Key Takeaways

  • A type of meditation known as mindfulness training can improve working memory by overcoming proactive interference, which occurs when old information prevents the recall of new information
  • Mindfulness training is associated with a boost in volume of the hippocampus, which is the region of the brain that plays a key role in both working memory and long-term memory
  • Overcoming proactive interference can improve essential cognitive functions such as problem-solving, language comprehension and reasoning

When a friend changes her phone number, have you ever noticed how difficult it is to replace the memory of the old number?

Learning new information often highlights how difficult it can be to replace old memories. This common problem is called "proactive interference," and a team of researchers from Massachusetts General Hospital found that it may be overcome with a type of meditation known as mindfulness training.

The Link Between Mindfulness and Memory

Mindfulness is the ability to focus on the present moment and tune out distractions such as random memories, or worries about a job or relationship. It is frequently used to treat patients with depression, anxiety and other mood disorders, but a study led by Jonathan Greenberg, PhD, a postdoctoral research fellow, and Sara W. Lazar, PhD, an associate researcher in the Department of Psychiatry, found that it could also help relieve many other conditions, including age-related memory loss and post-traumatic stress disorder.

The study, which was originally published in Brain Imaging and Behavior, found that mindfulness training boosts the density of the hippocampus, which is a region of the brain that plays a key role in both working memory and long-term memory.

How Researchers Studied Mindfulness Training

The study involved 79 people who were assigned either to undergo mindfulness training or to be part of a control group and complete creative writing exercises. In the mindfulness program, participants first learned how to focus on their breathing and bodily sensations. The instructor, who had 15 years of experience teaching meditation, trained them to be able to recognize when their minds were wandering and to dismiss those distractions rather than act on them.

The participants completed their training online in four weekly, hourlong sessions, and their working memory was measured both before and after their training with a 20-minute computerized test. Most participants also had their brains imaged with an MRI. Even though the images didn't show significant changes in the volume of the hippocampus in either group before or after training, a deeper analysis of the results painted a different picture: Growth in the volume of the left hippocampus was associated with a drop in errors on the memory test—but only in the group that underwent mindfulness training.

The study is the first to link memory improvements with changes in the hippocampus that occur after mindfulness training.

"These findings support the conceptualization of mindfulness as promoting attention to experience of the present moment while minimizing interference from past events," the researchers say.

Using Mindfulness to Promote Brain Health

The link between hippocampus size and working memory in healthy adults is important because working memory influences many other cognitive functions, like problem-solving, language comprehension and reasoning. All of those vital brain functions could be improved by reducing proactive interference with mindfulness meditation.

In addition to helping improve critical cognitive functions overall, mindfulness may be a beneficial component of treatment for other conditions that are associated with memory impairment and reduced hippocampal volume, such as post-traumatic stress disorder, childhood maltreatment and aging.

Contributors: Sara Lazar, PhD and Jonathan Greenberg, PhD