Search results for "Potentials"
showing 10 items of 1072 documents
Processing of word stress related acoustic information : A multi-feature MMN study
2016
In the present study, we investigated the processing of word stress related acoustic features in a word context. In a passive oddball multi-feature MMN experiment, we presented a disyllabic pseudo-word with two acoustically similar syllables as standard stimulus, and five contrasting deviants that differed from the standard in that they were either stressed on the first syllable or contained a vowel change. Stress was realized by an increase of f0, intensity, vowel duration or consonant duration. The vowel change was used to investigate if phonemic and prosodic changes elicit different MMN components. As a control condition, we presented non-speech counterparts of the speech stimuli. Result…
Aesthetic judgments of music in experts and laypersons--an ERP study.
2010
We investigated whether music experts and laypersons differ with regard to aesthetic evaluation of musical sequences 16 music experts and 16 music laypersons judged the aesthetic value (beauty judgment task) as well as the harmonic correctness (correctness judgment task) of chord sequences The sequences consisted of five chords with the final chord sounding congruous, ambiguous or incongruous relative to the harmonic context established by the preceding four chords On behavioural measures, few differences were observed between experts and laypersons However, several differences in event-related potential (ERP) parameters were observed in auditory, cognitive and aesthetic processing of chord…
Distributed analysis of simultaneous EEG-fMRI time-series: modeling and interpretation issues
2009
Functional magnetic resonance imaging (fMRI) and electroencephalography (EEG) represent brain activity in terms of a reliable anatomical localization and a detailed temporal evolution of neural signals. Simultaneous EEG-fMRI recordings offer the possibility to greatly enrich the significance and the interpretation of the single modality results because the same neural processes are observed from the same brain at the same time. Nonetheless, the different physical nature of the measured signals by the two techniques renders the coupling not always straightforward, especially in cognitive experiments where spatially localized and distributed effects coexist and evolve temporally at different …
Effects of scopolamine on dopamine neurons in the substantia nigra : role of the pedunculopontine tegmental nucleus
2009
Previous neurochemical and behavioral studies suggest that muscarinic receptor antagonism has an excitatory effect on the nigrostriatal dopamine (DA) system. Using in vivo extracellular single unit recording, this study examined whether blockade of the muscarinic receptor by scopolamine alters the firing properties of DA neurons in the substantia nigra (SN). Scopolamine was administered either systemically or locally to DA neurons using microiontophoresis. Surprisingly, scopolamine did not cause any significant change in either the firing rate or pattern of the spontaneously active DA neurons. However, systemic injection of scopolamine significantly increased the number of active DA neurons…
N-Valproyl-L-Phenylalanine as new potential antiepileptic drug: Synthesis, characterization and in vitro studies on stability, toxicity and anticonvu…
2013
Valproic acid (VPA) is considered first-line drug in treatment of generalized idiopathic seizures such as absence, generalized tonic-clonic and myoclonic seizures. Among major antiepileptic drugs, VPA is also considered effective in childhood epilepsies and infantile spasms. Due to its broad activity, VPA acts as a mood stabilizer in bipolar disorder and it is useful in migraine prophylaxis. Despite its long-standing usage, severe reactions to VPA, such as liver toxicity and teratogenicity, are reported. To circumvent side effects due to structural characteristics of VPA, we synthesized in good yield a new VPA-aminoacid conjugate, the N-valproyl-L-Phenylalanine, and characterized by FT-IR, …
Altered electrical activity in colonic smooth muscle cells from dystrophic (mdx) mice
2001
Because the colon from dystrophic (mdx) mice shows an altered motor pattern, probably due to neural disorders, our aim was to examine the electrophysiological properties of muscle cells and the functionality of nitrergic transmission in circular muscle from normal and mdx colon. Normal colonic cells (resting membrane potential [RMP] about -50 mV) showed spontaneous hyperpolarizations (inhibitory junction potentials; IJPs) and cyclic slow depolarizations were sometimes recorded. Mdx colon had a depolarized RMP (about -36 mV) and spontaneous IJPs, but the cyclic activity was never observed. In the normal colon, Nomega-nitro-L-arginine methyl ester (L-NAME) induced depolarization and abolished…
N1 and P2 components of auditory event-related potentials in children with and without reading disabilities.
2007
Abstract Objective The effects of within stimulus presentation rate and rise time on basic auditory processing were investigated in children with reading disabilities and typically reading children. Methods Children with reading disabilities (RD; N =19) and control children ( N =20) were studied using event-related potentials (ERPs). Paired stimuli were used with two different within-pair-intervals (WPI; 10 and 255ms) and two different rise times (10 and 130ms). Each stimulus was presented with equal probability and long between-pair inter-stimulus intervals (1–5s). The study focused on N1 and P2 components. Results The P2 responses to the first tone in the pair showed differences between c…
Time-resolved classification of dog brain signals reveals early processing of faces, species and emotion
2020
Dogs process faces and emotional expressions much like humans, but the time windows important for face processing in dogs are largely unknown. By combining our non-invasive electroencephalography (EEG) protocol on dogs with machine-learning algorithms, we show category-specific dog brain responses to pictures of human and dog facial expressions, objects, and phase-scrambled faces. We trained a support vector machine classifier with spatiotemporal EEG data to discriminate between responses to pairs of images. The classification accuracy was highest for humans or dogs vs. scrambled images, with most informative time intervals of 100–140 ms and 240–280 ms. We also detected a response sensitive…
Deficits in facial emotional valence processing in older people with subjective memory complaints: Behavioral and electrophysiological evidence
2021
Subjective memory complaints (SMCs), which occur in the absence of clinical memory deficits, may precede mild cognitive impairment (MCI) or Alzheimer''s disease (AD). Some studies have reported a deficit in facial emotion processing in people with MCI or AD. However, it is unclear whether this deficit is also present in older people with SMCs. The present study used behavioral measurements and event-related potentials (ERPs) to investigate the facial emotion processing of 41 older people with SMCs and 38 without SMCs. The task contained 204 images displaying facial emotions (positive, negative, and neutral). In terms of behavior, our results showed that participants with SMCs were slower an…
A Human-Humanoid Interaction Through the Use of BCI for Locked-In ALS Patients Using Neuro-Biological Feedback Fusion.
2018
This paper illustrates a new architecture for a human–humanoid interaction based on EEG-brain computer interface (EEG-BCI) for patients affected by locked-in syndrome caused by Amyotrophic Lateral Sclerosis (ALS). The proposed architecture is able to recognise users’ mental state accordingly to the biofeedback factor $\text {B}_{\text f}$ , based on users’ attention, intention, and focus, that is used to elicit a robot to perform customised behaviours. Experiments have been conducted with a population of eight subjects: four ALS patients in a near locked-in status with normal ocular movement and four healthy control subjects enrolled for age, education, and computer expertise. The results s…