1,721,476 research outputs found
Shared and specific neural correlates of attention deficit hyperactivity disorder and autism spectrum disorder: a meta-analysis of 243 task-based functional MRI studies
No full textObjective: to investigate shared and specific neural correlates of cognitive functions in attention deficit hyperactivity disorder (ADHD) and autism spectrum disorder (ASD), the authors performed a comprehensive meta-analysis and considered a balanced set of neuropsychological tasks across the two disorders. Methods: a broad set of electronic databases was searched up to December 4, 2022, for task-based functional MRI studies investigating differences between individuals with ADHD or ASD and typically developing control subjects. Spatial coordinates of brain loci differing significantly between case and control subjects were extracted. To avoid potential diagnosis-driven selection bias of cognitive tasks, the tasks were grouped according to the Research Domain Criteria framework, and stratified sampling was used to match cognitive component profiles. Activation likelihood estimation was used for the meta-analysis. Results: after screening 20,756 potentially relevant references, a meta-analysis of 243 studies was performed, which included 3,084 participants with ADHD (676 females), 2,654 participants with ASD (292 females), and 6,795 control subjects (1,909 females). ASD and ADHD showed shared greater activations in the lingual and rectal gyri and shared lower activations in regions including the middle frontal gyrus, the parahippocampal gyrus, and the insula. By contrast, there were ASD-specific greater and lower activations in regions including the left middle temporal gyrus and the left middle frontal gyrus, respectively, and ADHD-specific greater and lower activations in the amygdala and the global pallidus, respectively.Conclusions : although ASD and ADHD showed both shared and disorder-specific standardized neural activations, disorder-specific activations were more prominent than shared ones. Functional brain differences between ADHD and ASD are more likely to reflect diagnosis-related pathophysiology than bias from the selection of specific neuropsychological tasks.</p
What's in a smile? Neural correlates of facial embodiment during social interaction
No full textPrevious investigations have shown that the perception of socially relevant facial expressions, indicating someone else's intention to communicate (e.g., smiling), correlate with increased activity in zygomaticus major muscle regardless of whether the facial expressions seen are directed towards the human observer or toward someone else (Mojzisch et al., 2006). These spontaneous, involuntary reactions have been described as facial mimicry and seem to be of considerable importance for successful interpersonal communication. We investigated whether specific neural substrates underlie these responses by performing a finite impulse response (FIR) analysis of an experiment using functional magnetic resonance imaging (fMRI) to investigate the perception of socially relevant facial expressions (Schilbach et al., 2006). This analysis demonstrates that differential neural activity can be detected relative to the FIR time window in which facial mimicry occurs. The neural network found includes but extends beyond classical motor regions (face motor area) recruiting brain regions known to be involved in social cognition. This network is proposed to subserve the integration of emotional and action-related processes as part of a pre-reflective, embodied reaction to the perception of socially relevant facial expressions as well as a reflective representation of self and other
Naturalizing aesthetics: Brain areas for aesthetic appraisal across sensory modalities
Get PDFWe present here the most comprehensive analysis to date of neuroaesthetic processing by reporting the results of voxel-based meta-analyses of 93 neuroimaging studies of positive-valence aesthetic appraisal across four sensory modalities. The results demonstrate that the most concordant area of activation across all four modalities is the right anterior insula, an area typically associated with visceral perception, especially of negative valence (disgust, pain, etc.). We argue that aesthetic processing is, at its core, the appraisal of the valence of perceived objects. This appraisal is in no way limited to artworks but is instead applicable to all types of perceived objects. Therefore, one way to naturalize aesthetics is to argue that such a system evolved first for the appraisal of objects of survival advantage, such as food sources, and was later co-opted in humans for the experience of artworks for the satisfaction of social needs
To you I am listening: Perceived competence of advisors influences judgment and decision-making via recruitment of the amygdala
