Torture has long been used as a method of getting people to talk. However a leading Irish neuroscientist is insisting that the information obtained during torture sessions is ‘deeply unreliable'.

According to Prof Shane O'Mara, professor of experimental brain research and director of the Trinity Institute of Neuroscience, there is no scientific basis for the claim that torture leads to the extraction of reliable information from detainees.

"For ethical reasons, there are no scientific studies of torture. But neuroscientists know a lot about how the brain reacts to fear, extreme temperatures, starvation, thirst, sleep deprivation, and immersion in freezing water, all tools of the torturer's trade. These stressors create problems for memory, mood, and thinking, and suf­ferers predictably produce information that is deeply unreliable, and for intelligence purposes, even counterproductive," Prof O'Mara explained.

He noted that torture ‘works well to extract confessions', but it is ‘useless for extracting useful, reliable information from memory'.

"Torture may get someone to talk, but there's no evidence that it's the truth. Confession evidence derived from torture is voluminous and nonsensical - consider the numbers of witches that torture proved existed," he said.

As part of this research in this area, he looked at the use of torture in Northern Ireland, Algeria, Cambodia and Iraq. He also looked at the use of torture by the CIA. He found that it is, at best, ineffective, is usually counterproductive and is always inhumane.

He pointed out that different types of torture, such as sleep deprivation, drowning and pain, do not work in the way that torturers assume they do because they actually undermine the neurocognitive mechanisms required for recalling accurate information. They also damage memory, cognition and mood.

For example, sleep deprivation erodes memory processes and cognitive function. It also has a major negative impact on mood, which can compromise cognitive function even further.

Prof O'Mara insisted that interrogation must be carried out in a humane way.

"Ethical and humane interrogations based on fostering respect and modern brain and behavioural science yields usable, verifiable, and actionable intelligence. Interrogation needs to be conducted by highly skilled, well-educated, highly self-aware interviewers. They need to be able to actively listen to subjects, be genuinely curious about people, and able to establish a connection with them. As professional interrogators themselves say, ‘torture is for amateurs'", he said.

Details of his research are published in the book, Why Torture Doesn't Work: The Neuroscience of Interrogation, published by Harvard University Press.