“We are what we remember of ourselves,” says Michael Anderson, a professor of cognitive neuroscience at the University of Cambridge who studies memory. How you will remember your life as an 80-year-old will depend on the ways you hold on to, or let go of, memories. Your brain is always in the process of forgetting, but Anderson believes you can forget with more intentionality — what he calls motivated forgetting — and that you can get better at it with practice. “You sculpt your memories,” he says.
Memory relies on what cognitive scientists call retrieval cues. Say you’re trying not to think about a painful breakup, but then the same type of blue Prius your ex drove pulls up next to you at a red light. Memories flood in. If you’re trying to forget something, become attuned to that memory’s retrieval cues so you can reshape the way your brain responds to them. You can try to avoid such triggers, but that strategy rarely works. A Vietnam War veteran might take care to shun anything reminiscent of warfare and still get yanked back into combat imagery while trying to order dinner at a restaurant. “How could you anticipate that a bamboo place mat would remind you of war?” Anderson says.
Rather than total retrieval-cue avoidance, try a technique called thought substitution. If you had a bitter argument with your sister and think of it every time you see her, work to focus on other, more positive associations. Practice until your brain sees her face and surfaces those better memories first and not the fight. You can also work on what cognitive scientists call direct suppression. “You just kind of put up the mental hand and say, ‘Nope, I don’t want to think about that,’” Anderson says. While these two mechanisms for forgetting often work together, they’re neurologically distinct. Thought substitution relies on the left prefrontal cortex; direct suppression on the right.
Your ability to forget is determined, in part, by your specific neural architecture. Studies also show that extreme stress and lack of sleep will make you worse at motivated forgetting. People who have experienced more adversity in their lives are better at it than people who haven’t known such hardships. If you’ve lived through something traumatic, it’s unlikely that you’ll be able to wipe the experience from your brain entirely. What you can do is limit the extent to which those memories will intrude, unwanted.
