Study: Unwanted Memories Forgotten

A new study suggests that Sigmund Freud's concept of repression — forcing unwanted memories into the unconscious — exists, which could help explain why some people can't remember traumatizing events like child abuse.

Researchers at the University of Oregon report in today's Nature that they mimicked memory repression in the laboratory by having college students learn 40 pairs of unrelated words, such as "ordeal" and "roach." When presented with one word, subjects were asked to say the matching word aloud. Other times, subjects were told avoid thinking about the second word completely.

Researchers found that people who intentionally tried to forget certain words couldn't recall them later — even when they were offered cash for the right answer.

"People in these studies are, in essence, pushing unwanted memories in to the unconscious, causing them to be forgotten later on," says Michael Anderson, a University of Oregon psychology professor who began his research to find out why victims of childhood abuse have problems recalling the abuse.

Debate Continues Over Freud

The existence of repression has been controversial since Freud claimed people could consciously forget memories of traumatic experiences, like abuse, more than 100 years ago.

But in recent years, repression has been central to the turbulent debate over "recovered memory" — whether it is possible to repress a memory of a traumatic experience like childhood sexual abuse and then remember it many years later.

Anderson's study mirrors the findings of another University of Oregon professor, Jennifer Freyd, author of Betrayal Trauma: The Logic of Forgetting Childhood Abuse.

"Adults who report child abuse perpetrated by a caregiver are much more likely to report memory impairment than are adults who report child abuse perpetrated by a non-caregiver," says Freyd. "Anderson's new research technique may eventually prove very important for accounting for forgetting in real-life social situations."

But Anderson admits that forgetting a word in a memorized word pair remains very different from repressing traumatic experiences.

"In the current experiments, we use simple pairs of words that are not emotionally significant to the subject, and test their memory after a brief delay," says Anderson. "In amnesia for trauma, we are obviously dealing with much more distinctive, emotionally significant experiences."