De Couck et al. International Journal of Psychophysiology 139 (2019) 1–9. doi: 10.1016/j.ijpsycho.2019.02.011
THE BOTTOM LINE
In this experimental study of 56 undergrad and grad students in France, utilizing specialized breathing patterns (see image below), the researchers sought to determine the effect of breathing on stressful decision making. They found that using breath patterns for 5 minutes prior to stressful written multiple-choice tests allowed the experimental group to answer an additional question correctly. Additionally, they found that the breathing group felt significantly less perceived stress via a visual analog scale difference of >4 than the sham control group. Does this pertain to clincal scenarios where we think out loud or just to multiple choice questions? Do we really need to breath for 5 min to get an affect? Can we trust the French? Other than the last question, only time will tell…
Ok well we all know physiologically breathing is good for you but turns out it might be psychologically better for you also. This quick hit article was published in the aptly titled: Journal of pschyophysiology (no, not the physiology of psycho’s). This article looks at how breathing can impact the stress of decision making. Interestingly stress can negatively impact decision making. They cite a meta-analysis of 1829 pts that revealed stressful conditions lead participants to take a decision that was more risk taking than in non-stress conditions. In medicine we make stressful decision all the time so can breathing exercises help? This article tries to shed some light on the subject
In this study they postulate that deep slow breathing can increase vagal nerve activity, measured by heart rate variability (HRV) which they state is associated with better decision making. HRV is the physiological phenomenon of variation in the time interval between heartbeats. It is measured by the variation in the beat-to-beat interval.
There are anecdotes of tachycardia and stress in the military about soldiers running into battle without helmets. The thought here is stress leads to an aberrant decision and tachycardia (especially HR over 120) have been a marker of this (see “On Combat: The Psychology and Physiology of Deadly Conflict in War and in Peace by Grossman and Christensen). Therefore, we have to assume that HRV and vagal nerve stimulation are positively correlated with improved decision making.
Interestingly, and unlike most journals, this study reports two different studies under one article heading. I find this strange but we will look at them as two separate studies
The first study examines the effects of two breathing patterns on HRV, differing in their inspiratory to expiratory (I:E) ratios, in healthy men and women. In study 2, they examined whether one of the breathing patterns could result in better decision-making in stressful conditions. The research was conducted in a business school in France on 56 management students at the bachelors and masters level.
Study 1 found that both types of breathing pattern, a symmetric and a skewed pattern (with a longer exhalation period), increased several parameters of HRV.
Study 2 examined 56 patients in two groups of 28 who were directed not to smoke, consume alcohol or caffeine 3 h before participation and were rewarded for participation. They define HRV-B as a method where people learn to use deep breathing methods to enhance their HRV with electronic biofeedback. Beat to beat intervals are termed NN (much like an R-R interval on an ECGl with N signifying Normal beat to beat intervals). SDNN or the standard deviation of NN intervals, reflects all the cyclic components responsible for variability in the period of recording, therefore it represents total variability. The standard deviation of the average NN intervals calculated over short periods (5 minutes in this study) they use is 50 ms and an SD of 16 ms. They make this very confusing to figure out and there might be some typos in the methods as well. HRV was derived from an ECG with a biofeedback system. They utilized TWO different breathing patterns termed symmetric and skewed. As you can imagine the symmetric pattern was 5 minutes of inhalation on a 5 second count followed by breath holding for 2 count then 5 second count for exhalation. They skewed pattern was 5 minutes of inhalation on a 5 second count followed by breath holding for 2 count then 7 second count for exhalation.
The control group watched a 5 min “emotionally neutral” movie without music or sound. They utilized within subject experimental design (meaning these were repeated measures and paired statistical testing would be needed). A decision making scenario and questions were created as a business simulation consisting of two parts a reading part and a multiple choice decision part. They were asked to assume the role of someone in charge of a retail company and a writing test after with a strict time constraint. They state that “recently, Brugnera et al. (2018) found that verbal activity masked the vagal withdrawal through altered respiration patterns imposed by speaking. That is why, in this study, we opted for a task in which participants do not need to talk”. I find this interesting and we will get back to this later. Additionally, subjects were asked to evaluate their actual stress level using the VAS stress (for Pre-Stress levels).
They note in this first study that the deep breathing group had a significantly (that should be stated STATISTICALLY) higher percentage of correct choices (47% vs 32%; p=0.005) which translated to on average one more question right than the control (2.25 ± 1.35 vs 3.32 ± 1.36 correct answers). I think the more interesting part was the perceived stress by the two groups.
The control group had a VAS for pre- stress of 3.57 vs post stress of 8.16. The breathing group had a VAS for pre- stress of 4.40 vs post stress of 5.7. Assuming a clinically significant difference is 3 for a VAS on a 10-point scale (extrapolating from 30 on a 100 pt scale) then this would be significant.
So put together what does this all mean? It would seem that breathing might be associated with less perceived stress but the effect here seems small with such a small and specialized sample size. Does this apply to medicine where we can sometimes think out loud? The study cited here would suggest that there is masking of the difference when one can verbalize decision. Also does this study mean we have to breath from 2-5 min to reap a benefit of this breathing pattern? What is the optimal length of time for breathing? Does it have to be isolated or can I multitask and do it while I prepare for a stressful situation? Lastly, can we really trust the French? Certainly, my apple watch tells me that breathing will make me feel better! While all of this makes sense I’m not sure this really is conclusive evidence or always practical. I guess for my clinical practice I’ll try it out and see for myself. It certainly is interesting given the concern over bias in decision making these days.