Anokhin, A.P.; van Baal, G.C.M.; van Beijsterveldt, C.E.M.; de Geus, E.J.C.; Grant, J.; Boomsma, D.I.
Previous studies have demonstrated moderate heritability of the P300 component of event-related brain potentials (ERPs) and high heritability of background electroencephalogram (EEG) power spectrum. However, it is unclear whether EEG and ERPs are influenced by common or independent genetic factors.
Mørup, Morten; Hansen, Lars Kai; Hermann, Cristoph S.
-Montes, E., Valdes-Sosa, P.A., Nishiyama, N., Mizuhara, H., Yamaguchi, Y., 2004. Decomposing EEG data into space-time-frequency components using parallel factor analysis. Neuroimage 22, 1035-1045). In this article, PARAFAC is used for the first time to decompose wavelet transformed event-related EEG given...... of frequency transformed multi-channel EEG of channel x frequency x time data. The multi-way decomposition method Parallel Factor (PARAFAC), also named Canonical Decomposition (CANDECOMP), was recently used to decompose the wavelet transformed ongoing EEG of channel x frequency x time (Miwakeichi, F., Martinez......In the decomposition of multi-channel EEG signals, principal component analysis (PCA) and independent component analysis (ICA) have widely been used. However, as both methods are based on handling two-way data, i.e. two-dimensional matrices, multi-way methods might improve the interpretation...
Fernandez, Thalia; Harmony, Thalia; Mendoza, Omar; Lopez-Alanis, Paula; Marroquin, Jose Luis; Otero, Gloria; Ricardo-Garcell, Josefina
Learning disabilities (LD) are one of the most frequent problems for elementary school-aged children. In this paper, event-related EEG oscillations to semantically related and unrelated pairs of words were studied in a group of 18 children with LD not otherwise specified (LD-NOS) and in 16 children with normal academic achievement. We propose that…
van Beijsterveldt, C.E.M.; Boomsma, D.I.
Twin and family studies of normal variation in the human electroencephalogram (EEG) and event related potentials (ERPs) are reviewed. Most of these studies are characterized by small sample sizes. However, by summarizing these studies in one paper, we may be able to gain some insight into the
Wang, Li-qun; Wang, Mingshi; Mizuhara, Hiroaki
In this study, P300 that induced by visual stimuli was examined with simultaneous EEG/fMRI. For the purpose of combine the best temporary resolution with the best special resolution together to estimate the brain function, event-related analysis contributed to this methodological trial. A 64 channel MRT-compatible MR EEG amplifier (BrainAmp: made of Brain Production GmbH, Gennany) was used in the measurement simultaneously with fMRI scanning. The reference channel is between Fz, Cz and Pz. Sampling rate of raw EEG was 5 kHz, and the MRT noise reduction was performed. EEG recording synchronized with MRI scan by our original stimulus system, and an oddball paradigm (four-oriented Landolt Ring presentation) was performed in the official manner. After P300 segmentation, the timing of P300 was exported to event-related analysis of fMRI data with SPM99 software. In single subject study, the significant activations appear in the left superior frontal, Broca's area and on both sides of the parietal lobule when P300 occurred. It is suggest that P300 may be an integration carried out by top-down signal from frontal to the parietal lobule, which regulates an Attention-Logical Judgment process. Compared with other current methods, the event related analysis by simultaneous EEG/IMRI is excellent in the point that can describe the cognitive process with reality unifying further temporary and spatial information. It is expected that examination and demonstration of the obtained result will supply with the promotion of this powerful methods.
Full Text Available Brain-machine interfaces (BMI rely on the accurate classification of event-related potentials (ERPs and their performance greatly depends on the appropriate selection of classifier parameters and features from dense-array electroencephalography (EEG signals. Moreover, in order to achieve a portable and more compact BMI for practical applications, it is also desirable to use a system capable of accurate classification using information from as few EEG channels as possible. In the present work, we propose a method for classifying P300 ERPs using a combination of Fisher Discriminant Analysis (FDA and a multiobjective hybrid real-binary Particle Swarm Optimization (MHPSO algorithm. Specifically, the algorithm searches for the set of EEG channels and classifier parameters that simultaneously maximize the classification accuracy and minimize the number of used channels. The performance of the method is assessed through offline analyses on datasets of auditory ERPs from sound discrimination experiments. The proposed method achieved a higher classification accuracy than that achieved by traditional methods while also using fewer channels. It was also found that the number of channels used for classification can be significantly reduced without greatly compromising the classification accuracy.
Full Text Available Quick detection of motor intentions is critical in order to minimize the time required to activate a neuroprosthesis. We propose a Markov Switching Model (MSM to achieve quick detection of an event related desynchronization (ERD elicited by motor imagery (MI and recorded by electroencephalography (EEG. Conventional brain computer interfaces (BCI rely on sliding window classifiers in order to perform online continuous classification of the rest vs. MI classes. Based on this approach, the detection of abrupt changes in the sensorimotor power suffers from an intrinsic delay caused by the necessity of computing an estimate of variance across several tenths of a second. Here we propose to avoid explicitly computing the EEG signal variance, and estimate the ERD state directly from the voltage information, in order to reduce the detection latency. This is achieved by using a model suitable in situations characterized by abrupt changes of state, the MSM. In our implementation, the model takes the form of a Gaussian observation model whose variance is governed by two latent discrete states with Markovian dynamics. Its objective is to estimate the brain state (i.e., rest vs. ERD given the EEG voltage, spatially filtered by common spatial pattern (CSP, as observation. The two variances associated with the two latent states are calibrated using the variance of the CSP projection during rest and MI, respectively. The transition matrix of the latent states is optimized by the “quickest detection” strategy that minimizes a cost function of detection latency and false positive rate. Data collected by a dry EEG system from 50 healthy subjects, was used to assess performance and compare the MSM with several logistic regression classifiers of different sliding window lengths. As a result, the MSM achieves a significantly better tradeoff between latency, false positive and true positive rates. The proposed model could be used to achieve a more reactive and
Wang, Zhongjin; Wang, Shuang; Ding, Meiping
Quantitative EEG and event-related potential P300 were used to evaluate impairment of cerebral function in patient with partial epilepsy. W value was calculated (power of EEG δ and θ rhythm divided by power of α and β rhythm ) for the extent of focal cortical dysfunction. The W values in left partial epilepsy group, right partial epilepsy group and control group during interictal period compared. The latency, amplitude and reaction time of P300 potential change were observed in each groups. The W values in F(8), T(4) and T(6) regions in patients with left partial epilepsy (P P300 was 54. 76%, the latency, amplitude and reaction team were significantly different to the control group. The abnormal rate of P300 in left and right partial epilepsy groups were 77. 78% and 37.50%, respectively, and the former is significantly higher than the latter. The amplitudes of P300 in C(z) and P(z) of left partial epilepsy were significantly lower than those of right partial epilepsy and control group (P P300 in C(z) and P(z) of all partial epilepsy were significantly longer than those of control group (P < 0.05), however, no difference was found between left and right partial epilepsy. In partial epilepsy the cortical dysfunction occurs ipsilaterally to the epileptogenic zone, and extent of cortical dysfunction is positively correlated with duration of disease course. Cerebral dysfunction in left partial epilepsy is more severe than that in right partial epilepsy.
Beres, Anna M
The discovery of electroencephalography (EEG) over a century ago has changed the way we understand brain structure and function, in terms of both clinical and research applications. This paper starts with a short description of EEG and then focuses on the event-related brain potentials (ERPs), and their use in experimental settings. It describes the typical set-up of an ERP experiment. A description of a number of ERP components typically involved in language research is presented. Finally, the advantages and disadvantages of using ERPs in language research are discussed. EEG has an extensive use in today's world, including medical, psychology, or linguistic research. The excellent temporal resolution of EEG information allows one to track a brain response in milliseconds and therefore makes it uniquely suited to research concerning language processing.
Full Text Available Electroencephalograms (EEGs measure a brain signal that contains abundant information about the human brain function and health. For this reason, recent clinical brain research and brain computer interface (BCI studies use EEG signals in many applications. Due to the significant noise in EEG traces, signal processing to enhance the signal to noise power ratio (SNR is necessary for EEG analysis, especially for non-invasive EEG. A typical method to improve the SNR is averaging many trials of event related potential (ERP signal that represents a brain’s response to a particular stimulus or a task. The averaging, however, is very sensitive to variable delays. In this study, we propose two time delay estimation (TDE schemes based on a joint maximum likelihood (ML criterion to compensate the uncertain delays which may be different in each trial. We evaluate the performance for different types of signals such as random, deterministic, and real EEG signals. The results show that the proposed schemes provide better performance than other conventional schemes employing averaged signal as a reference, e.g., up to 4 dB gain at the expected delay error of 10°.
Krotkikh, S. S.; Kirichenko, L. O.
In this work we use discrete wavelet transform for analyzes the frequency structure of EEG signal with evoked potentials after effect of stimulus. The method for determining the response time to a stimulus, based on the evaluation of the wavelet entropy and relative wavelet entropy EEG, has been implemented.
Full Text Available The aim of this work is to show how Wavelet and S-transform Power Spectrum Analysis could be used for detection of the time-frequency spectral differences in series of Event-Related Potentials recorded from neurotic and stable persons. We compared the EEG records in simple counting task condition of 30 healthy subjects divided in stable and neurotic groups according to there scores in neuroticism scale on Eysenck's Personality Questionnaire. Significant differences were found in the theta and alpha EEG bands. The stable persons are characterized with more prominent theta and less prominent alpha spectral power compared to the neurotic group. The application of complex decomposed functions for both Wavelet and S-transform Power Spectrum Analysis showed to be more useful for the discrimination between both groups of subjects.
Badcock, Nicholas A; Preece, Kathryn A; de Wit, Bianca; Glenn, Katharine; Fieder, Nora; Thie, Johnson; McArthur, Genevieve
Background. Previous work has demonstrated that a commercial gaming electroencephalography (EEG) system, Emotiv EPOC, can be adjusted to provide valid auditory event-related potentials (ERPs) in adults that are comparable to ERPs recorded by a research-grade EEG system, Neuroscan. The aim of the current study was to determine if the same was true for children. Method. An adapted Emotiv EPOC system and Neuroscan system were used to make simultaneous EEG recordings in nineteen 6- to 12-year-old children under "passive" and "active" listening conditions. In the passive condition, children were instructed to watch a silent DVD and ignore 566 standard (1,000 Hz) and 100 deviant (1,200 Hz) tones. In the active condition, they listened to the same stimuli, and were asked to count the number of 'high' (i.e., deviant) tones. Results. Intraclass correlations (ICCs) indicated that the ERP morphology recorded with the two systems was very similar for the P1, N1, P2, N2, and P3 ERP peaks (r = .82 to .95) in both passive and active conditions, and less so, though still strong, for mismatch negativity ERP component (MMN; r = .67 to .74). There were few differences between peak amplitude and latency estimates for the two systems. Conclusions. An adapted EPOC EEG system can be used to index children's late auditory ERP peaks (i.e., P1, N1, P2, N2, P3) and their MMN ERP component.
Wascher, Edmund; Heppner, Holger; Hoffmann, Sven
In applied contexts, psychophysiological measures have a long tradition to evaluate the user state. EEG correlates that indicate mechanisms of information processing, however, are hardly accessible since discrete time stamps that are necessary for this approach are commonly not available in natural situations. However, eye blinks may close this gap. Eye blinks are assumed to mark distinct points in information processing, necessary to segment the incoming data stream. By using mobile EEG in a simulated working situation we demonstrate that eye-blink-related potentials provide reliable information about cognitive processing in distinct working environments. During cognitive tasks, an increase in the fronto-central N2 component as well as evoked theta activity can be shown, both indices of enhanced cognitive control. The posterior P3 is reduced during physical tasks (sorting of boxes), probably reflecting the more continuous nature of this task. The data are discussed within a model of dopaminergic modulation of blink activity that involves both task specific aspects like executive control and modulating influences of motivation or fatigue. © 2013.
Nicholas A. Badcock
Full Text Available Background. Previous work has demonstrated that a commercial gaming electroencephalography (EEG system, Emotiv EPOC, can be adjusted to provide valid auditory event-related potentials (ERPs in adults that are comparable to ERPs recorded by a research-grade EEG system, Neuroscan. The aim of the current study was to determine if the same was true for children.Method. An adapted Emotiv EPOC system and Neuroscan system were used to make simultaneous EEG recordings in nineteen 6- to 12-year-old children under “passive” and “active” listening conditions. In the passive condition, children were instructed to watch a silent DVD and ignore 566 standard (1,000 Hz and 100 deviant (1,200 Hz tones. In the active condition, they listened to the same stimuli, and were asked to count the number of ‘high’ (i.e., deviant tones.Results. Intraclass correlations (ICCs indicated that the ERP morphology recorded with the two systems was very similar for the P1, N1, P2, N2, and P3 ERP peaks (r = .82 to .95 in both passive and active conditions, and less so, though still strong, for mismatch negativity ERP component (MMN; r = .67 to .74. There were few differences between peak amplitude and latency estimates for the two systems.Conclusions. An adapted EPOC EEG system can be used to index children’s late auditory ERP peaks (i.e., P1, N1, P2, N2, P3 and their MMN ERP component.
Balogh, Lívia; Czobor, Pál
Error-related bioelectric signals constitute a special subgroup of event-related potentials. Researchers have identified two evoked potential components to be closely related to error processing, namely error-related negativity (ERN) and error-positivity (Pe), and they linked these to specific cognitive functions. In our article first we give a brief description of these components, then based on the available literature, we review differences in error-related evoked potentials observed in patients across psychiatric disorders. The PubMed and Medline search engines were used in order to identify all relevant articles, published between 2000 and 2009. For the purpose of the current paper we reviewed publications summarizing results of clinical trials. Patients suffering from schizophrenia, anorexia nervosa or borderline personality disorder exhibited a decrease in the amplitude of error-negativity when compared with healthy controls, while in cases of depression and anxiety an increase in the amplitude has been observed. Some of the articles suggest specific personality variables, such as impulsivity, perfectionism, negative emotions or sensitivity to punishment to underlie these electrophysiological differences. Research in the field of error-related electric activity has come to the focus of psychiatry research only recently, thus the amount of available data is significantly limited. However, since this is a relatively new field of research, the results available at present are noteworthy and promising for future electrophysiological investigations in psychiatric disorders.
Bekkedal, Marni Y V; Rossi, John; Panksepp, Jaak
At present there is no direct brain measure of basic emotional dynamics from the human brain. EEG provides non-invasive approaches for monitoring brain electrical activity to emotional stimuli. Event-related desynchronization/synchronization (ERD/ERS) analysis, based on power shifts in specific frequency bands, has some potential as a method for differentiating responses to basic emotions as measured during brief presentations of affective stimuli. Although there appears to be fairly consistent theta ERS in frontal regions of the brain during the earliest phases of processing affective auditory stimuli, the patterns do not readily distinguish between specific emotions. To date it has not been possible to consistently differentiate brain responses to emotion-specific affective states or stimuli, and some evidence to suggests the theta ERS more likely measures general arousal processes rather than yielding veridical indices of specific emotional states. Perhaps cortical EEG patterns will never be able to be used to distinguish discrete emotional states from the surface of the brain. The implications and limitations of such approaches for understanding human emotions are discussed. Copyright © 2011 Elsevier Ltd. All rights reserved.
Full Text Available The open-source toolbox “TopoToolbox” is a suite of functions that use sensor topography to calculate psychologically meaningful measures (similarity, magnitude, and timing from multisensor event-related EEG and MEG data. Using a GUI and data visualization, TopoToolbox can be used to calculate and test the topographic similarity between different conditions (Tian and Huber, 2008. This topographic similarity indicates whether different conditions involve a different distribution of underlying neural sources. Furthermore, this similarity calculation can be applied at different time points to discover when a response pattern emerges (Tian and Poeppel, 2010. Because the topographic patterns are obtained separately for each individual, these patterns are used to produce reliable measures of response magnitude that can be compared across individuals using conventional statistics (Davelaar et al. Submitted and Huber et al., 2008. TopoToolbox can be freely downloaded. It runs under MATLAB (The MathWorks, Inc. and supports user-defined data structure as well as standard EEG/MEG data import using EEGLAB (Delorme and Makeig, 2004.
Tian, Xing; Poeppel, David; Huber, David E
The open-source toolbox "TopoToolbox" is a suite of functions that use sensor topography to calculate psychologically meaningful measures (similarity, magnitude, and timing) from multisensor event-related EEG and MEG data. Using a GUI and data visualization, TopoToolbox can be used to calculate and test the topographic similarity between different conditions (Tian and Huber, 2008). This topographic similarity indicates whether different conditions involve a different distribution of underlying neural sources. Furthermore, this similarity calculation can be applied at different time points to discover when a response pattern emerges (Tian and Poeppel, 2010). Because the topographic patterns are obtained separately for each individual, these patterns are used to produce reliable measures of response magnitude that can be compared across individuals using conventional statistics (Davelaar et al. Submitted and Huber et al., 2008). TopoToolbox can be freely downloaded. It runs under MATLAB (The MathWorks, Inc.) and supports user-defined data structure as well as standard EEG/MEG data import using EEGLAB (Delorme and Makeig, 2004).
Freeman, Frederick G.
The increased use of automation in the cockpits of commercial planes has dramatically decreased the workload requirements of pilots, enabling them to function more efficiently and with a higher degree of safety. Unfortunately, advances in technology have led to an unexpected problem: the decreased demands on pilots have increased the probability of inducing 'hazardous states of awareness.' A hazardous state of awareness is defined as a decreased level of alertness or arousal which makes an individual less capable of reacting to unique or emergency types of situations. These states tend to be induced when an individual is not actively processing information. Under such conditions a person is likely to let his/her mind wander, either to internal states or to irrelevant external conditions. As a result, they are less capable of reacting quickly to emergency situations. Since emergencies are relatively rare, and since the high automated cockpit requires progressively decreasing levels of engagement, the probability of being seduced into a lowered state of awareness is increasing. This further decreases the readiness of the pilot to react to unique circumstances such as system failures. The HEM Lab at NASA-Langley Research Center has been studying how these states of awareness are induced and what the physiological correlates of these different states are. Specifically, they have been interested in studying electroencephalographic (EEG) measures of different states of alertness to determine if such states can be identified and, hopefully, avoided. The project worked on this summer involved analyzing the EEG and the event related potentials (ERP) data collected while subjects performed under two conditions. Each condition required subjects to perform a relatively boring vigilance task. The purpose of using these tasks was to induce a decreased state of awareness while still requiring the subject to process information. Each task involved identifying an infrequently
Full Text Available In brain-computer interface (BCI applications the detection of neural processing as revealed by event-related potentials (ERPs is a frequently used approach to regain communication for people unable to interact through any peripheral muscle control. However, the commonly used electroencephalography (EEG provides signals of low signal-to-noise ratio, making the systems slow and inaccurate. As an alternative noninvasive recording technique, the magnetoencephalography (MEG could provide more advantageous electrophysiological signals due to a higher number of sensors and the magnetic fields not being influenced by volume conduction. We investigated whether MEG provides higher accuracy in detecting event-related fields (ERFs compared to detecting ERPs in simultaneously recorded EEG, both evoked by a covert attention task, and whether a combination of the modalities is advantageous. In our approach, a detection algorithm based on spatial filtering is used to identify ERP/ERF components in a data-driven manner. We found that MEG achieves higher decoding accuracy (DA compared to EEG and that the combination of both further improves the performance significantly. However, MEG data showed poor performance in cross-subject classification, indicating that the algorithm's ability for transfer learning across subjects is better in EEG. Here we show that BCI control by covert attention is feasible with EEG and MEG using a data-driven spatial filter approach with a clear advantage of the MEG regarding DA but with a better transfer learning in EEG.
Reichert, Christoph; Dürschmid, Stefan; Heinze, Hans-Jochen; Hinrichs, Hermann
In brain-computer interface (BCI) applications the detection of neural processing as revealed by event-related potentials (ERPs) is a frequently used approach to regain communication for people unable to interact through any peripheral muscle control. However, the commonly used electroencephalography (EEG) provides signals of low signal-to-noise ratio, making the systems slow and inaccurate. As an alternative noninvasive recording technique, the magnetoencephalography (MEG) could provide more advantageous electrophysiological signals due to a higher number of sensors and the magnetic fields not being influenced by volume conduction. We investigated whether MEG provides higher accuracy in detecting event-related fields (ERFs) compared to detecting ERPs in simultaneously recorded EEG, both evoked by a covert attention task, and whether a combination of the modalities is advantageous. In our approach, a detection algorithm based on spatial filtering is used to identify ERP/ERF components in a data-driven manner. We found that MEG achieves higher decoding accuracy (DA) compared to EEG and that the combination of both further improves the performance significantly. However, MEG data showed poor performance in cross-subject classification, indicating that the algorithm's ability for transfer learning across subjects is better in EEG. Here we show that BCI control by covert attention is feasible with EEG and MEG using a data-driven spatial filter approach with a clear advantage of the MEG regarding DA but with a better transfer learning in EEG.
Adrian P Burgess
Full Text Available Although event-related potentials (ERPs are widely used to study sensory, perceptual and cognitive processes, it remains unknown whether they are phase-locked signals superimposed upon the ongoing electroencephalogram (EEG or result from phase-alignment of the EEG. Previous attempts to discriminate between these hypotheses have been unsuccessful but here a new test is presented based on the prediction that ERPs generated by phase-alignment will be associated with event-related changes in frequency whereas evoked-ERPs will not. Using empirical mode decomposition (EMD, which allows measurement of narrow-band changes in the EEG without predefining frequency bands, evidence was found for transient frequency slowing in recognition memory ERPs but not in simulated data derived from the evoked model. Furthermore, the timing of phase-alignment was frequency dependent with the earliest alignment occurring at high frequencies. Based on these findings, the Firefly model was developed, which proposes that both evoked and induced power changes derive from frequency-dependent phase-alignment of the ongoing EEG. Simulated data derived from the Firefly model provided a close match with empirical data and the model was able to account for i the shape and timing of ERPs at different scalp sites, ii the event-related desynchronization in alpha and synchronization in theta, and iii changes in the power density spectrum from the pre-stimulus baseline to the post-stimulus period. The Firefly Model, therefore, provides not only a unifying account of event-related changes in the EEG but also a possible mechanism for cross-frequency information processing.
