Slow Breathing Can Influence Brain Activity and Decision Behavior

A new study from the German Institute of Human Nutrition Potsdam–Rehbruecke (DIfE) and Charité – Universitätsmedizin Berlin shows for the first time that targeted control of human breathing rhythm can influence decision behavior by modulating heart and brain function. The research team led by ECN member Prof. Soyoung Q Parkan was able to demonstrate that prolonged exhalation increases heartrate variability and brain’s reward sensitivity, thus enabling us to make bolder decisions. The study was published in the journal Neuron.

^{Analysis of brain scans obtained using fMRI (representative image) photo: David Ausserhofer/DIfE}

Accelerated breathing and rapid heart rate often lead to quick decision–making. Judgements under these circumstances, can lead to a more cautious decisions to minimize potential loss – whether it is making investments under time pressure, during a critical employee meeting, or when quickly selecting a meal. In contrast, slow breathing and a calmer heart could presumably lead to assessing the situation more positively and making bolder decisions.

New Perspective: Body, Brain, and Decision in Harmony

Traditional theories assume that decisions arise in the brain. The present study investigated how the interplay of different organs can influence brain function and thereby control our decisions. It was spearheaded by Prof. Soyoung Q Park in cooperation with institutions such as Neuroscience Research Center at Charité – Universitätsmedizin Berlin, Freie Universität Berlin, and German Naval Institute of Maritime Medicine.

^{Prof. Soyoung Q Park, Head of the Department of Decision Neuroscience and Nutrition (photo: Michael Reinhardt/DIfE)}

"Our decisions are rarely determined solely by external information. Rather, our judgment emerges from the interplay between cognitive processes and our current bodily state. It was previously unknown how the conscious regulation of our body, for example through targeted breathing, could actively control our decision–making process. We wanted to create a physiological shift using slow breathing pattern to change the quality of our decisions," explains Soyoung Q Park, head of the Department of Decision Neuroscience and Nutrition at DIfE, summarizing the research question.

In the study, 41 healthy participants were observed in a state-of-the-art multi-methods research setting as they made risky decisions while adhering to specified breathing protocols. The participants followed visual breathing cues and breathed either in their individual natural rhythm or slower with an extended exhalation (2:8 inhale-exhale ratio). While they breathed, they were asked to make several risk decisions. Meanwhile, the researchers captured brain function using functional magnetic resonance imaging and simultaneously monitored breathing parameters, heart activity, skin conductance, and pupillary reactions. By combining these measurements, the researchers were able to investigate whether extended exhalation not only lowers heart rate but also leads causally to modulated reward processing in the brain.

^{Wenhao Huang, PhD student in the Department of Decision Neuroscience and Nutrition (photo: Carolin Schrandt/DIfE)}

The Body's State Influences Our Decisions

The scientists found that extended exhalation led to more risky decisions by slowing down heart rate. Notably, the risky decisions were more guided by potential rewards, while the consideration of potential losses remained unchanged. Furthermore, there was increased activity in the ventromedial prefrontal cortex and the precuneus area. These two key brain regions influence both the time intervals between heartbeats – known as heart rate variability – and reward sensitivity. "Our study thus underscores the transformative role of breath–based interventions. The interplay between breathing and cardiac dynamics makes the brain more receptive to rewards," explains lead author Wenhao Huang, interpreting the results.

The Practical Benefits of Breathing Techniques

The findings expand the field of body-brain interaction research and support so-called neurovisceral models, which posit that physical condition strongly influences cognitive processes. Park explains: "Breathing techniques have accompanied humanity for millennia across various religions and cultures. With this study, we provide scientific proof that it is a reliable and targeted method capable of controlling our decisions."

^{Graphical abstract (source: DIfE)}

Thus, breathing techniques represent a simple, inexpensive, and easy-to-learn option for everyday self-regulation. Moreover, they have immense potential value in clinical settings as an adjunctive, non-pharmacological strategy – for example, for conditions such as anxiety disorders or depression, which are characterized by autonomic dysregulation and altered reward perception.

The next step should be to investigate whether the observed effects can be generalized to a broader clinical population, such as people with overweight. "Since dietary decisions are strongly influenced by reward assessment and physical state, targeted breath regulation could also play a role in consciously perceiving and more effectively managing eating behavior," Park summarizes for future research activities.

Source: German Institute of Human Nutrition Potsdam-Rehbruecke