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, a fact noted by the agency in commenting on his work.
“The CIA’s former interrogation program was conducted pursuant to legal guidance from the Department of Justice. It produced intelligence on which our government acted to disrupt terrorist operations. Those are facts. The author of this study did not, to my knowledge, have direct contact with individuals who had been part of the agency’s high-value detainee program,” said CIA spokesman George Little.
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.”
Dr. Scott Allen, an internist and Brown University associate professor, is reviewing literature for the advocacy group Physicians for Human Rights and told the AP he has yet to find studies that would support the efficacy of harsh interrogation techniques.
“In fact what I’ve found is it seems like it would be a poor strategy,” Allen said.
The list of 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. Three CIA prisoners were waterboarded, two of them extensively.
Those methods cause the brain to release stress hormones that, if their release is repeated and prolonged, may result in compromised brain function and even tissue loss, O’Mara wrote.
He warned that this could lead to brain lobe disorders, making the prisoners vulnerable to confabulation — in this case, the pathological production of false memories based on suggestions from an interrogator. Those false memories mix with true information in the interrogation, making it difficult to distinguish between what is real and what is fabricated.
Waterboarding is especially stressful “with the potential to cause widespread stress-induced changes in the brain, especially when these are repeated frequently and intensively,” O’Mara wrote.
“The fact that the detrimental effects of these techniques on the brain are not visible to the naked eye makes them no less real,” he wrote.
The paper also asserted that forcibly exposing prisoners to what they are afraid of — the CIA got approval to use a suspect’s fear of insects against him — is actually a method used to cure phobias. The insects were never used, according to the government.
A 2006 Intelligence Science Board report on interrogation also noted possible negative effects of certain methods. For example, isolating suspects can be beneficial to interrogation because it shakes prisoners’ confidence and expectations, but extended isolation can significantly and negatively affect the ability of the source to recall information accurately, according to the report.
The board, created in 2002, provides independent advice to senior intelligence officials on emerging scientific and technical issues of special importance to intelligence work.