Burgess, Adrian P
Although event-related potentials (ERPs) are widely used to study sensory, perceptual and cognitive processes, it remains unknown whether they are phase-locked signals superimposed upon the ongoing electroencephalogram (EEG) or result from phase-alignment of the EEG. Previous attempts to discriminate between these hypotheses have been unsuccessful but here a new test is presented based on the prediction that ERPs generated by phase-alignment will be associated with event-related changes in frequency whereas evoked-ERPs will not. Using empirical mode decomposition (EMD), which allows measurement of narrow-band changes in the EEG without predefining frequency bands, evidence was found for transient frequency slowing in recognition memory ERPs but not in simulated data derived from the evoked model. Furthermore, the timing of phase-alignment was frequency dependent with the earliest alignment occurring at high frequencies. Based on these findings, the Firefly model was developed, which proposes that both evoked and induced power changes derive from frequency-dependent phase-alignment of the ongoing EEG. Simulated data derived from the Firefly model provided a close match with empirical data and the model was able to account for i) the shape and timing of ERPs at different scalp sites, ii) the event-related desynchronization in alpha and synchronization in theta, and iii) changes in the power density spectrum from the pre-stimulus baseline to the post-stimulus period. The Firefly Model, therefore, provides not only a unifying account of event-related changes in the EEG but also a possible mechanism for cross-frequency information processing.
Verleger, Rolf; Kuniecki, Michal; Möller, Friderike
An important aspect of human motor control is the ability to resolve conflicting response tendencies. Here we used single-pulse transcranial magnetic stimulation (TMS) to track the time course of excitability changes in the primary motor hand areas (M1(HAND)) while the motor system resolved...... response conflicts. Healthy volunteers had to respond fast with their right and left index fingers to right- and left-pointing arrows. These central target stimuli were preceded by flanking arrows, inducing premature response tendencies which competed with correct response activation. The time point...... in the contralateral first dorsal interosseus muscle was taken as an index of corticospinal excitability. Guided by the previous LRP measurement, magnetic stimuli were applied 0-90 ms after the individual LRP peak, to cover the epoch of conflict resolution. When flankers were incompatible with the target, excitability...
Marshall, Peter J.; Young, Thomas; Meltzoff, Andrew N.
There is increasing interest in neurobiological methods for investigating the shared representation of action perception and production in early development. We explored the extent and regional specificity of EEG desynchronization in the infant alpha frequency range (6-9 Hz) during action observation and execution in 14-month-old infants.…
Babiloni, Claudio; Brancucci, Alfredo; Arendt-Nielsen, Lars; Babiloni, Fabio; Capotosto, Paolo; Carducci, Filippo; Cincotti, Febo; Romano, Lara; Chen, Andrew C N; Rossini, Paolo Maria
The authors delineated the time evolution of alpha event-related desynchronization over human frontal, parietal, and primary sensorimotor areas during the expectancy of a go/no-go task. The main issue under investigation was whether anticipatory processes impinged upon cortical areas in sequential or parallel mode. Compared with the control condition, in the experimental condition there was an Alpha 1 desynchronization over the central midline, an Alpha 2 desynchronization increasing over primary sensorimotor areas, and an Alpha 3 desynchronization increasing in parallel over bilateral primary sensorimotor areas. These processes had different temporal features. Results disclose an anticipatory activity of central midline areas and primary sensorimotor areas in both parallel and sequential modes. This reflects an adaptive, energy-consuming strategy rather than an economic waiting for the go stimulus.
Full Text Available We present a program (Ragu; Randomization Graphical User interface for statistical analyses of multichannel event-related EEG and MEG experiments. Based on measures of scalp field differences including all sensors, and using powerful, assumption-free randomization statistics, the program yields robust, physiologically meaningful conclusions based on the entire, untransformed, and unbiased set of measurements. Ragu accommodates up to two within-subject factors and one between-subject factor with multiple levels each. Significance is computed as function of time and can be controlled for type II errors with overall analyses. Results are displayed in an intuitive visual interface that allows further exploration of the findings. A sample analysis of an ERP experiment illustrates the different possibilities offered by Ragu. The aim of Ragu is to maximize statistical power while minimizing the need for a-priori choices of models and parameters (like inverse models or sensors of interest that interact with and bias statistics.
Koenig, Thomas; Kottlow, Mara; Stein, Maria; Melie-García, Lester
We present a program (Ragu; Randomization Graphical User interface) for statistical analyses of multichannel event-related EEG and MEG experiments. Based on measures of scalp field differences including all sensors, and using powerful, assumption-free randomization statistics, the program yields robust, physiologically meaningful conclusions based on the entire, untransformed, and unbiased set of measurements. Ragu accommodates up to two within-subject factors and one between-subject factor with multiple levels each. Significance is computed as function of time and can be controlled for type II errors with overall analyses. Results are displayed in an intuitive visual interface that allows further exploration of the findings. A sample analysis of an ERP experiment illustrates the different possibilities offered by Ragu. The aim of Ragu is to maximize statistical power while minimizing the need for a-priori choices of models and parameters (like inverse models or sensors of interest) that interact with and bias statistics.
Koivisto, Mika; Grassini, Simone; Hurme, Mikko; Salminen-Vaparanta, Niina; Railo, Henry; Vorobyev, Victor; Tallus, Jussi; Paavilainen, Teemu; Revonsuo, Antti
Clinical data and behavioral studies using transcranial magnetic stimulation (TMS) suggest right-hemisphere dominance for top-down modulation of visual processing in humans. We used concurrent TMS-EEG to directly test for hemispheric differences in causal influences of the right and left intraparietal cortex on visual event-related potentials (ERPs). We stimulated the left and right posterior part of intraparietal sulcus (IPS1) while the participants were viewing and rating the visibility of bilaterally presented Gabor patches. Subjective visibility ratings showed that TMS of right IPS shifted the visibility toward the right hemifield, while TMS of left IPS did not have any behavioral effect. TMS of right IPS, but not left one, reduced the amplitude of posterior N1 potential, 180-220 ms after stimulus-onset. The attenuation of N1 occurred bilaterally over the posterior areas of both hemispheres. Consistent with previous TMS-fMRI studies, this finding suggests that the right IPS has top-down control on the neural processing in visual cortex. As N1 most probably reflects reactivation of early visual areas, the current findings support the view that the posterior parietal cortex in the right hemisphere amplifies recurrent interactions in ventral visual areas during the time-window that is critical for conscious perception. Copyright © 2017. Published by Elsevier Ltd.
Oknina, L B; Kuptsova, S V; Romanov, A S; Masherov, E L; Kuznetsova, O A; Sharova, E V
The going of present pilot study is an analysis of features changes of EEG short pieces registered from 32 sites, at perception of musical melodies healthy examinees depending on logic (cognizance) and emotional (it was pleasant it was not pleasant) melody estimations. For this purpose changes of event-related synchronization/desynchronization, and also wavelet-synchrony of EEG-responses at 31 healthy examinees at the age from 18 till 60 years were compared. It is shown that at a logic estimation of music the melody cognizance is accompanied the event-related desynchronization in the left fronto-parietal-temporal area. At an emotional estimation of a melody the event-related synchronization in left fronto - temporal area for the pleasant melodies, desynchronization in temporal area for not pleasant and desynchronization in occipital area for the melodies which are not causing the emotional response is typical. At the analysis of wavelet-synchrony of EEG characterizing jet changes of interaction of cortical zones, it is revealed that the most distinct topographical distinctions concern type of processing of the heard music: logic (has learned-hasn't learned) or emotional (it was pleasant-it was not pleasant). If at an emotional estimation changes interhemispheric communications between associative cortical zones (central, frontal, temporal), are more expressed at logic - between inter - and intrahemispheric communications of projective zones of the acoustic analyzer (temporal area). It is supposed that the revealed event-related synchronization/desynhronization reflects, most likely, an activation component of an estimation of musical fragments whereas the wavelet-analysis provides guidance on character of processing of musical stimulus.
Spence, Jeffrey S; Brier, Matthew R; Hart, John; Ferree, Thomas C
Linear statistical models are used very effectively to assess task-related differences in EEG power spectral analyses. Mixed models, in particular, accommodate more than one variance component in a multisubject study, where many trials of each condition of interest are measured on each subject. Generally, intra- and intersubject variances are both important to determine correct standard errors for inference on functions of model parameters, but it is often assumed that intersubject variance is the most important consideration in a group study. In this article, we show that, under common assumptions, estimates of some functions of model parameters, including estimates of task-related differences, are properly tested relative to the intrasubject variance component only. A substantial gain in statistical power can arise from the proper separation of variance components when there is more than one source of variability. We first develop this result analytically, then show how it benefits a multiway factoring of spectral, spatial, and temporal components from EEG data acquired in a group of healthy subjects performing a well-studied response inhibition task. Copyright © 2011 Wiley Periodicals, Inc.
Shah, Ankoor S.; Bressler, Steven L.; Knuth, Kevin H.; Ding, Ming-Zhou; Mehta, Ashesh D.; Ulbert, Istvan; Schroeder, Charles E.
There are two opposing hypotheses about the brain mechanisms underlying sensory event-related potentials (ERPs). One holds that sensory ERPs are generated by phase resetting of ongoing electroencephalographic (EEG) activity, and the other that they result from signal averaging of stimulus-evoked neural responses. We tested several contrasting predictions of these hypotheses by direct intracortical analysis of neural activity in monkeys. Our findings clearly demonstrate evoked response contributions to the sensory ERP in the monkey, and they suggest the likelihood that a mixed (Evoked/Phase Resetting) model may account for the generation of scalp ERPs in humans.
Mørup, Morten; Hansen, Lars Kai; Arnfred, Sidse M.
The toolbox 'ERPWAVELAB' is developed for multi-channel time-frequency analysis of event related activity of EEG and MEG data. The toolbox provides tools for data analysis and visualization of the most commonly used measures of time-frequency transformed event related data as well as data...
Yamagishi, Yuya; Tsubone, Tadashi; Wada, Yasuhiro
We applied event-related potential (ERP) to reinforcement signals that are equivalent to reward and punishment signals.We conducted an electroencephalogram (EEG) in which volunteers identified the success or failure of a task. We confirmed that there were differences in the EEG depending on whether the task was successful or not and suggested that ERP might be used as a reward of reinforcement leaning. We used a support vector machine (SVM) for recognizing the P300. We selected the feature vector in SVM that was composed of averages of each 50 ms for each of the six channels (C3,Cz,C4,P3,Pz,P4) for a total of 700 ms. We can suggest that reinforcement learning using P300 can be performed accurately.
Ohla, Kathrin; Hudry, Julie; le Coutre, Johannes
Electrogustometry (EGM) is the standard tool to assess gustatory functions in clinical environments. The stimulation elicits a percept often described as metallic, sour or salty, also referred to as electric taste. To date, the neuronal mechanisms that underlie electric taste perception are not yet fully understood. Electroencephalographic (EEG) approaches will certainly complement behavioral procedures and, furthermore, extend the understanding of gustatory processing in general and disturbances of gustatory functions in particular. We used anodal pulses applied to the tip of the participants' tongue while EEG was recorded. The major disadvantage of combining EEG and EGM, namely the electrical stimulation artifact, was overcome by means of Independent Component Analysis (ICA), which separated the EGM artifact from the neural portion of the EEG. After artifact correction, we found a largely uncontaminated electrogustatory event-related potential (eGERP) at both individual and group level. Furthermore, source analysis revealed an early involvement of bilateral insular cortices and the adjacent operculi, the areas comprising the primary taste cortex. The procedures, described in detail, pave the way for the eGERP to become an affordable and objective tool for the assessment of taste function, and thus to complement behavioral measures (i.e. EGM detection thresholds). Furthermore, they render the access to different levels of the electrogustatory processing pathway possible and by doing so they may aid the identification and localisation of lesions that cause taste disturbances.
Andrew, Colin; Fein, George
It has been proposed that event-related oscillation (ERO) measures of EEG activity recorded in P300 tasks provide more powerful biomarkers of alcoholism than event-related potential (ERP) measures. This study examines this question in a group of long-term abstinent alcoholics (LTAAs). EEGs were recorded on 48 LTAAs and 48 age and gender-matched nonalcoholic controls (NACs) during the performance of a 3-condition visual target detection task. The event-related data were analyzed to extract ERP amplitude measures and total and evoked ERO power measures. Data were analyzed using multivariate analysis of covariance to determine the contributions of ERO versus ERP measures to discriminate between the LTAA versus NAC groups. The LTAA group showed significantly lower evoked delta ERO power and total delta and theta ERO power compared to the control group. The evoked and total ERO power measures provide an alternative (but not more powerful) representation of the group difference than does P3b amplitude. There was a weak suggestion that nonphase-locked theta ERO power (which contributes to total ERO power) might provide independent discriminatory information. Reduced evoked ERO power in the response to target stimuli provided an alternative and comparable representation of the reduced P3b amplitude in LTAA. This is not surprising as the evoked ERO power measures are derived from time-frequency representations of the ERP waveform. Induced theta oscillations might provide independent discriminatory information beyond ERP amplitude measures, but separate analysis of the event-related nonphase-locked activity is required to investigate this further.
Wessel, J.R.; Ullsperger, M.
Following the development of increasingly precise measurement instruments and fine-grain analysis tools for electroencephalographic (EEG) data, analysis of single-trial event-related EEG has considerably widened the utility of this non-invasive method to investigate brain activity. Recently,
Vznik EEG aktivity v mozku, rozdělení EEG vln podle frekvence, způsob měření EEG, přístroje pro měření EEG. Dále popis biofeedback metody, její možnosti a návrh biofeedback her. Popis zpracování naměřených EEG signálů. EEG generation, brain rhythms, methods of recording EEG, EEG recorder. Description of biofeedback, potentialities of biofeedback, proposal of biofeedback games. Description of processing measured EEG signals. B
Singh, R; Shukla, R.; Dalal, P. K.; Sinha, P.K.; Trivedi, J.K.
P300 component of the event related potential (ERP) provides one neurophysiological index of cognitive dysfunction in depression. Forty subjects fulfilling DSM-III criteria for depression were compared to 40 age and sex matched normal controls. The P300 was recorded using the auditory odd-ball paradigm. Depressives had a significantly prolonged P300 latency and reduced P300 amplitude as compared to the controls. The P300 latency showed a significant positive correlation with age of the patien...
Simon, David M.; Noel, Jean-Paul; Wallace, Mark T.
Asynchronous arrival of multisensory information at the periphery is a ubiquitous property of signals in the natural environment due to differences in the propagation time of light and sound. Rapid adaptation to these asynchronies is crucial for the appropriate integration of these multisensory signals, which in turn is a fundamental neurobiological process in creating a coherent perceptual representation of our dynamic world. Indeed, multisensory temporal recalibration has been shown to occur at the single trial level, yet the mechanistic basis of this rapid adaptation is unknown. Here, we investigated the neural basis of rapid recalibration to audiovisual temporal asynchrony in human participants using a combination of psychophysics and electroencephalography (EEG). Consistent with previous reports, participant’s perception of audiovisual temporal synchrony on a given trial (t) was influenced by the temporal structure of stimuli on the previous trial (t−1). When examined physiologically, event related potentials (ERPs) were found to be modulated by the temporal structure of the previous trial, manifesting as late differences (>125 ms post second-stimulus onset) in central and parietal positivity on trials with large stimulus onset asynchronies (SOAs). These findings indicate that single trial adaptation to audiovisual temporal asynchrony is reflected in modulations of late evoked components that have previously been linked to stimulus evaluation and decision-making. PMID:28381993
Onofrj, M; Fulgente, T; Thomas, A
Visual evoked potentials (VEPs) to central and lateral half field patterned stimuli of 1, 2 and 4 cycles per degree (cpd) were recorded in a patient with Dorsal Simultanagnosia due to bilateral lesions of parieto-occipital junction. VEPs consisted of the normal N1-P1-N2 components with same spatial frequency sensitivity as in controls. VEPs had similar latencies and amplitudes whether the patient could see or not the patterned stimuli. Event related potentials (ERPs) to visual and acoustic odd-ball paradigm were also recorded in the same patient. Visual ERPs consisted of an early NA-effect, and of N2-P3 components. P3 was recorded only from frontal, central and temporal derivations. The topographical P3 abnormality was, however, the same for visual and acoustic odd-ball paradigms. The amplitude of P3 was smaller when the patient missed visual stimuli. These findings show that severe bilateral lesions at the parieto-occipital junction, inducing Simultanagnosia, do not obliterate VEPs or ERPs components.
Atchley, Rachel; Klee, Dan; Memmott, Tabatha; Goodrich, Elena; Wahbeh, Helané; Oken, Barry
Objective This cross-sectional study evaluated event-related potentials (ERPs) across three groups: naïve, novice, and experienced meditators as potential physiological markers of mindfulness meditation competence. Methods Electroencephalographic (EEG) data was collected during a target tone detection task and a Breath Counting task. The Breath Counting task served as the mindfulness meditation condition for the novice and experienced meditator groups. Participants were instructed to respond to target tones with a button press in the first task (Tones), and then ignore the primed tones while breath counting. The primary outcomes were ERP responses to target tones, namely the N2 and P3, as markers of stimulus discrimination and attention, respectively. Results As expected, P3 amplitudes elicited by target tones were attenuated within groups during the Breath Counting task in comparison to the Tones task (p < .001). There was a task by group interaction for P3 (p = .039). Both meditator groups displayed greater change in peak-to-trough P3 amplitudes, with higher amplitudes during the Tones condition and more pronounced reductions in P3 amplitudes during the Breath Counting meditation task in comparison to the naïve group. Conclusions Meditators had stronger P3 amplitude responses to target tones when instructed to attend to the tones, and a greater attenuation of P3 amplitudes when instructed to ignore the same tones during the Breath Counting task. This study introduces the idea of identifying ERP markers as a means of measuring mindfulness meditation competence, and results suggest this may be a valid approach. This information has the potential to improve mindfulness meditation interventions by allowing objective assessment of mindfulness meditation quality. PMID:26850995
Razavipour, Fatemeh; Sameni, Reza
Event related potentials (ERP) are time-locked electrical activities of the brain in direct response to a specific sensory, cognitive, or motor stimulus. ERP components, such as the P300 wave, which are involved in the process of decision-making, help scientists diagnose specific cognitive disabilities. In this study, we utilize the angles between multichannel electroencephalogram (EEG) subspaces in different frequency bands, as a similarity factor for studying the spatial coherency between ERP frequency responses. A matched filter is used to enhance the ERP from background EEG. While previous researches have focused on frequencies below 10 Hz, as the major frequency band of ERP, it is shown that by using the proposed method, significant ERP-related information can also be found in the 25-40 Hz band. These frequency bands are selected by calculating the correlation coefficient between P300 response segments and synthetic EEG, and ERP segments without P300 waves, and by rejecting the bands having the most association with background EEG and non-P300 components. The significance of the results is assessed by real EEG acquired in brain computer interface experiments versus synthetic EEG produced by existing methods in the literature, to assure that the results are not systematic side effects of the proposed framework. The overall results show that the equivalent dipoles corresponding to narrow-band events in the brain are spatially coherent within different (not necessarily adjacent) frequency bands. The results of this study can lead into novel perspectives in ERP studies. Copyright © 2015 Elsevier B.V. All rights reserved.
Aniyan, Arun Kumar; Philip, Ninan Sajeeth; Samar, Vincent J; Desjardins, James A; Segalowitz, Sidney J
Event related potentials (ERPs) are very feeble alterations in the ongoing electroencephalogram (EEG) and their detection is a challenging problem. Based on the unique time-based parameters derived from wavelet coefficients and the asymmetry property of wavelets a novel algorithm to separate ERP components in single-trial EEG data is described. Though illustrated as a specific application to N170 ERP detection, the algorithm is a generalized approach that can be easily adapted to isolate different kinds of ERP components. The algorithm detected the N170 ERP component with a high level of accuracy. We demonstrate that the asymmetry method is more accurate than the matching wavelet algorithm and t-CWT method by 48.67 and 8.03 percent, respectively. This paper provides an off-line demonstration of the algorithm and considers issues related to the extension of the algorithm to real-time applications. Copyright © 2014 Elsevier B.V. All rights reserved.
Takahashi, M; Arito, H
The objective of this study was to examine the relationship between post-nap measures of alertness and performance and non-rapid eye movement (NREM) sleep and parasympathetic activity during brief naps. Thirty healthy subjects were randomly assigned to no-nap, 15-min, and 45-min nap conditions after normal home sleep at prior night. Each nap was taken after lunch and monitored by electroencephalogram (EEG), electromyogram, electrooculogram, and electrocardiogram (ECG). Deep NREM sleep was quantified by EEG delta power density and the parasympathetic activity was quantified by the ECG high-frequency (HF) component of R-R interval variability during the 15- and 45-min naps. The P300 event-related potential, subjective sleepiness, and performance on a 90-min English transcription task were measured 30 min and 3 hr after the naps and tested for their association with the EEG and ECG measures. A positive correlation was obtained between EEG delta power density during the naps and P300 latency 30 min after the naps (r = 0.476, p sleep inertia prolongs the P300 latency immediately after the naps, and that the parasympathetic predominance during the naps may improve subsequent alertness as assessed by the shortened P300 latency 3 hr after the naps.
