electron lasers generate these kinds of pulses, but there is a catch: the pulses vary in duration and energy. An international research team has now presented a solution: Using a ring of 16 detectors and a circularly polarized laser beam, they can determine both factors with attosecond accuracy.

Free-electron lasers (FELs) generate extremely short and intense X-ray flashes. Researchers can use these flashes to resolve structures with diameters on the...

All Focus news of the innovation-report >>>

Anzeige

Anzeige

VideoLinks
Industry & Economy
Event News

Leading experts in Diabetes, Metabolism and Biomedical Engineering discuss Precision Medicine

13.07.2018 | Event News

Conference on Laser Polishing – LaP: Fine Tuning for Surfaces

12.07.2018 | Event News

11th European Wood-based Panel Symposium 2018: Meeting point for the wood-based materials industry

03.07.2018 | Event News

 
Latest News

Global study of world's beaches shows threat to protected areas

19.07.2018 | Earth Sciences

New creepy, crawly search and rescue robot developed at Ben-Gurion U

19.07.2018 | Power and Electrical Engineering

Metal too 'gummy' to cut? Draw on it with a Sharpie or glue stick, science says

19.07.2018 | Materials Sciences

VideoLinks
Science & Research
Overview of more VideoLinks >>>