The Experts below are selected from a list of 5817 Experts worldwide ranked by ideXlab platform
Einat Liebenthal - One of the best experts on this subject based on the ideXlab platform.
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within subject joint independent component analysis of simultaneous fmri erp in an auditory Oddball Paradigm
NeuroImage, 2012Co-Authors: Jain Mangalathuarumana, Einat Liebenthal, Scott A BeardsleyAbstract:The integration of event-related potential (ERP) and functional magnetic resonance imaging (fMRI) can contribute to characterizing neural networks with high temporal and spatial resolution. This research aimed to determine the sensitivity and limitations of applying joint independent component analysis (jICA) within-subjects, for ERP and fMRI data collected simultaneously in a parametric auditory frequency Oddball Paradigm. In a group of 20 subjects, an increase in ERP peak amplitude ranging 1-8 μV in the time window of the P300 (350-700 ms), and a correlated increase in fMRI signal in a network of regions including the right superior temporal and supramarginal gyri, was observed with the increase in deviant frequency difference. JICA of the same ERP and fMRI group data revealed activity in a similar network, albeit with stronger amplitude and larger extent. In addition, activity in the left pre- and post-central gyri, likely associated with right hand somato-motor response, was observed only with the jICA approach. Within-subject, the jICA approach revealed significantly stronger and more extensive activity in the brain regions associated with the auditory P300 than the P300 linear regression analysis. The results suggest that with the incorporation of spatial and temporal information from both imaging modalities, jICA may be a more sensitive method for extracting common sources of activity between ERP and fMRI.
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simultaneous erp and fmri of the auditory cortex in a passive Oddball Paradigm
NeuroImage, 2003Co-Authors: Einat Liebenthal, Michael L Ellingson, Marianna V Spanaki, Thomas E Prieto, Kristina M Ropella, Jeffrey R BinderAbstract:Infrequent occurrences of a deviant sound within a sequence of repetitive standard sounds elicit the automatic mismatch negativity (MMN) event-related potential (ERP). The main MMN generators are located in the superior temporal cortex, but their number, precise location, and temporal sequence of activation remain unclear. In this study, ERP and functional magnetic resonance imaging (fMRI) data were obtained simultaneously during a passive frequency Oddball Paradigm. There were three conditions, a STANDARD, a SMALL deviant, and a LARGE deviant. A clustered image acquisition technique was applied to prevent contamination of the fMRI data by the acoustic noise of the scanner and to limit contamination of the electroencephalogram (EEG) by the gradient-switching artifact. The ERP data were used to identify areas in which the blood oxygenation (BOLD) signal varied with the magnitude of the negativity in each condition. A significant ERP MMN was obtained, with larger peaks to LARGE deviants and with frontocentral scalp distribution, consistent with the MMN reported outside the magnetic field. This result validates the experimental procedures for simultaneous ERP/fMRI of the auditory cortex. Main foci of increased BOLD signal were observed in the right superior temporal gyrus [STG; Brodmann area (BA) 22] and right superior temporal plane (STP; BA 41 and 42). The imaging results provide new information supporting the idea that generators in the right lateral aspect of the STG are implicated in processes of frequency deviant detection, in addition to generators in the right and left STP.
Yoshiyuki Kuroiwa - One of the best experts on this subject based on the ideXlab platform.
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Multiple Dipole Analysis of Visual Event-Related Potentials During Oddball Paradigm with Silent Counting
Brain Topography, 2001Co-Authors: Toshimasa Yamazaki, Ken-ichi Kamijo, Tomoharu Kiyuna, Yoko Takaki, Yoshiyuki KuroiwaAbstract:In order to cope with the non-uniqueness of multiple equivalent current dipole source (ECD) solutions, a priori knowledge about P300 generators of visual event-related potentials (ERPs) during an Oddball Paradigm with silent counting task was incorporated into the multiple ECD localization method. Four-ECD solutions for the target P300 were selected which had the left frontal ECD. The rest of the ECDs were localized to the inferior parietal lobule, the hippocampal formation and subcortical region. By comparing the present results with those on the visual ERPs with button-pressing task, the P300 dipoles common to both the tasks were located at the frontal cortices, the hippocampal formation and the thalamus, suggesting that these structures are the main P300 generators.