Bhaganagarapu, Kaushik; Jackson, Graeme D; Abbott, David F
Event-related ICA (eICA) is a partially data-driven analysis method for event-related fMRI that is particularly suited to analysis of simultaneous EEG-fMRI of patients with epilepsy. EEG-fMRI studies in epileptic patients are typically analyzed using the general linear model (GLM), often with assumption that the onset and offset of neuronal activity match EEG event onset and offset, the neuronal activation is sustained at a constant level throughout the epileptiform event and that associated fMRI signal changes follow the canonical HRF. The eICA method allows for less constrained analyses capable of detecting early, non-canonical responses. A key step of eICA is the initial deconvolution which can be confounded by various sources of structured noise present in the fMRI signal. To help overcome this, we have extend the eICA procedure by utilizing a fully standalone and automated fMRI de-noising procedure to process the fMRI data from an EEG-fMRI acquisition prior to running eICA. Specifically we first apply ICA to the entire fMRI time-series and use a classifier to remove noise-related components. The automated objective de-noiser, "Spatially Organized Component Klassificator" (SOCK) is used; it has previously been shown to distinguish a substantial fraction of noise from true activation, without rejecting the latter, in resting-state fMRI. A second ICA is then performed, this time on the event-related response estimates derived from the denoised data (according to the usual eICA procedure). We hypothesize that SOCK + eICA has the potential to be more sensitive than eICA alone. We test the effectiveness of SOCK by comparing activation obtained in an eICA analysis of EEG-fMRI data with and without the use of SOCK for 14 patients with rolandic epilepsy who exhibited stereotypical IEDs arising from a focus in the rolandic fissure.
Full Text Available Event-related ICA (eICA is a partially data-driven analysis method for event-related fMRI that is particularly suited to analysis of simultaneous EEG-fMRI of patients with epilepsy. EEG-fMRI studies in epileptic patients are typically analyzed using the general linear model (GLM, often with assumption that the onset and o□set of neuronal activity match EEG event onset and o□set, the neuronal activation is sustained at a constant level throughout the epileptiform event and that associated fMRI signal changes follow the canonical HRF. The eICA method allows for less constrained analyses capable of detecting early, non-canonical responses. A key step of eICA is the initial deconvolution which can be confounded by various sources of structured noise present in the fMRI signal. To help overcome this, we have extend the eICA procedure by utilizing a fully standalone and automated fMRI de-noising procedure to process the fMRI data from an EEG-fMRI acquisition prior to running eICA. Specifically we first apply ICA to the entire fMRI time-series and use a classifier to remove noise-related components. The automated objective de-noiser, Spatially Organised Component Klassificator (SOCK is used; it has previously been shown to distinguish a substantial fraction of noise from true activation, without rejecting the latter, in resting-state fMRI. A second ICA is then performed, this time on the event-related response estimates derived from the denoised data (according to the usual eICA procedure. We hypothesize that SOCK + eICA has the potential to be more sensitive than eICA alone. We test the e□effectiveness of SOCK by comparing activation obtained in an eICA analysis of EEG-fMRI data with and without the use of SOCK for 14 patients with rolandic epilepsy who exhibited stereotypical IEDs arising from a focus in the rolandic fissure.
Full Text Available In EEG research, the classical Event-Related Potential (ERP model often proves to be a limited method when studying complex brain dynamics. For this reason, spectral techniques adapted from signal processing such as Event-Related Spectral Perturbation (ERSP – and its variant ERS (Event-Related Synchronization and ERD (Event-Related Desynchronization – have been used over the past 20-years. They represent average spectral changes in response to a stimulus.These spectral methods do not have strong consensus for comparing pre and post-stimulus activity. When computing ERSP, pre-stimulus baseline removal is usually performed after averaging the spectral estimate of multiple trials. Correcting the baseline of each single-trial prior to averaging spectral estimates is an alternative baseline correction method. However, we show that this method leads to positively skewed post-stimulus ERSP values. We eventually present new single-trial based ERSP baseline correction methods that perform trial normalization or centering prior to applying classical baseline correction methods. We show that single-trial correction methods minimize the contribution of artifactual data trials with high-amplitude spectral estimates and are robust to outliers when performing statistical inference testing. We then characterize these methods in terms of their time-frequency responses and behavior when performing statistical inference testing compared to classical ERSP methods.
Tanaka, Motoshi; Miyashita, Takayuki; Inoue, Hiroshi; Niiyama, Yoshitsugu
As a fundamental study on the objective evaluation of TV picture degradation by electromagnetic noise with visual physiological information, the electroencephalogram (EEG) activity was measured when a still TV picture was degraded by the burst noise whose rms and duration were changed. A degradation was subjectively evaluated by three-grade impairment scale of “Not Annoying”, “Slightly Annoying”, and “Annoying”. Measured EEGs were analyzed by an averaging technique. In the results, the amplitude of the event related potential P300 becomes larger when the subjects feel the noise “Annoying”.
Fogh, Kasper Wandahl; Greve, Marc
This project is investigating EEG-technology, and how this can be used in games. Specificly, we are investigating how EEG measures brain activity, how you can interact with the technology and how good it works. Furthermore we investigate how the interaction can be used in a game. We investigate through theory on EEG, classification algorithms, Emotivs software and our own game working with both active and passive interaction. We found that even though the technology is new at a consumerlev...
The relationship among brain electrophysiological activity, motor activity, and cognition has been a matter of great interest. For example, it has been discussed whether hippocampal theta rhythm reflects motor activity or cognitive activity, whereas it is widely accepted that the P300 event-related potential (ERP) reflects cognitive processes such as updating working memory. Here, we investigated the interrelationships among motor activity, hippocampal theta rhythm, and hippocampal P300 ERP using electrophysiological and behavioral data recorded from rats performing an auditory discrimination task (i.e., the auditory oddball paradigm) in a chamber with and without a running-wheel. We found that the hippocampal theta rhythm generated during locomotion codes information about self-motion, and event-related increases in hippocampal theta rhythm observed when rats performed the auditory discrimination cognitive task reflect a change in motor behavior after learning the cognitive task. Interestingly, the hippocampal P300 ERP occurred coincidently with increases in the power and frequency of hippocampal theta rhythm. In addition, we found that changes in theta rhythm observed during spontaneous wheel running without performing a cognitive task as well as when performing the cognitive task are associated with changes in delta- and gamma-band EEG activities. These major findings are discussed with respect to current hypotheses regarding P300 ERP and theta-, delta-, and gamma-band EEG activities in brain functions. Copyright © 2010 Wiley-Liss, Inc.
Atchley, Rachel; Ellingson, Roger; Klee, Daniel; Memmott, Tabatha; Oken, Barry
In this experiment, we developed and evaluated the Portland Arithmetic Stress Task (PAST) as a cognitive stressor to evaluate acute and sustained stress reactivity for event-related potential (ERP) studies. The PAST is a titrated arithmetic task adapted from the Montreal Imaging Stress Task (MIST), with added experimental control over presentation parameters, improved and synchronized acoustic feedback and generation of timing markers needed for physiological analyzes of real-time brain activity. Thirty-one older adults (M = 60 years) completed the PAST. EEG was recorded to assess feedback-related negativity (FRN) and the magnitude of the stress response through autonomic nervous system activity and salivary cortisol. Physiological measures other than EEG included heart rate, respiration rate, heart rate variability, blood pressure and salivary cortisol. These measures were collected at several time points throughout the task. Feedback-related negativity evoked-potential responses were elicited and they significantly differed depending on whether positive or negative feedback was received. The PAST also increased systolic blood pressure, heart rate variability and respiration rates compared to a control condition attentional task. These preliminary results suggest that the PAST is an effective cognitive stressor. Successful measurement of the feedback-related negativity suggests that the PAST is conducive to EEG and time-sensitive ERP experiments. Moreover, the physiological findings support the PAST as a potent method for inducing stress in older adult participants. Further research is needed to confirm these results, but the PAST shows promise as a tool for cognitive stress induction for time-locked event-related potential experiments.
Full Text Available ERPLAB Toolbox is a freely available, open-source toolbox for processing and analyzing event-related potential (ERP data in the MATLAB environment. ERPLAB is closely integrated with EEGLAB, a popular open-source toolbox that provides many EEG preprocessing steps and an excellent user interface design. ERPLAB adds to EEGLAB’s EEG processing functions, providing additional tools for filtering, artifact detection, re-referencing, and sorting of events, among others. ERPLAB also provides robust tools for averaging EEG segments together to create averaged ERPs, for creating difference waves and other recombinations of ERP waveforms through algebraic expressions, for filtering and re-referencing the averaged ERPs, for plotting ERP waveforms and scalp maps, and for quantifying several types of amplitudes and latencies. ERPLAB’s tools can be accessed either from an easy-to-learn graphical user interface or from MATLAB scripts, and a command history function makes it easy for users with no programming experience to write scripts. Consequently, ERPLAB provides both ease of use and virtually unlimited power and flexibility, making it appropriate for the analysis of both simple and complex ERP experiments. Several forms of documentation are available, including a detailed user’s guide, a step-by-step tutorial, a scripting guide, and a set of video-based demonstrations.
Jausovec, Norbert; Habe, Katarina
The event-related responses of 18 individuals were recorded while they were listening to 3 music clips of 6 s duration which were repeated 30 times each. The music clips differed in the level of their complex structure, induced mood, musical tempo and prominent frequency. They were taken from Mozart's sonata (K. 448), and Brahms' Hungarian dance (no. 5). The third clip was a simplified version of the theme taken from Haydn's symphony (no. 94) played by a computer synthesizer. Significant differences in induced event-related desynchronization between the 3 music clips were only observed in the lower-1 alpha band which is related to attentional processes. A similar pattern was observed for the coherence measures. While respondents listened to the Mozart clip, coherence in the lower alpha bands increased more, whereas in the gamma band a less pronounced increase was observed as compared with the Brahms and Haydn clips. The clustering of the three clips based on EEG measures distinguished between the Mozart clip on the one hand, and the Haydn and Brahms clips on the other, even though the Haydn and Brahms clips were at the opposite extremes with regard to the mood they induced in listeners, musical tempo, and complexity of structure. This would suggest that Mozart's music--with no regard to the level of induced mood, musical tempo and complexity--influences the level of arousal. It seems that modulations in the frequency domain of Mozart's sonata have the greatest influence on the reported neurophysiological activity.
Wang, Xue; Ding, Mingzhou
Recent reports show that theta-band (4-7 Hz) power is enhanced by target detection in the standard oddball paradigm, which, together with increased P300, is considered as providing complementary neural mechanisms supporting memory and attention processes. We hypothesize that the increased theta event-related synchronization (ERS) may stem largely from not accounting for the trial-to-trial variability of the P300 evoked component and may not reflect a separate mechanism for target detection and related cognitive processing. EEG was recorded from healthy volunteers performing visual and auditory odd-ball tasks. Ongoing-activity was obtained using two methods: (a) subtracting the ASEO-estimated (analysis of single-trial event-related potentials and ongoing-activity) single-trial ERP from corresponding single-trial EEG time series and (b) subtracting the average event-related potential (AERP) from single-trial EEG time series. Event-related oscillatory activities obtained from the two methods were compared. The amount of power increase in the theta-band was greatly attenuated for the single-trial based method relative to the traditional AERP method. Our results suggest that the theta-ERS arises largely from not modeling the trial-to-trial variability of the P300. ERP components such as the P300 vary from trial-to-trial in both amplitude and latency. The traditional AERP method leaves traces of evoked responses in the residual data which can negatively impact the inference of ongoing oscillatory dynamics. Thus, caution should be exercised in interpreting such phenomena in basic and clinical contexts. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Wessel, Jan R; Ullsperger, Markus
Following the development of increasingly precise measurement instruments and fine-grain analysis tools for electroencephalographic (EEG) data, analysis of single-trial event-related EEG has considerably widened the utility of this non-invasive method to investigate brain activity. Recently, independent component analysis (ICA) has become one of the most prominent techniques for increasing the feasibility of single-trial EEG. This blind source separation technique extracts statistically independent components (ICs) from the EEG raw signal. By restricting the signal analysis to those ICs representing the processes of interest, single-trial analysis becomes more flexible. Still, the selection-criteria for in- or exclusion of certain ICs are largely subjective and unstandardized, as is the actual selection process itself. We present a rationale for a bottom-up, data-driven IC selection approach, using clear-cut inferential statistics on both temporal and spatial information to identify components that significantly contribute to a certain event-related brain potential (ERP). With time-range being the only necessary input, this approach considerably reduces the pre-assumptions for IC selection and promotes greater objectivity of the selection process itself. To test the validity of the approach presented here, we present results from a simulation and re-analyze data from a previously published ERP experiment on error processing. We compare the ERP-based IC selections made by our approach to the selection made based on mere signal power. The comparison of ERP integrity, signal-to-noise ratio, and single-trial properties of the back-projected ICs outlines the validity of the approach presented here. In addition, functional validity of the extracted error-related EEG signal is tested by investigating whether it is predictive for subsequent behavioural adjustments. Copyright © 2010 Elsevier Inc. All rights reserved.
Full Text Available BACKGROUND: The recording of olfactory and trigeminal chemosensory event-related potentials (ERPs has been proposed as an objective and non-invasive technique to study the cortical processing of odors in humans. Until now, the responses have been characterized mainly using across-trial averaging in the time domain. Unfortunately, chemosensory ERPs, in particular, olfactory ERPs, exhibit a relatively low signal-to-noise ratio. Hence, although the technique is increasingly used in basic research as well as in clinical practice to evaluate people suffering from olfactory disorders, its current clinical relevance remains very limited. Here, we used a time-frequency analysis based on the wavelet transform to reveal EEG responses that are not strictly phase-locked to onset of the chemosensory stimulus. We hypothesized that this approach would significantly enhance the signal-to-noise ratio of the EEG responses to chemosensory stimulation because, as compared to conventional time-domain averaging, (1 it is less sensitive to temporal jitter and (2 it can reveal non phase-locked EEG responses such as event-related synchronization and desynchronization. METHODOLOGY/PRINCIPAL FINDINGS: EEG responses to selective trigeminal and olfactory stimulation were recorded in 11 normosmic subjects. A Morlet wavelet was used to characterize the elicited responses in the time-frequency domain. We found that this approach markedly improved the signal-to-noise ratio of the obtained EEG responses, in particular, following olfactory stimulation. Furthermore, the approach allowed characterizing non phase-locked components that could not be identified using conventional time-domain averaging. CONCLUSION/SIGNIFICANCE: By providing a more robust and complete view of how odors are represented in the human brain, our approach could constitute the basis for a robust tool to study olfaction, both for basic research and clinicians.
Poikonen, Hanna; Alluri, Vinoo; Brattico, Elvira
Brain responses to discrete short sounds have been studied intensively using the event-related potential (ERP) method, in which the electroencephalogram (EEG) signal is divided into epochs time-locked to stimuli of interest. Here we introduce and apply a novel technique which enables one to isolate...... ERPs in human elicited by continuous music. The ERPs were recorded during listening to a Tango Nuevo piece, a deep techno track and an acoustic lullaby. Acoustic features related to timbre, harmony, and dynamics of the audio signal were computationally extracted from the musical pieces. Negative...... changes in these musical features, long phases of low values that precede a rapid increase – and that we will call Preceding Low-Feature Phases – followed by a rapid increase enhanced the amplitudes of N100 and P200 responses. These ERP responses resembled those to simpler sounds, making it possible...
Takata, Yohei; Kondo, Toshiyuki; Saeki, Midori; Izawa, Jun; Takeda, Kotaro; Otaka, Yohei; It, Koji
Recently there has been an increase in the number of stroke patients with motor paralysis. Appropriate re-afferent sensory feedback synchronized with a voluntary motor intention would be effective for promoting neural plasticity in the stroke rehabilitation. Therefore, BCI technology is considered to be a promising approach in the neuro-rehabilitation. To estimate human motor intention, an event-related desynchronization (ERD), a feature of electroencephalogram (EEG) evoked by motor execution or motor imagery is usually used. However, there exists various factors that affect ERD production, and its neural mechanism is still an open question. As a preliminary stage, we evaluate mutual effects of intrinsic (voluntary motor imagery) and extrinsic (visual and somatosensory stimuli) factors on the ERD production. Experimental results indicate that these three factors are not always additively interacting with each other and affecting the ERD production.
Hajcak, Greg; MacNamara, Annmarie; Olvet, Doreen M
Progress in the study of emotion and emotion regulation has increasingly been informed by neuroscientific methods. This article focuses on two components of the event-related potential (ERP)--the P300 and the late positive potential (LPP)--and how they can be used to understand the interaction between the more automatic and controlled processing of emotional stimuli. Research is reviewed exploring: the dynamics of emotional response as indexed at early and late latencies; neurobiological correlates of emotional response; individual and developmental differences; ways in which the LPP can be utilized as a measure of emotion regulation. Future directions for the application of ERP/electroencephalogram (EEG) in achieving a more complete understanding of emotional processing and its regulation are presented.
Bachiller, Alejandro; Poza, Jesús; Gómez, Carlos; Molina, Vicente; Suazo, Vanessa; Hornero, Roberto
Objective. The aim of this research is to explore the coupling patterns of brain dynamics during an auditory oddball task in schizophrenia (SCH). Approach. Event-related electroencephalographic (ERP) activity was recorded from 20 SCH patients and 20 healthy controls. The coupling changes between auditory response and pre-stimulus baseline were calculated in conventional EEG frequency bands (theta, alpha, beta-1, beta-2 and gamma), using three coupling measures: coherence, phase-locking value and Euclidean distance. Main results. Our results showed a statistically significant increase from baseline to response in theta coupling and a statistically significant decrease in beta-2 coupling in controls. No statistically significant changes were observed in SCH patients. Significance. Our findings support the aberrant salience hypothesis, since SCH patients failed to change their coupling dynamics between stimulus response and baseline when performing an auditory cognitive task. This result may reflect an impaired communication among neural areas, which may be related to abnormal cognitive functions.
Full Text Available Abstract Background The event-related desynchronization (ERD in EEG is known to appear during motor imagery, and is thought to reflect cortical processing for motor preparation. The aim of this study is to examine the modulation of ERD with motor impairment in ALS patients. ERD during hand motor imagery was obtained from 8 ALS patients with a variety of motor impairments. ERD was also obtained from age-matched 11 healthy control subjects with the same motor task. The magnitude and frequency of ERD were compared between groups for characterization of ALS specific changes. Results The ERD of ALS patients were significantly smaller than those of control subjects. Bulbar function and ERD were negatively correlated in ALS patients. Motor function of the upper extremities did was uncorrelated with ERD. Conclusions ALS patients with worsened bulbar scales may show smaller ERD. Motor function of the upper extremities did was uncorrelated with ERD.
Full Text Available The perceptual processing of emotional stimuli is subject to the regulation of brain function. This study investigated whether frontal electroencephalography (EEG alpha asymmetry at resting conditions predicted the evaluation of emotional picture stimuli by event-related potentials (ERPs. In this study, participants first completed a 2-min resting task, and then passively viewed emotional pictures. The results showed that left active individuals had smaller frontal EEG alpha asymmetry scores to negative pictures than to positive and neutral pictures, whereas right active individuals had similar frontal EEG alpha asymmetry scores to negative, positive, and neutral pictures. Furthermore, the study showed a larger P300 to negative pictures than to positive and neutral pictures for left active individuals; however, there were no significant ERP differences to negative, positive, and neutral pictures for right active individuals. These findings suggest that frontal EEG alpha asymmetry at resting conditions can reflect interindividual differences in emotional perception tendencies to emotional picture stimuli.
Bai, Yan; Yao, Zhong; Cong, Fengyu; Zhang, Linlin
There is an increasing interest regarding the use of electroencephalography (EEG) in social commerce and electronic commerce (e-commerce) research. There are several reviews in the field of social commerce or e-commerce; these have great potential value and mining them is fundamental and significant. To our knowledge, EEG is rarely applied to study these. In this study, we examined the neural correlates of social commerce reviews (SCRs) and e-commerce reviews (ECRs) by using them as stimuli to evoke event-related potentials. All SCRs were from friends through a social media platform, whereas ECRs were from strangers through an e-commerce platform. The experimental design was similar to that of a priming paradigm, and included 40 pairs of stimuli consisting of product information (prime stimulus) and reviews (target stimulus). The results showed that the P300 component was successfully evoked by SCR and ECR stimuli. Moreover, the P300 components elicited by SCRs had higher amplitudes than those elicited by ECRs. These findings indicate that participants paid more attention to SCRs than to ECRs. In addition, the associations between neural responses and reviews in social commerce have the potential to assist companies in studying consumer behaviors, thus permitting them to enhance their social commerce strategies.
Mu, Yan; Kitayama, Shinobu; Han, Shihui; Gelfand, Michele J
Humans are unique among all species in their ability to develop and enforce social norms, but there is wide variation in the strength of social norms across human societies. Despite this fundamental aspect of human nature, there has been surprisingly little research on how social norm violations are detected at the neurobiological level. Building on the emerging field of cultural neuroscience, we combine noninvasive electroencephalography (EEG) with a new social norm violation paradigm to examine the neural mechanisms underlying the detection of norm violations and how they vary across cultures. EEG recordings from Chinese and US participants (n = 50) showed consistent negative deflection of event-related potential around 400 ms (N400) over the central and parietal regions that served as a culture-general neural marker of detecting norm violations. The N400 at the frontal and temporal regions, however, was only observed among Chinese but not US participants, illustrating culture-specific neural substrates of the detection of norm violations. Further, the frontal N400 predicted a variety of behavioral and attitudinal measurements related to the strength of social norms that have been found at the national and state levels, including higher culture superiority and self-control but lower creativity. There were no cultural differences in the N400 induced by semantic violation, suggesting a unique cultural influence on social norm violation detection. In all, these findings provided the first evidence, to our knowledge, for the neurobiological foundations of social norm violation detection and its variation across cultures.
