Tuesday, September 22, 2009

Tortured Brains Tell Tall Tales

OR: Neuroscience Shows Why Torture Doesn't Work

Former CIA Agent Speaks Out - The controversial interrogation technique known as waterboarding, which the CIA agent says was used on [Abu] Zubaydah [see this Justice Department memo, PDF], occurs when a suspect has water poured over his mouth and nose to stimulate a drowning reflex as demonstrated in the picture [above]. (ABC News)

With the Obama administration's recent release of the voluminous Bush-era memos authorizing torture, much has been written about whether or not "aggressive interrogation of captured terrorists" 1 works, i.e. produces the desired result of extracting accurate and useful information.

Excerpt of Jay Bybee's memo (see
Glen Greenwald's column in salon.com).

In a new Science and Society article in Trends in Cognitive Sciences, 2 Shane O'Mara outlines the scientific reasons why a brain subjected to extreme stress will not yield accurate information:
The use of such techniques appears motivated by a folk psychology that is demonstrably incorrect. 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.
O'Mara didn't actually study the brains of individuals subjected to torture. Instead, he carefully read the memos and then made inferences from the literature on how memory is affected by physical and psychological stress, sleep deprivation, and anxiety.
Stress causes heightened excitability or arousal in the brain and body, a perception that present or future events will be very unpleasant combined with a lack of controllability over these events. Experiencing stress causes release of stress hormones (cortisol; catecholamines such as noradrenaline). Stress hormones provoke and control the ‘fight or flight’ response (the immediate and rapid preparation by body and brain for action in response to threat) which, if overly-prolonged, may result in compromised cognitive neurobiological function (and even tissue loss) in these brain regions. Both the hippocampus and the prefrontal cortex are particularly rich in receptors activated by stress hormones. Cortisol binds preferentially to glucocorticoid receptors in hippocampus and prefrontal cortex, increasing Ca++ access, and thus neuronal excitability which will compromise normal physiological functioning of neurons if it is sustained.
Importantly, O'Mara then reviews specific evidence that torture is likely to produce the exact opposite of the intended effect: false memories, confabulations, and less accurate information.
Extreme stress studies in Special Operations Soldiers (Morgan et al., 2006) have found impaired visuo-spatial capacity and impaired recall of previously-learned information in stressed soldiers (who undergo stress, including food and sleep deprivation, during training modelled on the experiences of American prisoners-of-war). Brain imaging in persons previously subjected to severe torture suggests that abnormal patterns of activation are present in the frontal and temporal lobes, leading to deficits in verbal memory for the recall of traumatic events (Ray et al., 2006; Catani et al. 2009).
A previous post by The Neurocritic covered The Guantánamo Testimonials Project and The Neurobiology of Psychological Torture. These research projects are being conducted at the Center for the Study of Human Rights in the Americas. CSHRA summarizes their work on The Neurobiology of Psychological Torture as follows:
... Psychological torture (henceforth PT) is a set of practices that are used worldwide to inflict pain or suffering without resorting to direct physical violence. PT includes the use of sleep deprivation, sensory disorientation, forced self-induced pain, solitary confinement, mock execution, severe humiliation, mind-altering drugs and threats of violence—as well as the exploitation of personal or cultural phobias. The psychiatric sequelae of PT are severe. They include delirium, psychosis, regression, self-mutilation, cognitive impairment, and anxiety disorders, including post-traumatic stress disorder. Neuroscience research on these and related mental disorders continues to establish their neurobiological underpinnings, thus challenging the popular view that PT is not physical, not serious, and perhaps not even torture at all.

Rendered brain showing abnormal brain activity in torture victims. This picture (white-gray matter border) shows regions in red with excess slow wave activity which is strongest in the left insula (see Kolassa et al. "Imaging the trauma: altered cortical dynamics after repeated traumatic stress") and the left frontal inferior region (see Ray, Elbert, et al. "Survivors of organized violence often left with traumatic memories." Psychological Science Volume 17, Issue 10, October 2006). Blue indicates less activity than normal. Photo: Courtesy of Dr. Thomas Elbert, Univerity of Konstanz, Germany.

The proceedings from a workshop conducted in 2006 were published as a book, The Trauma of Psychological Torture. Let's see Dick Cheney, John Yoo, Jay Bybee, and their ilk produce any scientific evidence to the contrary.

ADDENDUM: The paper is now available for download from Trends in Cognitive Sciences. DOI: 10.1016/j.tics.2009.09.001 [download PDF]


1 "The Latest Euphemism From The Torture Party" according to Andrew Sullivan. I also recommend The Gestapo Precedent for "EITs" [Enhanced interrogation techniques]. For more on O'Mara's paper, read The Tortured Brain by Sharon Begley.

2 Also covered by ScienceInsider, which made the paper available before it appeared on the TICS website. See Torture Can't Provide Good Information, Argues Neuroscientist (by John Bohannon).


Catani C, Adenauer H, Keil J, Aichinger H, Neuner F. (2009). Pattern of cortical activation during processing of aversive stimuli in traumatized survivors of war and torture. Eur Arch Psychiatry Clin Neurosci 259:340-51

Morgan CA 3rd, Doran A, Steffian G, Hazlett G, Southwick SM. (2006). Stress-induced deficits in working memory and visuo-constructive abilities in Special Operations soldiers. Biol Psychiatry 60:722-729.

O'Mara S (2009). Torturing the Brain: On the folk psychology and folk neurobiology motivating ‘enhanced and coercive interrogation techniques’. Trends in Cognitive Sciences. DOI: 10.1016/j.tics.2009.09.001

Ray WJ, Odenwald M, Neuner F, Schauer M, Ruf M, Wienbruch C, Rockstroh B, Elbert T. (2006). Decoupling neural networks from reality: dissociative experiences in torture victims are reflected in abnormal brain waves in left frontal cortex. Psychol Sci. 17:825-829.

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