bioRxiv Science⌕ Search

Biology subjects

Delplanque, S.

Publications and source records attributed to Delplanque, S..

6 recordsLinked to original sources

Hippocampal-somatomotor coactivation and perceived benefit following Mindfulness-Based Cognitive Therapy for Life in healthcare students: An exploratory randomized study

Mindfulness-based interventions are known to enhance emotion regulation and stress management, yet their neural mechanisms remain incompletely understood. Effective coping strategies for emotion regulation and stress management would be particularly beneficial for healthcare students, frequently exposed to highly stressful situations. Based on prior work implicating hippocampal-somatomotor dynamics in emotion regulation, we tested whether Mindfulness-Based Cognitive Therapy for Life (MBCT-L) modulates hippocampal micro-coactivation patterns (CAPs) in healthcare students. In a randomized controlled study including 161 healthcare students, 57 participants (39 females; mean age: 23+/-5 years old) completed resting-state fMRI before and after the 8-weeks intervention and were allocated to MBCT-L (N = 24) or a no-intervention control (N = 33) condition. Hippocampus-seeded CAPs analysis identified six recurrent patterns, including a somatomotor network. MBCT-L improved self-reported mindfulness, but no significant Group*Time interaction for hippocampus-somatomotor coactivation or resting physiological measures was found. In the MBCT-L group, higher hippocampus-somatomotor co-activity was associated with higher perceived importance of the intervention, perceived long-lasting benefits, and post-intervention mindfulness scores. This study suggests that the capacity to up-regulate hippocampus-somatomotor coactivation may index part of the individual benefit derived from mindfulness, supporting its role as a tool for emotion regulation and stress management.

neuroscience↗

Shared book reading promotes experience-dependent autonomic synchrony in parent-preterm infant dyads

Preterm birth is associated with alterations in early caregiver-infant regulation, with potential consequences for socio-emotional and physiological development. However, the mechanisms through which early interactional experience shapes these processes remain unclear. Here, we tested whether a structured dyadic intervention could modify co-regulatory dynamics across physiological, behavioral, and relational levels. Fifty-four 7-month-old preterm infants and their parents were assigned to either a shared book reading intervention (n = 22) or an active control condition based on a shared building activity (n = 32) and compared with 39 full-term infants. The intervention consisted of an 8-week program of shared book reading, designed to structure parent-infant interaction. Physiological synchrony was assessed at the dyadic level, alongside infants autonomic regulation and cardiovascular signal complexity. Behavioral engagement and parental attachment representations were also evaluated. Results showed that mother-infant physiological synchrony emerged selectively within the interactional context trained by the intervention and only in the intervention group. This context-specific synchrony was accompanied by modulation of vagal activity and increased cardiovascular complexity in preterm infants, consistent with enhanced flexibility of autonomic control. At the behavioral and relational levels, intervention infants showed increased initiating joint attention, while parents reported higher secure attachment. These findings support a model of experience-dependent early synchrony, in which repeated dyadic interaction through shared book reading shapes the coupling between interpersonal coordination and individual physiological regulation. By linking synchrony, autonomic flexibility, and social engagement, this study identifies a mechanism through which early caregiving experience can organize developmental trajectories following prematurity.

developmental biology↗

Interpersonal physiological synchrony: estimation and clinical application to cardiac dynamics of parent-infant dyads

