Halifax Daily News

Imagined memories

Study shows false events can be planted in the mind

Sunday, January 10, 1999
SHAUNE MacKINLAY -- The Daily News

A study by a Dalhousie University psychologist shows just how easily adults can remember significant childhood events, even when they didn't happen.

Stephen Porter and University of British Columbia psychologists John Yuille and Darrin Lehman investigated whether false childhood memories could be implanted in adults using suggestive interviewing techniques.

Legal implications

They found 26 per cent of the 77 participants in the B.C.-based study experienced a complete false memory, and a further 30 per cent had a partial false memory.

The implications could be far-reaching for criminal investigators, therapists, and courts tasked with deciding whether or not to believe evidence in sexual-abuse cases based on recovered memories.

For ethical reasons, Porter's study did not attempt to implant abuse memories.

"I think mental-health professionals and investigators can take this information and use it," Porter said.

"It should drive home the possibility that abusive memories can be implanted, and they should exert caution in their interview techniques, should it be the case that that is so."

Porter, who completed his doctoral thesis at UBC on childhood memory and became an assistant professor at Dalhousie in September, said the study should not be used to dismiss real abuse memories.

"These kinds of results have to be taken in context and we have to recognize that in general, highly emotional events are remembered quite well over time," he said.

The study asked parents of adult children, with a mean age of 19, to describe a highly emotional event in their child's life between the ages of four and 10.

The study subjects were then asked if they remembered the event, and a second false event which they were also told happened to them.

"It could be something like in 1972, in the wintertime, you were walking up the road with your father and a dog attacked you," Porter said.

In their attempt to implant the memory, interviewers used suggestive techniques such as bringing the person's mind back to the scene.

Over the course of three interviews during a week, they were encouraged to recover the memory.

"We were more aiming to see how many interviews we could implant under extremely suggestive circumstances, rather than mocking a typical psychotherapy session," Porter said.

"But we did use techniques that some therapists are apparently still utilizing."

When questioned after the experiment, some participants said the implanted memory was very vivid, even though, overall, the participants rated the false memories as less vivid than their true memories.

By contrast, when asked to make up a memory and lie to their interviewer, participants came up with stories rich in detail.

Reviewed for publication

When the study was over, the people who experienced the implanted memories were surprised when told the event didn't happen, Porter said.

The study is now being reviewed for publication by a psychology journal.