Iturrate, I.; Chavarriaga, R.; Montesano, L.; Minguez, J.; Millán, JdR
Objective. A fundamental issue in EEG event-related potentials (ERPs) studies is the amount of data required to have an accurate ERP model. This also impacts the time required to train a classifier for a brain-computer interface (BCI). This issue is mainly due to the poor signal-to-noise ratio and the large fluctuations of the EEG caused by several sources of variability. One of these sources is directly related to the experimental protocol or application designed, and may affect the amplitude or latency of ERPs. This usually prevents BCI classifiers from generalizing among different experimental protocols. In this paper, we analyze the effect of the amplitude and the latency variations among different experimental protocols based on the same type of ERP. Approach. We present a method to analyze and compensate for the latency variations in BCI applications. The algorithm has been tested on two widely used ERPs (P300 and observation error potentials), in three experimental protocols in each case. We report the ERP analysis and single-trial classification. Main results. The results obtained show that the designed experimental protocols significantly affect the latency of the recorded potentials but not the amplitudes. Significance. These results show how the use of latency-corrected data can be used to generalize the BCIs, reducing the calibration time when facing a new experimental protocol.
Delorme, Arnaud; Polich, John
Long-term Vipassana meditators sat in meditation vs. a control (instructed mind wandering) states for 25 min, electroencephalography (EEG) was recorded and condition order counterbalanced. For the last 4 min, a three-stimulus auditory oddball series was presented during both meditation and control periods through headphones and no task imposed. Time-frequency analysis demonstrated that meditation relative to the control condition evinced decreased evoked delta (2–4 Hz) power to distracter stimuli concomitantly with a greater event-related reduction of late (500–900 ms) alpha-1 (8–10 Hz) activity, which indexed altered dynamics of attentional engagement to distracters. Additionally, standard stimuli were associated with increased early event-related alpha phase synchrony (inter-trial coherence) and evoked theta (4–8 Hz) phase synchrony, suggesting enhanced processing of the habituated standard background stimuli. Finally, during meditation, there was a greater differential early-evoked gamma power to the different stimulus classes. Correlation analysis indicated that this effect stemmed from a meditation state-related increase in early distracter-evoked gamma power and phase synchrony specific to longer-term expert practitioners. The findings suggest that Vipassana meditation evokes a brain state of enhanced perceptual clarity and decreased automated reactivity. PMID:22648958
van Noordt, Stefon J R; White, Lars O; Wu, Jia; Mayes, Linda C; Crowley, Michael J
Social exclusion is a potent elicitor of distress. Previous studies have shown that medial frontal theta oscillations are modulated by the experience of social exclusion. Using the Cyberball paradigm, we examined event-related dynamics of theta power in the EEG at medial frontal sites while children aged 8-12 years were exposed to conditions of fair play and social exclusion. Using an event-related design, we found that medial frontal theta oscillations (4-8Hz) increase during both early (i.e., 200-400ms) and late (i.e., 400-800ms) processing of rejection events during social exclusion relative to perceptually identical "not my turn" events during inclusion. Importantly, we show that only for the later time window (400-800ms) slow-wave theta power tracks self-reported ostracism distress. Specifically, greater theta power at medial frontal sites to "rejection" events predicted higher levels of ostracism distress. Alpha and beta oscillations for rejection events were unrelated to ostracism distress at either 200-400ms or 400-800ms time windows. Our findings extend previous studies by showing that medial frontal theta oscillations for rejection events are a neural signature of social exclusion, linked to experienced distress in middle childhood. Copyright © 2015 Elsevier Inc. All rights reserved.
Lopez-Gordo, M A; Padilla, P; Pelayo Valle, F
Acquisition of event-related potentials (ERPs) requires a nearly perfect synchronization between the stimulus player and the EEG acquisition unit that clinical systems implement at hardware level by means of a wired link...
Csukly, Gábor; Stefanics, Gábor; Komlósi, Sarolta; Czigler, István; Czobor, Pál
Growing evidence suggests that abnormalities in the synchronized oscillatory activity of neurons in schizophrenia may lead to impaired neural activation and temporal coding and thus lead to neurocognitive dysfunctions, such as deficits in facial affect recognition. To gain an insight into the neurobiological processes linked to facial affect recognition, we investigated both induced and evoked oscillatory activity by calculating the Event Related Spectral Perturbation (ERSP) and the Inter Trial Coherence (ITC) during facial affect recognition. Fearful and neutral faces as well as nonface patches were presented to 24 patients with schizophrenia and 24 matched healthy controls while EEG was recorded. The participants' task was to recognize facial expressions. Because previous findings with healthy controls showed that facial feature decoding was associated primarily with oscillatory activity in the theta band, we analyzed ERSP and ITC in this frequency band in the time interval of 140-200 ms, which corresponds to the N170 component. Event-related theta activity and phase-locking to facial expressions, but not to nonface patches, predicted emotion recognition performance in both controls and patients. Event-related changes in theta amplitude and phase-locking were found to be significantly weaker in patients compared with healthy controls, which is in line with previous investigations showing decreased neural synchronization in the low frequency bands in patients with schizophrenia. Neural synchrony is thought to underlie distributed information processing. Our results indicate a less effective functioning in the recognition process of facial features, which may contribute to a less effective social cognition in schizophrenia. PsycINFO Database Record (c) 2014 APA, all rights reserved.
Full Text Available We compared pre-movement event-related desynchronization (ERD of μ rhythm over the primary motor cortex using surface electrodes in a group of five healthy subjects during self-paced wrist movement and the wrist movement when playing a Nintendo Wii. We present a method that uses ERD to detect the onset of movement in single-trial electroencephalographic (EEG data. This algorithm produced a mean detection accuracy of 83% for the self-paced movement and 75% for the Wii-included sessions, without requiring subject training. This technique can be employed in an EEG-based brain–computer interface due to its high recognition rate and simplicity in computation.
Kaare Bjarke Mikkelsen
Full Text Available A method for measuring electroencephalograms (EEG from the outer ear, so-called ear-EEG, has recently been proposed. The method could potentially enable robust recording of EEG in natural environments. The objective of this study was to substantiate the ear-EEG method by using a larger population of subjects and several paradigms. For rigour, we considered simultaneous scalp and ear-EEG recordings with common reference. More precisely, 32 conventional scalp electrodes and 12 ear electrodes allowed a thorough comparison between conventional and ear electrodes, testing several different placements of references.The paradigms probed of auditory onset response, mismatch negativity, auditory steady state response and alpha power attenuation.By comparing event related potential (ERP waveforms from the mismatch response paradigm, the signal measured from the ear electrodes was found to reflect the same cortical activity as that from nearby scalp electrodes. It was also found that referencing the ear-EEG electrodes to another within-ear electrode affects the time-domain recorded waveform (relative to scalp recordings, but not the timing of individual components. It was furthermore found that auditory steady state responses and alpha-band modulation were measured reliably with the ear-EEG modality. Finally, our findings showed that the auditory mismatch response was difficult to monitor with the ear-EEG. We conclude that ear-EEG yields similar performance as conventional EEG for spectrogram-based analysis, similar timing of ERP components, and equal signal strength for sources close to the ear. Ear-EEG can reliably measure activity from regions of the cortex which are located close to the ears, especially in paradigms employing frequency-domain analyses.
Brázdil, M.; Rektor, I.; Daniel, P.; Dufek, M.; Jurák, Pavel
Roč. 112, č. 4 (2001), s. 650-661 ISSN 1388-2457 R&D Projects: GA ČR GA309/98/0490 Institutional research plan: CEZ:AV0Z2065902 Keywords : event-related potentials * intracerebral recordings * oddball paradigm Subject RIV: FA - Cardiovascular Diseases incl. Cardiotharic Surgery Impact factor: 1.922, year: 2001
Jiang, Lei; Wang, Yun; Cai, Bangyu; Wang, Yueming; Wang, Yiwen
The event-related potential (ERP) is the brain response measured in electroencephalography (EEG), which reflects the process of human cognitive activity. ERP has been introduced into brain computer interfaces (BCIs) to communicate the computer with the subject's intention. Due to the low signal-to-noise ratio of EEG, most ERP studies are based on grand-averaging over many trials. Recently single-trial ERP detection attracts more attention, which enables real time processing tasks as rapid face identification. All the targets needed to be retrieved may appear only once, and there is no knowledge of target label for averaging. More interestingly, how the features contribute temporally and spatially to single-trial ERP detection has not been fully investigated. In this paper, we propose to implement a local-learning-based (LLB) feature extraction method to investigate the importance of spatial-temporal components of ERP in a task of rapid face identification using single-trial detection. Comparing to previous methods, LLB method preserves the nonlinear structure of EEG signal distribution, and analyze the importance of original spatial-temporal components via optimization in feature space. As a data-driven methods, the weighting of the spatial-temporal component does not depend on the ERP detection method. The importance weights are optimized by making the targets more different from non-targets in feature space, and regularization penalty is introduced in optimization for sparse weights. This spatial-temporal feature extraction method is evaluated on the EEG data of 15 participants in performing a face identification task using rapid serial visual presentation paradigm. Comparing with other methods, the proposed spatial-temporal analysis method uses sparser (only 10% of the total) features, and could achieve comparable performance (98%) of single-trial ERP detection as the whole features across different detection methods. The interesting finding is that the N250 is
Caat, Michael ten
Electroencephalography (EEG) measures electrical brain activity by electrodes attached to the scalp. Multichannel EEG refers to a measurement with a large number of electrodes. EEG has clinical as well as scientific applications, including neurology, psychology, pharmacy, linguistics, and biology.
Full Text Available ERP is common abbreviation for event-related brain potentials, which are measured and used in clinical practice as well as in research practice. Contemporary studies of placebo effect are often based on functional neuromagnetic resonance (fMRI, positron emission tomography (PET, and event related potentials (ERP. This paper considers an ERP instrumentation system used in experimental researches of placebo effect. This instrumentation system can be divided into four modules: electrodes and cables, conditioning module, digital measurement module, and PC module for stimulations, presentations, acquisition and data processing. The experimental oddball paradigm is supported by the software of the instrumentation. [Projekat Ministarstva nauke Republike Srbije, br. TR32019 and Provincial Secretariat for Science and Technological Development of Autonomous Province of Vojvodina (Republic of Serbia under research grant No. 114-451-2723
Domján, Nóra; Csifcsák, Gábor; Janka, Zoltán
The investigation of schizophrenia's aetiology and pathomechanism is of high importance in neurosciences. In the recent decades, analyzing event-related potentials have proven to be useful to reveal the neuropsychological dysfunctions in schizophrenia. Even the very early stages of auditory stimulus processing are impaired in this disorder; this might contribute to the experience of auditory hallucinations. The present review summarizes the recent literature on the relationship between auditory hallucinations and event-related potentials. Due to the dysfunction of early auditory sensory processing, patients with schizophrenia are not able to locate the source of stimuli and to allocate their attention appropriately. These deficits might lead to auditory hallucinations and problems with daily functioning. Studies involving high risk groups may provide tools for screening and early interventions; thus improving the prognosis of schizophrenia.
Ito, Takayuki; Ostry, David J; Gracco, Vincent
International audience; Cortical processing associated with orofacial somatosensory function in speech has received limited experimental attention due to the difficulty of providing precise and controlled stimulation. This article introduces a technique for recording somatosensory event-related potentials (ERP) that uses a novel mechanical stimulation method involving skin deformation using a robotic device. Controlled deformation of the facial skin is used to modulate kinesthetic inputs thro...
Rebekah L Blakemore
Full Text Available OBJECTIVE: Conversion paresis patients and healthy people feigning weakness both exhibit weak voluntary movement without detectable neuropathology. Uniquely, conversion patients lack a sense of conscious awareness of the origin of their impairment. We investigated whether conversion paresis patients show distinct electroencephalographic (EEG markers associated with their unconscious movement deficits. METHODS: Six unilateral upper limb conversion paresis patients, 12 feigning participants asked to mimic weakness and 12 control participants performed a precued reaction time task, requiring movements of either hand, depending on precue information. Performance measures (force, reaction and movement time, and event-related EEG potentials (ERP were compared, between groups and across hands or hemisphere, using linear mixed models. RESULTS: Feigners generated the same inter-hand difference in reaction and movement time as expressed by patients, even though no specific targets were set nor feedback given on these measures. We found novel ERP signatures specific to patients. When the symptomatic hand was precued, the P3 ERP component accompanying the precue was dramatically larger in patients than in feigning participants. Additionally, in patients the earlier N1 ERP component was diminished when the precue signalled either the symptomatic or asymptomatic hand. CONCLUSIONS: These results are consistent with previous suggestions that lack of awareness of the origin of their symptoms in conversion disorder patients may result from suppression of brain activity normally related to self-agency. In patients the diminished N1 to all precues is consistent with a generalised reduction in cognitive processing of movement-related precues. The P3 enhancement in patients is unlikely to simply reflect changes required for generation of impaired movements, because it was not seen in feigners showing the same behavioural deficits. Rather, this P3 enhancement in
I. U. Berezina
Full Text Available RELEVANCE. Patients with encephalopathy due to acute chemical agents poisoning have some brain functioning changes and a cognitive impairment during the rehabilitation program. These changes require correction of appropriate diagnostic protocol and treatment.AIM. The aim of this study was to estimate changes of electroencephalography (EEG and the P3 component of the event related potential (P300 ERP that are observed in patients with encephalopathy due to acute chemical agents poisoning during stage of rehabilitation.MATERIAL AND METHODS. The study was included 25 patients (age 37 (32; 51 poisoned different kind of neurotoxic substances (drugs, ethanol and complicated by toxic and hypoxic encephalopathy. They have got the treatment of encephalopathy by mexidol intravenously, mesodiencephalic modulation (MDM and hyperbaric oxygen therapy (HBOT. All patients were recoded EEG (electroencephalograph of “MBN” company, Russia and P300 ERP (“Neuron-Spectrum-5/EP” of “Neurosoft”, Russia according to the international recommendations of clinical neurophysiologists. Neuropsychological testing was used for the assessment of cognitive functions.RESULTS. There were some disturbances in primary electroencephalograms of all subjects. The follow-up EEG recording showed the main group of patients who had got the treatment (mexidol, MDM, HBOT had more often (11 patients the EEG improvements compared to the controls (1 patient. The main group had more rarely the EEG impairments compared to the control group. 6 patients of main group and 3 patients of controls did not have EEG changes during the follow-up EEG recordings. All controls and 17 patients of the main group patients had different cognitive disturbances. After the treatment 15 patients of the main group had improved on neuropsychological tests (MMSE, Munsterberg test, Schulte table, Number Connecting Test. They also had a decrease in the N200, P300 peak latency and an increase in the N200, P300
Alexandra P. Key
Full Text Available Human communication and language skills rely heavily on the ability to detect and process auditory inputs. This paper reviews possible applications of the event-related potential (ERP technique to the study of cortical mechanisms supporting human auditory processing, including speech stimuli. Following a brief introduction to the ERP methodology, the remaining sections focus on demonstrating how ERPs can be used in humans to address research questions related to cortical organization, maturation and plasticity, as well as the effects of sensory deprivation, and multisensory interactions. The review is intended to serve as a primer for researchers interested in using ERPs for the study of the human auditory system.
Taguchi, Akira; Ono, Youhei; Kimura, Tomoaki
The event related potential (ERP) is often measured through the oddball task. On the oddball task, subjects are given “rare stimulus” and “frequent stimulus”. Measured ERPs were analyzed by the averaging technique. In the results, amplitude of the ERP P300 becomes large when the “rare stimulus” is given. However, measured ERPs are included samples without an original feature of ERP. Thus, it is necessary to reject unsuitable measured ERPs when using the averaging technique. In this paper, we propose the rejection method for unsuitable measured ERPs for the averaging technique. Moreover, we combine the proposed method and Woody's adaptive filter method.
Ghaderi, Foad; Kim, Su Kyoung; Kirchner, Elsa Andrea
With respect to single trial detection of event-related potentials (ERPs), spatial and spectral filters are two of the most commonly used pre-processing techniques for signal enhancement. Spatial filters reduce the dimensionality of the data while suppressing the noise contribution and spectral filters attenuate frequency components that most likely belong to noise subspace. However, the frequency spectrum of ERPs overlap with that of the ongoing electroencephalogram (EEG) and different types of artifacts. Therefore, proper selection of the spectral filter cutoffs is not a trivial task. In this research work, we developed a supervised method to estimate the spatial and finite impulse response (FIR) spectral filters, simultaneously. We evaluated the performance of the method on offline single trial classification of ERPs in datasets recorded during an oddball paradigm. The proposed spatio-spectral filter improved the overall single-trial classification performance by almost 9% on average compared with the case that no spatial filters were used. We also analyzed the effects of different spectral filter lengths and the number of retained channels after spatial filtering. Copyright © 2016. Published by Elsevier Ltd.
Poikonen, H; Alluri, V; Brattico, E; Lartillot, O; Tervaniemi, M; Huotilainen, M
Brain responses to discrete short sounds have been studied intensively using the event-related potential (ERP) method, in which the electroencephalogram (EEG) signal is divided into epochs time-locked to stimuli of interest. Here we introduce and apply a novel technique which enables one to isolate ERPs in human elicited by continuous music. The ERPs were recorded during listening to a Tango Nuevo piece, a deep techno track and an acoustic lullaby. Acoustic features related to timbre, harmony, and dynamics of the audio signal were computationally extracted from the musical pieces. Negative deflation occurring around 100 milliseconds after the stimulus onset (N100) and positive deflation occurring around 200 milliseconds after the stimulus onset (P200) ERP responses to peak changes in the acoustic features were distinguishable and were often largest for Tango Nuevo. In addition to large changes in these musical features, long phases of low values that precede a rapid increase - and that we will call Preceding Low-Feature Phases - followed by a rapid increase enhanced the amplitudes of N100 and P200 responses. These ERP responses resembled those to simpler sounds, making it possible to utilize the tradition of ERP research with naturalistic paradigms. Crown Copyright © 2015. Published by Elsevier Ltd. All rights reserved.
Laudien, Joachim H; Wencker, Sonja; Ferstl, Roman; Pause, Bettina M
The present study aimed to investigate the effects of cognitive/emotional bias on central nervous odor processing. Forty-five female participants were divided into three groups and were either led to believe the odor was a natural, healthy extract (positive bias), potentially hazardous (negative bias), or a common test odorant (control). The odor (isobornyl acetate) was presented via a constant-flow olfactometer and the EEG was recorded from 60 scalp locations. In the negative bias condition, participants reported reduced well-being and judged the odor as less pleasant. However, neither the thresholds nor the intensity ratings were changed by the context condition. Chemosensory event-related potential (CSERP) analysis revealed that the latencies of the N1 and P2 components were prolonged in the negative bias condition and shortened in the positive bias condition. Current source densities were most prominent in the frontal lobe in negatively biased participants. The findings show that expecting to perceive an emotionally significant odor affects the early encoding of odors.
Güntekin, Bahar; Başar, Erol
In the last decade, the brain's oscillatory responses have invaded the literature. The studies on delta (0.5-3.5Hz) oscillatory responses in humans upon application of cognitive paradigms showed that delta oscillations are related to cognitive processes, mainly in decision making and attentional processes. The present manuscript comprehensively reviews the studies on delta oscillatory responses upon cognitive stimulation in healthy subjects and in different pathologies, namely Alzheimer's disease, Mild Cognitive Impairment (MCI), bipolar disorder, schizophrenia and alcoholism. Further delta oscillatory response upon presentation of faces, facial expressions, and affective pictures are reviewed. The relationship between pre-stimulus delta activity and post-stimulus evoked and event-related responses and/or oscillations is discussed. Cross-frequency couplings of delta oscillations with higher frequency windows are also included in the review. The conclusion of this review includes several important remarks, including that delta oscillatory responses are involved in cognitive and emotional processes. A decrease of delta oscillatory responses could be a general electrophysiological marker for cognitive dysfunction (Alzheimer's disease, MCI, bipolar disorder, schizophrenia and alcoholism). The pre-stimulus activity (phase or amplitude changes in delta activity) has an effect on post-stimulus EEG responses. Copyright © 2015 Elsevier B.V. All rights reserved.
Brooks, Justin; Kerick, Scott
Previously we derived a new measure relating the driver's steering wheel responses to the vehicle's heading error velocity. This measure, the relative steering wheel compensation (RSWC), changes at times coincident with an alerting stimulus, possibly representing shifts in control strategy as measured by a change in the gain between visual input and motor output. In the present study, we sought to further validate this novel measure by determining the relationship between the RSWC and electroencephalogram (EEG) activity in brain regions associated with sensorimotor transformation processes. These areas have been shown to exhibit event-related spectral perturbation (ERSP) in the alpha frequency band that occurs with the onset of corrective steering wheel maneuvers in response to vehicle perturbations. We hypothesized that these regions would show differential alpha activity depending on whether the RSWC was high or low, reflecting changes in gain between visual input and motor output. Interestingly, we find that low RSWC is associated with significantly less peak desynchronization than larger RSWC. In addition we demonstrate that these differences are not attributable to the amount the steering wheel is turned nor the heading error velocity independently. Collectively these results suggest that neural activity in these sensorimotor regions scales with alertness and may represent differential utilization of multisensory information to control the steering wheel. Published by Elsevier Inc.
Kamarajan, Chella; Porjesz, Bernice; Jones, Kevin; Chorlian, David; Padmanabhapillai, Ajayan; Rangaswamy, Madhavi; Stimus, Arthur; Begleiter, Henri
Event-related oscillations (EROs) are increasingly being used to assess neurocognitive functioning in normal and clinical populations. The current study compares different frequency activities in offspring of alcoholics (OA) and in normal control subjects (NC) to examine whether the OA group exhibits any abnormality in oscillatory activity while performing a Go/NoGo task. The S-transform algorithm was employed to decompose the electroencephalographic (EEG) signals into different time-frequency bands, and the oscillatory responses in the P300 time window (300-700 milliseconds) were statistically analyzed in both groups. The OA group manifested significantly decreased activity in delta (1-3 Hz), theta (4-7 Hz), and alpha1 (8-9 Hz) bands during the NoGo condition, as well as reduced delta and theta activity during the Go condition. This reduction was more prominent in the NoGo than in the Go condition. The decreased response in delta, theta, and alpha1 oscillations, especially during the NoGo condition in high-risk individuals, is perhaps suggestive of cognitive and neural disinhibition and may serve as an endophenotypic marker in the development of alcoholism and/or other disinhibitory disorders.
