Biology subjects

Beranger, B.

Publications and source records attributed to Beranger, B..

10 recordsLinked to original sources

bioRxiv2026

Saccadic network dysfunction underlies eye-movement variability in early Parkinson's disease

Parkinsons disease is a neurodegenerative disorder characterized by altered subcortical-cortical connectivity, leading to motor and cognitive deficits. Saccadic eye movement abnormalities are among the earliest and most persistent markers of the disease, serving as sensitive indicators of disrupted oculomotor and cognitive control. While changes in average saccadic behavioral measures are widely reported in Parkinson's disease, intra-individual variability in saccadic performance and the underlying network dysfunction remain poorly understood. Here, we quantified intra-individual saccadic variability in early-stage Parkinsons disease and identified its functional correlates within the resting-state saccadic network. We analyzed data from 91 patients with early-stage Parkinsons disease and 46 healthy controls who underwent oculomotor testing and resting-state functional magnetic resonance imaging. First, at the behavioral level, we assessed intra-individual variability in saccadic performance within each group using the coefficient of variation of reaction time and normalized peak velocity across trials. Second, at the brain level, we assessed group differences in static and dynamic functional connectivity across 39 regions comprising the saccadic network. We examined the relationship between network connectivity and saccadic variability using partial least squares analysis. We also quantified network organization using graph-theory measures of global efficiency and clustering coefficient. Finally, we tested the relevance of intra-individual saccadic variability and network features in distinguishing patients from healthy controls using a multivariate Mahalanobis classifier. Our results showed that, compared to HC, patients had higher intra-individual variability in saccadic behavioral measures of reaction time (pHolm = 0.012) and normalized peak velocity (pHolm = 0.012). Interestingly, patients had (i) reduced static and dynamic connectivity within the saccadic network and (ii) weaker associations between network connectivity and intra-individual saccadic variability of specifically normalized peak velocity. These results were particularly driven by regions within the cognitive saccade network. The classifier that integrated intra-individual saccadic variability and network connectivity achieved 95.62% accuracy in distinguishing patients from healthy controls, with dynamic connectivity contributing more strongly to classification performance than static connectivity. We demonstrate that elevated intra-individual variability of saccades, underpinned by altered functional connectivity within cognitive-oculomotor networks, is a prominent feature of early-stage Parkinsons disease. Emerging as a promising physiological marker of disease pathophysiology, intra-individual variability offers a powerful new framework to refine early diagnosis and improve the tracking of neurodegeneration before severe clinical milestones are reached.

neuroscience↗

bioRxiv2026

Bifurcation dynamics in a shared network beyond sensory areas characterize conscious auditory perception independently of report

The neural correlates of conscious perception remain debated, particularly regarding the role of extra-sensory regions such as the prefrontal cortex. One promising approach is to study the dynamical properties of neural processing in task-related and task-free contexts. A previous EEG study showed that conscious perception is associated with all-or-none late activations, giving rise to bifurcation dynamics even without a task. Here we used fMRI and near-threshold auditory stimulation to ask which brain networks give rise to these bifurcations, and how they differ depending on task. In both contexts, stimulus intensity modulated activity within broad networks spanning sensory and extra-sensory regions, including the prefrontal cortex. These networks showed both shared and distinct components. Single-trial modelling further revealed bifurcation dynamics beyond primary sensory cortices and enabled single-trial prediction of conscious perception in both contexts. These findings resolve previous conflicting results and reveal common networks and dynamics underlying conscious perception irrespective of task.

neuroscience↗

bioRxiv2026

FAST BOLD FMRI REVEALS THE SPATIOTEMPORAL COMPLEXITY OF NEUROVASCULAR COUPLING ALTERATIONS IN CEREBRAL SMALL VESSEL DISEASE

Recent advances in neurophysiology highlighted the potential of high temporal resolution in Blood-Oxygen Level Dependent (BOLD) functional MRI (fMRI), although it is not yet standard practice. We demonstrated that fast BOLD fMRI can detect single-subject, single-stimulus visually evoked responses to brief stimuli at 3T. We used fast fMRI in patients with Cerebral Autosomal Dominant Arteriopathy with Subcortical Infarcts and Leukoencephalopathy (CADASIL), a genetic form of cerebral small vessel disease (cSVD). Using 2- and 10-second visual stimuli, we probed different neurovascular coupling regimes and showed that different regions of interest detect different facets of vascular dynamics. CADASIL patients showed significant changes in the amplitude and timing of the BOLD response, indicating early-age neurovascular impairment unrelated to anatomical lesions, and providing strong discriminative and generalization performance. These findings resolve prior inconsistencies in fMRI studies of CADASIL, supporting the use of fast fMRI to develop non-invasive biomarkers for cSVD and other neurodegenerative disorders.

