Phase‐locked breathing does not affect episodic visual recognition memory but does shape its corresponding ERPs

Abstract

Recent studies have indicated that breathing shapes the underlying oscillatory brain activity critical for episodic memory, potentially impacting memory performance. However, the literature has presented conflicting results, with some studies suggesting that nasal inhalation enhances visual memory performance, while others have failed to observe any significant effects. Furthermore, the specific influence of breathing route (nasal vs. mouth) and the precise phase of the respiratory cycle during which stimuli are presented have remained elusive. To address this, we employed a visual recognition memory (VRM) and electroencephalography paradigm in which stimuli presentation was phase‐locked to either inhalation or exhalation onset, using a within‐subject design where participants performed the memory task while engaging in separate sessions of nose and mouth breathing. We show that neither breathing route nor breathing phase has a significant impact on VRM performance as measured by d‐prime, with the data supporting the null hypothesis. However, we did find an effect of breathing phase on response bias, with participants adopting a more conservative decision criterion during exhalation. Moreover, we found that breathing phase during memory encoding shaped the late parietal effect (LPE) amplitude, while the Frontal Negative Component (FN400) and LPE during recognition were less impacted. While our study demonstrates that breathing does not shape VRM performance, it shows that it influences brain activity, reinforcing the importance of further research to elucidate the extent of respiratory influence on perception, cognition, and behavior.

The Respiratory-Pupillary Phase Effect: Pupils size is smallest around inhalation onset and largest during exhalation

“…However, nasal breathing also includes an additional oscillator—the olfactory bulb. Olfactory sensory neurons at the roof of the nasal cavity detect mechanical pressure caused by airflow in the nostrils, even in the absence of odors (Grosmaitre et al, 2007), and project this information to the olfactory bulb, which in turn generates brain oscillations that propagate globally and may uniquely affect perceptual and cognitive functions (Arshamian et al, 2018; Fontanini & Bower, 2006; Heck et al, 2017; Karalis & Sirota, 2022; Kay et al, 2009; Kocsis et al, 2018; Negro et al, 2018; Schaefer et al, 2024; Tort et al, 2018). This indicates that nasal and oral breathing might shape pupil dynamics differently.…”