bioRxiv Science⌕ Search

Biology subjects

Volle, E.

Publications and source records attributed to Volle, E..

8 recordsLinked to original sources

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↗

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↗

How subjective idea valuation energizes and guides creative idea generation

What drives us to search for creative ideas, and why does it feel good to find one? While previous studies demonstrated the positive influence of motivation on creative abilities, how reward and subjective values play a role in creativity remains unknown. This study proposes to characterize the role of individual preferences (how people value ideas) in creative ideation via behavioral experiments and computational modeling. Using the Free Generation of Associates Task coupled with rating tasks, we demonstrate the involvement of valuation processes during idea generation: preferred ideas are provided faster. We found that valuation depends on the adequacy and originality of ideas and guides response selection and creativity. Finally, our computational model correctly predicts the speed and quality of human creative responses, as well as interindividual differences in creative abilities. Altogether, this model introduces the mechanistic role of valuation in creativity. It paves the way for a neurocomputational account of creativity mechanisms. Public Significance StatementThis study addresses the role of individual preferences in creativity. It demonstrates that preferences for ideas energize creative idea production: the more participants like their ideas, the faster they provide them. Moreover, preferences rely on an equilibrium between the adequacy and originality of ideas and vary across individuals. This study introduces a computational model which incorporates individual preferences and that correctly predicts the speed and quality of responses in a creative idea generation task, as well as inter-individual differences in creative abilities. Comparison of several versions of this model demonstrated that preferences guide the selection of creative responses.

neuroscience↗

Time course of EEG power during creative problem-solving with insight or remote thinking

Problem-solving often requires creativity and is critical in everyday life. However, the neurocognitive mechanisms underlying creative problem-solving remain poorly understood. Two mechanisms have been highlighted: forming new connections from and between the problem elements and insight solving (with a sudden realization of a solution). We examined EEG activity during an adapted version of a classical insight problem task, the Remote Associates Test, that requires finding a word connecting three words. It allowed us to explore remoteness in semantic connections (by varying the remoteness of the solution word across trials) and insight solving (identified as a "Eureka" moment reported by the participants). Semantic remoteness was associated with a power increase in alpha band (8-12Hz) in a left parieto-temporal cluster, beta band (13-30Hz) in a right fronto-temporal cluster in the early phase of the task, and theta band (3-7Hz) in frontal cluster before the participants responded. Insight solving was associated with power increase preceding the response in alpha and gamma band (31-60Hz) in left temporal clusters and theta band in a frontal cluster. Source reconstructions show the brain regions associated with these clusters. Overall, our findings shed new light on the dynamic of some of the mechanisms involved in creative problem-solving.

neuroscience↗

Subcortical Anatomy of the Default Mode Network: a functional and structural connectivity study

Most existing research into the default-mode network (DMN) has taken a corticocentric approach. Despite the resemblance of the DMN with the unitary model of the limbic system, the anatomy and contribution of subcortical structures to the network may be underappreciated due to methods limitation. Here, we propose a new and more comprehensive neuroanatomical model of the DMN including the basal forebrain and anterior and mediodorsal thalamic nuclei and cholinergic nuclei. This has been achieved by considering functional territories during interindividual brain alignment. Additionally, tractography of diffusion-weighted imaging was employed to explore the structural connectivity of the DMN and revealed that the thalamus and basal forebrain had high importance in term of values of node degree and centrality in the network. The contribution of these neurochemically diverse brain nuclei reconciles previous neuroimaging with neuropathological findings in diseased brain and offers the potential for identifying a conserved homologue of the DMN in other mammalian species.

neuroscience↗

Anterior temporal lobe morphometry predicts categorization ability

Categorization is the mental operation by which the brain classifies objects and events. It is classically assessed using semantic and non-semantic matching or sorting tasks. These tasks show a high variability in performance across healthy controls and the cerebral bases supporting this variability remain unknown. In this study we performed a voxel-based morphometry study to explore the relationships between semantic and shape categorization tasks and brain morphometric differences in 50 controls. We found significant correlation between categorization performance and the volume of the grey matter in the right anterior middle and inferior temporal gyri. Semantic categorization tasks were associated with more rostral temporal regions than shape categorization tasks. A significant relationship was also shown between white matter volume in the right temporal lobe and performance in the semantic tasks. Tractography revealed that this white matter region involved several projection and association fibers, including the arcuate fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, and inferior longitudinal fasciculus. These results suggest that categorization abilities are supported by the anterior portion of the right temporal lobe and its interaction with other areas.\n\nHighlightsO_LIAnterior temporal lobe morphometry correlates with categorization performances\nC_LIO_LISemantic is associated with a more rostral temporal region than shape categorization\nC_LIO_LISemantic categorization performances are associated with right temporal connections\nC_LI

neuroscience↗

"A mosquito bites and a butterfly flies": a specific response type of frontal patients in a similarity task

BackgroundPatients with neurodegenerative diseases affecting the frontal lobes have difficulties in categorization tasks, such as the similarity tasks. They give two types of unusual response to the question: \"In what way are an orange and a banana alike?\", either a differentiation (\"one is yellow, the other is orange\") or a concrete similarity (\"they are sweet\").\n\nObjectiveTo characterize the categorization deficit of frontal patients and develop a short diagnostic tool to assess the nature of these difficulties.\n\nMethodWe analyzed the responses provided by frontal and non-frontal neurodegenerative patients in a novel verbal similarity task (SimiCat). We included 40 frontal patients with behavioral variant fronto-temporal dementia (bvFTD) and progressive supranuclear palsy (PSP), 23 patients with Alzheimers disease (AD) and 41 healthy matched controls. Responses that did not correspond to the expected taxonomic category (e.g.: fruits) were considered as errors.\n\nResultsAll patients groups were impaired at the SimiCat test compared to controls. Differentiation errors were specific of frontal patients. Receiver operating characteristic analyses showed that a cut-off of two differentiation errors or more achieved 85% sensitivity of 100% specificity to discriminate bvFTD from AD. A short version of the test (<5 min) showed similar discriminative validity as the full version.\n\nConclusionDifferentiation responses were specific of frontal patients. The SimiCat demonstrates good discriminative validity to differentiate bvFTD and AD. The short version of the test is a promising diagnostic tool that will need validation in future studies.

neuroscience↗

Advanced Lesion Symptom Mapping Analyses And Implementation As BCBtoolkit

BackgroundPatients with brain lesions provide a unique opportunity to understand the functioning of the human mind. However, even when focal, brain lesions have local and remote effects that impact functionally and structurally connected circuits. Similarly, function emerges from the interaction between brain areas rather than their sole activity. For instance, category fluency requires the association between executive, semantic and language production functions.\n\nFindingsHere we provide, for the first time, a set of complementary solutions to measure the impact of a given lesion upon the neuronal circuits. Our methods, which were applied to 37 patients with a focal frontal brain lesion, revealed a large set of directly and indirectly disconnected brain regions that had significantly impacted category fluency performance. The directly disconnected regions corresponded to areas that are classically considered as functionally engaged in verbal fluency and categorization tasks. These regions were also organized into larger directly and indirectly disconnected functional networks, including the left ventral fronto-parietal network, whose cortical thickness correlated with performance on category fluency.\n\nConclusionsThe combination of structural and functional connectivity together with cortical thickness estimates reveals the remote effects of brain lesions, provide for the identification of the affected networks and strengthen our understanding of their relationship with cognitive and behavioural measures. The methods presented are available and freely accessible in the BCBtoolkit as supplementary software (http://toolkit.bcblab.com).

neuroscience↗