Full Text Available The present research investigated metacognitive awareness of emotional stimuli and its psychophysiological correlates. We used a backward masking task presenting participants with fearful or neutral faces. We asked participants for face discrimination and then probed their metacognitive awareness with confidence rating (CR and post-decision wagering (PDW scales. We also analysed psychophysiological correlates of awareness with event-related potential (ERP components: P1, N170, early posterior negativity (EPN, and P3. We have not observed any differences between PDW and CR conditions in the emotion identification task. However, the "aware" ratings were associated with increased accuracy performance. This effect was more pronounced in PDW, especially for fearful faces, suggesting that emotional stimuli awareness may be enhanced by monetary incentives. EEG analysis showed larger N170, EPN and P3 amplitudes in aware compared to unaware trials. It also appeared that both EPN and P3 ERP components were more pronounced in the PDW condition, especially when emotional faces were presented. Taken together, our ERP findings suggest that metacognitive awareness of emotional stimuli depends on the effectiveness of both early and late visual information processing. Our study also indicates that awareness of emotional stimuli can be enhanced by the motivation induced by wagering.
Yih-Choung Yu; Sicheng Wang; Gabel, Lisa A
The use of an individual's neural response to stimuli (the event-related potential or ERP) has potential as a biometric because it is highly resistant to fraud relative to other conventional authentication systems. P300 is an ERP in human electroencephalography (EEG) that occurs in response to an oddball stimulus when an individual is actively engaged in a target detection task. Because P300 is consistently detectable from almost every subject, it is considered a potential signal for biometric applications. This paper presents a feasibility study of using topological plots of P300 as a biometric in subject authentication. The variation in latency and location of P300 response of 24 participants performing the P300Speller task were studied. Data sets from four participants were used for algorithm training; data from the other 20 participants were used as imposters for algorithm validation. The result showed that the algorithm was able to correctly identify three out of these four participants. Validation test also proved that the algorithm was able to reject 95% of the imposters for those three authenticated participants.
Yamagishi, Yuya; Tsubone, Tadashi; Wada, Yasuhiro
Recently, Brain computer interface (BCI) which is a direct connecting pathway an external device such as a computer or a robot and a human brain have gotten a lot of attention. Since BCI can control the machines as robots by using the brain activity without using the voluntary muscle, the BCI may become a useful communication tool for handicapped persons, for instance, amyotrophic lateral sclerosis patients. However, in order to realize the BCI system which can perform precise tasks on various environments, it is necessary to design the control rules to adapt to the dynamic environments. Reinforcement learning is one approach of the design of the control rule. If this reinforcement leaning can be performed by the brain activity, it leads to the attainment of BCI that has general versatility. In this research, we paid attention to P300 of event-related potential as an alternative signal of the reward of reinforcement learning. We discriminated between the success and the failure trials from P300 of the EEG of the single trial by using the proposed discrimination algorithm based on Support vector machine. The possibility of reinforcement learning was examined from the viewpoint of the number of discriminated trials. It was shown that there was a possibility to be able to learn in most subjects.
Mayaud, L; Congedo, M; Van Laghenhove, A; Orlikowski, D; Figère, M; Azabou, E; Cheliout-Heraut, F
A brain-computer interface aims at restoring communication and control in severely disabled people by identification and classification of EEG features such as event-related potentials (ERPs). The aim of this study is to compare different modalities of EEG recording for extraction of ERPs. The first comparison evaluates the performance of six disc electrodes with that of the EMOTIV headset, while the second evaluates three different electrode types (disc, needle, and large squared electrode). Ten healthy volunteers gave informed consent and were randomized to try the traditional EEG system (six disc electrodes with gel and skin preparation) or the EMOTIV Headset first. Together with the six disc electrodes, a needle and a square electrode of larger surface were simultaneously recording near lead Cz. Each modality was evaluated over three sessions of auditory P300 separated by one hour. No statically significant effect was found for the electrode type, nor was the interaction between electrode type and session number. There was no statistically significant difference of performance between the EMOTIV and the six traditional EEG disc electrodes, although there was a trend showing worse performance of the EMOTIV headset. However, the modality-session interaction was highly significant (P<0.001) showing that, while the performance of the six disc electrodes stay constant over sessions, the performance of the EMOTIV headset drops dramatically between 2 and 3h of use. Finally, the evaluation of comfort by participants revealed an increasing discomfort with the EMOTIV headset starting with the second hour of use. Our study does not recommend the use of one modality over another based on performance but suggests the choice should be made on more practical considerations such as the expected length of use, the availability of skilled labor for system setup and above all, the patient comfort. Copyright © 2013 Elsevier Masson SAS. All rights reserved.
John M Henderson
Full Text Available Eyetracking during reading has provided a critical source of on-line behavioral data informing basic theory in language processing. Similarly, event-related potentials have provided an important on-line measure of the neural correlates of language processing. Recently there has been strong interest in co-registering eyetracking and ERPs from simultaneous recording to capitalize on the strengths of both techniques, but a challenge has been devising approaches for controlling artifacts produced by eye movements in the EEG waveform. In this paper we describe our approach to correcting for eye movements in EEG and demonstrate its applicability to reading. The method is based on independent components analysis, and uses three criteria for identifying components tied to saccades: (1 component loadings on the surface of the head are consistent with eye movements; (2 source analysis localizes component activity to the eyes, and (3 the temporal activation of the component occurred at the time of the eye movement and differed for right and left eye movements. We demonstrate this method’s applicability to reading by comparing ERPs time-locked to fixation onset in two reading conditions. In the text-reading condition, participants read paragraphs of text. In the pseudo-reading control condition, participants moved their eyes through spatially similar pseudo-text that preserved word locations, word shapes, and paragraph spatial structure, but eliminated meaning. The corrected EEG, time-locked to fixation onsets, showed effects of reading condition in early ERP components. The results indicate that co-registration of eyetracking and EEG in connected-text paragraph reading is possible, and has the potential to become an important tool for investigating the cognitive and neural bases of on-line language processing in reading.
Henderson, John M; Luke, Steven G; Schmidt, Joseph; Richards, John E
Eyetracking during reading has provided a critical source of on-line behavioral data informing basic theory in language processing. Similarly, event-related potentials (ERPs) have provided an important on-line measure of the neural correlates of language processing. Recently there has been strong interest in co-registering eyetracking and ERPs from simultaneous recording to capitalize on the strengths of both techniques, but a challenge has been devising approaches for controlling artifacts produced by eye movements in the EEG waveform. In this paper we describe our approach to correcting for eye movements in EEG and demonstrate its applicability to reading. The method is based on independent components analysis, and uses three criteria for identifying components tied to saccades: (1) component loadings on the surface of the head are consistent with eye movements; (2) source analysis localizes component activity to the eyes, and (3) the temporal activation of the component occurred at the time of the eye movement and differed for right and left eye movements. We demonstrate this method's applicability to reading by comparing ERPs time-locked to fixation onset in two reading conditions. In the text-reading condition, participants read paragraphs of text. In the pseudo-reading control condition, participants moved their eyes through spatially similar pseudo-text that preserved word locations, word shapes, and paragraph spatial structure, but eliminated meaning. The corrected EEG, time-locked to fixation onsets, showed effects of reading condition in early ERP components. The results indicate that co-registration of eyetracking and EEG in connected-text paragraph reading is possible, and has the potential to become an important tool for investigating the cognitive and neural bases of on-line language processing in reading.
Laursen, Bettina; Bundgaard, Cecilie H; Graversen, Carina; Grupe, Morten; Sanchez, Connie; Leiser, Steven C; Sorensen, Helge B D; Drewes, Asbjørn M; Bastlund, Jesper F
Studies of the antidepressant vortioxetine have demonstrated beneficial effects on cognitive dysfunction associated with depression. To elucidate how vortioxetine modulates neuronal activity during cognitive processing we investigated the effects of vortioxetine (3 and 10mg/kg) in rats performing an auditory oddball (deviant target) task. We investigated neuronal activity in target vs non-target tone responses in vehicle-treated animals using electroencephalographic (EEG) recordings. Furthermore, we characterized task performance and EEG changes in target tone responses of vortioxetine vs controls. Quantification of event-related potentials (ERPs) was supplemented by analyses of spectral power and inter-trial phase-locking. The assessed brain regions included prelimbic cortex, the hippocampus, and thalamus. As compared to correct rejection of non-target tones, correct target tone responses elicited increased EEG power in all regions. Additionally, neuronal synchronization was increased in vehicle-treated rats during both early and late ERP responses to target tones. This indicates a significant consistency of local phases across trials during high attentional load. During early sensory processing, vortioxetine increased both thalamic and frontal synchronized gamma band activity and EEG power in all brain regions measured. Finally, vortioxetine increased the amplitude of late hippocampal P3-like ERPs, the rodent correlate of the human P300 ERP. These findings suggest differential effects of vortioxetine during early sensory registration and late endogenous processing of auditory discrimination. Strengthened P3-like ERP response may relate to the pro-cognitive profile of vortioxetine in rodents. Further investigations are warranted to explore the mechanism by which vortioxetine increases network synchronization during attentive and cognitive processing. Copyright © 2017 Elsevier B.V. All rights reserved.
Sabeti, Malihe; Boostani, Reza
Synchronous averaging over time locked single-trial of event-related potential (ERP) is known as the simplest scheme to extract P300 component. This method assumes the P300 features are invariant through the time while they are affected by factors like brain fatigue and habitation. In this study, a new scheme is proposed termed as time-varying time-lag blind source separation (TT-BSS) which is upon the second order statistics of signal to separate P300 waveform from the background electroencephalogram (EEG) while it captures the time variation of P300 component. The time-lag parameter for all channels is determined by maximizing the correlation (similarity) between two successive trials. As the time-lag parameter is varying by time (trial to trial), an average is taken over the time-lag covariance matrices of all two consecutive trials. TT-BSS finally estimates a transform (separating matrix) by joint diagnolization of the covariance matrix of trials and the averaged covariance matrix of the time varying time-lag. To assess the proposed scheme, synthetic and real EEGs containing P300 are used. The EEG signals were collected from twenty schizophrenic and twenty age-matched normal subjects via 20 channels through the resting state and in presence of the oddball audio stimulus. Empirical achievements over the simulated and real EEGs imply on the superiority of TT-BSS in dynamic estimation of P300 characteristics compared to state-of-the-art counterparts such as constant time-lag BSS, constrained BSS and synchronous averaging. Copyright © 2017 Elsevier B.V. All rights reserved.
Coulson, Seana; Van Petten, Cyma
Event-related brain potentials (ERPs) were recorded from 18 normal adults as they read sentences that ended with words used literally, metaphorically, or in an intermediate literal mapping condition. In the latter condition, the literal sense of the word was used in a way that prompted readers to map conceptual structure from a different domain. ERPs measured from 300 to 500 msec after the onset of the sentence-final words differed as a function of metaphoricity: Literal endings elicited the smallest N400, metaphors the largest N400, whereas literal mappings elicited an N400 of intermediate amplitude. Metaphoric endings also elicited a larger posterior positivity than did either literal or literal mapping words. Consistent with conceptual blending theory, the results suggest that the demands of conceptual integration affect the difficulty of both literal and metaphorical language.
Anamarta Sbeghen Cervo
Full Text Available Aimed at verifying the occurrence of adverse events related to enteral nutrition use in patients of a public hospital in the countryside of Rio Grande do Sul. A quantitative, longitudinal and descriptive study, conducted in January-May 2012, that accompanied 46 patients admitted to the Intensive Care Unit and Medical Clinic. For evaluating the adverse events, we used quality indicators: inadvertent exit, tube obstruction and volume of infused diet. For analysis, we used descriptive statistics. The results showed that inadvertent exit of the tube and obstruction presented incidence rates of 4.6% and 2.1%, respectively. The volume of diet infused was less than that prescribed, due to pauses for body hygiene, tests and procedures, nausea / vomiting and delay in the availability of installation of the bottle in the unit. We conclude that the use of quality indicators in the assessment of care can help reduce damage to the patient.
Full Text Available In recent years there has been increasing interest in the neural mechanisms underlying altered emotional processes in children and adolescents with psychopathology. This review provides a brief overview of the most up-to-date findings in the field of Event-Related Potentials (ERPs to facial and vocal emotional expressions in the most common child psychopathological conditions. In regards to externalising behaviour (i.e. ADHD, CD, ERP studies show enhanced early components to anger, reflecting enhanced sensory processing, followed by reductions in later components to anger, reflecting reduced cognitive-evaluative processing. In regards to internalising behaviour, research supports models of increased processing of threat stimuli especially at later more elaborate and effortful stages. Finally, in autism spectrum disorders abnormalities have been observed at early visual-perceptual stages of processing. An affective neuroscience framework for understanding child psychopathology can be valuable in elucidating underlying mechanisms and inform preventive intervention.
Ito, Takayuki; Ostry, David J; Gracco, Vincent L
Cortical processing associated with orofacial somatosensory function in speech has received limited experimental attention due to the difficulty of providing precise and controlled stimulation. This article introduces a technique for recording somatosensory event-related potentials (ERP) that uses a novel mechanical stimulation method involving skin deformation using a robotic device. Controlled deformation of the facial skin is used to modulate kinesthetic inputs through excitation of cutaneous mechanoreceptors. By combining somatosensory stimulation with electroencephalographic recording, somatosensory evoked responses can be successfully measured at the level of the cortex. Somatosensory stimulation can be combined with the stimulation of other sensory modalities to assess multisensory interactions. For speech, orofacial stimulation is combined with speech sound stimulation to assess the contribution of multi-sensory processing including the effects of timing differences. The ability to precisely control orofacial somatosensory stimulation during speech perception and speech production with ERP recording is an important tool that provides new insight into the neural organization and neural representations for speech.
Barriga-Paulino, Catarina I; Rodríguez-Martínez, Elena I; Arjona, Antonio; Morales, Manuel; Gómez, Carlos M
Working memory is an important cognitive function, and it is crucial to better understand its neurophysiological mechanisms. The developmental trajectories of the Event Related Potentials related to this important function have hardly been studied. However, these ERPs may provide some clues about the individual state of maturation, as has been demonstrated for anatomical brain images. The present study aims to determine the behavioral and neurophysiological development of Working Memory (WM) processes. For this purpose, 170 subjects with ages ranging from 6 to 26 years performed a visual Delayed Match-to-Sample task (DMTS). The RTs, total errors, and Event Related Potentials (ERPs) in the phases of encoding, retention, and matching were obtained. Results revealed a decrease in the amplitude of ERPs with age, paralleled by improved performance on the DMTS task (i.e., shorter RTs and fewer errors). None of these variables were affected by gender. To determine whether memory performance was influenced by the individual pattern of maturation beyond age, the amplitude of the different ERP components was correlated with RT and errors on the WM task after removing the effect of age. Frontal N2 and posterior P1 and the Late Positive Component were the only ERPs that presented significant correlations with behavioral errors. Behavioral performance was predicted by age and by the scores on the first component extracted from Principal Component Analysis (PCA) of the ERPs. Age (under 17 years old) explained 85.04% and the PCA component explained 14.96% of the variance explained by the bivariate model predicting behavioral errors (1/age + scores of 1st PCA component). From the age of 17 on, the principal PCA component ceases to be an independent component predicting error performance. The results suggest that the individual maturation of ERP components seems to be of particular importance in controlling behavioral errors in WM, as measured by the DMTS. Copyright © 2016
Full Text Available Disorders of consciousness were amply studied in the recent years. At this regards new methodologies and technologies were applied to explore the diagnostic and prognostic criteria that may be applied to the patients. Specifically electrophysiological measures were used to verify the degree of awareness and responsiveness in coma, vegetative states (VS, minimal consciousness state (MC, and locked-in syndrome (LI. Recently, ERPs (event-related potentials were adopted to integrate the classical neuroimaging measures. Between the others, MMN (mismatch negativity and P300 deflections were found to represent a consistent index of the present state of consciousness and to be predictive of successive modifications of this state. Also frequency-based EEG measures, such as brain oscillations, were revealed to be relevant marker of consciousness and awareness, able to predict the future evolution of pathology.
Davidson, R J; Saron, C; McClelland, D C
Two groups of subjects classified as high vs. low in the need for power (n power) were assessed for augmenting versus reducing in the event-related potential (ERP) elicited by neutral and power-related words. Words at four different intensity levels in each of these two classes were randomly presented and ERPs in response to each word class at each of the four intensity levels were computed from EEG recorded at Fz. The results indicated that the two groups responded differentially to the power-related vs. neutral words. HIgh n power subjects showed reduction in response to both power-related and neutral words while low n power subjects showed augmentation in response to the power-related words.
Previous research on meditation and the EEG is described, and findings relating to EEG patterns during meditation are discussed. Comparisons of meditation with other altered states are reviewed and it is concluded that, on the basis of existing EEG evidence, there is some reason for differentiating between meditation and drowsing. Research on alpha-blocking and habituation of the blocking response during meditation is reviewed, and the effects of meditation on EEG patterns outside of meditati...
Askamp, Jessica; van Putten, Michel Johannes Antonius Maria
The sensitivity of routine EEG recordings for interictal epileptiform discharges in epilepsy is limited. In some patients, inpatient video-EEG may be performed to increase the likelihood of finding abnormalities. Although many agree that home EEG recordings may provide a cost-effective alternative
Pollina, D A; Squires, N K
In previous experiments on event-related potentials (ERPs) during linguistic judgments, the subjects' decisions have been categorical (e.g., true vs false). In this experiment, more realistic variations in truth value and subject certainty were used. Thirty-eight naive undergraduates read a story about a fictional murder. ERPs were recorded as the subjects rated the strength of their beliefs about statements relating to suspects in the crime. Because no subject was sure which of the suspects was guilty of committing the crime, binary (true-false) category judgments were inappropriate. Three components of the ERP waveforms were affected by the experimental manipulations. An early positive component was largest to sentences concerning the suspect considered most likely to have committed the crime. A subsequent broad posterior positivity (LPC) also showed significant sentence-type differences, but it was larger to sentences considered probable--whether they were true or false--than to more ambiguous sentences. A third ERP component (N400) was negative at midline electrode sites and peaked at approximately 420 ms. Subjects' truth-value judgments had no effect on the N400. N400 was, however, affected by the subject's task. It was more negative when subjects made graded judgments about truth value than when they made binary true-false judgments. Overall, naturalistic judgments of sentence validity produced a variety of brain responses that reflected different aspects of linguistic decision making.
Guney, Figen; Genc, Bulent Oguz; Kutlu, Ruhusen; Ilhan, Bilge Cetin
The aim of this study was to elucidate the chronic effects of tobacco smoking on the P300, a neurophysiological index of cognitive function. Prospective study participants were recruited from a family medicine polyclinic. We selected 32 right-handed smokers who had smoked more than 15 cigarettes per day, by inhalation, for more than 2 years. The control population consisted of 32 right-handed, age-matched healthy individuals who had never smoked. Event-related potentials (ERPs) were recorded with the auditory "oddball" two-tone discrimination task. The data from the central (Cz) and frontal (Fz) electrodes were analyzed. The P300 and N1 amplitudes at Fz were lower in the study population compared to the control group. The early component of ERP, the measure of mental speed (N1) latency at Fz was prolonged in the study group compared to the controls, possibly because early cognitive processes such as sensory input or initial encoding of sensory information were delayed in this group. For those who smoke, a decreased N1 amplitude might indicate delayed information processing and possibly short-term memory disturbance. Thus, chronic tobacco smoking may produce prefrontal cognitive dysfunction.
Gopalakrishnan, Raghavan; Burgess, Richard C; Plow, Ela B; Floden, Darlene P; Machado, Andre G
Pain experience is not only a function of somatosensory inputs. Rather, it is strongly influenced by cognitive and affective pathways. Pain anticipatory phenomena, an important limitation to rehabilitative efforts in the chronic state, are processed by associative and limbic networks, along with primary sensory cortices. Characterization of neurophysiological correlates of pain anticipation, particularly during very early stages of neural processing is critical for development of therapeutic interventions. Here, we utilized magnetoencephalography to study early event-related fields (ERFs) in healthy subjects exposed to a 3 s visual countdown task that preceded a painful stimulus, a non-painful stimulus or no stimulus. We found that the first countdown cue, but not the last cue, evoked critical ERFs signaling anticipation, attention and alertness to the noxious stimuli. Further, we found that P2 and N2 components were significantly different in response to first-cues that signaled incoming painful stimuli when compared to non-painful or no stimuli. The findings indicate that early ERFs are relevant neural substrates of pain anticipatory phenomena and could be potentially serve as biomarkers. These measures could assist in the development of neurostimulation approaches aimed at curbing the negative effects of pain anticipation during rehabilitation. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Blayney, Jessica A; Read, Jennifer P
Sexual assault (SA) is a potent psychological stressor, linked to harmful mental health outcomes in both the short- and long-term. Specific assault characteristics can add to the toxicity of SA events. Although research has assessed characteristics of the assault itself (e.g., force, penetration), few studies have examined the larger socioenvironmental context in which SA takes place. This was the purpose of the present study. Young adults (N = 220; 80% female; 54% current students) reported on their most recent SA during college. Cross-sectional associations were tested via structural equation modeling to determine the contributions of socioenvironmental context and assault characteristics in predicting event-related distress. Socioenvironmental context from the most recent assault included assault setting, intoxication at the time of the assault, perpetrator relationship, and prior consensual sexual experiences with the perpetrator. We also examined assault characteristics, including physical force and penetration. Participants reported how upsetting the most recent assault was (a) at the time it occurred and (b) currently. Results revealed differential patterns for socioenvironmental context and assault characteristics based on the timing of distress (past or present). Notably, many of the socioenvironmental factors showed associations with distress above and beyond the powerful effects of physical force and penetration. These findings have important implications for our understanding of the unique factors that contribute to and maintain psychological distress in sexually victimized young adults. © The Author(s) 2015.
