Biology subjects

Flament, B.

Publications and source records attributed to Flament, B..

4 recordsLinked to original sources

bioRxiv2026

Prefrontal cortex resting-state connectivity is moderated by hunger expectations induced by a placebo intervention in healthy female participants.

Placebo effects, in which a patient's symptoms and subjective well-being improve in response to an inactive treatment, medication, or intervention (a placebo), are well known in clinical research. Basic research in human cognition and neuroscience has shown that these effects are linked to prognostic expectations of effectiveness and to recruitment of prefrontal cortex regions, including the medial (mPFC), ventromedial (vmPFC), and dorsolateral prefrontal cortex (dlPFC). Here, we examined how the intrinsic functional connectivity of these three brain regions at rest, in the absence of any explicit task, was affected by internal beliefs such as placebo-induced hunger expectations. We conducted a seed-based resting-state functional connectivity analysis in 60 healthy female participants who underwent a placebo intervention targeting their hunger. In line with previously published results, the intervention induced hunger expectations and biased hunger sensations. Importantly, these effects were underpinned by attenuated functional connectivity between the mPFC and the angular gyrus within the default mode network the more participants expected the placebo to decrease their hunger. Hunger-increasing expectations attenuated connectivity between the vmPFC and the dm/dlPFC within the frontoparietal network and increased connectivity between the dlPFC and the thalamus. These results suggest that placebo-induced hunger expectations shift the way the prefrontal cortex connects to other brain regions associated with valuation, cognitive control, and interoception. This evidence sheds light on how the brain may translate incoming sensory information into biased sensations under placebo conditions and improves our understanding of the neural and psychological factors that influence a person's response to a placebo.

neuroscience↗

bioRxiv2026

When adiposity and listening to reasons for behavioral change make food choices healthier: Behavioral and neural mediators of weight status effects on dietary decision-making following behavioral change interventions.

Resolving the inner conflict between improving eating habits (change talk) and sticking to unhealthy ones (sustain talk) is a key target in communication-based behavioral change interventions such as motivational interviewing (MI). Recent work has shown that this inner conflict affects how tastiness and healthiness are traded off in dietary decision-making. The effect varied with body mass index (BMI). Here we aimed to identify why participants with higher BMI shifted toward healthier food choices after listening to change talk. An evidence accumulation model found that BMI affected health evidence sampling when listening to change talk, and taste evidence sampling when listening to sustain talk. A serial mediation analysis showed that the effect of BMI on change-talk-induced health evidence sampling was explained by stronger resting-state connectivity in the ventromedial prefrontal cortex within the default mode network (DMN), which in turn predicted greater motivation to change eating habits. These cross-sectional findings indicate that the intrinsic functional organization of valuation-related regions within the DMN is associated with motivation to change. They provide evidence that these neural and behavioral factors need to align with contextual cues, such as weight status (as reflected by BMI), and with reasons for behavioral change to promote healthier decision-making.

neuroscience↗

bioRxiv2023

Neural circuits underlying context-dependent competition between defensive actions in Drosophila larva

To ensure their survival, animals must be able to respond adaptively to threats within their environment. However, the precise neural circuit mechanisms that underlie such flexible defensive behaviors remain poorly understood. Using neuronal manipulations, machine-learning-based behavioral detection, Electron Microscopy (EM) connectomics and calcium imaging in Drosophila larva, we have mapped the second-order interneurons differentially involved in the competition between different defensive actions and the main pathways to the motor side putatively involved in inhibiting startle-type behaviors and promoting escape behaviors in a context dependent manner. We found that mechanosensory stimulation modulates the nociceptive escape sequences and inhibits C-shape bends and Rolls in favor of startle-like behaviors. This suggests a competition between mechanosensory-induced startle responses and escape behaviors. Structural and functional connectivity revealed that the second order interneurons receive their main input from projection neurons that integrate mechanosensory and nociceptive stimuli. The analysis of their postsynaptic connectivity in EM revealed that they make indirect connections to the pre-motor and motor neurons. Finally, we identify a pair of descending neurons that could promote modulate the escape sequence and promote startle behaviors. Altogether, these results characterize the pathways involved in the Startle and Escape competition, modulated by the sensory context.

neuroscience↗

bioRxiv2023

Listen to yourself: How motivational interviewing shifts food choices and craving-related brain responses to healthier options

Changing ones habits is challenging. Motivational interviewing (MI) has been proposed as a communication-based approach to overcome this challenge. Here, we tested how change and sustain talk suggestions, elicited by MI, influenced value-based dietary decision-making and responses of a recently developed neurobiological craving signature (NCS) in female adults. We found that following change talk, compared to sustain talk, participants food choices and activity in the ventromedial prefrontal cortex were more driven by the healthiness and less by the tastiness of food. These findings were paralleled by lower NCS responses to tasty food after change compared to sustain talk. Further, following change talk, participants body mass indices moderated the NCS decoding of healthy and tasty food choices. These results show that MI can shift value-based decision-making and reduce craving-related brain marker responses to highly palatable food items. The findings contribute to a better understanding of behavioral change interventions toward healthier eating.

neuroscience↗