Discrimination of Timbre in Early Auditory Responses of the Human Brain

The issue of how differences in timbre are represented in the neural response still has not been well addressed, particularly with regard to the relevant brain mechanisms. Here we employ phasing and clipping of tones to produce auditory stimuli differing to describe the multidimensional nature of timbre. We investigated the auditory response and sensory gating as well, using by magnetoencephalography (MEG).Thirty-five healthy subjects without hearing deficit participated in the experiments. Two different or same tones in timbre were presented through conditioning (S1) – testing (S2) paradigm as a pair with an interval of 500 ms. As a result, the magnitudes of auditory M50 and M100 responses were different with timbre in both hemispheres. This result might support that timbre, at least by phasing and clipping, is discriminated in the auditory early processing. The second response in a pair affected by S1 in the consecutive stimuli occurred in M100 of the left hemisphere, whereas both M50 and M100 responses to S2 only in the right hemisphere reflected whether two stimuli in a pair were the same or not. Both M50 and M100 magnitudes were different with the presenting order (S1 vs. S2) for both same and different conditions in the both hemispheres.Our results demonstrate that the auditory response depends on timbre characteristics. Moreover, it was revealed that the auditory sensory gating is determined not by the stimulus that directly evokes the response, but rather by whether or not the two stimuli are identical in timbre

Neurofeedback in fibromyalgia syndrome

PubMed ID: 18095199EEG Biofeedback (Neurofeedback-NFB) is a learning strategy that enables people to alter their brainwaves. In the present case study, we applied a NFB protocol on three patients with Fibromyalgia Syndrome (FMS). The existing symptoms and clinical conditions of the patients attributed to FMS, Visual Analog Scale for pain and fatigue, Hamilton Depression and Anxiety Inventory Scales, Beck Depression and Anxiety Inventory Scales, and SF-36 were recorded before and after NFB training. Most of the symptoms were decreased after ten sessions. There was also improvement in all of the scales after the treatment. The results of the present study may suggest NFB training as a novel treatment method in FMS

Neurofeedback intervention in fibromyalgia syndrome; A randomized, controlled, rater blind clinical trial

We designed a randomized, rater blind study to assess the efficacy of EEG Biofeedback (Neurofeedback-NFB) in patients with fibromyalgia syndrome (FMS). Eighteen patients received twenty sessions of NFB-sensory motor rhythm (SMR) treatment (NFB group) during 4 weeks, and eighteen patients were given 10 mg per day escitalopram treatment (control group) for 8 weeks. Visual Analog Scales for pain and fatigue, Hamilton and Beck Depression and Anxiety Inventory Scales, Fibromyalgia Impact Questionnaire and Short Form 36 were used as outcome measures which were applied at baseline and 2nd, 4th, 8th, 16th, 24th weeks. Mean amplitudes of EEG rhythms (delta, theta, alpha, SMR, beta1 and beta2) and theta/SMR ratio were also measured in NFB group. All post-treatment measurements showed significant improvements in both of the groups (for all parameters p0.05 for all). However, theta/SMR ratio showed a significant decrease at 4th week compared to baseline in the NFB group (p<0.05). These data support the efficacy of NFB as a treatment for pain, psychological symptoms and impaired quality of life associated with fibromyalgia

EVALUATION OF COGNITIVE FUNCTION ELECTROPHYSIOLOGICALLY IN CHILDREN WITH BEHCET DISEASE

WOS: 000388065900143

Effects of cold stress on early and late stimulus gating

The P50 component of the event-related potential (ERP) mainly reflects early pre-attentional processing. Along with P50, the N100 component and mismatch negativity (MMN) were postulated to represent a complex multistage and multi-component gating system. If some variable threshold or gating is exceeded by the MMN signal, the MMN is often followed by a relatively sharp fronto-central positive wave, the P3a component, which reflects an attentional switch to an environmental change. The P50 was shown to be affected by mental and cold stress, and the P3a amplitude was shown to be increased by the anticipation of threat. The aim of this study is to examine concurrently the early and late ERP indices of gating during acute stress. The ERPs to auditory stimuli in a passive oddball paradigm were recorded in 15 normal subjects during the cold pressor test and a control condition. The cold pressor test diminished P50 gating, increased N 100 amplitude, elicited P3a responses and had no significant effect on MMN. Transient stress could impair early sensory gating and the ability to ignore irrelevant information that can cause passive attention switches indexed by the P3a component. (c) 2005 Elsevier Ireland Ltd. All rights reserved

Event-related potentials to visual, auditory, and bimodal (combined auditory-visual) stimuli

PubMed ID: 17365112The purpose of this study was to investigate the response properties of event related potentials to unimodal and bimodal stimulations. The amplitudes of N1 and P2 were larger during bimodal evoked potentials (BEPs) than auditory evoked potentials (AEPs) in the anterior sites and the amplitudes of P1 were larger during BEPs than VEPs especially at the parieto-occipital locations. Responses to bimodal stimulation had longer latencies than responses to unimodal stimulation. The N1 and P2 components were larger in amplitude and longer in latency during the bimodal paradigm and predominantly occurred at the anterior sites. Therefore, the current bimodal paradigm can be used to investigate the involvement and location of specific neural generators that contribute to higher processing of sensory information. Moreover, this paradigm may be a useful tool to investigate the level of sensory dysfunctions in clinical samples. Copyright © 2007 Informa Healthcare.1739/21122001 Fundamental Research Fund of Shandong UniversityReceived 17 November 2005. This work was supported by the Research Fund of the University of ?stanbul, project number: 1739/21122001. The authors thank Prof. Dr. ?hsan Kara and Assoc. Prof. Dr. Asiye Nurten for help and for permission to use the data recording and processing system in the Institute for Experimental Medicine (DTAE) Department of Neuroscience, ?stanbul University. Adress correspondence to Prof. Dr. Ümmühan Isoglu-Alkac, MD, ?stanbul University, ?stanbul Medical Faculty, Department of Physiology, 34390-Capa, ?stanbul, Turkey. E-mail: [email protected]