WASHINGTON - Prolonged stress from the CIA's harsh interrogations could have impaired the memories of terrorist suspects, diminishing their ability to recall and provide the detailed information the spy agency sought, according to a scientific paper published Monday.
The methods could even have caused the suspects to create - and believe - false memories, contends the paper, which scrutinizes the techniques used by the CIA under the Bush administration through the lens of neurobiology. It suggests the methods are actually counterproductive, no matter how much suspects might eventually say.
"Solid scientific evidence on how repeated and extreme stress and pain affect memory and executive functions (such as planning or forming intentions) suggests these techniques are unlikely to do anything other than the opposite of that intended by coercive or enhanced interrogation," according to the paper in the scientific journal Trends in Cognitive Sciences.
In the paper, Shane O'Mara, a professor at Ireland's Trinity College Institute of Neuroscience, wrote that the severe interrogation techniques appear based on "folk psychology" - a layman's idea of how the brain works as opposed to science-based understanding of memory and cognitive function.
O'Mara told the Associated Press on Monday he reviewed the scientific literature about the effect of stress on memory and brain function after reading descriptions of the CIA's Bush-era interrogation methods. The methods were detailed in previously classified legal memos released in April.
O'Mara did not examine or interview any of those interrogated by the CIA.
O'Mara said that in general, "The assumption is that the (methods) are without effect on memory, or indeed facilitate the retrieval of information from memory."
But overwhelmingly, scientific literature shows the opposite: Chronic stress and trauma - the likely result of the CIA's methods, particularly for long-term prisoners, according to O'Mara - can damage the hippocampus, the part of the brain that integrates memory.
O'Mara's findings reflect the review of scientific and medical literature on the effect of acute stress on memory and cognitive function.
"We've known for quite a while that stress radically impairs cognition. We know memory is very fragile to begin with," said Stephen Soldz, president-elect of Psychologists for Social Responsibility and a professor at Boston Graduate School of Psychoanalysis. "It's just amazing that this has not been taken into account."
Techniques the CIA used included prolonged sleep deprivation - six days in at least one instance - being chained in painful positions, exploitation of prisoners' phobias and waterboarding, a form of simulated drowning that President Barack Obama has called torture.