The Experts below are selected from a list of 39 Experts worldwide ranked by ideXlab platform
Petr Janata - One of the best experts on this subject based on the ideXlab platform.
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Music and the self
2015Co-Authors: Petr JanataAbstract:Aswe pass through life we interact with and experiencemusic inmanyways. Sometimes we pay attention to it; other times we do not. Often we move along with music, not only as performers but also as engaged listeners who tap their feet, bob their heads, or simply follow the music with their minds. Perhaps for most, music intertwines itself with our life narratives. Hearing songs from our past often evokes vivid memories and strong emotions (Sloboda and ONeill 2001, Juslin and Laukka 2004, Janata et al. 2007). Given the many ways in which we experiencemusic, and the central role it plays in cultures around the world, one is drawn to the questions of why music engages the human brain so strongly and how it is that the brain enables these various forms of musical experience? Part of answering these questions depends on understanding what constellations of brain Areas might allow music to interact so profoundly with the self. In other words, what are the brain Areas that allow music to move us or to evoke such strong memories? In this article I suggest a context for thinking about these questions. The context is derived from the broader neuroimaging literature and it emphasizes the contrapuntal roles of two classes of brain networks, one for engagement with the external world and the other for engagement with ones own thoughts, memories, and emotions. 8.1. A network for external engagement The best studied and understood of the networks is the network generally associated with cognitive functions of language, semantics, working memory, imagery, attention, error-monitoring, and preparation of near-term action sequences (see Cabeza and Nyberg 2000, Corbetta and Shulman 2002, Janata and Grafton 2003, Ridderinkhof et al. 2004, Rushworth et al. 2004 for reviews). The principal regions of this network are parietal Areas around the intra-parietal sulcus (IPS), and regions surrounding the inferior frontal gyrus, in particular dorsolateral prefrontal cortex (DLPFC) and ventrolateral prefrontal cortex (VLPFC). This Area is commonly known as Brocas Area and serves a variety of sequencing functions (Fiebach and Schubotz 2006). The action portions of this network include both medial Areas – the supplementary motor Area (SMA) and pre-SMA – and lateral premotor corte
Aleman Andre - One of the best experts on this subject based on the ideXlab platform.
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When Broca Goes Uninformed:Reduced Information Flow to Brocas Area in Schizophrenia Patients With Auditory Hallucinations
2013Co-Authors: Curcic-blake Branislava, Liemburg Edith, Vercammen Ans, Swart Marte, Knegtering Henderikus, Bruggeman Richard, Aleman AndreAbstract:Auditory-verbal hallucinations (AVHs) are frequently associated with activation of the left superior temporal gyrus (including Wernickes Area), left inferior frontal gyrus (including Brocas Area), and the right hemisphere homologs of both Areas. It has been hypothesized that disconnectivity of both interhemispheric transfer and frontal and temporal Areas may underlie hallucinations in schizophrenia. We investigated reduced information flow in this circuit for the first time using dynamic causal modeling, which allows for directional inference. A group of healthy subjects and 2 groups of schizophrenia patientsuwith and without AVHuperformed a task requiring inner speech processing during functional brain scanning. We employed connectivity models between left hemispheric speech-processing Areas and their right hemispheric homologs. Bayesian model averaging was used to estimate the connectivity strengths and evaluate group differences. Patients with AVH showed significantly reduced connectivity from Wernickes to Brocas Area (97% certainty) and a trend toward a reduction in connectivity from homologs of Brocas and Wernickes Areas to Brocas Area (93% and 94% certainty). The connectivity magnitude in patients without hallucinations was found to be intermediate. Our results point toward a reduced input from temporal to frontal language Areas in schizophrenia patients with AVH, suggesting that Brocas activity may be less constrained by perceptual information received from the temporal cortex. In addition, a lack of synchronization between Broca and its homolog may lead to the erroneous interpretation of emotional speech activity from the right hemisphere as coming from an external source.
Leggio Maria - One of the best experts on this subject based on the ideXlab platform.
