Search results for "Neuroimaging"
showing 10 items of 281 documents
Maternal history of reading difficulty is associated with reduced language-related gray matter in beginning readers.
2012
Family history and poor preliteracy skills (referred to here as familial and behavioral risk, respectively) are critical predictors of developmental dyslexia. This study systematically investigated the independent contribution of familial and behavioral risks on brain structures, which had not been explored in past studies. We also examined the differential effects of maternal versus paternal history on brain morphometry, and familial risk dimensionally versus categorically, which were also novel aspects of the study. We assessed 51 children (5 to 6 years of age) with varying degrees of familial and behavioral risks for developmental dyslexia and examined associations with brain morphometry…
Conceptual proposition selection and the LIFG: neuropsychological evidence from a focal frontal group.
2010
Much debate surrounds the role of the left inferior frontal gyrus (LIFG). Evidence from lesion and neuroimaging studies suggests the LIFG supports a selection mechanism used in single word generation. Single case studies of dynamic aphasic patients with LIFG damage concur with this and extend the finding to selection of sentences at the conceptual preparation stage of language generation. A neuropsychological group with unselected focal frontal and non-frontal lesions is assessed on a sentence generation task that varied the number of possible conceptual propositions available for selection. Frontal patients with LIFG damage when compared to Frontal patients without LIFG damage and Posterio…
Time course of emotion-related responding during distraction and reappraisal
2014
Theoretical accounts of emotion regulation (ER) discriminate various cognitive strategies to voluntarily modify emotional states. Amongst these, attentional deployment (i.e. distraction) and cognitive change (i.e. reappraisal), have been shown to successfully down-regulate emotions. Neuroimaging studies found that both strategies differentially engage neural structures associated with selective attention, working memory and cognitive control. The aim of this study was to further delineate similarities and differences between the ER strategies reappraisal and distraction by investigating their temporal brain dynamics using event-related potentials (ERPs) and their patterns of facial expressi…
Evidence for a white matter lesion size threshold to support the diagnosis of relapsing remitting multiple sclerosis
2018
Abstract Background The number of white matter lesions (WML) in brain MRI is the most established paraclinical tool to support the diagnosis of multiple sclerosis (MS) and to monitor its course. Diagnostic criteria have stipulated a minimum detectable diameter of 3 mm per WML, although this threshold is not evidence-based. We aimed to provide a rationale for a WML size threshold for three-dimensional MRI sequences at 3 T by comparing patients with relapsing-remitting MS (RRMS) to control subjects (CS). Methods We analyzed MR images from two cohorts, obtained at scanners from two different vendors, each comprising patients with RRMS and CS. Both cohorts were examined with FLAIR and T1w seque…
Effects of valence and arousal on implicit approach/ avoidance tendencies: A fMRI study.
2018
To date, it is still a matter of debate, whether valence or valence and arousal interactively foster implicit approach and avoidance tendencies, and which neural circuitries underlie these effects. To address these questions, we investigated the effects of valence and arousal on implicit approach/avoidance tendencies during fMRI in healthy volunteers (N=46). The implicit approach of positive social scenes was associated with shorter response preparation times and increased activation of the lingual, parahippocampal and fusiform gyri. Valence and arousal did not influence reaction times interactively, but we observed increased activation of prefrontal, motor, temporal, middle cingulate and p…
Visuospatial attention shifts by gaze and arrow cues: an ERP study.
2007
Orienting of visual attention can be automatically triggered not only by illumination changes occurring in the visual periphery but also by centrally presented gaze and arrow cues. We investigated whether the automatic shifts of visuospatial attention triggered by centrally displayed gaze and arrow cues rely on the same neural systems. To this end we measured event-related potentials (ERPs) time-locked to the cue and target onsets while the participants (n=17) performed a spatial cuing task. In the task, the participants detected and responded to laterally presented targets preceded by centrally presented, non-predictive, gaze or arrow cues. Manual reaction times and target-triggered ERP da…
Anatomical correlate of positive spontaneous visual phenomena: a voxelwise lesion study.
2010
Objectives: Visual phenomena such as phosphenes, photopsias, or complex visual hallucinations occur in patients with lesions affecting the occipital, parietal, or temporal lobe. Whether these phenomena are provoked by lesions in specific anatomical regions is still uncertain. To determine which brain regions might be involved in such visual phenomena, we used new brain imaging and lesion analysis tools that allow a direct comparison with control patients. Methods: Visual phenomena were investigated in a total of 23 patients with acute infarctions along the visual pathways (6 patients with left-sided and 17 patients with right-sided lesions). Results: Ten of these 23 patients (43%) reported …
Neural mechanisms of training an auditory event‐related potential task in a brain–computer interface context
2019
Effective use of brain-computer interfaces (BCIs) typically requires training. Improved understanding of the neural mechanisms underlying BCI training will facilitate optimisation of BCIs. The current study examined the neural mechanisms related to training for electroencephalography (EEG)-based communication with an auditory event-related potential (ERP) BCI. Neural mechanisms of training in 10 healthy volunteers were assessed with functional magnetic resonance imaging (fMRI) during an auditory ERP-based BCI task before (t1) and after (t5) three ERP-BCI training sessions outside the fMRI scanner (t2, t3, and t4). Attended stimuli were contrasted with ignored stimuli in the first-level fMRI…
Motivational factors modulate left frontoparietal network during cognitive control in cocaine addiction
2020
Cocaine addiction is characterized by alterations in motivational and cognitive processes involved in goal-directed behavior. Recent studies have shown that addictive behaviors can be attributed to alterations in the activity of large functional networks. The aim of this study was to investigate how cocaine addiction affected the left frontoparietal network during goal-directed behavior in a stop-signal task (SST) with reward contingencies by correct task performance. Twenty-eight healthy controls (HC) and 30 abstinent cocaine-dependent patients (ACD) performed SST with monetary reward contingencies while undergoing a functional magnetic resonance imaging scan. The results showed that the l…
The Functional Role of Large-scale Brain Network Coordination in Placebo-induced Anxiolysis
2018
Abstract Anxiety reduction through mere expectation of anxiolytic treatment effects (placebo anxiolysis) has enormous clinical importance. Recent behavioral and electrophysiological data suggest that placebo anxiolysis involves reduced vigilance and enhanced internalization of attention; however, the underlying neurobiological mechanisms are not yet clear. Given the fundamental function of intrinsic connectivity networks (ICNs) in basic cognitive processes, we investigated ICN activity patterns associated with externally and internally directed mental states under the influence of an anxiolytic placebo medication. Based on recent findings, we specifically analyzed the functional role of the…