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Multiple Equivalent Current Dipole Source Localization of Visual Event-Related Potentials During Oddball Paradigm With Motor Response
Brain Topography, 2000Co-Authors: Toshimasa Yamazaki, Ken-ichi Kamijo, Tomoharu Kiyuna, Yoko Takaki, Akihisa Kenmochi, Shin-ichi Fukuzumi, Yoshiyuki KuroiwaAbstract:Event-related potentials (ERPs) during a visual Oddball Paradigm with button-pressing responses were recorded in 12 right-handed subjects from 32 scalp electrodes. The single equivalent current dipole (ECD) of the target C1 (weak occipito-parietal negativity from 30-80ms) was consistently located at the primary visual cortex. From the 4-ECD localization of the target P1/N1 (temporally coincident frontal positivity and occipito-temporal negativity), it was suggested that this complex reflected activities from distributed sources along both dorsal occipito-parietal and ventral occipito-temporal areas. The stable multiple ECD solutions for the target P3b were chosen as those including the left primary motor and/or sensorimotor dipole and satisfying goodness-of-fit (GOF) of more than 98% and confidence limit (CL) of less than 1mm. The obtained frontal dipoles were discussed in terms of visual working memory and sustained attention in reference to the previous PET, fMRI and MEG studies. The distributed multiple ECDs may suggest that P3 should be interpreted as being the embodiment of the cortico-limbic-thalamic network which involves Halgren and Marinkovic's emotional and behavioral model and Mesulam's attentional circuit.
Dominique Morlet - One of the best experts on this subject based on the ideXlab platform.
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the auditory Oddball Paradigm revised to improve bedside detection of consciousness in behaviorally unresponsive patients
Psychophysiology, 2017Co-Authors: Dominique Morlet, Perrine Ruby, Nathalie Andreobadia, Catherine FischerAbstract:Active Paradigms requiring subjects to engage in a mental task on request have been developed to detect consciousness in behaviorally unresponsive patients. Using auditory ERPs, the active condition consists in orienting patient's attention toward Oddball stimuli. In comparison with passive listening, larger P300 in the active condition identifies voluntary processes. However, contrast between these two conditions is usually too weak to be detected at the individual level. To improve test sensitivity, we propose as a control condition to actively divert the subject's attention from the auditory stimuli with a mental imagery task that has been demonstrated to be within the grasp of the targeted patients: navigate in one's home. Twenty healthy subjects were presented with a two-tone Oddball Paradigm in the three following condition: (a) passive listening, (b) mental imagery, (c) silent counting of deviant stimuli. Mental imagery proved to be more efficient than passive listening to lessen P300 response to deviant tones as compared with the active counting condition. An effect of attention manipulation (oriented vs. diverted) was observed in 19/20 subjects, of whom 18 showed the expected P300 effect and 1 showed an effect restricted to the N2 component. The only subject showing no effect also proved insufficient engagement in the tasks. Our study demonstrated the efficiency of diverting attention using mental imagery to improve the sensitivity of the active Oddball Paradigm. Using recorded instructions and requiring a small number of electrodes, the test was designed to be conveniently and economically used at the patient's bedside.
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what is the specificity of the response to the own first name when presented as a novel in a passive Oddball Paradigm an erp study
Brain Research, 2012Co-Authors: Jeanbaptiste Eichenlaub, Dominique Morlet, Perrine RubyAbstract:One's own first-name is a special stimulus: one's attention is more likely captured by hearing one's own first-name than by hearing another first-name. Previous event-related potential (ERP) studies demonstrated that this special stimulus produces differential responses both in active and in passive condition. Such results suggest that passively hearing one's own first-name triggers processing levels generally activated by the explicit detection of stimuli. This questions about the particular power of the own first-name to automatically orient attention, but no study investigated the specific response to this special stimulus in a Paradigm designed to study automatic attention orienting. In this ERP study, we compared the responses elicited by the own first-name (OWN) and one unfamiliar first-name (OTHER) presented, rarely, randomly and at the same frequency among repetitive tones (i.e., as novel stimuli in an Oddball Paradigm) while subjects (N=36) were watching a silent movie with subtitles. We tested at what latency the responses to OWN and OTHER diverge, and whether OWN modulates the brain orienting response (novelty P3). Data analysis showed specific responses to OWN after 300 ms. OWN only evoked a central negativity (320 ms) and a parietal positivity (550 ms). However, OWN had no significant effect on the brain orienting response (260 ms). Our results confirm that the own first-name does elicit a late specific brain response. However, they challenge the idea that in passive condition, the own first-name is systematically more powerful than another first-name to orient attention when it is heard unexpectedly.
Erich Schroger - One of the best experts on this subject based on the ideXlab platform.
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the effects of response sharing and stimulus presentation frequency on event related potentials in an auditory Oddball Paradigm
Psychophysiology, 2010Co-Authors: Janos Horvath, Urte Roeber, Erich SchrogerAbstract:An experimental model for investigating the processes involved in reacting to unpredictable events is the Oddball Paradigm. We investigated how the commonality or independence of response options (i.e., many-to-one vs. one-to-one stimulus-response mappings) influences processing in an auditory Oddball Paradigm. Participants performed a discrimination task with two one-to-one and one two-to-one mappings. The pattern of conflict- and Oddball-related N2 event-related potentials suggest that information that would allow correct responding is represented at the latency of the N2. Integration of this information takes place only by the latency of P3b, and longer reaction times to rare stimuli are probably due to processes preventing the utilization of this information. We also suggest that, in the given task context, conflict-related N2 may reflect the number of alternative stimuli leading to alternative response options.