Synchrony is a key mechanism that builds up the foundations of human interactions. Quantifying the level of physiological synchronization that occurs during dyadic exchanges is essential to fully comprehend social phenomena. We present a new index to characterize the coupling of complex physiological dynamics: the optimized Multichannel Complexity Index (opMCI). We validated this approach using synthetic time series of two coupled Henon Maps, with four different coupling levels in unidirectional and bidirectional manners. We demonstrated that the opMCI method allows to effectively discern between all coupling levels. Then, we applied the opMCI metric on heart rate variability data collected from 37 parent-infant dyads, during shared reading and playing activities, in the framework of the Shared Emotional Reading (SHER) project, with the aim of assessing the effects of early intervention in preterm babies. Two groups presented preterm infants: an intervention group, who participated in a two-month shared reading program, and a control group, who practiced shared play activities. A full-term group provided additional control data. The opMCI values were significantly higher for the intervention dyads with respect to the other groups during the shared reading task, showing that an early reading intervention program could increase parent-infant synchrony in preterm babies. Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=112 SRC="FIGDIR/small/712915v2_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@22f13forg.highwire.dtl.DTLVardef@c623eorg.highwire.dtl.DTLVardef@10605b5org.highwire.dtl.DTLVardef@60d594_HPS_FORMAT_FIGEXP M_FIG C_FIG HighlightsO_LIInterpersonal physiological synchrony is a fundamental mechanism for the evolutionary path C_LIO_LIAn ad-hoc methodological framework to assess nonlinear cardiac coupling is lacking C_LIO_LIThe opMCI has been shown to be a reliable tool for assessing the degree of synchrony C_LIO_LIEarly shared book reading may increase parent-infant synchrony in a clinical setting C_LI

bioengineering↗

Different armpits under my new nose: olfactory sex but not gender affects implicit measures of embodiment

Research has shown that conflicting multisensory signals may alter embodiment to the point of self-identifying with a foreign body, but the role of olfaction in this process has been overlooked. Here, we study in healthy participants how sex (male and female sweat odors) and gender (male and female cosmetic scents) olfactory stimuli contribute to embodiment. Participants saw from the perspective of a sex mismatching person in virtual reality and received synchronous visuo-tactile stimulation to elicit illusory embodiment of the seen body while smelling either sex- or gender-congruent stimuli. We assessed implicit (skin conductance responses to visual threats) and explicit (questionnaire) measures of embodiment. Stronger responses to threat were found when participants smelled the sex-congruent compared to the sex-incongruent odor, while no such differences were found for the cosmetic scents. According to the questionnaire, embodiment did not differ between conditions. Post-experimental assessment of the presented cues, suggest that while both sweat odors were considered generally male, cosmetic scents were not. The presented scents were generally not associated to the embodied body. Our results suggest that sex-related body odors influence implicit but not explicit aspects of embodiment and are in line with unique characteristics of olfaction in other aspects of cognition.

neuroscience↗

3D printed pacifier-shaped mouthpiece for fMRI-compatible gustometers

Gustometers have allowed the delivery of liquids in fMRI settings for decades and mouthpieces are a critical part of those taste delivery systems. Here we propose an innovative 3D printed mouthpiece inspired by childrens pacifiers that allow participants to swallow while lying down in an MRI scanner. Our results validate the effectiveness of our method by showing significant clusters of activation in the insular and piriform cortex which are regions that have been consistently identified to compute taste processing. We used a large sample (n=85) to validate our method. Our mouthpiece fulfills several criteria guarantying a gustatory stimulus of quality, making the delivery more precise and reliable. Moreover, this new pacifier-shaped design is: simple and cheap to manufacture, hygienic, comfortable to keep in mouth, and flexible to diverse use cases.We hope that this new method will promote and facilitate the study of taste and flavor perception in the context of reward processing in affective neuroscience and thus help provide an integrative approach to the study of the emotional nature of rewards.

neuroscience↗

Differential contributions of ventral striatum subregions to the motivational and hedonic components of the affective processing of the reward

The ventral striatum is implicated in the affective processing of the reward, which can be divided into a motivational and a hedonic component. Here, we examined whether these two components rely on distinct neural substrates within the ventral striatum in humans. We used a high-resolution fMRI protocol targeting the ventral striatum combined with a Pavlovian-instrumental task and a hedonic reactivity task. Both tasks involved an olfactory reward, thereby allowing us to measure Pavlovian-triggered motivation and sensory pleasure for the same reward within the same participants. Our findings show that different subregions of the ventral striatum are dissociable in their contributions to the motivational and the hedonic component of the affective processing of the reward. Parsing the neural mechanisms and the interplay between Pavlovian incentive processes and hedonic processes might have important implications for understanding compulsive reward-seeking behaviors such as addiction, binge eating, or gambling.

neuroscience↗