Search results for "neuroimaging"
showing 10 items of 281 documents
Dynamic Functional Connectivity Captures Individuals’ Unique Brain Signatures
2020
Recent neuroimaging evidence suggest that there exists a unique individual-specific functional connectivity (FC) pattern consistent across tasks. The objective of our study is to utilize FC patterns to identify an individual using a supervised machine learning approach. To this end, we use two previously published data sets that comprises resting-state and task-based fMRI responses. We use static FC measures as input to a linear classifier to evaluate its performance. We additionally extend this analysis to capture dynamic FC using two approaches: the common sliding window approach and the more recent phase synchrony-based measure. We found that the classification models using dynamic FC pa…
Concept of Spectrobiopsy Facing Gliomas: Rational and Future Perspectives Related to Target Therapy
2020
Gliomas represent the most common primary intracranial tumors with an estimated incidence of 31% of all central nervous system neoplasms. Lesions originated from glial cells are extremely heterogeneous, ranging from low grade to high grade with different clinical and biological malignancy. Glioblastoma multiforme (GBM) is the most aggressive and frequent primary malignant tumor of the central nervous system in adults. Even though in the past decades considerable efforts have been made in the therapeutic management of this type of tumor,2 the prognosis after diagnosis of GBM remains extremely poor, reaching a median overall survival of 12–18 months. In 2016 the World Health Organization clas…
Magnetic Resonance Spectrobiopsy for Prediction of Isocitrate Dehydrogenase Mutation in Glioma
2020
Despite the existence of multimodal therapy paradigm, high-grade gliomas (HGGs) remain devastating tumors associated with one of the worst prognoses. Glioblastoma (GBM) is the most frequent reported histologic type with a median survival, after surgery and combined treatment with chemotherapy and radiotherapy, ranging from 12 to 16 months. The poor prognosis is due to the lack of therapeutic efficacy of chemical agents and irradiation in hypoxic tumor areas. Experimental studies have investigated several molecules with the aim to counteract several downstream signaling important in tumor progression, unfortunately without conclusive results. Several studies have shown that the extent of res…
Inattention and Uncertainty in the Predictive Brain
2021
Negative effects of inattention on task performance can be seen in many contexts of society and human behavior, such as traffic, work, and sports. In traffic, inattention is one of the most frequently cited causal factors in accidents. In order to identify inattention and mitigate its negative effects, there is a need for quantifying attentional demands of dynamic tasks, with a credible basis in cognitive modeling and neuroscience. Recent developments in cognitive science have led to theories of cognition suggesting that brains are an advanced prediction engine. The function of this prediction engine is to support perception and action by continuously matching incoming sensory input with to…
Aberrant Subnetwork and Hub Dysconnectivity in Adult Bipolar Disorder: A Multicenter Graph Theory Analysis
2021
Abstract Neuroimaging evidence implicates structural network-level abnormalities in bipolar disorder (BD); however, there remain conflicting results in the current literature hampered by sample size limitations and clinical heterogeneity. Here, we set out to perform a multisite graph theory analysis to assess the extent of neuroanatomical dysconnectivity in a large representative study of individuals with BD. This cross-sectional multicenter international study assessed structural and diffusion-weighted magnetic resonance imaging data obtained from 109 subjects with BD type 1 and 103 psychiatrically healthy volunteers. Whole-brain metrics, permutation-based statistics, and connectivity of h…
Interindividual synchronization of brain activity during live verbal communication
2013
Verbal social interaction plays an important role both in the etiology and treatment of psychiatric disorders. However, the neural basis of social interaction has primarily been studied in the individual brain, neglecting the inter-individual perspective. Here, we show inter-individual neuronal coupling of brain activity during live verbal interaction, by investigating 11 pairs of good female friends who were instructed to speak about autobiographical life events during simultaneous fMRI acquisition. The analysis revealed that the time course of neural activity in areas associated with speech production was coupled with the time course of neural activity in the interlocutor's auditory corte…
Spatiotemporal Neurodynamics Underlying Internally and Externally Driven Temporal Prediction: A High Spatial Resolution ERP Study
2015
Abstract Temporal prediction (TP) is a flexible and dynamic cognitive ability. Depending on the internal or external nature of information exploited to generate TP, distinct cognitive and brain mechanisms are engaged with the same final goal of reducing uncertainty about the future. In this study, we investigated the specific brain mechanisms involved in internally and externally driven TP. To this end, we employed an experimental paradigm purposely designed to elicit and compare externally and internally driven TP and a combined approach based on the application of a distributed source reconstruction modeling on a high spatial resolution electrophysiological data array. Specific spatiotemp…
Seeking the “Beauty Center” in the Brain: A Meta-Analysis of fMRI Studies of Beautiful Human Faces and Visual Art
2020
AbstractThe existence of a common beauty is a long-standing debate in philosophy and related disciplines. In the last two decades, cognitive neuroscientists have sought to elucidate this issue by exploring the common neural basis of the experience of beauty. Still, empirical evidence for such common neural basis of different forms of beauty is not conclusive. To address this question, we performed an activation likelihood estimation (ALE) meta-analysis on the existing neuroimaging studies of beauty appreciation of faces and visual art by non-expert adults (49 studies, 982 participants, meta-data are available at https://osf.io/s9xds/). We observed that perceiving these two forms of beauty a…
Dynamic image denoising for voxel-wise quantification with Statistical Parametric Mapping in molecular neuroimaging.
2018
Purpose PET and SPECT voxel kinetics are highly noised. To our knowledge, no study has determined the effect of denoising on the ability to detect differences in binding at the voxel level using Statistical Parametric Mapping (SPM). Methods In the present study, groups of subject-images with a 10%- and 20%- difference in binding of [123I]iomazenil (IMZ) were simulated. They were denoised with Factor Analysis (FA). Parametric images of binding potential (BPND) were produced with the simplified reference tissue model (SRTM) and the Logan non-invasive graphical analysis (LNIGA) and analyzed using SPM to detect group differences. FA was also applied to [123I]IMZ and [11C]flumazenil (FMZ) clinic…
Clinical and neuroimaging findings in 33 patients with MCAP syndrome: A survey to evaluate relevant endpoints for future clinical trials
2021
Megalencephaly-CApillary malformation-Polymicrogyria (MCAP) syndrome results from somatic mosaic gain-of-function variants in PIK3CA. Main features are macrocephaly, somatic overgrowth, cutaneous vascular malformations, connective tissue dysplasia, neurodevelopmental delay, and brain anomalies. The objectives of this study were to describe the clinical and radiological features of MCAP, to suggest relevant clinical endpoints applicable in future trials of targeted drug therapy. Based on a French collaboration, we collected clinical features of 33 patients (21 females, 12 males, median age of 9.9 years) with MCAP carrying mosaic PIK3CA pathogenic variants. MRI images were reviewed for 21 pat…