Bednark, Jeffery G; Franz, Elizabeth A
Knowledge about the effects of our actions is an underlying feature of voluntary behavior. Given the importance of identifying the outcomes of our actions, it has been proposed that the sensory outcomes of self-made actions are inherently different from those of externally caused outcomes. Thus, the outcomes of self-made actions are likely to be more motivationally significant for an agent. We used event-related potentials to investigate the relationship between the perceived motivational significance of an outcome and the attribution of agency in the presence of others. In our experiment, we assessed agency attribution in the presence of another agent by varying the degree of contiguity between participants' self-made actions and the sensory outcome. Specifically, we assessed the feedback correct-related positivity (fCRP) and the novelty P3 measures of an outcome's motivational significance and unexpectedness, respectively. Results revealed that both the fCRP and participants' agency attributions were significantly influenced by action-outcome contiguity. However, when action-outcome contiguity was ambiguous, novelty P3 amplitude was a reliable indicator of agency attribution. Prior agency attributions were also found to influence attribution in trials with ambiguous and low action-outcome contiguity. Participants' use of multiple cues to determine agency is consistent with the cue integration theory of agency. In addition to these novel findings, this study supports growing evidence suggesting that reinforcement processes play a significant role in the sense of agency.
Katayama, J; Miyata, Y; Yagi, A
The purpose of this study was to examine whether the decision process affected scalp recorded event-related brain potentials (ERPs). ERPs were recorded while 10 subjects evaluated the veracity of four types of Japanese sentences; true-affirmative (TA), true-negative (TN), false-affirmative (FA), and false-negative (FN). Each sentence was presented visually, one word at a time in the following order: Subject (S); object (O); and verb (V). This order of words, which is normal in Japanese grammar, allowed the ERP waveforms associated with semantic mismatch between the S and O occurring in the middle of the sentence to be separated from those elicited by the decision concerning the sentence's truth or falsity occurring at the end of the sentence. Semantic mismatch was associated with a negative component (N310) following the O-word. In addition, P3s were elicited by sentence final words. Affirmative sentences elicited larger P3s than did negative sentences, and true sentences elicited earlier P3s than did false sentences. P3s were smaller in amplitude when they followed a mismatch between the S and O words. The result suggested that by using Japanese sentences, it may be possible to examine sentence-level rather than word-level processes.
Kanou, Naoyuki; Sakuma, Kenji; Nakashima, Kenji
Amyotrophic Lateral Sclerosis(ALS) patients are unable to successfully communicate their desires, although their mental capacity is the same as non-affected persons. Therefore, the authors put emphasis on Event-Related Potential(ERP) which elicits the highest outcome for the target visual and hearing stimuli. P300 is one component of ERP. It is positive potential that is elicited when the subject focuses attention on stimuli that appears infrequently. In this paper, the authors focused on P200 and N200 components, in addition to P300, for their great improvement in the rate of correct judgment in the target word-specific experiment. Hence the authors propose the algorithm that specifies target words by detecting these three components. Ten healthy subjects and ALS patient underwent the experiment in which a target word out of five words, was specified by this algorithm. The rates of correct judgment in nine of ten healthy subjects were more than 90.0%. The highest rate was 99.7%. The highest rate of ALS patient was 100.0%. Through these results, the authors found the possibility that ALS patients could communicate with surrounding persons by detecting ERP(P200, N200 and P300) as their desire.
Pauletti, C; Mannarelli, D; Locuratolo, N; Vanacore, N; De Lucia, M C; Mina, C; Fattapposta, F
Clinically subtle executive dysfunctions have recently been described in essential tremor (ET), though the presence of attentional deficits is still unclear. We investigated the psychophysiological aspects of attention in ET, using event-related potentials (ERPs). Twenty-one non-demented patients with ET and 21 age- and sex-matched healthy controls underwent a psychophysiological evaluation. P300 components and the Contingent Negative Variation (CNV) were recorded. The latencies and amplitudes of the P3a and P3b subcomponents and CNV areas were evaluated. Possible correlations between clinical parameters and ERP data were investigated. P3a latency was significantly longer in the ET group (p memory context-updating process appears to be spared. This selective cognitive dysfunction does not appear to interfere with the attentional set linked to the expectancy evaluated during a complex choice-reaction time task, which is preserved in ET. This multitask psychophysiological approach reveals the presence of a peculiar attentional deficit in patients with ET, thus expanding the clinical features of this disease.
Prinzel, Lawrence J 3rd; Freeman, Frederick G.; Scerbo, Mark W.; Mikulka, Peter J.; Pope, Alan T.
The present study examined the effects of an electroencephalographic- (EEG-) based system for adaptive automation on tracking performance and workload. In addition, event-related potentials (ERPs) to a secondary task were derived to determine whether they would provide an additional degree of workload specificity. Participants were run in an adaptive automation condition, in which the system switched between manual and automatic task modes based on the value of each individual's own EEG engagement index; a yoked control condition; or another control group, in which task mode switches followed a random pattern. Adaptive automation improved performance and resulted in lower levels of workload. Further, the P300 component of the ERP paralleled the sensitivity to task demands of the performance and subjective measures across conditions. These results indicate that it is possible to improve performance with a psychophysiological adaptive automation system and that ERPs may provide an alternative means for distinguishing among levels of cognitive task demand in such systems. Actual or potential applications of this research include improved methods for assessing operator workload and performance.
Higashi, Hiroshi; Minami, Tetsuto; Nakauchi, Shigeki
The probability of an event's occurrence affects event-related potentials (ERPs) on electroencephalograms. The relation between probability and potentials has been discussed by using a quantity called surprise that represents the self-information that humans receive from the event. Previous studies have estimated surprise based on the probability distribution in a stationary state. Our hypothesis is that state transitions also play an important role in the estimation of surprise. In this study, we compare the effects of surprise on the ERPs based on two models that generate an event sequence: a model of a stationary state and a model with state transitions. To compare these effects, we generate the event sequences with Markov chains to avoid a situation that the state transition probability converges with the stationary probability by the accumulation of the event observations. Our trial-by-trial model-based analysis showed that the stationary probability better explains the P3b component and the state transition probability better explains the P3a component. The effect on P3a suggests that the internal model, which is constantly and automatically generated by the human brain to estimate the probability distribution of the events, approximates the model with state transitions because Bayesian surprise, which represents the degree of updating of the internal model, is highly reflected in P3a. The global effect reflected in P3b, however, may not be related to the internal model because P3b depends on the stationary probability distribution. The results suggest that an internal model can represent state transitions and the global effect is generated by a different mechanism than the one for forming the internal model. PMID:28289380
Luo, Qiuling; Huang, Hong; Mo, Lei
Although there has been extensive research on the processing of the emotional meaning of music, little is known about other aspects of listeners’ experience of music. The present study investigated the neural correlates of the iconic meaning of music. Event-related potentials (ERP) were recorded while a group of 20 music majors and a group of 20 non-music majors performed a lexical decision task in the context of implicit musical iconic meaning priming. ERP analysis revealed a significant N400 effect of congruency in time window 260-510 ms following the onset of the target word only in the group of music majors. Time-course analysis using 50 ms windows indicated significant N400 effects both within the time window 410-460 ms and 460-510 ms for music majors, whereas only a partial N400 effect during time window 410-460 ms was observed for non-music majors. There was also a trend for the N400 effects in the music major group to be stronger than those in the non-major group in the sub-windows of 310-360ms and 410-460ms. Especially in the sub-window of 410-460 ms, the topographical map of the difference waveforms between congruent and incongruent conditions revealed different N400 distribution between groups; the effect was concentrated in bilateral frontal areas for music majors, but in central-parietal areas for non-music majors. These results imply probable neural mechanism differences underlying automatic iconic meaning priming of music. Our findings suggest that processing of the iconic meaning of music can be accomplished automatically and that musical training may facilitate the understanding of the iconic meaning of music. PMID:26161561
Cai, Liman; Huang, Ping; Luo, Qiuling; Huang, Hong; Mo, Lei
Although there has been extensive research on the processing of the emotional meaning of music, little is known about other aspects of listeners' experience of music. The present study investigated the neural correlates of the iconic meaning of music. Event-related potentials (ERP) were recorded while a group of 20 music majors and a group of 20 non-music majors performed a lexical decision task in the context of implicit musical iconic meaning priming. ERP analysis revealed a significant N400 effect of congruency in time window 260-510 ms following the onset of the target word only in the group of music majors. Time-course analysis using 50 ms windows indicated significant N400 effects both within the time window 410-460 ms and 460-510 ms for music majors, whereas only a partial N400 effect during time window 410-460 ms was observed for non-music majors. There was also a trend for the N400 effects in the music major group to be stronger than those in the non-major group in the sub-windows of 310-360 ms and 410-460 ms. Especially in the sub-window of 410-460 ms, the topographical map of the difference waveforms between congruent and incongruent conditions revealed different N400 distribution between groups; the effect was concentrated in bilateral frontal areas for music majors, but in central-parietal areas for non-music majors. These results imply probable neural mechanism differences underlying automatic iconic meaning priming of music. Our findings suggest that processing of the iconic meaning of music can be accomplished automatically and that musical training may facilitate the understanding of the iconic meaning of music.
Theo O J Gruendler
Full Text Available Performance-monitoring as a key function of cognitive control covers a wide range of diverse processes to enable goal directed behavior and to avoid maladjustments. Several event-related brain potentials (ERP are associated with performance-monitoring, but their conceptual background differs. For example, the feedback-related negativity (FRN is associated with unexpected performance feedback and might serve as a teaching signal for adaptational processes, whereas the error-related negativity (ERN is associated with error commission and subsequent behavioral adaptation. The N2 is visible in the EEG when the participant successfully inhibits a response following a cue and thereby adapts to a given stop-signal. Here, we present an innovative paradigm to concurrently study these different performance-monitoring-related ERPs. In 24 participants a tactile time-estimation task interspersed with infrequent stop-signal trials reliably elicited all three ERPs. Sensory input and motor output were completely lateralized, in order to estimate any hemispheric processing preferences for the different aspects of performance monitoring associated with these ERPs. In accordance with the literature our data suggest augmented inhibitory capabilities in the right hemisphere given that stop-trial performance was significantly better with left- as compared to right-hand stop-signals. In line with this, the N2 scalp distribution was generally shifted to the right in addition to an ipsilateral shift in relation to the response hand. Other than that, task lateralization affected neither behavior related to error and feedback processing nor ERN or FRN. Comparing the ERP topographies using the Global Map Dissimilarity index, a large topographic overlap was found between all considered components.With an evenly distributed set of trials and a split-half reliability for all ERP components ≥.85 the task is well suited to efficiently study N2, ERN, and FRN concurrently which
Kashiwase, Yoshiyuki; Matsumiya, Kazumichi; Kuriki, Ichiro; Shioiri, Satoshi
How attentional modulation on brain activities determines behavioral performance has been one of the most important issues in cognitive neuroscience. This issue has been addressed by comparing the temporal relationship between attentional modulations on neural activities and behavior. Our previous study measured the time course of attention with amplitude and phase coherence of steady-state visual evoked potential (SSVEP) and found that the modulation latency of phase coherence rather than that of amplitude was consistent with the latency of behavioral performance. In this study, as a complementary report, we compared the time course of visual attention shift measured by event-related potentials (ERPs) with that by target detection task. We developed a novel technique to compare ERPs with behavioral results and analyzed the EEG data in our previous study. Two sets of flickering stimulus at different frequencies were presented in the left and right visual hemifields, and a target or distracter pattern was presented randomly at various moments after an attention-cue presentation. The observers were asked to detect targets on the attended stimulus after the cue. We found that two ERP components, P300 and N2pc, were elicited by the target presented at the attended location. Time-course analyses revealed that attentional modulation of the P300 and N2pc amplitudes increased gradually until reaching a maximum and lasted at least 1.5 s after the cue onset, which is similar to the temporal dynamics of behavioral performance. However, attentional modulation of these ERP components started later than that of behavioral performance. Rather, the time course of attentional modulation of behavioral performance was more closely associated with that of the concurrently recorded SSVEPs analyzed. These results suggest that neural activities reflected not by either the P300 or N2pc, but by the SSVEPs, are the source of attentional modulation of behavioral performance. PMID:23976966
Bastuji, Hélène; Perrin, Fabien; Garcia-Larrea, Luis
Sleep propensity and sleep inertia were assessed in 43 patients with excessive daytime sleepiness (EDS) and 21 sleep-deprived controls, using a forced awakening test under continuous electroencephalographic (EEG) recording. Event-related potentials (ERPs) were first obtained in waking, while participants performed a target detection auditory task. Subjects were then allowed to take a nap with lights off and sleep latency was calculated. After 3 min of continuous sleep, frequent and rare tones were suddenly presented again (and ERPs recorded) in a forced awakening condition, which was repeated a second time if patients fell asleep. ERPs in pre-nap wakefulness did not differ in patients and controls. On forced awakening, almost half (48%) of EDS patients retained morphologically normal ERPs, but showed a significant delay of P300 relative to waking. In the other half of the patients (and none of the controls), the N200/P300 complex to targets was replaced on forced awakening by high-amplitude negative waves ('sleep negativities'). Single subject analysis showed that 65% of patients had abnormal responses during forced awakening (significant P3 delay or sleep negativities), while only three of them (7%) had abnormal ERPs on wakefulness. The presence of sleep negativities was associated with shorter sleep latencies and increased target detection errors on forced awakening. Sleep negativities were more prevalent in narcolepsy and idiopathic hypersomnia than in EDS associated to psychiatric disorders. By combining sleep latency and ERP measures, the forced awakening test provided a robust and relatively rapid tool (45-60 min) to evaluate both sleep propensity and sleep inertia within a single recording session. The test allows each subject to act as his/her own control, thus increasing sensitivity. In the present series, it proved to be much more discriminative than waking ERPs alone to demonstrate specific abnormalities in patients complaining of excessive daytime
Full Text Available An interesting fact about language cognition is that stimulation involving incongruence in the merge operation between verb and complement has often been related to a negative event-related potential (ERP of augmented amplitude and latency of ca. 400 ms - the N400. Using an automatic ERP latency and amplitude estimator to facilitate the recognition of waves with a low signal-to-noise ratio, the objective of the present study was to study the N400 statistically in 24 volunteers. Stimulation consisted of 80 experimental sentences (40 congruous and 40 incongruous, generated in Brazilian Portuguese, involving two distinct local verb-argument combinations (nominal object and pronominal object series. For each volunteer, the EEG was simultaneously acquired at 20 derivations, topographically localized according to the 10-20 International System. A computerized routine for automatic N400-peak marking (based on the ascendant zero-cross of the first waveform derivative was applied to the estimated individual ERP waveform for congruous and incongruous sentences in both series for all ERP topographic derivations. Peak-to-peak N400 amplitude was significantly augmented (P < 0.05; one-sided Wilcoxon signed-rank test due to incongruence in derivations F3, T3, C3, Cz, T5, P3, Pz, and P4 for nominal object series and in P3, Pz and P4 for pronominal object series. The results also indicated high inter-individual variability in ERP waveforms, suggesting that the usual procedure of grand averaging might not be considered a generally adequate approach. Hence, signal processing statistical techniques should be applied in neurolinguistic ERP studies allowing waveform analysis with low signal-to-noise ratio.
Torii, Tetsuya; Sato, Aya; Iwahashi, Masakuni; Iramina, Keiji
The present study analyzed the effects of repetitive transcranial magnetic stimulation (rTMS) on brain activity. P300 latency of event-related potential (ERP) was used to evaluate the effects of low-frequency and short-term rTMS by stimulating the supramarginal gyrus (SMG), which is considered to be the related area of P300 origin. In addition, the prolonged stimulation effects on P300 latency were analyzed after applying rTMS. A figure-eight coil was used to stimulate left-right SMG, and intensity of magnetic stimulation was 80% of motor threshold. A total of 100 magnetic pulses were applied for rTMS. The effects of stimulus frequency at 0.5 or 1 Hz were determined. Following rTMS, an odd-ball task was performed and P300 latency of ERP was measured. The odd-ball task was performed at 5, 10, and 15 min post-rTMS. ERP was measured prior to magnetic stimulation as a control. Electroencephalograph (EEG) was measured at Fz, Cz, and Pz that were indicated by the international 10-20 electrode system. Results demonstrated that different effects on P300 latency occurred between 0.5-1 Hz rTMS. With 1 Hz low-frequency magnetic stimulation to the left SMG, P300 latency decreased. Compared to the control, the latency time difference was approximately 15 ms at Cz. This decrease continued for approximately 10 min post-rTMS. In contrast, 0.5 Hz rTMS resulted in delayed P300 latency. Compared to the control, the latency time difference was approximately 20 ms at Fz, and this delayed effect continued for approximately 15 min post-rTMS. Results demonstrated that P300 latency varied according to rTMS frequency. Furthermore, the duration of the effect was not similar for stimulus frequency of low-frequency rTMS.
Sabeti, Malihe; Moradi, Ehsan; Katebi, Serajeddin
The P300 event-related potential (ERP) is associated with attention and memory operations of the brain. P300 is changed in many cognitive disorders such as dementia, Alzheimer, schizophrenia, and major depression disorder. Therefore, investigation on basis of this component can help to improve our understanding of pathophysiology of such disorders and fundamentals of memory and attention mechanism. In this study, electroencephalography (EEG) signals of 20 schizophrenic patients and 20 age-matched normal subjects are analyzed. The oddball paradigm has been used to record the P300, where two stimuli including target and standard are presented with different probabilities in a random order. Data analysis is carried out using conventional averaging techniques as well as P300 source localization with low-resolution brain electromagnetic tomography (LORETA). The results show that the P300 components stem from a wide cerebral cortex network and defining a small definite cortical zone as its generator is impossible. In normal group, cingulate gyrus, one of the essential components of working memory circuit that was reported by Papez, is found to be the most activated area and it can be in line with the hypothesis that at least a part of the P300 is elicited by working-memory circuit. In schizophrenic group, frontal lobe is the most activated area that was responsible for P300 sources. Our results show that the cingulate gyrus is not activated in comparison with normal group, which is in line with previous results that dysfunction of the anterior cingulate cortex plays a prominent role in the schizophrenia disorder.
Full Text Available Estimation of human emotions from Electroencephalogram (EEG signals plays a vital role in affective Brain Computer Interface (BCI. The present study investigated the different event-related synchronization (ERS and event-related desynchronization (ERD of typical brain oscillations in processing Facial Expressions under nonattentional condition. The results show that the lower-frequency bands are mainly used to update Facial Expressions and distinguish the deviant stimuli from the standard ones, whereas the higher-frequency bands are relevant to automatically processing different Facial Expressions. Accordingly, we set up the relations between each brain oscillation and processing unattended Facial Expressions by the measures of ERD and ERS. This research first reveals the contributions of each frequency band for comprehension of Facial Expressions in preattentive stage. It also evidences that participants have emotional experience under nonattentional condition. Therefore, the user’s emotional state under nonattentional condition can be recognized in real time by the ERD/ERS computation indexes of different frequency bands of brain oscillations, which can be used in affective BCI to provide the user with more natural and friendly ways.
Lyu, Yuanyuan; Guo, Xiaoli; Bekrater-Bodmann, Robin; Flor, Herta; Tong, Shanbao
Mental rotation of body parts involves sequential cognitive processes, including visual processing, categorization and the mental rotation process itself. However, how these processes are affected by the amputation of a limb is still unclear. Twenty-five right upper-limb amputees and the same number of matched healthy controls participated in a hand mental rotation task. Thirty-two-channel electroencephalography (EEG) was recorded and the event-related potentials (ERPs) were analyzed. In the early visual processing phase, amputees and controls showed a similar P100. During the categorization phase, the amputees exhibited a decreased N200 compared with controls, and the decline was positively correlated with the time since amputation. In the mental rotation phase, controls had a larger ERP for the right upright hand than for the left upright hand, while amputees had a larger ERP for the left (intact) upright hand than for the right (affected) upright hand. Early visual processing was not affected by limb amputation. However, the perceptual salience of hand pictures decreased and the intact hand gained more significance in the amputees. Event-related potentials had the capability of showing the differences in categorization and mental rotation phases between amputees and controls. Copyright © 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.
Park, Jin Young; Min, Byoung-Kyong; Jung, Young-Chul; Pak, Hyensou; Jeong, Yeon-Hong; Kim, Eosu
Illumination conditions appear to influence working efficacy in everyday life. In the present study, we obtained electroencephalogram (EEG) correlates of working-memory load, and investigated how these waveforms are modulated by illumination conditions. We hypothesized that illumination conditions may affect cognitive performance. We designed an EEG study to monitor and record participants' EEG during the Sternberg working memory task under four different illumination conditions. Illumination conditions were generated with a factorial design of two color-temperatures (3000 and 7100 K) by two illuminance levels (150 and 700 lx). During a working memory task, we observed that high illuminance led to significantly lower frontal EEG theta activity than did low illuminance. These differences persisted despite no significant difference in task performance between illumination conditions. We found that the latency of an early event-related potential component, such as N1, was significantly modulated by the illumination condition. The fact that the illumination condition affects brain activity but not behavioral performance suggests that the lighting conditions used in the present study did not influence the performance stage of behavioral processing. Nevertheless, our findings provide objective evidence that illumination conditions modulate brain activity. Further studies are necessary to refine the optimal lighting parameters for facilitating working memory. Copyright © 2013 IBRO. Published by Elsevier Ltd. All rights reserved.
