AI Insight
This study challenges previous claims that breathing patterns influence brain activity preceding voluntary movements. Researchers reanalyzed original data and collected new data, demonstrating that the apparent link between respiratory phase and the readiness potential was actually a statistical artifact caused by both variables being independently related to movement timing. When properly controlling for this confound, no relationship between breathing phase and pre-movement brain activity was found during natural breathing.
Why it matters
This research corrects a potential misunderstanding about how breathing influences voluntary action in the brain, which is important for neuroscience theories of motor control and decision-making. The findings also highlight a critical methodological issue in phase-amplitude coupling analyses that could affect interpretation of results in other neuroscience studies examining relationships between physiological rhythms and neural signals.
Understand the Science
by Lucas Jeay-Bizot, Raniyah Chishti, Uri Maoz, Aaron Schurger
Respiratory processes are increasingly implicated in shaping neural activity and behavior. Recent studies have reported a coupling between respiratory phase and the cortical readiness potential (RP), suggesting that breathing may modulate the neural processes preceding voluntary action. Here, using electroencephalography recordings in humans, we re-examine this claim using the original dataset and a new independent dataset, as well as in simulated data with no coupling. We show that the reported association arises from a confound: both RP amplitude and respiratory phase are coupled to movement onset. The original analysis does not control for this dependency, leading to a spurious effect that is also observed in simulated data. When trials are instead grouped by respiratory phase at the time of movement, thereby controlling for this confound, the apparent coupling disappears. Across datasets, Bayesian analyses provide evidence for the absence of an effect under natural breathing conditions. These findings indicate that respiratory phase does not directly modulate RP amplitude during spontaneous behavior. More broadly, they reveal a shortcoming of phase-amplitude coupling analyses applied to epoched data with slowly varying signals, and highlight the importance of controlling for shared dependencies when interpreting physiological–neural relationships.
Source: No evidence for modulation of the readiness potential by respiratory phase during natural breathing