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the utility of brief spectrally rich dynamic sounds in the passive Oddball Paradigm
Neuroscience Letters, 2009Co-Authors: Janos Horvath, Urte Roeber, Erich SchrogerAbstract:Abstract Experiments investigating auditory processing often utilize spectrally rich, dynamic stimuli to simulate an ecologically valid auditory environment in the laboratory. Often, however, these stimuli do not allow for a strict control of the timing of auditory sensory information which may be distributed over the whole duration of a given sound. In the present study, brief (20 ms long), dynamic, spectrally rich sounds were presented in the context of a passive Oddball Paradigm to young adults. The short duration made certain that the sensory information was delivered entirely within a 20 ms interval. Two sounds were presented as standards (45–45% probability), other two as deviants (5–5% probability) in random sequences, with a stimulus onset asynchrony (SOA) of 1500 ms. Deviants elicited the mismatch negativity and late difference negativity (LDN) event-related potential components. No N1-effect was produced by deviants, which suggests that the acoustic energy is spread over many different features due to the dynamic spectral properties, which, combined with the brief duration, causes insignificant refractoriness-effects at the present SOA. These results support the usefulness of brief natural sounds in auditory research. The elicitation of LDN in an adult group was an unexpected finding, because LDN is mostly found in children, but not in adults. This result might indicate that LDN elicitation depends on stimulation complexity: stimulus settings in which an LDN is registered in children but not in adults may be perceived as more complex by children than by adults.
Risto Naatanen - One of the best experts on this subject based on the ideXlab platform.
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effects of an nmda receptor antagonist mk 801 on an mmn like response recorded in anesthetized rats
Brain Research, 2008Co-Authors: Dmitry Tikhonravov, Risto Naatanen, Tuomas Neuvonen, Antti Pertovaara, Kati Savioja, Timo Ruusuvirta, Synnove CarlsonAbstract:In the human brain, auditory sensory memory has been extensively studied using a well-defined component of event-related potential named the mismatch negativity (MMN). The MMN is generated in the auditory and frontal cortices in response to deviant stimuli. In monkeys, cortical N-methyl-d-aspartate (NMDA) receptors have a central role in the generation of the MMN. MMN-like responses have also been recorded in other animals, including rats. The present study aimed at determining whether the MMN-like response in rats depends on an intact NMDA-receptor system. We recorded auditory evoked responses during an Oddball Paradigm epidurally in anesthetized rats that had received intraperitoneal injections of saline or an NMDA-receptor antagonist MK-801. An MMN-like response was recorded in the Oddball Paradigm in saline-treated rats. Further, this response was dose-dependently blocked by MK-801. These results suggest that the MMN-like response in rats depends on an intact NMDA-receptor system.
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evaluation of multi attribute auditory discrimination in dyslexia with the mismatch negativity
Clinical Neurophysiology, 2006Co-Authors: Teija Kujala, Riikka Lovio, Tuulia Lepisto, Marja Laasonen, Risto NaatanenAbstract:Objective: Dyslexia is associated with impairments in the phonological system or with more general auditory dysfunctions. We determined the discrimination of 5 sound contrasts (pitch, duration, intensity, location, and the presence of a gap) in dyslexia with the mismatch negativity (MMN). Methods: We compared MMNs of 9 adult dyslexic and 11 control subjects with a new 5-deviant Paradigm which enables one to assess the discrimination of each of these features in 15 min. Also, a control Oddball condition with pitch and duration deviants was included. In the new Paradigm, all deviant stimuli are presented in the same stimulus block so that the standard stimuli, of which there are 50%, alternate with the deviant stimuli. Results: In the 5-deviant Paradigm, a diminished pitch-MMN and an enhanced location-MMN were found in dyslexic individuals. Furthermore, pitch and duration MMNs in this and in the Oddball Paradigms suggested that smaller MMNs are elicited in the new than Oddball Paradigm in dyslexic subjects. Conclusions: Pitch discrimination is impaired in dyslexia. However, location discrimination, not addressed previously with MMN, is enhanced. Furthermore, dyslexic subjects are more impaired in detecting changes in sound streams with than without variation. Significance: In dyslexia research, the new 5-deviant MMN Paradigm is feasible and even more sensitive than the traditional Oddball Paradigm.