Askamp, Jessica; van Putten, Michel J A M
The sensitivity of routine EEG recordings for interictal epileptiform discharges in epilepsy is limited. In some patients, inpatient video-EEG may be performed to increase the likelihood of finding abnormalities. Although many agree that home EEG recordings may provide a cost-effective alternative to these recordings, their use is still not introduced everywhere. We surveyed Dutch neurologists and patients and evaluated a novel mobile EEG device (Mobita, TMSi). Key specifications were compared with three other current mobile EEG devices. We shortly discuss algorithms to assist in the review process. Thirty percent (33 out of 109) of Dutch neurologists reported that home EEG recordings are used in their hospital. The majority of neurologists think that mobile EEG can have additional value in investigation of unclear paroxysms, but not in the initial diagnosis after a first seizure. Poor electrode contacts and signal quality, limited recording time and absence of software for reliable and effective assistance in the interpretation of EEGs have been important constraints for usage, but in recent devices discussed here, many of these problems have been solved. The majority of our patients were satisfied with the home EEG procedure and did not think that our EEG device was uncomfortable to wear, but they did feel uneasy wearing it in public. © 2013.
Grozea, Cristian; Voinescu, Catalin D.; Fazli, Siamac
In this paper, we present a new, low-cost dry electrode for EEG that is made of flexible metal-coated polymer bristles. We examine various standard EEG paradigms, such as capturing occipital alpha rhythms, testing for event-related potentials in an auditory oddball paradigm and performing a sensory motor rhythm-based event-related (de-) synchronization paradigm to validate the performance of the novel electrodes in terms of signal quality. Our findings suggest that the dry electrodes that we developed result in high-quality EEG recordings and are thus suitable for a wide range of EEG studies and BCI applications. Furthermore, due to the flexibility of the novel electrodes, greater comfort is achieved in some subjects, this being essential for long-term use.
Shou, Guofa; Ding, Lei
The present study aimed to investigate the sensitivity of independent component analysis (ICA)- and channel-based methods in detecting electroencephalography (EEG) spatial-spectral-temporal signatures of performance errors. 128-channel EEG signals recorded from 18 subjects, who performed a color-word matching Stroop task, were analyzed. The spatial-spectral-temporal patterns in event-related potentials (ERPs) and oscillatory activities (i.e., power and phase) were measured at four selected channels, i.e., FCz, Pz, O1 and O2, from original EEG data after preprocessing, EEG data after additional current source density (CSD) transform, and back-projected EEG data from individual ICs after additional ICA analysis. Pair-wise correlation coefficient (CC) and mutual information (MI), calculated from three EEG data at four selected channels, were compared to examine mutual correlations in EEG signals obtained through three different means. Thereafter, EEG signatures of errors from these three means were statistically compared at multiple time windows in the contrast of error and correct responses. Significantly decreased CC and MI values were observed in CSD- and ICA-processed EEGs as compared with original EEG, with the smallest CC and MI in ICA EEG. Similar error patterns in ERPs and peri-response oscillatory activities were detected in all three EEGs, whereas the pre-stimulus and post-stimulus error-related oscillatory patterns identified in ICA EEG were either not or only partially detected in both original EEG and CSD EEGs in general. Both CSD and ICA processes can largely reduce signal correlations due to the volume conduction effect in original EEG, and EEG signatures of errors are better detected by ICA-based method than channel-based method (i.e., original and CSD EEGs). ICA provides the best sensitivity to detect EEG signatures linked to specific neural processes via disentangling superimposed channel-level EEG signals into distinct neurocognitive process
Ogawa, Yutaro; Takeno, Shohei; Kotani, Kiyoshi; Jimbo, Yasuhiko
Event Related Potential (ERP) of brain EEG (Electroencephalogram) activity plays an important role in EEG phase synchronization and/or hemodynamic responses measured by fMRI (functional Magnetic Resonance Imaging). However, the specific mechanism of ERP generation is still unclear. In this study, pulse and noise type visual stimuli are administered to subjects. Then the phase response of the EEG in α-waves is analyzed. As a result, the magnitudes of the phase response are varied by the stimulus administered phase and no power increase is observed. These results indicate that the ERP in α-waves is generated by the phase resetting of brain activity.
Davenport, Tristan; Coulson, Seana
Conceptual mapping, or making connections between conceptual structure in different domains, is a key mechanism of creative language use whose neural underpinnings are not well understood. The present study involved the combination of event-related potentials (ERPs) with the divided visual field presentation technique to explore the relative contributions of the left and right hemispheres (LH and RH) to the construction of novel meanings in fully literal language. Electroencephalogram (EEG) was recorded as healthy adults read sentences that supported either a conventional literal reading of the sentence final word ("His main method of transportation is a boat,"), or a novel literal meaning derived from conceptual mapping ("The clever boys used a cardboard box as a boat,"). The novel and conventional conditions were matched for cloze probability (a measure of predictability based on the sentence context), lexical association between the sentence frame and the final word (using latent semantic analysis), and other factors known to influence ERPs to language stimuli. To compare effects of novelty to previously reported effects of predictability, a high-cloze conventional condition ("The only way to get around Venice is to navigate the canals in a boat.") was included. ERPs were time-locked to sentence final words ("boat") presented in either the left visual field, to preferentially stimulate the RH (lvf/RH), or in the right visual field, targeting the LH (rvf/LH). The N400 component of the ERP was affected by predictability in both presentation sides, but by novelty only in rvf/LH. Two distinct late frontal positive effects were observed. Word predictability modulated a frontal positivity with a LH focus, but semantic novelty modulated a frontal positivity focused in RH. This is the first demonstration that the frontal positivity may be composed of multiple overlapping components with distinct functional and anatomical characteristics. Extending contemporary accounts
Barrès, Victor; Simons, Arthur; Arbib, Michael
Our previous work developed Synthetic Brain Imaging to link neural and schema network models of cognition and behavior to PET and fMRI studies of brain function. We here extend this approach to Synthetic Event-Related Potentials (Synthetic ERP). Although the method is of general applicability, we focus on ERP correlates of language processing in the human brain. The method has two components: Phase 1: To generate cortical electro-magnetic source activity from neural or schema network models; and Phase 2: To generate known neurolinguistic ERP data (ERP scalp voltage topographies and waveforms) from putative cortical source distributions and activities within a realistic anatomical model of the human brain and head. To illustrate the challenges of Phase 2 of the methodology, spatiotemporal information from Friederici's 2002 model of auditory language comprehension was used to define cortical regions and time courses of activation for implementation within a forward model of ERP data. The cortical regions from the 2002 model were modeled using atlas-based masks overlaid on the MNI high definition single subject cortical mesh. The electromagnetic contribution of each region was modeled using current dipoles whose position and orientation were constrained by the cortical geometry. In linking neural network computation via EEG forward modeling to empirical results in neurolinguistics, we emphasize the need for neural network models to link their architecture to geometrically sound models of the cortical surface, and the need for conceptual models to refine and adopt brain-atlas based approaches to allow precise brain anchoring of their modules. The detailed analysis of Phase 2 sets the stage for a brief introduction to Phase 1 of the program, including the case for a schema-theoretic approach to language production and perception presented in detail elsewhere. Unlike Dynamic Causal Modeling (DCM) and Bojak's mean field model, Synthetic ERP builds on models of networks
May 20, 2004 ... Epilepsy is primarily a clinical diagnosis, but the EEG ... seizure onset and the epilepsy syndrome. However, a normal inter-ictal EEG can never refute or exclude a clinical diagno- sis of epilepsy. Organic mental disorders is increasingly an ... to metabolic changes, infections, toxins, trauma and tumours.
Lopes da Silva, F.; Mulert, C.; Lemieux, L.
The existence of the electrical activity of the brain (i.e. the electroencephalogram or EEG) was discovered more than a century ago by Caton. After the demonstration that the EEG could be recorded from the human scalp by Berger in the 1920s, it made a slow start before it became accepted as a method
... test. If it's necessary for your child to sleep during the EEG, the doctor will suggest ways to help make this easier. The Procedure An EEG can be done in the doctor's office, a lab, or a hospital. Your child will be asked to lie on ...
May 20, 2004 ... 13th National Psychiatry Congress. The EEG in psychiatry. Roland Eastman. Division of Neurology, University of Cape Town, Cape Town, South Africa orders. Epilepsy is primarily a clinical diagnosis, but the EEG may provide strong support by the finding of inter-ictal epi- leptogenic discharges and also be ...
Johnson, Matthew R.; McCarthy, Gregory; Muller, Kathleen A.; Brudner, Samuel N.; Johnson, Marcia K.
Refreshing is the component cognitive process of directing reflective attention to one of several active mental representations. Previous studies using functional magnetic resonance imaging (fMRI) suggested that refresh tasks involve a component process of initiating refreshing as well as the top-down modulation of representational regions central to refreshing. However, those studies were limited by fMRI’s low temporal resolution. In the present study, we used electroencephalography (EEG) to examine the timecourse of refreshing on the scale of milliseconds rather than seconds. Event-related potential (ERP) analyses showed that a typical refresh task does have a distinct electrophysiological response as compared to a control condition, and includes at least two main temporal components: an earlier (~400ms) positive peak reminiscent of a P3 response, and a later (~800ms–1400ms) sustained positivity over several sites reminiscent of the late directing attention positivity (LDAP). Overall, the evoked potentials for refreshing representations from three different visual categories (faces, scenes, words) were similar, but multivariate pattern analysis (MVPA) showed that some category information was nonetheless present in the EEG signal. When related to previous fMRI studies, these results are consistent with a two-phase model, with the first phase dominated by frontal control signals involved in initiating refreshing and the second by the top-down modulation of posterior perceptual cortical areas that constitutes refreshing a representation. This study also lays the foundation for future studies of the neural correlates of reflective attention at a finer temporal resolution than is possible using fMRI. PMID:25961640
This thesis presents electroencephalography (EEG) brain imaging by covering topics as empirical evaluation of source confusion, probabilistic inverse methods, and source analysis performed on infant EEG data. In terms of source confusion we inspect how current sources within the brain may be conf...... the principled computation of sparse spatial and smooth temporal EEG source reconstructions consistent with neurophysiological assumptions in a variety of event-related imaging paradigms....... topics in EEG source reconstruction, namely, the forward progation model (describing the mapping from the current sources within the brain to the sensors at the scalp) and the temporal patterns present in the EEG. As forward models may suffer from a number of errors including the geometrical...... distributions over the unknown sources given the observed data. Here, we propose a hierarchical Bayesian model that attempts to minimize the influence of uncertainties associated with the forward model on the source estimates. Similarly, we develop a hierarchical spatio-temporal Bayesian model that accommodates...
Yu, K.; Prasad, I.; Mir, H.; Thakor, N.; Al-Nashash, H.
Objective. Our experiments explored the effect of visual stimuli degradation on cognitive workload. Approach. We investigated the subjective assessment, event-related potentials (ERPs) as well as electroencephalogram (EEG) as measures of cognitive workload. Main results. These experiments confirm that degradation of visual stimuli increases cognitive workload as assessed by subjective NASA task load index and confirmed by the observed P300 amplitude attenuation. Furthermore, the single-trial multi-level classification using features extracted from ERPs and EEG is found to be promising. Specifically, the adopted single-trial oscillatory EEG/ERP detection method achieved an average accuracy of 85% for discriminating 4 workload levels. Additionally, we found from the spatial patterns obtained from EEG signals that the frontal parts carry information that can be used for differentiating workload levels. Significance. Our results show that visual stimuli can modulate cognitive workload, and the modulation can be measured by the single trial EEG/ERP detection method.
Full Text Available Language processing is commonly characterized by an event-related increase in theta power (4-7 Hz in scalp EEG. Oscillatory brain dynamics underlying alcohol's effects on language are poorly understood despite impairments on verbal tasks. To investigate how moderate alcohol intoxication modulates event-related theta activity during visual word processing, healthy social drinkers (N=22, 11 females participated in both alcohol (0.6 g/kg ethanol for men, 0.55 g/kg for women and placebo conditions in a counterbalanced design. They performed a double-duty lexical decision task as they detected real words among nonwords. An additional requirement to respond to all words that also referred to animals induced response conflict. High density whole head MEG signals and midline scalp EEG data were decomposed for each trial with Morlet wavelets. Each person’s reconstructed cortical surface was used to constrain noise-normalized distributed minimum norm inverse solutions for theta frequencies. Alcohol intoxication increased reaction time and marginally affected accuracy. The overall spatiotemporal pattern is consistent with the left-lateralized fronto-temporal activation observed in language studies applying time domain analysis. Event-related theta power was sensitive to the two functions manipulated by the task. First, theta estimated to the left-lateralized fronto-temporal areas reflected lexical-semantic retrieval, indicating that this measure is well suited for investigating the neural basis of language functions. While alcohol attenuated theta power overall, it was particularly deleterious to semantic retrieval since it reduced theta to real words but not pseudowords. Second, a highly overlapping prefrontal network comprising lateral prefrontal and anterior cingulate cortex was sensitive to decision conflict and was also affected by intoxication, in agreement with previous studies indicating that executive functions are especially vulnerable to
Liu, Tongran; Shi, Jiannong; Zhao, Daheng; Yang, Jie
Using time-frequency analysis techniques to investigate the event-related low-frequency (delta: 0.5-4 Hz; theta: 4-8 Hz) activity of auditory event-related potentials (ERPs) data of highly and average intelligent children, 18 intellectually gifted children, and 18 intellectually average children participated the present study. Present findings…
van der Lubbe, Robert Henricus Johannes; Wauschkuhn, Bernd; Wascher, Edmund; Niehoff, Torsten; Kömpf, Detlef; Verleger, Rolf
During preparation of horizontal saccades in humans, several lateralized (relative to saccade direction), event-related EEG components occur that have been interpreted as reflecting activity of frontal and parietal eye fields. We investigated to what degree these components are specific to saccade
Trimmel, Karin; Sachsenweger, Jens; Lindinger, Gerald; Auff, Eduard; Zimprich, Fritz; Pataraia, Ekaterina
Language functional magnetic resonance imaging (fMRI) represents the clinical standard for language lateralization assessment in presurgical epilepsy evaluation, but still many patients experience postoperative language deficits. Event-related potentials (ERPs), especially the negative component around and after 400ms, are related to language processing and could therefore represent a complementary method of language lateralization assessment. Scalp EEG was recorded from 64 locations in 36 epilepsy patients and 37 controls during three visually presented language tasks: A short-term language memory task (differentiation memorized vs. unknown words), a phonological task (detection of rhymes in word pairs), and a semantic decision task (differentiation words vs. pseudowords). ERPs were analyzed in the 300ms-800ms epoch. Language fMRI was routinely obtained in patients. ERPs were significantly more negative over the left compared to the right hemisphere in all three tasks in patients and controls. Laterality indices showed highest concordance with fMRI for the Word/Pseudoword Task. ERPs of language processing were lateralized to the left hemisphere in the majority of epilepsy patients and controls. In patients, single-subject laterality indices showed high concordance with fMRI results. Results indicate that scalp-derived ERPs are a promising tool to investigate lateralization of language function in epilepsy patients. Copyright Â© 2017 International Federation of Clinical Neurophysiology. Published by Elsevier B.V. All rights reserved.
Minami, T; Nakajima, K; Changvisommid, L; Nakauchi, S
Faces are important for social interaction because much can be perceived from facial details, including a person's race, age, and mood. Recent studies have shown that both configural (e.g. face shape and inversion) and surface information (e.g. surface color and reflectance properties) are important for face perception. Therefore, the present study examined the effects of facial color and inverted face properties on event-related potential (ERP) responses, particularly the N170 component. Stimuli consisted of natural and bluish-colored faces. Faces were presented in both upright and upside down orientations. An ANOVA was used to analyze N170 amplitudes and verify the effects of the main independent variables. Analysis of N170 amplitude revealed the significant interactions between stimulus orientation and color. Subsequent analysis indicated that N170 was larger for bluish-colored faces than natural-colored faces, and N170 to natural-colored faces was larger in response to inverted stimulus as compared to upright stimulus. Additionally, a multivariate pattern analysis (MVPA) investigated face-processing dynamics without any prior assumptions. Results distinguished, above chance, both facial color and orientation from single-trial electroencephalogram (EEG) signals. Decoding performance for color classification of inverted faces was significantly diminished as compared to an upright orientation. This suggests that processing orientation is predominant over facial color. Taken together, the present findings elucidate the temporal and spatial distribution of orientation and color processing during face processing. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.
O'Regan, L M; Farina, F R; Hussey, I; Roche, R A P
This research aimed to explore the neural correlates of relational learning by recording high-density EEG during a behavioural task involving derivation levels of varying complexity. A total of 15 participants (5 male; age range 18-23 years; mean age=20.0 years) completed contextual cue training, relational learning, function training and a derivation task while 128-channel event-related potentials (ERPs) were recorded from the scalp (Background). Differences in response latencies were observed between the two derived (symmetry and equivalence) and directly trained relations, with longest latencies found for equivalence and shortest for the directly trained relations. This pattern failed to reach statistical significance. Importantly, ERPs revealed an early P3a positivity (from 230 to 350ms) over right posterior scalp sites. Significantly larger mean amplitudes were found at three channels (P6, E115 and E121) for the equivalence relations compared to the two other types (Results). We believe this may constitute a first demonstration of differences in brain electrophysiology in the transformation of stimulus functions through derived relations of hierarchical levels of complexity (Conclusions). Copyright © 2014 Elsevier B.V. All rights reserved.
Full Text Available Human emotions are perceived from multi-modal information including facial expression and voice tone. We aimed to investigate development of neural mechanism for cross-modal perception of emotions. We presented congruent and incongruent combinations of facial expression (happy and voice tone (happy or angry, and measured EEG to analyze event-related brain potentials for 8-10 month-old infants and adults. Ten repetitions of 10 trials were presented in random order for each participant. Half of them performed 20% congruent (happy face with happy voice and 80% incongruent (happy face with angry voice trials, and the others performed 80% congruent and 20% incongruent trials. We employed the oddball paradigm, but did not instruct participants to count a target. The odd-ball (infrequent stimulus increased the amplitude of P2 and delayed its latency for infants in comparison with the frequent stimulus. When the odd-ball stimulus was also emotionally incongruent, P2 amplitude was more increased and its latency was more delayed than for the odd-ball and emotionally congruent stimulus. However, we did not find difference of P2 amplitude or latency for adults between conditions. These results suggested that the 8–10 month-old infants already have a neural basis for detecting emotional incongruence of facial expression and voice tone.
Casper H. van Heck
Full Text Available Empathy describes the ability to understand another person’s feelings. Psychopathy is a disorder that is characterized by a lack of empathy. Therefore, empathy and psychopathy are interesting traits to investigate with respect to experiencing and observing pain. The present study aimed to investigate pain empathy and pain sensitivity by measuring event-related potentials (ERPs extracted from the ongoing EEG in an interactive setup. Each participant fulfilled subsequently the role of “villain” and “victim”. In addition, mode of control was modulated resulting in four different conditions; passive villain, active villain, active victim and passive victim. Response-, visual- and pain ERPs were compared between the four conditions. Furthermore, the role of psychopathic traits in these outcomes was investigated. Our findings suggested that people experience more conflict when hurting someone else than hurting themselves. Furthermore, our results indicated that self-controlled pain was experienced as more painful than uncontrolled pain. People that scored high on psychopathic traits seemed to process and experience pain differently. According to the results of the current study, social context, attention and personality traits seem to modulate pain processing and the empathic response to pain in self and others. The within-subject experimental design described here provides an excellent approach to further unravel the influence of social context and personality traits on social cognition.
Full Text Available Response inhibition has been a core issue in addictive behavior. Many previous studies have found that response inhibition abilities are damaged in those with drug dependence. However, whether heroin addicts who are treated with methadone maintenance have an abnormal response inhibition ability is not clear. In order to investigate the response inhibition functions in heroin addicts who were treated with methadone maintenance, electroencephalography (EEG was used to examine 14 heroin addicts treated with methadone maintenance (HDM, 17 heroin addicts (HD, and 18 healthy controls (HC in an equiprobability Go∖NoGo task. The reaction times (RTs for the Go stimuli in the HD group were slower than those in the HDM and HC groups. Event-related potential (ERP measurements showed that NoGo stimuli elicited larger N2 amplitudes than Go stimuli in the HDM and HC groups. However, for the HD group, the N2 amplitudes were similar for the two conditions. In addition, the HDM and HD groups were associated with longer P3 latencies. Our results demonstrated that methadone maintenance treatment might ease the deficits in response inhibition that result from long-term drug abuse. However, compared to normal people, HDM patients have serious problems evaluating and inhibiting inappropriate behaviors.