No full textConsidering advice from others is a pervasive element of human social life. We used the judge-advisor paradigm to investigate the neural correlates of advice evaluation and advice integration by means of functional magnetic resonance imaging. Our results demonstrate that evaluating advice recruits the 'mentalizing network,' brain regions activated when people think about others' mental states. Important activation differences exist, however, depending upon the perceived competence of the advisor. Consistently, additional analyses demonstrate that integrating others' advice, i.e., how much participants actually adjust their initial estimate, correlates with neural activity in the centromedial amygdala in the case of a competent and with activity in visual cortex in the case of an incompetent advisor. Taken together, our findings, therefore, demonstrate that advice evaluation and integration rely on dissociable neural mechanisms and that significant differences exist depending upon the advisor's reputation, which suggests different modes of processing advice depending upon the perceived competence of the advisor
Going Beyond Counting First Authors in Author Co-citation Analysis
Get PDFThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
dMRI: Diffusion Magnetic Resonance Imaging as a Window onto Structural Brain Networks and White Matter Microstructure
No full textDiffusion magnetic resonance imaging (dmri) can be used to probe the connectivity and microstructure of human brain tissue non-invasively in vivo. The diffusion-weighted mr signal has sensitivity to micrometer-scale tissue properties averaged over the imaging voxel size, for example, intra-cellular and extra-cellular volumes and the 3d orientations of axonal bundles. It derives its contrast from sensitivity to the bulk displacement of water through what is known as thermal motion, brownian motion, or passive (self-)diffusion. In the brain, cell membranes, organelles, and myelin sheaths create barriers and form biological compartments that constrain the displacement of water molecules, modifying the statistical behavior of bulk diffusion over time. This review therefore focuses on the use of dmri for estimates of the local orientations and estimates of microstructure of fiber tracts, and on an understanding of dmri signal mechanisms and appropriate signal processing and modeling for this purpose. It first discusses basic diffusion mri acquisition principles and diffusion contrast and the constraints the acquisition places on the modeling of diffusion. It then sets out the diffusion tensor model, the most used model in dmri that underlies diffusion tensor imaging, in a way which prepares a discussion of its limitations. The next sections set out advances in dmri beyond dti as focusing on tractography and connectomics, with a need to accurately model spatially complex fiber configurations and on diffusion microstructure, with a need to accurately model restricted diffusion and compartmentalization. Throughout, the emphasis is on a thorough understanding of basic principles and assumptions underlying techniques, as well as their possibilities and limitations for inference of brain connectivity, with a minimum of technical detail and mathematics. This review ends with an outlook on future developments emanating from current trends
Variations on the Author
Get PDF“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Coordinate-based (ALE) meta-analysis of brain activation in patients with fibromyalgia
No full textThere are an increasing number of neuroimaging studies that allow a better understanding of symptoms, neural correlates and associated conditions of fibromyalgia. However, the results of these studies are difficult to compare, as they include a heterogeneous group of patients, use different stimulation paradigms, tasks, and the statistical evaluation of neuroimaging data shows high variability. Therefore, this meta-analytic approach aimed at evaluating potential alterations in neuronal brain activity or structure related to pain processing in fibromyalgia syndrome (FMS) patients, using quantitative coordinate-based “activation likelihood estimation” (ALE) meta-analysis. 37 FMS papers met the inclusion criteria for an ALE analysis (1,264 subjects, 274 activation foci). A pooled ALE analysis of different modalities of neuroimaging and additional analyses according functional and structural changes indicated differences between FMS patients and controls in the insula, amygdala, anterior/mid cingulate cortex, superior temporal gyrus, the primary and secondary somatosensory cortex, and lingual gyrus. Our analysis showed consistent results across FMS studies with potential abnormalities especially in pain-related brain areas. Given that similar alterations have already been demonstrated in patients with other chronic pain conditions and the lack of adequate control groups of chronic pain subjects in most FMS studies, it is not clear however, whether these findings are associated with chronic pain in general or are unique features of patients with FM
Appropriate Similarity Measures for Author Cocitation Analysis
Get PDFWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
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