Forcing Yourself to Forget

July 12, 2007 — -- While the old saw says that it is easier to forgive than to forget, new research reveals that the latter may still be possible, even for very emotional memories.

Researchers at the University of Colorado worked with 16 subjects to see if they could actively suppress their own memories.

To do this, the researchers had subjects memorize 40 pairs of pictures, which were chosen because they provoked emotional responses.

The subjects were then shown the pictures again, this time instructed by the researchers to either remember or forget specific ones. At the same time, the researchers ran brain scans on the subjects to see which areas of the brain became active when the subjects were told to remember or forget a picture.

Finally, subjects were shown one picture from each of the pairs to see if they remembered its mate.

What researchers found was that subjects had much better memories of the pictures they were instructed to remember than of those they were told to forget.

The research appears in this week's issue of the journal Science.

"The big step forward is they showed how memory suppression in the brain can operate successfully with emotionally intensive material," said John Gabrieli, a professor in cognitive neuroscience at MIT who was not involved with the study.

In 2004, a team of researchers led by Michael Anderson, head of the Memory Control Lab in the psychology department at the University of Oregon, had first shown that the brain had mechanisms to suppress memories.

But, as Anderson explained, this experiment is the first to show that the brain can apply those same mechanisms to suppress complex, emotionally intense scenes.

The findings could have implications for those suffering from posttraumatic stress disorder or others whose traumatic memories have a negative impact on their lives.

"In the future, this will hopefully guide therapeutic approaches," said lead researcher Brendan Depue, a neuroscience doctoral student at the University of Colorado.

Gabrieli, who works with patients in addition to his lab work, sees two potential clinical applications for this research.