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Impact of cerebellar atrophy on cortical grey matter and cerebellar peduncles as assessed by voxel based morphometry and high angular resolution diffusion imaging
'CIC Edizioni Internazionali', 2016Co-Authors: Michael Dayan, Giusy Olivito, Marco Molinari, Mara Cercignani, Marco Bozzali, Leggio MariaAbstract:Aims: Since recent years the cerebellum has been attributed a more impor¬tant role in higher level functions than previously believed. We examined a cohort of patients suffering from cerebellar atrophy and resulting in ataxia to investigate not only which regions of the cerebrum were affected but also if diffusion magnetic resonance imaging (dMRI) metrics within the medial (MCP) and superior cerebellar peduncle (SCP), namely fractional anisotropy (FA) and radial diffusivity (RD), could be used as a biomarker in patients suf¬fering from this condition. Methods: Structural and dMRI data of 7 patients (2 spinocerebellar atrophy type 2, 1 Friedreichs ataxia, 4 unknown etiol¬ogy) with cerebellar atrophy and without visible cortical lesions and cortical atrophy were investigated with voxel based morphometry (VBM) of both GM as well as MCP and SCP FA maps. Correlation between MCP and SCP mean FA with ataxia scores and subscores was also evaluated. Results: VBM demonstrated significantly lower GM density in patients, notably in the head of the caudate nucleus, posterior cingulate gyrus and orbito-frontal cortex bilaterally, as well as in Brocas Area in the left hemisphere, and sig-nificant RD increase in the MCP and SCP of each hemisphere. Correlation was found significant between MCP mean FA and total ataxia score (R=- 0.7, p=0.03), and coordination [R=-0.74 , p=0.03] and oculomotor [R=-0.70, p=0.04] subscores. Discussion and conclusion: Regions of the cerebrum with significantly lower GM density have been described to be involved in initia¬tion of voluntary movements, emotional control, memory retrieval and gen¬eral cognition, which supports recent findings pointing at an important role played by the cerebellum in higher level functions. The significant difference in the MCP and SCP dMRI metrics between patients and controls as well as the significant correlation with ataxia total score and subscores supports the use of dMRI metrics as an imaging biomarker for cerebellar degeneration and ataxia
Hodges, John R, Neuroscience Research Australia, Faculty Of Medicine Unsw - One of the best experts on this subject based on the ideXlab platform.
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The relationship between clinical and pathological variables in Richardson's syndrome
'Springer Science and Business Media LLC', 2012Co-Authors: Schofield, Emma C, Neuroscience Research Australia, Faculty Of Medicine Unsw, Hodges, John R, Neuroscience Research Australia, Faculty Of Medicine Unsw, Thomas H Bak, Xuereb, John H, Department Of Pathology, University Of Cambridge U.k.Abstract:In order to determine the relationship between regional neuropathology and severity of clinical features in Richardsons syndrome (PSP-RS), the following hypotheses were tested; 1) executive dysfunction relates to prefrontal pathology; 2) language difficulties to pathology in Brocas Area and/or the perirhinal cortex and 3) visuospatial impairment to pathology in the supramarginal region. A prospectively studied case series of brain donors at a specialist clinic in Addenbrookes Hospital Cambridge, UK, were examined. All those fulfilling postmortem criteria for PSP-RS and their last cognitive assessment within 24 months of death (N=11/25) were included. The degree of regional neuronal loss and neuronal tau deposition across a number of cortical brain regions was performed and compared to 10 age and sex matched controls from the Sydney Brain Bank. Stepwise multiple linear regressions were used to determine the neuropathological correlates to cognitive scores and revealed the following. Executive dysfunction, as indexed by letter fluency, related to the degree of tau deposition in the superior frontal gyrus and supramarginal cortices (p
Neggers, Sebastiaan F. W. - One of the best experts on this subject based on the ideXlab platform.
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Auditory verbal hallucinations predominantly activate the right inferior frontal Area
2008Co-Authors: Sommer, Iris E. C., Diederen, Kelly M. J., Blom Jan-dirk, Willems Anne, Kushan Leila, Slotema Karin, Boks, Marco P. M., Daalman Kirstin, Hoek, Hans W., Neggers, Sebastiaan F. W.Abstract:The pathophysiology of auditory verbal hallucinations (AVH) is largely unknown. Several functional imaging studies have measured cerebral activation during these hallucinations, but sample sizes were relatively small (one to eight subjects) and findings inconsistent. In this study cerebral activation was measured using fMRI in 24 psychotic patients while they experienced AVH in the scanner and, in another session, while they silently generated words. All patients were right handed and diagnosed with schizophrenia, schizo-affective disorder or psychotic disorder not otherwise specified. Group analysis for AVH revealed activation in the right homologue of Brocas Area, bilateral insula, bilateral supramarginal gyri and right superior temporal gyrus. Brocas Area and left superior temporal gyrus were not activated. Group analysis for word generation in these patients yielded activation in Brocas and Wernickes Areas and to a lesser degree their right-sided homologues, bilateral insula and anterior cingulate gyri. Lateralization of activity during AVH was not correlated with language lateralization, but rather with the degree to which the content of the hallucinations had a negative emotional valence. The main difference between cerebral activity during AVH and activity during normal inner speech appears to be the lateralization. The predominant engagement of the right inferior frontal Area during AVH may be related to the typical low semantic complexity and negative emotional content
