Biology subjects

Karjalainen, S.

Publications and source records attributed to Karjalainen, S..

3 recordsLinked to original sources

bioRxiv2025

Oscillatory markers of interoceptive attention: beta suppression as a neural signature of heartbeat processing

Interoceptive attention--the ability to selectively focus on internal bodily signals--has been linked to distinct neural responses, yet the contribution of oscillatory dynamics to this process remains underexplored. This study investigates the neural mechanisms underlying interoceptive attention by examining beta-band power suppression during heartbeat and auditory discrimination tasks. Fifty-one healthy participants engaged in interoceptive (heartbeat detection) and exteroceptive (auditory discrimination) tasks while their brain activity was measured using magnetoencephalography (MEG). The results revealed significant beta suppression time-locked to the R-peak in the somatosensory cortex, anterior cingulate cortex, mid-cingulate cortex, and dorsolateral prefrontal cortex from 310 to 530 ms post-R-peak. Beta suppression was more pronounced during interoceptive attention, correlating positively with interoceptive accuracy. The findings support the notion that beta suppression in fronto-cingulo-somatosensory network may serve as a neural marker of interoceptive processing, contributing to predictive coding models of interoception. This study highlights the potential for using beta suppression as an objective measure of interoceptive accuracy and suggests that neural oscillations play a critical role in the brains regulation of heartbeat-related information. Furthermore, the study proposes that interoceptive attention involves a top-down mechanism that dynamically adjusts the brains response to cardiac afferent signals, enhancing the precision of interoceptive processing. These findings have implications for understanding how the brain integrates interoceptive signals and may provide insights into clinical applications targeting interoceptive dysfunctions.

neuroscience↗

bioRxiv2024

Heart-brain coupling and its relevance for individual trait characteristics

A bulk of recent neurophysiological research has focused on how bodily functions are intertwined with neural activity, but the dynamic heart-brain coupling and its relevance for individual trait characteristics remains largely unexamined. Thus, our aim was to investigate how ongoing oscillatory brain activity is modulated by the natural fluctuations in heart rate variability (HRV). We further explored whether heart-brain coupling is associated with individual trait characteristics. Magnetoencephalography (MEG) together with electrocardiography (ECG) were used to record neural activity and HRV during rest. Self-reported trait characteristics were examined using Behavioral Inhibition and Activation Systems Scale (BIS/BAS) and attunement to internal bodily sensations using Body Vigilance Scale (BVS). Statistically significant increases were observed for low HRV vs. high HRV state in alpha and beta power (p < 0.05) indicating that oscillatory brain activity is modulated by fluctuations in HRV. Moreover, we demonstrated that heart-brain coupling was associated with self-reported behavioral approach and avoidance tendencies. The results of the moderator analysis further indicated that the relationship between heart-brain coupling and trait characteristics is at least partly moderated by the attunement to internal bodily sensations. Our findings bring insights to the intricate interplay between cardiac and neural signaling and its relationship with individual trait characteristics. HighlightsO_LIOscillatory brain activity is modulated by the natural fluctuations in HRV C_LIO_LIAlpha and beta power increase during states of lower parasympathetic activity C_LIO_LIHeart-brain coupling is linked with self-reported individual trait characteristics C_LIO_LIThis association is influenced by the attunement to the internal bodily milieu C_LI

neuroscience↗

bioRxiv2023

Neural activity is modulated by spontaneous and volitionally controlled breathing

Recent studies have provided evidence regarding respiration-brain coupling, but how continuously varying dynamics of breathing modulate neural activity is not known. We examined whether the neural state differs between spontaneous and volitionally controlled breathing and across the phases of breathing, inspiration and expiration. Magnetoencephalography with a respiratory belt was used to record cortical oscillatory activity during spontaneous, deep, and square breathing (n=33). Alpha power was suppressed during inspiration and increased during expiration (p<0.01) indicating dynamically fluctuating neural states across the respiratory cycle. Compared to spontaneous and square breathing, alpha power increased during deep breathing (p<0.01). We also observed a steeper aperiodic slope and a broadband shift in the power spectrum during square breathing in comparison with spontaneous breathing suggesting that spectral characteristics of neural activity are modulated by the rate, depth, and pattern of breathing. Altogether, we demonstrate that neural activity is modulated by breathing techniques and phases of breathing.

neuroscience↗