Brain imaging could replace lie detector

<body leftmargin="0" bgcolor="#000060" text="#FFFFFF" link="#FFFF00" vlink="#FF9900"> <b> <p class="MsoNormal"><font face="Arial" size="4">Brain imaging could replace lie detector</font></p> </b> <p class="MsoNormal"><font size="1">Posted Dec. 29, 2004<br> Courtesy Radiological Society of North America<br> and World Science Staff</font> </p> <b> <p class="MsoNormal"><font face="Arial" size="2">When people lie, they use different parts of their brains than when they tell the truth. These brain changes can be measured by brain scanners, researcher have found.</font></p> <p class="MsoNormal"><font face="Arial" size="2">The technique, called functional magnetic resonance imaging (fMRI), may one day prove a more accurate lie detector than the standard lie-detector test, called a polygraph, according to a study presented earlier this month at the annual meeting of the Radiological Society of North America.</font></p> <p class="MsoNormal"><font face="Arial" size="2">“There may be unique areas in the brain involved in deception that can be measured with fMRI,” said the study’s lead author, Scott H. Faro, of Temple University School of Medicine in Philadelphia.</font></p> <p class="MsoNormal"><font face="Arial" size="2">Faro and colleagues conducted a study simulating a lie-and-detection situation for a group of 11 volunteers.</font></p> <p class="MsoNormal"><font face="Arial" size="2">Six of the volunteers were asked to shoot a toy gun with blank bullets and then to lie about their participation. The non-shooters were asked to tell the truth about the situation. The researchers examined the individuals with fMRI, while simultaneously administering a polygraph exam.</font></p> <p class="MsoNormal"><font face="Arial" size="2">The polygraph measures three physiologic responses: respiration, blood pressure and the skin’s ability to conduct electricity, which increases when an individual sweats.</font></p> <p class="MsoNormal"><font face="Arial" size="2">The volunteers were asked questions that pertained to the situation. In all cases, the polygraph and fMRI accurately distinguished truthful responses from deceptive ones. fMRI showed different patterns of brain activation depending on whether the response was truthful or false. Furthermore, there were more areas of the brain activated during the deception process compared to the truth-telling condition.</font></p> <p class="MsoNormal"><font face="Arial" size="2">Dr. Faro’s study is the first to use polygraph correlation and a modified version of positive control questioning techniques in conjunction with fMRI. It is also the first to involve a real-life stimulus. “I believe this is a vital approach to understand this very complex type of cognitive behavior,” Dr. Faro said.</font></p> <p class="MsoNormal"><font face="Arial" size="2">But the polygraph isn’t considered a totally reliable lie-detection method because the physiologic responses that it measures can vary among individuals, and some people can consciously control them.</font></p> <p class="MsoNormal"><font face="Arial" size="2">According to Dr. Faro, it is too early to tell if fMRI can be “fooled” in the same manner, but the results are promising in that they suggest a consistency in brain patterns that might be beyond conscious control.</font></p> <p class="MsoNormal"><font face="Arial" size="2">“We have just begun to understand the potential of fMRI in studying deceptive behavior,” Dr. Faro said. “We plan to investigate the potential of fMRI both as a stand-alone test and as a supplement to the polygraph with the goal of creating the most accurate test for deception.”</font></p> </b> <p class="MsoNormal"> <b> <font size="2" face="Arial"><a href="http://groups.yahoo.com/group/world-science">http://groups.yahoo.com/group/world-science</a></font> </b> </p> </body>