Search results for "Neural"

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…

Differences in sensory processing of German vowels and physically matched non-speech sounds as revealed by the mismatch negativity (MMN) of the human…

2014

We compared processing of speech and non-speech by means of the mismatch negativity (MMN). For this purpose, the MMN elicited by vowels was compared to those elicited by two non-speech stimulus types: spectrally rotated vowels, having the same stimulus complexity as the speech stimuli, and sounds based on the bands of formants of the vowels, representing non-speech stimuli of lower complexity as compared to the other stimulus types. This design allows controlling for effects of stimulus complexity when comparing neural correlates of processing speech to non-speech. Deviants within a modified multi-feature design differed either in duration or spectral property. Moreover, the difficulty to d…

Diaphragmatic paralysis following minor cervical trauma.

2007

Two asthmatic patients developed unilateral diaphragmatic paralysis from phrenic nerve injury, in one case following cervical chiropractic manipulation and in the other after a motorcycle accident. Both presented with increased dyspnea and orthopnea. Diagnosis, severity, and level of the lesion were established by neurophysiological methods, which are preferred to chest radiography and diaphragmatic ultrasonography. In spite of only partial electrophysiological recovery of the nerve, both patients were asymptomatic 1 year later.

Synergy and masking in odor mixtures: an electrophysiological study of orthonasal vs. retronasal perception

2008

Perceptual interactions in a model of wine woody–fruity binary mixtures were previously reported in a psychophysical study performed through orthonasal stimulation only. However, recent studies suggested that the perception of food-like and nonfood-like odors may depend on the route of stimulation. The aim of the present study was two-fold: first to examine the neural correlates of perceptual interactions using electroencephalogram (EEG)-derived event-related potentials (ERPs) and second to test the influence of the stimulation route on quality perception. Therefore, we designed an experiment with 30 subjects to study perceptual interactions in woody–fruity mixtures and compared ortho- vs. …

Effects of Botulinum Toxin A on Allodynia in Chronic Migraine: An Observational Open-Label Two-Year Study.

2019

<b><i>Background:</i></b> Onabotulinumtoxin A (OBT-A) is a treatment option for chronic migraine (CM), though the possible effect on central sensitization and allodynia is still unknown. <b><i>Aims:</i></b> The present study aimed to evaluate (1) the long-term outcome of allodynia in a group of CM treated with OBT-A (2) if the presence and severity of allodynia could predict the long-term effect of OBT-A (3) if the improvement of allodynia, could contribute to the clinical efficacy of OBT-A. <b><i>Methods:</i></b> This was an observational, open-label, cohort study conducted on 99 CM patients treated for 1 year and 44 p…

Modulation of cortical motor outputs by the symbolic meaning of visual stimuli.

2010

Abstract The observation of an action modulates motor cortical outputs in specific ways, in part through mediation of the mirror neuron system. Sometimes we infer a meaning to an observed action based on integration of the actual percept with memories. Here, we conducted a series of experiments in healthy adults to investigate whether such inferred meanings can also modulate motor cortical outputs in specific ways. We show that brief observation of a neutral stimulus mimicking a hand does not significantly modulate motor cortical excitability (Study 1) although, after prolonged exposure, it can lead to a relatively nonspecific modulation (Study 2). However, when such a neutral stimulus is p…

Discovering dynamic task-modulated functional networks with specific spectral modes using MEG.

2019

Efficient neuronal communication between brain regions through oscillatory synchronization at certain frequencies is necessary for cognition. Such synchronized networks are transient and dynamic, established on the timescale of milliseconds in order to support ongoing cognitive operations. However, few studies characterizing dynamic electrophysiological brain networks have simultaneously accounted for temporal non-stationarity, spectral structure, and spatial properties. Here, we propose an analysis framework for characterizing the large-scale phase-coupling network dynamics during task performance using magnetoencephalography (MEG). We exploit the high spatiotemporal resolution of MEG to m…

Conduction times of cortical projections to paravertebral muscles in controls and in patients with multiple sclerosis

1994

Memory detection using fMRI - does the encoding context matter?

2015

Recent research revealed that the presentation of crime related details during the Concealed Information Test (CIT) reliably activates a network of bilateral inferior frontal, right medial frontal and right temporal-parietal brain regions. However, the ecological validity of these findings as well as the influence of the encoding context are still unclear. To tackle these questions, three different groups of subjects participated in the current study. Two groups of guilty subjects encoded critical details either only by planning (guilty intention group) or by really enacting (guilty action group) a complex, realistic mock crime. In addition, a group of informed innocent subjects encoded hal…

The Laparoscopic Approach to Control Intractable Pelvic Neuralgia: From Laparoscopic Pelvic Neurosurgery to the LION Procedure

2007

OBJECTIVE: To present different aspects and advantages of the laparoscopic approach to the pelvic nerves aimed at treating intractable pelvic neuralgia. METHODS: We report on a nonconsecutive series of 7 patients with different types and etiologies of chronic pelvic neuralgia, all of whom underwent laparoscopy. In all 7 cases, the neuralgia was refractory to medical management and had profound socioeconomic consequences for the patients. RESULTS: Techniques of laparoscopic transperitoneal neurolysis of several pelvic somatic nerves are described but also our technique of laparoscopic implantation of neuroprothesis for neuromodulation on somatic pelvic nerves or on autonomic pelvic nerves as…