Mindfulness meditation, in which practitioners focus their awareness on the present moment, can modulate activity within the brain’s default mode network, which is so named because it is most active when a person is not focused on any particular task. Two hubs within the default mode network, the medial prefrontal cortex and the posterior cingulate cortex, are of particular interest to McGovern Institute research affiliate Whitfield-Gabrieli and her colleagues, due to a potential role in the symptoms of depression and anxiety.

“These two core hubs are very engaged when we're thinking about the past or the future and we're not really engaged in the present moment,” she explains. “If we're in a healthy state of mind, we may be reminiscing about the past or planning for the future. But if we're depressed, that reminiscing may turn into rumination or obsessively rehashing the past. If we're particularly anxious, we may be obsessively worrying about the future.”

Whitfield-Gabrieli explains that these key hubs are often hyperconnected in people with anxiety and depression. The more tightly correlated the activity of the two regions are, the worse a person’s symptoms are likely to be. Mindfulness, she says, can help interrupt that hyperconnectivity.