neuroscience↗

bioRxiv2026

Functional cerebellar connectomes interfacing motor adaptation and reinforcement feedback

Motor adaptation is driven by sensory prediction errors, yet reinforcement feedback can alter the speed and retention of adaptive behaviors. The cerebellum is central in motor adaptation, but posterior lobules, especially Lobule VI (CB6) and Crus I (CBcrus1), also participate in reinforcement-related signaling. Serotoninergic and dopaminergic systems, key modulators of motivational processes, directly influence cerebellar activity. However, how these neuromodulatory systems contribute to cerebellar network organization and to reinforcement-based adaptation in humans remains unclear. We employed a multimodal framework (Receptor-Enriched Analysis of functional Connectivity by Targets; REACT) using PET-derived Serotonin/Dopamine Transporter (SERT/DAT) templates to enrich resting-state functional Magnetic Resonance Imaging (rs-fMRI). We estimated SERT- and DAT-enriched functional connectivity from CB6 and CBcrus1 within motor-adaptation and reinforcement-learning networks, and tested their correlations with performance in a visuomotor adaptation task completed under reward and punishment. Our findings show lobule-specific neuromodulatory organization within the cerebellum. CB6 exhibited predominantly DAT- and SERT-enriched connectivity with motor adaptation networks, while CBcrus1 showed stronger SERT-enriched communication extending to both motor and reinforcement networks. Crucially, distinct cerebello-cortical neuromodulatory networks predicted individual differences in adaptation rate. DAT-enriched CBcrus1 connectivity was linked to punishment-driven adaptation, whereas SERT-enriched cerebello-orbitofrontal connectivity predicted faster adaptation across both reward and punishment contingencies. Furthermore, we observed overlaps between SERT- and DAT-enriched networks in the medial orbitofrontal area for Crus I, which predicted retention following punishment, underscoring the role of convergent neuromodulation in stabilizing adapted movements. We conclude that partially segregated yet convergent cerebello-cortical networks support interactions between motor and motivational behaviors, with combined and opposing effects of serotonergic and dopaminergic neuromodulation accounting for the speed and retention of adaptive behaviors.

neuroscience↗

bioRxiv2026

From default to creativity: prefrontal and cerebellar contributions of the default mode network to goal-directed remote thinking

Creativity is a hallmark of human cognition, characterized by the ability to connect seemingly distant concepts or ideas. Existing theories suggest that remote thinking can be achieved either spontaneously (constrained by the structure of semantic memory) or in a goal-directed manner (constrained by a creative goal). The present study investigates the neural correlates of goal-directed remote thinking, defined as the intentional production of semantically distant associations. Using a simple word-to-word association task comprising both a spontaneous condition and a goal-directed creative condition, we investigated Goal-directed Remoteness as the extra semantic distance traveled away from spontaneous responses when instructed to think creatively. Task-based functional MRI in 38 healthy young adults identified brain regions whose activation scaled with Goal-directed Remoteness. The results revealed that activity in the rostromedial and dorsomedial prefrontal cortex and the right cerebellar Crus I & II was positively modulated by Goal-directed Remoteness. Control analyses confirmed the robustness of these findings independently of the cue-words semantic or linguistic properties. Follow-up seed-based resting-state functional connectivity analyses characterized the intrinsic connectivity profiles of the revealed regions. They showed that rostromedial and dorsomedial prefrontal and cerebellar Crus I & II regions formed a functionally interconnected network primarily overlapping with the default-mode network (DMN). Our findings challenge the traditional view of the DMN as supporting only passive or spontaneous cognition. Instead, they reveal a prefronto-cerebellar DMN subnetwork supporting goal-directed remote thinking, a key component of creative cognition. Within this network, the rostromedial and dorsomedial prefrontal cortex and cerebellar Crus I & II play an active role in the intentional generation of connections between distant concepts.

neuroscience↗

bioRxiv2026

Neural investigation of idea selection during creative thinking reveals value-based mechanisms

Creative thinking enables humans to innovate and solve problems, via the generation of candidate ideas, their evaluation and the selection of the most promising one. While recent studies have demonstrated that idea evaluation relies on the assignment of subjective values (the assessment of how much one likes an idea, or valuation), the selection mechanism remains unknown. Using behavioral experiments and fMRI, we tested whether the selection step of creative thinking is driven by the same value comparison circuits that guide economic decisions. Participants performed creative idea production, rating, and choice tasks. We found behavioral evidence of value-based comparison during both isolated choice and overall creative idea production, in a manner that predicts creative abilities. Critically, we demonstrate that creative idea selection involves the brain valuation system and the dorsal anterior cingulate cortex: during creative thinking, these neural circuits compare candidate idea values, mirroring economic choice. Our findings reveal that idea selection is mediated by the brains generic valuation system, rather than specialized creative machinery, unifying theories of decision-making and creativity.

neuroscience↗

bioRxiv2024

Creativity involves the subjective valuation of ideas via the Brain Valuation System.

