1,720,995 research outputs found
CHRONIC LOW BACK PAIN PATIENTS WITH HIGH AND LOW KINESIOPHOBIA IMAGINE PAINFUL AND NEUTRAL MOVEMENTS - FMRI STUDY OF NEURAL CORRELATES
No full textNEURAL CORRELATES OF TINNITUS ANNOYANCE AND ITS REDUCTION AFTER COGNITIVE-BEHAVIORAL TRAINING: RESULTS FROM AN EMOTIONAL STROOP TASK
No full textSerum 24S-hydroxycholesterol and hippocampal size in middle-aged normal individuals
No full textThe present study assessed the association between serum 24S-hydroxycholesterol (24S-OH-Chol) and 27-hydroxycholesterol (27-OH-Chol) and hippocampal volumes in 69 middle-aged cognitively normal individuals. Results showed that subjects with high levels of oxysterols, had significantly larger hippocampal volumes than subjects with low levels of oxysterols. Multiple regression analysis revealed that 24S-OH-Chol, but not 27-OH-Chol or cholesterol, was able to significantly predict hippocampal size. Future studies should elucidate whether high brain cholesterol metabolism in the middle age is protective against hippocampal atrophy and cognitive decline. (C) 2007 Elsevier Inc. All rights reserved.Deutsche Forschungsgemeinschaft [IR 15/6-2]; University of Gottinge
Neural correlates of tinnitus annoyance and its reduction after cognitive-behavioural training: results from an emotional stroop task
No full textTinnitus describes the perception of sound in the absence of external noise. About 5% of the population is affected by chronic tinnitus. About 20% of the tinnitus afflicted individuals experience severe distress due to the phantom noise. Negative cognitive emotional evaluation of tinnitus and its assumed consequences are commonly believed to be a major factor determining tinnitus-related distress. Models of tinnitus distress and recently conducted research propose a fronto-parietal-cingulate network to be more active in highly distressed tinnitus patients. The aim of the study was to identify brain regions, which are more active in highly distressed tinnitus patients during the processing of tinnitus-related stimuli in comparison to low distressed tinnitus patients and healthy controls. We examined three groups of age and sex matched participants; highly distressed tinnitus patients (n = 16; mean age: 53.38; SD = 12.33), low distressed tinnitus patients (n = 16; mean age: 52.25; SD = 11.73) and healthy controls (n = 16; mean age: 52.75; SD = 9.40) by the means of functional magnetic resonance imaging (fMRI). The participants underwent fMRI while performing an emotional Stroop task, which consisted of colored tinnitus-related words and neutral words. The participants had to name the color of each presented word via button press on a four-button-response pad. A subgroup of the highly distressed tinnitus patients received a cognitive-behavioral training, which aimed to reduce tinnitus-related distress. Responders to the training and age and sex matched low distressed tinnitus patients underwent the emotional Stroop task for a second time. The final results will be presented
CHRONIC LOW BACK PAIN PATIENTS WITH HIGH AND LOW KINESIOPHOBIA IMAGINE PAINFUL AND NEUTRAL MOVEMENTS - FMRI STUDY OF NEURAL CORRELATES
No full textNEURAL CORRELATES OF TINNITUS ANNOYANCE AND ITS REDUCTION AFTER COGNITIVE-BEHAVIORAL TRAINING: RESULTS FROM AN EMOTIONAL STROOP TASK
No full textRhythmic gamma stimulation affects bistable perception
No full textWhen our brain is confronted with ambiguous visual stimuli, perception spontaneously alternates between different possible interpretations although the physical stimulus remains the same. Both alpha (8-12 Hz) and gamma (>30 Hz) oscillations have been reported to correlate with such spontaneous perceptual reversals. However, whether these oscillations play a causal role in triggering perceptual switches remains unknown. To address this question, we applied transcranial alternating current stimulation (tACS) over the posterior cortex of healthy human participants to boost alpha and gamma oscillations. At the same time, participants were reporting their percepts of an ambiguous structure-from-motion stimulus. We found that tACS in the gamma band (60 Hz) increased the number of spontaneous perceptual reversals, whereas no significant effect was found for tACS in alpha (10 Hz) and higher gamma (80 Hz) frequencies. Our results suggest a mechanistic role of gamma but not alpha oscillations in the resolution of perceptual ambiguity.Herman and Lilly Schilling Foundatio
