“We are what we remember about ourselves,” says Michael Anderson, professor of cognitive neuroscience at the University of Cambridge who studies memory. How you remember your 80s life will depend on how you hold on or let go of your memories. Your brain is always forgetting, but Anderson believes that you can forget with more intention – what he calls motivated forgetting – and that you can improve with practice. “You carve your memories,” he says.
Memory relies on what cognitive scientists call recovery cues. Say you try not to think about a painful breakup, but the same type of blue Prius your ex was driving pulls up beside you at a red light. Memories flow in. If you are trying to forget something, listen to the signals of memory recovery so that you can reshape the way your brain responds to them. You can try to avoid such triggers, but this strategy rarely works. A Vietnam War veteran might be careful to avoid anything reminiscent of war and get drawn into the combat footage while trying to order dinner at a restaurant. “How can you expect a bamboo placemat to remind you of war?” Anderson said.
Rather than avoiding recovery cues altogether, try a technique called thought substitution. If you’ve had a bitter argument with your sister and think about it every time you see her, focus on other more positive associations. Practice until your brain sees his face and surfaces on those fondest memories first, not the fight. You can also work on what cognitive scientists call direct suppression. “You just put your hand up and said, ‘No, I don’t want to think about that,’” Anderson says. While these two forgetting mechanisms often work together, they are neurologically distinct. Thought substitution relies on the left prefrontal cortex; direct right deletion.
Your ability to forget is determined, in part, by your specific neural architecture. Studies also show that extreme stress and insufficient sleep will make motivated forgetfulness worse. People who have experienced more adversity in their life are better than those who have not experienced such hardships. If you’ve been through something traumatic, it’s unlikely that you will be able to completely erase the experience from your brain. What you can do is limit the extent to which these unwanted memories will creep in.