Nina Kahlbrock

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Tinnitus is an auditory phantom phenomenon characterized by the sensation of sounds without objectively identifiable sound sources. To date, its causes are not well understood. Previous research found altered patterns of spontaneous brain activity in chronic tinnitus sufferers compared to healthy controls, yet it is unknown whether these abnormal(More)
OBJECTIVE Hepatic encephalopathy (HE) is associated with motor symptoms and attentional deficits, which are related to pathologically slowed oscillatory brain activity. Here, potential alterations of oscillatory activity in the somatosensory system were investigated. METHODS 21 patients with liver cirrhosis and varying HE severity and 7 control subjects(More)
Cortical gamma band synchronization is associated with attention. Accordingly, directing attention to certain visual stimuli modulates gamma band activity in visual cortical areas. However, gradual effects of attention and behavior on gamma band activity in early visual areas have not yet been reported. In the present study, the degree of selective visual(More)
Oscillatory activity is modulated by sensory stimulation but can also fluctuate in the absence of sensory input. Recent studies have demonstrated that such fluctuations of oscillatory activity can have substantial influence on the perception of subsequent stimuli. In the present study, we employed a simultaneity task in the somatosensory domain to study the(More)
Extensive work using magneto- and electroencephalography (M/EEG) suggests that cortical alpha activity represents a top-down controlled gating mechanism employed by processes like attention across different modalities. However, it is not yet clear to what extent this presumed gating function of alpha activity also applies to the processing of pain. In the(More)
Visual attention is associated with occipital gamma band activity. While gamma band power can be modulated by attention, the frequency of gamma band activity is known to decrease with age. The present study tested the hypothesis that reduced visual attention is associated with a change in induced gamma band activity. To this end, 26 patients with liver(More)
OBJECTIVES Previous evoked potential studies indicated central impairments of somatosensory function in patients suffering from hepatic encephalopathy (HE). The aim of this study was to quantify the somatosensory perception in patients with minimal and overt HE. MATERIALS AND METHODS Forty-two patients with liver cirrhosis and HE up to grade 2 and 12(More)
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