Experimentelle Modelle für räumlichen Neglect (Studien in humanen und nicht-humanen Primaten)
No full textZusammenfassung
Räumlicher Neglect stellt eine schwerwiegende Konsequenz von Hirnläsionen dar und ist durch die perzeptuelle und motorische Vernachlässigung einer Raumhälfte gekennzeichnet. Die zu Neglect führenden Läsionen treten innerhalb verteilter Netzwerke auf, die sich sowohl aus kortikalen Arealen (z.B. fronto-parietalen) als auch aus subkortikalen Strukturen (z.B. dem thalamischen Pulvinar) zusammensetzen. Die Entwicklung effektiver therapeutischer Strategien setzt ein detailliertes Verständnis der wichtigen Knotenpunkte und ihrer Interaktionen voraus. Allerdings sind präzise Informationen dazu aus Patientenstudien, aufgrund der Größe und Variabilität der mit Neglect assoziierten Läsionen, oft nur schwer zu erhalten. Experimentelle Modelle, bei denen definierte Gehirnregionen systematisch inaktiviert werden können, stellen daher eine wichtige Ergänzung zu den klassischen Läsionsstudien dar. Neglect-Modelle wurden beispielsweise bei nicht-humanen Primaten mithilfe lokaler, reversibler pharmakologischer Inaktivierung entwickelt, sowie bei gesunden Probanden mithilfe nicht-invasiver Stimulations-/Inaktivierungsmethoden wie der transkraniellen Magnetstimulation. In diesem Artikel diskutieren wir Theorien zum räumlichen Neglect, insbesondere die des hemisphärischen Ungleichgewichtes, und ihre empirische Evidenz. Ein Fokus liegt dabei auf Ergebnissen aus funktionellen Bildgebungsstudien, welche die Auswirkungen lokaler Läsionen auf dynamische Netzwerkaktivität untersuchen.</jats:p
Tinnitus- related distress: evidence from fMRI of an emotional stroop task
No full textAbstract Background Chronic tinnitus affects 5 % of the population, 17 % suffer under the condition. This distress seems mainly to be dependent on negative cognitive-emotional evaluation of the tinnitus and selective attention to the tinnitus. A well-established paradigm to examine selective attention and emotional processing is the Emotional Stroop Task (EST). Recent models of tinnitus distress propose limbic, frontal and parietal regions to be more active in highly distressed tinnitus patients. Only a few studies have compared high and low distressed tinnitus patients. Thus, this study aimed to explore neural correlates of tinnitus-related distress. Methods Highly distressed tinnitus patients (HDT, n = 16), low distressed tinnitus patients (LDT, n = 16) and healthy controls (HC, n = 16) underwent functional magnetic resonance imaging (fMRI) during an EST, that used tinnitus-related words and neutral words as stimuli. A random effects analysis of the fMRI data was conducted on the basis of the general linear model. Furthermore correlational analyses between the blood oxygen level dependent response and tinnitus distress, loudness, depression, anxiety, vocabulary and hypersensitivity to sound were performed. Results Contradictory to the hypothesis, highly distressed patients showed no Stroop effect in their reaction times. As hypothesized HDT and LDT differed in the activation of the right insula and the orbitofrontal cortex. There were no hypothesized differences between HDT and HC. Activation of the orbitofrontal cortex and the right insula were found to correlate with tinnitus distress. Conclusions The results are partially supported by earlier resting-state studies and corroborate the role of the insula and the orbitofrontal cortex in tinnitus distress
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