Mindfulness-based programs (MBPs) for psychological health have been well-supported in the literature, and are a staple for treating anxiety, depression, pain and post-traumatic stress disorder. Now a literature review, published in Neuropsychology Review, answers questions posed by scores of diversely designed, randomized controlled studies in recent years about the relationship between MBPs and ways to improve cognitive function.
David Vago, Ph.D., a research associate professor of psychology at Vanderbilt University, is a senior author on the paper. “Anecdotal evidence has shown that many MBP practitioners learn to control their attention, improve self-regulation and change maladaptive behavior and their perspective of themselves,” Vago said. “That led us to ask whether some of these changes would be mirrored in objective cognitive tests.”
The new publication, Vago explains, is the first systematic review and meta-analysis to examine objective cognitive outcomes in rigorously controlled clinical trials.
“What we found was a bit surprising – there was little difference in outcomes between standard MPBs and the active control groups that similarly met in a group setting but did not meditate,” Vago said. “However, some changes rose to significance, specifically in executive function and working memory, and more so in older adults.”
Probing the Limits of MBPs
Mindfulness-based interventions use three basic techniques to train the mind to experience life in vivid moment-to-moment attentiveness: sitting meditation, mindful movement and informal mindfulness practices throughout daily life. During meditation, neuroimaging research has demonstrated changes in brain waves and alterations in activity in brain networks associated with enhanced self-awareness and self-regulation, including attention and emotion regulation, decreased mind wandering and improved sensory awareness.
“This supports the hypothesis that these programs do more to close a deficit than extend cognitive capacities past a developmental peak.”
Long-term – and sometimes even short-term – meditation practice can be a powerful tool in moderating mood swings and impulsiveness, coping with pain and quelling anxiety. Mindfulness-based interventions can also lower the risk of drug addiction and long-term disability in people with chronic pain, Vago says.
The question has remained, do MBPs improve the mind’s self-regulatory functions, working memory, long-term memory, or flexibility to move fluidly between tasks? In other words, do these meditation practices translate to improve cognitive function and performance on objective measures?
Improvements in Executive Function
Vago and colleagues looked at 46 studies that reported cognitive outcome data amenable to the final meta-analysis. They exclusively examined the effect MBP participation had on neuropsychological or laboratory-based cognitive tests of attention, perception, declarative memory, language, construction, reasoning and executive function.
The MBP interventions included in the study were limited mostly to mindfulness-based stress reduction and mindfulness-based cognitive therapy programs. The intensity and duration of practices varied as well, with the number of sessions included by MBPs ranging from four to 72, and most programs being delivered over six to 12 sessions.
“Mindfulness meditation is not a plug-in therapy, it would be hard to conclude from these diverse studies how a committed practice of mindfulness and meditation over years impacts cognitive function over a lifetime.”
Overall findings showed that only executive function demonstrated significant improvements. Changes in working memory, a subcategory of executive function, rose to slightly higher significance. Notably, MBPs only outperformed inactive comparators (no comparison intervention), but not active comparators (participants in other therapies or social support groups).
Clearest Benefits for Older Adults
An important outcome, given the trend toward higher rates and earlier onset of dementia, is that MBP practitioners over 60 often have the most to gain. In several of the studies, older adults demonstrated a substantial benefit, even relative to active comparators. “Since loss of cognitive function is common in older people, this supports the hypothesis that these programs do more to close a deficit than extend cognitive capacities past a developmental peak,” Vago said.
“Additional studies support the idea that mindfulness training can be neuroprotective for age-related cognitive deficits, and neuroimaging data demonstrate that older adults who meditate have less atrophy in brain areas activated by meditation.”
Vago says the team was surprised that non-clinical (healthy) participants benefitted more than clinical participants (those with physical or mental health diagnoses). He explains this may reflect the difficulty clinical participants may have relaxing into practice states.
The Durable Impact of Habitual Practice
Studies that looked at long-term practitioners found greater benefits in attention to cognitive flexibility. “But it is mixed,” Vago said. “And it’s probably because it’s a mixed bag of people practicing meditation, with different motivations and backgrounds.”
“Mindfulness meditation is not a plug-in therapy,” he added. “Jon Kabat-Zinn, the father of this movement in America, would remind us that even the standard practice across eight weeks is intended to be a training, not an end in itself. It would be hard to conclude from these diverse studies how a committed practice of mindfulness and meditation over years impacts cognitive function over a lifetime.”