Creative thinking is composed of a generation phase, where individuals form candidate ideas, and an evaluation phase, where individuals monitor the quality of their ideas, in terms of both their originality and adequacy, to select the best one. Here, we conceptualize creative evaluation as a specific type of decision-making, where participants attribute subjective values to ideas to guide their choice. Yet, while subjective values and preferences have been the focus of many studies in classical decision-making, their involvement in creative decision-making remains largely unexplored. Combining creative generation tasks and rating tasks, the present study demonstrates that individuals assign subjective values to ideas and that these values depend on a relative balance of the ideas originality and adequacy, which is determined by individual preferences and predicts their creative abilities. Using functional Magnetic Resonance Imaging, we found that the human reward system encodes the subjective value of ideas, and that the Default Mode and the Executive Control Networks, rather than being split into idea generation and evaluation, respectively reflect the originality and adequacy of ideas. Interestingly, the relative functional connectivity of the Default Mode and Executive Control Networks with the human reward system correlates with the relative balance of adequacy and originality in individuals preferences. These results bridge a gap in the current literature by providing new evidence regarding the neural bases for originality and adequacy monitoring and add valuation to the incomplete behavioral and neural accounts of creativity, offering perspectives on the influence of individual preferences on creative abilities.

neuroscience↗

bioRxiv2024

Dynamic connectivity profiles characteristic of conscious states are associated with enhanced conscious processing of external stimuli

One of the goals of the neuroscience of consciousness is to identify neural markers capable of distinguishing brain dynamics in awake, healthy individuals from unconscious conditions. This problem also has a clinical diagnostic interest in disorders of consciousness. Recent research has shown that brain connectivity patterns characterized by long-range interactions and anticorrelations are associated with conscious states and diminish with loss of consciousness in human and non-human primates. However, the precise contribution of these patterns to conscious processing and subjective experience formation remains unclear. In this study, we investigated the functional role of these brain patterns in shaping conscious content by examining their influence on participants ability to process external information during wakefulness. Participants underwent fMRI recordings during an auditory detection task. Phase coherence-based functional connectivity and k-means clustering confirmed that the ongoing dynamics were underpinned by brain patterns consistent with those identified in previous research, including the "high pattern" characteristic of conscious states. We found that the detection of auditory stimuli at threshold was specifically improved when the connectivity pattern at the time of presentation corresponded to this high-pattern. In return, the occurrence of the high-pattern increased after detection, indicating that participants were more likely to transition to a high-pattern following stimulus detection. Our findings suggest that ongoing brain dynamics and conscious perception mutually influence each other and that certain brain configurations are more favorable for conscious processing of external stimuli. In the future, targeting these moments of favorable patterns in patients with disorders of consciousness may help us identify windows of greater receptivity to the external world, paving the way for developing individualized patient care protocols.

neuroscience↗

bioRxiv2021

Brain connectivity-based prediction of real-life creativity is mediated by semantic memory structure

Creative cognition relies on the ability to form remote associations between concepts, which allows to generate novel ideas or solve new problems. Such an ability is related to the organization of semantic memory; yet whether real-life creative behavior relies on semantic memory organization and its neural substrates remains unclear. Therefore, this study explored associations between brain functional connectivity patterns, network properties of individual semantic memory, and real-life creativity. We acquired multi-echo functional MRI data while participants underwent a semantic relatedness judgment task. These ratings were used to estimate their individual semantic memory networks, whose properties significantly predicted their real-life creativity. Using a connectome-based predictive modeling approach, we identified patterns of task-based functional connectivity that predicted creativity-related semantic memory network properties. Furthermore, these properties mediated the relationship between functional connectivity and real-life creativity. These results provide new insights into how brain connectivity supports the associative mechanisms of creativity.

neuroscience↗

bioRxiv2017

Stomach-brain synchrony binds neural representations of the body in a novel, delayed-connectivity resting-state network

Resting-state networks offer a unique window into the brains functional architecture, but their characterization remains limited to instantaneous connectivity thus far. Here, we describe a novel resting-state network based on the delayed connectivity between the brain and the slow electrical rhythm (0.05 Hz) generated in the stomach. The gastric network cuts across classical resting-state networks with little overlap with autonomic regulation areas. This network is composed of regions with convergent functional properties involved in mapping bodily space through touch, action or vision, as well as mapping external space in bodily coordinates. The network is characterized by a precise temporal sequence of activations within a gastric cycle, beginning with somato-motor cortices and ending with the extrastriate body area and dorsal precuneus. Our results demonstrate that canonical resting-state networks based on instantaneous connectivity represent only one of the possible partitions of the brain into coherent networks based on temporal dynamics.

neuroscience↗