Mind tricks take memories for a ride, scientists assert

2/17/2003

DENVER - What you remember of last week may not be real, a panel of scientific experts cautioned here yesterday.

That's because the human brain is “frighteningly susceptible” to suggestive comments, subliminal messages, and other tricks that can form false memories.

Among the brain's memory scams is a strange but surprisingly common phenomenon called “sleep paralysis.” Scientists identified it as the likely explanation in people claiming they have been abducted and molested by space aliens.

“Twenty years of research has given us almost a recipe for planting and embellishing false memories in people,” said Dr. Elizabeth F. Loftus. She is a professor of psychology and criminology at the University of California at Irvine.

“This has serious implications for false memory problems that are occurring in society, which are really memory-distortion episodes,” she added.

Dr. Loftus and other experts on false memories, who spoke at a meeting of the American Association for the Advancement of Science, cited several concerns.

Police interrogation practices, for instance, may intentionally or unwittingly plant false memories in suspects or witnesses, they said, and embellish the memories with lifelike detail.

Simply telling one witness “truthfully or not” what others have described at a crime scene can plant the seeds of a false memory.

Media publicity about accidents or crimes may plant false memories that taint witnesses and interfere with investigations, she said, citing the Washington-area sniper episode.

After media reports linked the sniper to a “white van,” witnesses reported seeing white vans speeding away from later attacks. When caught, the sniper suspects were driving a blue car.

Political and other advertisements may exploit the knowledge to manipulate public opinion by inserting subliminal messages. Those may be words, which viewers do not consciously notice but still influence behavior.

Dr. Joel Weinberger, a psychologist at Adelphi University, said experts are doing a turnabout on subliminal persuasion and think it really does work.

A controversial practice in which psychologists try to recover “repressed memories” of childhood sexual abuse also got attention at the session. In some cases, psychologists may actually create in their patients memories of childhood events that never occurred.

Innocent people can be prosecuted and jailed as a result.

Dr. Loftus described planting false memories in more than 20,000 research volunteers. They included recollections of accidents, leisure-time activities, childhood trauma, and other events that never occurred.

Research has shown that it is possible to do more just than change a detail or two in a memory, she said. Totally false memories of events that never occurred can be planted “intentionally or unintentionally.”

The process involves, in part, making a person believe that an event could have happened and suggesting that it could have happened to them even if they do not remember it.

Dr. Loftus proposed establishing a “National Memory Safety Board.” A counterpart to the National Transportation Safety Board, it would investigate memory problems that led to injustices in the legal system.

Harvard University's Dr. Richard J. McNally described research on another memory trick believed to be the basis of alien abduction stories.

“People who claim to have been abducted by space aliens are not mentally ill,” he said, citing numerous studies.

Rather, they probably are victims of sleep paralysis, a condition that occurs when people awaken from deep sleep, are only partially conscious of their surroundings, and cannot move.

About one in three people have experienced it, he said, with one in 20 having a severe form accompanied by hallucinations. Some involve other-worldly sensations that can be mistaken for alien encounters, he said.