Sensory Deprivation

An interesting report in the Times:

[A] new televised experiment reveals how badly the brain is affected if isolation is complete and there is no sensory stimulation. It can take just hours for us to become more forgetful, worse at problem-solving, worse at finding words and, perhaps most worrying of all, more open to suggestion from other people. The findings may have implications for how we bring up children, look after the elderly and treat prisoners.
Next week’s Horizon on BBC Two recreates an experiment in sensory deprivation so controversial that it hasn’t been conducted for 40 years. Six volunteers were observed as they spent 48 hours completely isolated in pitch-black rooms, unable to see or hear anything. These are the sort of conditions endured by hostages such as Brian Keenan, who was isolated for eight months during his four-year captivity in Beirut, which ended in 1990.
Similar experiments were held in the 1950s, after thousands of American and Canadian prisoners of war had been held in conditions of sensory deprivation during the Korean War. Prompted by frequent accounts of PoWs seeming to have become “brainwashed” and taking on the views of their captors, North American psychologists examined how isolation affected the minds of volunteers. The experiments were closed down because they were deemed too cruel. But now the psychologist Ian Robbins – a professor at the University of Surrey and a specialist in supporting victims of torture, who has treated British detainees from Guantanamo Bay on their release – has reconstructed some of the sensory deprivation experiments in Horizon, but only for short periods, which are unlikely to result in long-term effects for the volunteers.
Before being isolated, the volunteers underwent tests of visual memory (reproducing a complex drawing); information processing (filtering out confusing information); verbal fluency (naming words starting with a certain letter); and suggestibility (how likely they were to accept something their questioner said at face value, without pointing out that it was wrong). Then they spent two days and nights in isolation.
Two of the participants coped well, sleeping through much of the period. All found it profoundly boring; most found it distressing. One young woman became convinced that her sheets were wet even though, when she checked, they were found not to be. Most of the volunteers started pacing their small rooms like caged animals during the second day and felt less and less safe as time went on. Three experienced auditory and visual hallucinations – snakes, piles of oyster shells, tiny cars, zebras.
“It was weird,” said Mickey, a postman. “I started to imagine things; a load of fighter planes buzzing round, a swarm of mosquitoes. I thought the room was taking off at one time. That was frightening.”
Conducting the same tests again, when the “prisoners” were gratefully released after 48 hours, Professor Robbins found that their ability to do even the simplest tasks had deteriorated. Mickey’s memory capacity fell by 36 per cent. All the subjects had trouble thinking even of one or two words beginning with “F”. And all four of the men (though interestingly not the women) were markedly more suggestible.
It’s the last of these findings that Professor Robbins thinks has an immediate social and political relevance. “People being held for questioning in police stations, for example, may be treated humanely, but they get virtually no sensory input,” he says. “If the detention is for short periods of time, I don’t think that’s a problem, but there is talk of extending the period of time for which people can be held on suspicion of terrorist offences. And if people are indeed more suggestible, the longer they are held in isolation, the more that must raise questions about the reliability of their evidence.”