Search results for "FM"
showing 10 items of 626 documents
Increased Neural Activity in Mesostriatal Regions after Prefrontal Transcranial Direct Current Stimulation and L-DOPA Administration
2019
Dopamine dysfunction is associated with a wide range of neuropsychiatric disorders commonly treated pharmacologically or invasively. Recent studies provide evidence for a nonpharmacological and noninvasive alternative that allows similar manipulation of the dopaminergic system: transcranial direct current stimulation (tDCS). In rodents, tDCS has been shown to increase neural activity in subcortical parts of the dopaminergic system, and recent studies in humans provide evidence that tDCS over prefrontal regions induces striatal dopamine release and affects reward-related behavior. Based on these findings, we used fMRI in healthy human participants and measured the fractional amplitude of low…
Prominence vs. aboutness in sequencing: a functional distinction within the left inferior frontal gyrus
2009
Prior research on the neural bases of syntactic comprehension suggests that activation in the left inferior frontal gyrus (lIFG) correlates with the processing of word order variations. However, there are inconsistencies with respect to the specific subregion within the IFG that is implicated by these findings: the pars opercularisor the pars triangularis. Here, we examined the hypothesis that the dissociation between parsopercularis and pars triangularis activation may reflect functional differences between clause-medial and clause-initial word order permutations, respectively. To this end, we directly compared clause-medial and clause-initial object-before-subject orders in German in a wi…
Dynamics of brain activity underlying working memory for music in a naturalistic condition
2014
We aimed at determining the functional neuroanatomy of working memory (WM) recognition of musical motifs that occurs while listening to music by adopting a non-standard procedure. Western tonal music provides naturally occurring repetition and variation of motifs. These serve as WM triggers, thus allowing us to study the phenomenon of motif tracking within real music. Adopting a modern tango as stimulus, a behavioural test helped to identify the stimulus motifs and build a time-course regressor of WM neural responses. This regressor was then correlated with the participants' (musicians') functional magnetic resonance imaging (fMRI) signal obtained during a continuous listening condition. In…
Metabolic connectivity as index of verbal working memory
2015
Positron emission tomography (PET) data are commonly analyzed in terms of regional intensity, while covariant information is not taken into account. Here, we searched for network correlates of healthy cognitive function in resting state PET data. PET with [18F]-fluorodeoxyglucose and a test of verbal working memory (WM) were administered to 35 young healthy adults. Metabolic connectivity was modeled at a group level using sparse inverse covariance estimation. Among 13 WM-relevant Brodmann areas (BAs), 6 appeared to be robustly connected. Connectivity within this network was significantly stronger in subjects with above-median WM performance. In respect to regional intensity, i.e., metaboli…
Functional connectivity analysis using whole brain and regional network metrics in MS patients
2016
In the present study we investigated brain network connectivity differences between patients with relapsing-remitting multiple sclerosis (RRMS) and healthy controls (HC) as derived from functional resonance magnetic imaging (fMRI) using graph theory. Resting state fMRI data of 18 RRMS patients (12 female, mean age ± SD: 42 ± 12.06 years) and 25 HC (8 female, 29.2 ± 5.38 years) were analyzed. In order to obtain information of differences in entire brain network, we focused on both, local and global network connectivity parameters. And the regional connectivity differences were assessed using regional network parameters. RRMS patients presented a significant increase of modularity in comparis…
Differential expression of specific microRNA and their targets in acute myeloid leukemia
2010
Acute myeloid leukemia (AML) the most common acute leukemia in adults is characterized by various cytogenetic and molecular abnormalities. However, the genetic etiology of the disease is not yet fully understood. MicroRNAs (miRNA) are small noncoding RNAs which regulate the expression of target mRNAs both at transcriptional and translational level. In recent years, miRNAs have been identified as a novel mechanism in gene regulation, which show variable expression during myeloid differentiation. We studied miRNA expression of leukemic blasts of 29 cases of newly diagnosed and genetically defined AML using quantitative reverse transcription polymerase chain reaction (RT-PCR) for 365 human miR…
The temporal dynamics of postanoxic burst-suppression EEG.
2002
Burst-suppression EEG (BS-EEG) after cardiopulmonary resuscitation implies a bad prognosis, but little is known of the temporal dynamics of postanoxic BS-EEG. The authors studied 24 consecutive patients who developed BS-EEG within 24 hours after cardiopulmonary resuscitation, and followed 20 of these patients with serial EEGs. Except for one patient, BS-EEG was followed by another EEG pattern within 1 day, mainly areactive alpha EEG (n = 6), isoelectric EEG (n = 5), generalized continuous epileptiform discharges (n = 4), or theta; EEG (n = 3). The coexistence of different EEG patterns in the same recording was seen in 10 patients. Serial recordings disclosed a variety of EEG sequences with …
Increased amygdala and parahippocampal gyrus activation in schizophrenic patients with auditory hallucinations: An fMRI study using independent compo…
2010
Objective: Hallucinations in patients with schizophrenia have strong emotional connotations. Functional neuroimaging techniques have been widely used to study brain activity in patients with schizophrenia with hallucinations or emotional impairments. However, few of these Studies have investigated the association between hallucinations and emotional dysfunctions using an emotional auditory paradigm. Independent component analysis (ICA) is an analysis method that is especially useful for decomposing activation during complex cognitive tasks in which multiple operations occur simultaneously. Our aim in this Study is to analyze brain activation after the presentation of emotional auditory stim…
Patterned functional network disruption in amyotrophic lateral sclerosis
2019
Abstract Amyotrophic lateral sclerosis (ALS) is a progressive neurodegenerative disease primarily affecting motor function, with additional evidence of extensive nonmotor involvement. Despite increasing recognition of the disease as a multisystem network disorder characterised by impaired connectivity, the precise neuroelectric characteristics of impaired cortical communication remain to be fully elucidated. Here, we characterise changes in functional connectivity using beamformer source analysis on resting‐state electroencephalography recordings from 74 ALS patients and 47 age‐matched healthy controls. Spatiospectral characteristics of network changes in the ALS patient group were quantifi…
Model order effects on ICA of resting-state complex-valued fMRI data : application to schizophrenia
2018
Abstract Background Component splitting at higher model orders is a widely accepted finding for independent component analysis (ICA) of functional magnetic resonance imaging (fMRI) data. However, our recent study found that intact components occurred with subcomponents at higher model orders. New method This study investigated model order effects on ICA of resting-state complex-valued fMRI data from 82 subjects, which included 40 healthy controls (HCs) and 42 schizophrenia patients. In addition, we explored underlying causes for distinct component splitting between complex-valued data and magnitude-only data by examining model order effects on ICA of phase fMRI data. A best run selection me…