How Does Mindfulness Work?

Scientists Search for An Answer

A recent study performed at the University of Buffalo in New York offers new evidence about mindfulness that runs contrary to the popular view of what mindfulness does and how mindfulness works.

The study, which included over a thousand participants, measured physiological responses to short-term stressors in people who reported having various levels of dispositional mindfulness.

If you’re not familiar with that phrase, it refers to how mindful a person is by default, as they go through their day-to-day routine and perform tasks that range from boring to stressful to everything in between. And if the phrase mindful is unfamiliar to you, it refers to the quality of attention an individual brings to any given moment. Mindfulness refers to the ability to focus on the present without ruminating about the past or worrying about the future.

In general, research shows that people with high levels of dispositional mindfulness also report high levels of personal wellbeing and life satisfaction. People with high levels of dispositional mindless also report that they can handle chronic stress efficiently, process past trauma productively, and that mindfulness helps them keep an even keel during moments of acute stress.

The study we address in this article, as mentioned above, measured physiological responses to stress. Measures included heart rate, heartbeat strength, stroke volume (how much blood each heartbeat moves), and blood vessel dilation. Heightened attention to external stimuli causes increased heart rate, increased stroke volume, and increased blood vessel dilation. In the study – Facing the Facets: No Association Between Dispositional Mindfulness Facets and Positive Momentary Stress Responses During Active Stressors – researchers assumed that during a moment of acute stress, participants with high levels of dispositional mindfulness would show increases in those physiological measures.

That’s not what they found.

Contradictory Physiological Responses

To simulate stress on the participants, researchers asked them to perform two activities that most people agree involve some degree of stress. One was giving a speech in public. The other was taking a cognitive ability/reasoning ability test. The cardiovascular responses they chose to measure indicate how much an individual cares about the task they’re involved in. The higher the heart rate and the more powerful the heartbeat, the more important the task, the experts say. Measures of stroke volume and blood vessel dilation indicate – according to scientific consensus – an individual’s level of confidence about how well they can accomplish the task they’re performing, and how capable they feel when performing it.

The results came as a surprise to the researcher conducting the study. What they found was that the physiological metrics recorded during the stressful experience did not necessarily match the experience described by participants.

People who reported high levels of dispositional mindfulness, when compared to people who reported low levels of dispositional mindfulness, showed:

  • Typical increases in heart rate
  • Typical increases in heartbeat strength
  • No change in stroke volume
  • No change in blood vessel dilation

Lets’ go over what those physiological responses are supposed to mean. Increase in heart rate and heartbeat strength indicates that the task is more important than other tasks. Increase in stroke volume and blood vessel dilation indicates the task creates a positive psychological experience. By those definitions, the relative level of dispositional mindfulness reported by the study participants made no difference at all. Where researchers expected mindfulness to temper physiological response – heart rate and heartbeat strength – they found no evidence that it did. Where researchers expected mindfulness to indicate a positive experience – stroke volume and blood vessel dilation – they likewise found no evidence that it did.

What the Results Mean

In a nutshell, these results mean scientists still don’t understand how mindfulness helps people handle stressful experiences while they’re happening.

Evidence from previous studies, which we link to above, shows that activities like mindful meditation can reduce common stress indicators. For instance, meditation can reduce circulating levels of cortisol after a meditation session. This result appears with meditation courses that last from a couple of weeks to a couple of months. This study, however, was unable to connect dispositional mindfulness with physiological metrics that should indicate a decreased stress response to stressful experiences.

Here’s the real conundrum at the heart of this story. People with higher dispositional mindfulness reported they had a positive experience during the simulated stress experiences. They reported this despite the absence of observable changes in their physiological state to indicate that a positive experience occurred.

This data does not change the fact that for countless people – children, adolescents, and adults alike – mindfulness yields practical benefits they can point to in their daily lives. Evidence shows mindfulness can reduce stress, improve self-esteem, and lead to higher levels of wellbeing and life satisfaction.

Mark Saltsman, the lead researcher on the study, addresses that fact in a press release published by the University of Buffalo:

“Although those benefits seem unambiguous, the specific ways in which mindfulness should impact people’s psychological experiences during stress remain unclear.”

Here’s another way to look at what these results mean. In order to understand how mindfulness works on a physiological level, researchers have more work to do. This study teaches them – and the general public – that if mindfulness involves physiological mechanisms that help people handle acute stress, those mechanisms do not affect cardiovascular measures such as heart rate, heartbeat strength, stroke volume, or blood vessel dilation.

We’re confident that at some point, research will identify how mindfulness works – but we’re not quite there yet.