Severe interrogation techniques like waterboarding, sleep deprivation, stress positions and the exploitation of phobias aren't just morally reprehensible, they're based on bad science, destroying the very memories they're supposed to recover.

"There is a vast literature on the effects of extreme stress on motivation, mood and memory, using both animals and humans," writes Shane O'Mara, a stress researcher at Ireland's Trinity College Institute of Neuroscience. "These techniques cause severe, repeated and prolonged stress, which compromises brain tissue supporting memory and executive function."

So-called "enhanced interrogation" was used on suspected terrorists during the Bush administration, and sparked a bitter argument over the nature of torture and its use by the United States. Enhanced interrogation was officially banned by President Obama, but almost certainly continues as part of Obama's ongoing rendition program, which sends suspects to torture-practicing countries.

Some intelligence officials, from former Vice President Dick Cheney to current intelligence chief Dennis Blair, defend enhanced interrogation as an useful tool in pulling information from terrorists who refuse to talk. But many intelligence officers say that such information has little value, because people being tortured will say anything to make it stop.

A report published by the Intelligence Science Board in 2007 found that no research existed to support the use of enhanced interrogation. And O'Mara's review, published Monday in Trends in Cognitive Science, describes a wealth of science that supports ending the practice.

O'Mara derides the belief that extreme stress produces reliable memory as "folk neurobiology" that "is utterly unsupported by scientific evidence." The hippocampus and prefrontal cortex — the brain's centers of memory processing, storage and retrieval — are profoundly altered by stress hormones. Keep the stress up long enough, and it will "result in compromised cognitive function and even tissue loss," warping the minds that interrogators want to read.

What's more, tortured suspects might not even realize when they're lying. Frontal lobe damage can produce false memories: As torture is maintained for weeks or months or years, suspects may incorporate their captors' allegations into their own version of reality.

The "ticking time bomb" argument has been used to justify torture in situations where the information it retrieves could immediately save lives. But it will be "difficult or impossible to determine during interrogation whether the information a suspect reveals is true," writes O'Mara — and the bomb will continue to tick.

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*Citation: "Torturing the Brain: On the Folk Psychology and Folk Neurobiology Motivating ‘Enhanced and Coercive Interrogation Techniques.'" By Shane O'Mara. Trends in Cognitive Sciences, Vol. 13, Issue 10, Sept. 21, 2009. *

Image: A waterboarding device used by the Khmer Rouge/Courtesy Tuol Sleng Genocide Museum and Wikimedia Commons.

Brandon Keim's Twitter stream and reportorial outtakes, Wired Science on Twitter.