Formaggio, Emanuela; Storti, Silvia Francesca; Boscolo Galazzo, Ilaria; Gandolfi, Marialuisa; Geroin, Christian; Smania, Nicola; Spezia, Laura; Waldner, Andreas; Fiaschi, Antonio; Manganotti, Paolo
Robot-assisted therapy in patients with neurological disease is an attempt to improve function in a moderate to severe hemiparetic arm. A better understanding of cortical modifications after robot-assisted training could aid in refining rehabilitation therapy protocols for stroke patients. Modifications of cortical activity in healthy subjects were evaluated during voluntary active movement, passive robot-assisted motor movement, and motor imagery tasks performed under unimanual and bimanual protocols. Twenty-one channel electroencephalography (EEG) was recorded with a video EEG system in 8 subjects. The subjects performed robot-assisted tasks using the Bi-Manu Track robot-assisted arm trainer. The motor paradigm was executed during one-day experimental sessions under eleven unimanual and bimanual protocols of active, passive and imaged movements. The event-related-synchronization/desynchronization (ERS/ERD) approach to the EEG data was applied to investigate where movement-related decreases in alpha and beta power were localized. Voluntary active unilateral hand movement was observed to significantly activate the contralateral side; however, bilateral activation was noted in all subjects on both the unilateral and bilateral active tasks, as well as desynchronization of alpha and beta brain oscillations during the passive robot-assisted motor tasks. During active-passive movement when the right hand drove the left one, there was predominant activation in the contralateral side. Conversely, when the left hand drove the right one, activation was bilateral, especially in the alpha range. Finally, significant contralateral EEG desynchronization was observed during the unilateral task and bilateral ERD during the bimanual task. This study suggests new perspectives for the assessment of patients with neurological disease. The findings may be relevant for defining a baseline for future studies investigating the neural correlates of behavioral changes after robot
Cheron, Guy; Petit, Géraldine; Cheron, Julian; Leroy, Axelle; Cebolla, Anita; Cevallos, Carlos; Petieau, Mathieu; Hoellinger, Thomas; Zarka, David; Clarinval, Anne-Marie; Dan, Bernard
Brain dynamics is at the basis of top performance accomplishment in sports. The search for neural biomarkers of performance remains a challenge in movement science and sport psychology. The non-invasive nature of high-density electroencephalography (EEG) recording has made it a most promising avenue for providing quantitative feedback to practitioners and coaches. Here, we review the current relevance of the main types of EEG oscillations in order to trace a perspective for future practical applications of EEG and event-related potentials (ERP) in sport. In this context, the hypotheses of unified brain rhythms and continuity between wake and sleep states should provide a functional template for EEG biomarkers in sport. The oscillations in the thalamo-cortical and hippocampal circuitry including the physiology of the place cells and the grid cells provide a frame of reference for the analysis of delta, theta, beta, alpha (incl.mu), and gamma oscillations recorded in the space field of human performance. Based on recent neuronal models facilitating the distinction between the different dynamic regimes (selective gating and binding) in these different oscillations we suggest an integrated approach articulating together the classical biomechanical factors (3D movements and EMG) and the high-density EEG and ERP signals to allow finer mathematical analysis to optimize sport performance, such as microstates, coherency/directionality analysis and neural generators.
Full Text Available Brain dynamics is at the basis of top performance accomplishment in sports. The search for neural biomarkers of performance remains a challenge in movement science and sport psychology. The noninvasive nature of high-density electroencephalography (EEG recording has made it a most promising avenue for providing quantitative feedback to practitioners and coaches. Here, we review the current relevance of the main types of EEG oscillations in order to trace a perspective for future practical applications of EEG and event-related potentials (ERP in sport. In this context, the hypotheses of unified brain rhythms and continuity between wake and sleep states should provide a functional template for EEG biomarkers in sport. The oscillations in the thalamo-cortical and hippocampal circuitry including the physiology of the place cells and the grid cells provide a frame of reference for the analysis of delta, theta, beta, alpha (incl.mu and gamma oscillations recorded in the space field of human performance. Based on recent neuronal models facilitating the distinction between the different dynamic regimes (selective gating and binding in these different oscillations we suggest an integrated approach articulating together the classical biomechanical factors (3D movements and EMG and the high-density EEG and ERP signals to allow finer mathematical analysis to optimize sport performance, such as microstates, coherency/directionality analysis and neural generators.
Horvath, Andras; Szucs, Anna; Csukly, Gabor; Sakovics, Anna; Stefanics, Gabor; Kamondi, Anita
Here we critically review studies that used electroencephalography (EEG) or event-related potential (ERP) indices as a biomarker of Alzheimer's disease. In the first part we overview studies that relied on visual inspection of EEG traces and spectral characteristics of EEG. Second, we survey analysis methods motivated by dynamical systems theory (DST) as well as more recent network connectivity approaches. In the third part we review studies of sleep. Next, we compare the utility of early and late ERP components in dementia research. In the section on mismatch negativity (MMN) studies we summarize their results and limitations and outline the emerging field of computational neurology. In the following we overview the use of EEG in the differential diagnosis of the most common neurocognitive disorders. Finally, we provide a summary of the state of the field and conclude that several promising EEG/ERP indices of synaptic neurotransmission are worth considering as potential biomarkers. Furthermore, we highlight some practical issues and discuss future challenges as well.
Vossen, C.J.; Vossen, H.G.M.; Marcus, M.A.E.; van Os, J.; Lousberg, R.
In analyzing time-locked event-related potentials (ERPs), many studies have focused on specific peaks and their differences between experimental conditions. In theory, each latency point after a stimulus contains potentially meaningful information, regardless of whether it is peak-related. Based on
Swee Sim Kok
Full Text Available This paper describes the development of a brainwave controlled wheelchair. The main objective of this project is to construct a wheelchair which can be directly controlled by the brain without requires any physical feedback as controlling input from the user. The method employed in this project is the Brain-computer Interface (BCI, which enables direct communication between the brain and the electrical wheelchair. The best method for recording the brain’s activity is electroencephalogram (EEG. EEG signal is also known as brainwaves signal. The device that used for capturing the EEG signal is the Emotiv EPOC headset. This headset is able to transmit the EEG signal wirelessly via Bluetooth to the PC (personal computer. By using the PC software, the EEG signals are processed and converted into mental command. According to the mental command (e.g. forward, left... obtained, the output electrical signal is sent out to the electrical wheelchair to perform the desired movement. Thus, in this project, a computer software is developed for translating the EEG signal into mental commands and transmitting out the controlling signal wirelessly to the electrical wheelchair.
Full Text Available Event relation recognition, as one of natural language processing technologies, faces information stream of texts detecting event relation. By analyzing the influence of the words of different parts of speech on the relevance of events. And use the form of lexical chain to extract and store the relevant vocabulary between events, this paper propose an event relation recognization method based on lexical chain to detect latent semantic relation between events: whether events hold logical relation or not. Cornpared with the method based on dependency cue inference, the proposed method achieves 7. 68% improvement.
Bai, Yan; Yao, Zhong; Cong, Fengyu; Zhang, Linlin
There is an increasing interest regarding the use of electroencephalography (EEG) in social commerce and electronic commerce (e-commerce) research. There are several reviews in the field of social commerce or e-commerce; these have great potential value and mining them is fundamental and significant. To our knowledge, EEG is rarely applied to study these. In this study, we examined the neural correlates of social commerce reviews (SCRs) and e-commerce reviews (ECRs) by using them as stimuli t...
Full Text Available Abstract Background The integration of EEG and fMRI is attractive because of their complementary precision regarding time and space. But the relationship between the indirect hemodynamic fMRI signal and the more direct EEG signal is uncertain. Event-related EEG responses can be analyzed in two different ways, reflecting two different kinds of brain activity: evoked, i.e. phase-locked to the stimulus, such as evoked potentials, or induced, i.e. non phase-locked to the stimulus such as event-related oscillations. In order to determine which kind of EEG activity was more closely related with fMRI, EEG and fMRI signals were acquired together, while subjects were presented with two kinds of rare events intermingled with frequent distractors. Target events had to be signaled by pressing a button and Novel events had to be ignored. Results Both Targets and Novels triggered a P300, of larger amplitude in the Novel condition. On the opposite, the fMRI BOLD response was stronger in the Target condition. EEG event-related oscillations in the gamma band (32–38 Hz reacted in a way similar to the BOLD response. Conclusions The reasons for such opposite differential reactivity between oscillations / fMRI on the one hand, and evoked potentials on the other, are discussed in the paper. Those results provide further arguments for a closer relationship between fast oscillations and the BOLD signal, than between evoked potentials and the BOLD signal.
Rozenkrants, Bella; Olofsson, Jonas K.; Polich, John
Event-related potentials (ERPs) were used to assess arousal (low, high), valence (negative, positive), and stimulus repetition effects for normal and distorted images from the International Affective Pictures System (IAPS). Distorted stimuli were constructed by dividing each image into 108 one cm squares and rearranging the segments randomly to produce a “scrambled” picture. Event-related potentials (ERPs) were elicited by presenting the normal and scrambled images as target stimuli, with a r...
Thorsten Oliver Zander
Full Text Available Although it ranks among the oldest tools in neuroscientific research, electroencephalography (EEG still forms the method of choice in a wide variety of clinical and research applications. In the context of Brain-Computer Interfacing (BCI, EEG recently has become a tool to enhance Human-Machine Interaction (HMI. EEG could be employed in a wider range of environments, especially for the use of BCI systems in a clinical context or at the homes of patients. However, the application of EEG in these contexts is impeded by the cumbersome preparation of the electrodes with conductive gel that is necessary to lower the impedance between electrodes and scalp. Dry electrodes could provide a solution to this barrier and allow for EEG applications outside the laboratory. In addition, dry electrodes may reduce the time needed for neurological exams in clinical practice. This study evaluates a prototype of a three-channel dry electrode EEG system, comparing it to state-of-the-art conventional EEG electrodes. Two experimental paradigms were used: first, Event-Related Potentials (ERP were investigated with a variant of the oddball paradigm. Second, features of the frequency domain were compared by a paradigm inducing occipital alpha. Furthermore, both paradigms were used to evaluate BCI classification accuracies of both EEG systems. Amplitude and temporal structure of ERPs as well as features in the frequency domain did not differ significantly between the EEG systems. BCI classification accuracies were equally high in both systems when the frequency domain was considered. With respect to the oddball classification accuracy, there were slight differences between the wet and dry electrode systems. We conclude that the tested dry electrodes were capable to detect EEG signals with good quality and that these signals can be used for research or BCI applications. Easy to handle electrodes may help to foster the use of EEG among a wider range of potential users.
This study shows longitudinal development of human-dog interactions in a guide dog raising program. Social play interactions between potential guide dogs for the blind (puppies) and their adult female raisers (PWs) were videotaped at home during the period from two months to 11 or 12 months of the puppies' age. The puppies and PWs established close proximity relationships by two to three months of age. The older the puppies became, the shorter time the puppies and PWs spent in intensive fighting and chasing play. The older the puppies became, the longer the puppies and PWs spent in waiting, seeking and possessing together play which needed the puppies' self-control, concentration and ability to cooperate with the PWs. Whether or not these behavioral tendencies which the puppies showed were appropriate for guide dog candidates is also discussed.
Inappropriate behaviors of potential guide dogs (puppies) for the blind and coping behaviors of their adult female raisers (puppy walkers: PWs) were videotaped in their play situation at home from when the puppies were 2-11 or 12 months of age. The frequency of inappropriate behavior decreased with an increase in the puppies' age, suggesting that human-dog relationships became friendlier. The PWs tended to use moderate coping behaviors to stop the inappropriate behaviors of the puppies. Rejecting interaction with the puppies was effective for stopping the puppies from biting the PWs. Forcible stopping was effective for stopping the puppies from damaging objects. Not responding to the puppies was effective for stopping the puppies from biting the PWs, barking/growling and damaging objects.
Houdayer, E; Degardin, A; Salleron, J; Bourriez, J L; Defebvre, L; Cassim, F; Derambure, P
We sought to characterize cortical activity related to motor control in patients presenting with isolated cortical tremor, in order to determine whether or not myoclonus-related impairments are a source of event-related desynchronization/synchronization (ERD/ERS) disruption. Nine patients presenting with isolated cortical tremor were compared with controls. Mu and beta ERD/ERS were computed over the scalp and brain surfaces using 128-channel electroencephalographic (EEG) recording during voluntary and passive finger extensions. We recorded somatosensory-evoked potentials following median nerve stimulation and performed myoclonic jerk-locked back-averaging of EEG activity. Back-averaging revealed a cortical premyoclonic spike in all patients. Five of the nine patients had exaggerated SEPs. The amplitude of mu ERD was greater in patients. Beta ERD/ERS did not differ from that seen in controls. Localizations of mu and beta ERD/ERS did not differ from controls and were identified in pre- and post-central sensorimotor cortical areas. The present results suggest a hyperexcitability of the cortico-subcortical loops responsible for movement preparation and execution. Post-movement inhibition related to cortical processing of afferent input is unaffected in isolated cortical myoclonus. Intracortical abnormalities can differ in patients suffering from cortical myoclonus, according to whether or not the individuals have associated epileptic symptoms. Copyright © 2011 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Lin, Yuan-Pin; Jung, Tzyy-Ping; Chen, Jyh-Horng
This study explores the electroencephalographic (EEG) correlates of emotions during music listening. Principal component analysis (PCA) is used to correlate EEG features with complex music appreciation. This study also applies machine-leaning algorithms to demonstrate the feasibility of classifying EEG dynamics in four subjectively-reported emotional states. The high classification accuracy (81.58+/-3.74%) demonstrates the feasibility of using EEG features to assess emotional states of human subjects. Further, the spatial and spectral patterns of the EEG most relevant to emotions seem reproducible across subjects.
Full Text Available Spatial component analysis is often used to explore multidimensional time series data whose sources cannot be measured directly. Several methods may be used to decompose the data into a set of spatial components with temporal loadings. Component selection is of crucial importance, and should be supported by objective criteria. In some applications, the use of a well defined component selection criterion may provide for automation of the analysis.In this paper we describe a novel approach for ranking of spatial components calculated from the EEG or MEG data recorded within evoked response paradigm. Our method is called Mutual Information Spectrum and is based on gauging the amount of mutual information of spatial component temporal loadings with a synthetically created reference signal. We also describe the appropriate randomization based statistical assessment scheme that can be used for selection of components with statistically significant amount of mutual information. Using simulated data with realistic trial to trial variations and SNR corresponding to the real recordings we demonstrate the superior performance characteristics of the described mutual information based measure as compared to a more conventionally used power driven gauge. We also demonstrate the application of the Mutual Information Spectrum for the selection of task-related independent components from real MEG data. We show that the Mutual Information spectrum allows to identify task-related components reliably in a consistent fashion, yielding stable results even from a small number of trials. We conclude that the proposed method fits naturally the information driven nature of ICA and can be used for routine and automatic ranking of independent components calculated from the functional neuroimaging data collected within event-related paradigms.
Full Text Available To investigate response inhibition after total sleep deprivation (TSD and the restorative effects of one night of recovery sleep (RS.Fourteen healthy male participants performed a visual Go/NoGo task, and electroencephalogram recordings were conducted at five time points: (1 baseline, (2 after 12 h of TSD, (3 after 24 h of TSD, (4 after 36 h of TSD, and (5 following 8 h of RS. The dynamic changes in response inhibition during TSD and after 8 h of RS were investigated by examining the NoGo-N2 and NoGo-P3 event-related potential components.Compared with baseline, NoGo-P3 amplitudes were decreased, while the NoGo-N2 latency increased along with the awake time prolonged. NoGo anteriorization, which was minimized after 24 h of TSD, progressively decreased with increasing TSD. After 8 h of RS, recoveries of both the NoGo-P3 amplitude and NoGo-N2 latency in the prefrontal cortex were observed compared with the values after 36 h of TSD.TSD induced a dose-dependent functional decline in the response inhibition of NoGo-N2 and NoGo-P3 on prefrontal cortex activation, and 8 h of RS resulted in recovery or maintenance of the response inhibition. However, it was not restored to baseline levels.Participants were chosen male college students only, thus the findings cannot be generalized to older people and women. Additionally, the sample size was small, and, thus, speculations on the meaning of the results of this study should be cautious. The EEG continuous recording should be employed to monitor the decline of alertness following TSD.
Full Text Available BACKGROUND: A growing body of evidence suggests a link between cognitive and pathological changes in amyotrophic lateral sclerosis (ALS and in frontotemporal lobar dementia (FTLD. Cognitive deficits have been investigated much less extensively in primary lateral sclerosis (PLS than in ALS. OBJECTIVE: to investigate bioelectrical activity to Stroop test, assessing frontal function, in ALS, PLS and control groups. METHODS: 32 non-demented ALS patients, 10 non-demented PLS patients and 27 healthy subjects were included. Twenty-nine electroencephalography (EEG channels with binaural reference were recorded during covert Stroop task performance, involving mental discrimination of the stimuli and not vocal or motor response. Group effects on event related potentials (ERPs latency were analyzed using statistical multivariate analysis. Topographic analysis was performed using low resolution brain electromagnetic tomography (LORETA. RESULTS: ALS patients committed more errors in the execution of the task but they were not slower, whereas PLS patients did not show reduced accuracy, despite a slowing of reaction times (RTs. The main ERP components were delayed in ALS, but not in PLS, compared with controls. Moreover, RTs speed but not ERP latency correlated with clinical scores. ALS had decreased frontotemporal activity in the P2, P3 and N4 time windows compared to controls. CONCLUSION: These findings suggest a different pattern of psychophysiological involvement in ALS compared with PLS. The former is increasingly recognized to be a multisystems disorder, with a spectrum of executive and behavioural impairments reflecting frontotemporal dysfunction. The latter seems to mainly involve the motor system, with largely spared cognitive functions. Moreover, our results suggest that the covert version of the Stroop task used in the present study, may be useful to assess cognitive state in the very advanced stage of the disease, when other cognitive tasks are not
Jin, Xiao; Ye, Enmao; Qi, Jianlin; Wang, Lubin; Lei, Yu; Chen, Pinhong; Mi, Guiyun; Zou, Feng; Shao, Yongcong; Yang, Zheng
To investigate response inhibition after total sleep deprivation (TSD) and the restorative effects of one night of recovery sleep (RS). Fourteen healthy male participants performed a visual Go/NoGo task, and electroencephalogram recordings were conducted at five time points: (1) baseline, (2) after 12 h of TSD, (3) after 24 h of TSD, (4) after 36 h of TSD, and (5) following 8 h of RS. The dynamic changes in response inhibition during TSD and after 8 h of RS were investigated by examining the NoGo-N2 and NoGo-P3 event-related potential components. Compared with baseline, NoGo-P3 amplitudes were decreased, while the NoGo-N2 latency increased along with the awake time prolonged. NoGo anteriorization, which was minimized after 24 h of TSD, progressively decreased with increasing TSD. After 8 h of RS, recoveries of both the NoGo-P3 amplitude and NoGo-N2 latency in the prefrontal cortex were observed compared with the values after 36 h of TSD. TSD induced a dose-dependent functional decline in the response inhibition of NoGo-N2 and NoGo-P3 on prefrontal cortex activation, and 8 h of RS resulted in recovery or maintenance of the response inhibition. However, it was not restored to baseline levels. Participants were chosen male college students only, thus the findings cannot be generalized to older people and women. Additionally, the sample size was small, and, thus, speculations on the meaning of the results of this study should be cautious. The EEG continuous recording should be employed to monitor the decline of alertness following TSD.
Ney, JP; Van Der Goes, DN; Nuwer, MR; Nelson, L; Eccher, MA
Objectives: To evaluate the effect of intensive care unit continuous EEG (cEEG) monitoring on inpatient mortality, hospital charges, and length of stay. Methods: A retrospective cross-sectional study was conducted using the Nationwide Inpatient Sample, a dataset representing 20% of inpatient discharges in nonfederal US hospitals. Adult discharge records reporting mechanical ventilation and EEG (routine EEG or cEEG) were included. cEEG was compared with routine EEG alone in association with th...
Moore, Adrienne; Gorodnitsky, Irina; Pineda, Jaime
Simulation theories for the perceptual processing of emotional faces assert that observers recruit the neural circuitry involved in creating their own emotional facial expressions in order to recognize the emotions and infer the feelings of others. The EEG mu rhythm is a sensorimotor oscillation hypothesized to index simulation of some actions during perceptual processing of these actions. The purpose of this research was to extend the study of mu rhythm simulation responses during perceptual tasks to the domain of emotional face perception. Subjects viewed happy and disgusted face photos with empathy and non-empathy task instructions while EEG responses were measured. EEG components were isolated and analyzed using a blind source separation (BSS) method. Mu components were found to respond to the perception of happy and disgusted faces during both empathy and non-empathy tasks with an event-related desynchronization (ERD), activation that is consistent with face simulation. Significant differences were found between responses to happy and to disgusted faces across the right hemisphere mu components beginning about 500ms after stimulus presentation. These findings support a simulation account of perceptual face processing based on a sensorimotor mirroring mechanism, and are the first report of distinct EEG mu responses to observation of positively and negatively valenced emotional faces. Copyright © 2011 Elsevier B.V. All rights reserved.
Hassan B. Hawsawi
Full Text Available Understanding the brain and its activity is one of the great challenges of modern science. Normal brain activity (cognitive processes, etc. has been extensively studied using electroencephalography (EEG since the 1930's, in the form of spontaneous fluctuations in rhythms, and patterns, and in a more experimentally-driven approach in the form of event-related potentials (ERPs allowing us to relate scalp voltage waveforms to brain states and behavior. The use of EEG recorded during functional magnetic resonance imaging (EEG-fMRI is a more recent development that has become an important tool in clinical neuroscience, for example for the study of epileptic activity. The purpose of this review is to explore the magnetic resonance imaging safety aspects specifically associated with the use of scalp EEG and other brain-implanted electrodes such as intracranial EEG electrodes when they are subjected to the MRI environment. We provide a theoretical overview of the mechanisms at play specifically associated with the presence of EEG equipment connected to the subject in the MR environment, and of the resulting health hazards. This is followed by a survey of the literature on the safety of scalp or invasive EEG-fMRI data acquisitions across field strengths, with emphasis on the practical implications for the safe application of the techniques; in particular, we attempt to summarize the findings in terms of acquisition protocols when possible.
Martin, F; Delpont, E; Suisse, G; Richelme, C; Dolisi, C
In children, P3 latency decreases with increasing age. This decrease could be linked with the maturation of cognitive processes. According to this hypothesis, event-related potentials P3 were recording in gifted children to research an electrophysiological correlation with the mental precocity. Auditory long latency event-related potentials were recorded in 10 gifted children (IQs over 140) and 23 control subjects. The part of variance related to age was extracted by comparing deviations from regression line as a function of age. Stimulus-evoked N1 component latency was not statistically different in the two populations. Event-related P3 component latency was significantly shorter in the gifted children at Cz (P children.
Olbrich, S.; Dinteren, R.J.R. van; Arns, M.W.
Personalized medicine in psychiatry is in need of biomarkers that resemble central nervous system function at the level of neuronal activity. Electroencephalography (EEG) during sleep or resting-state conditions and event-related potentials (ERPs) have not only been used to discriminate patients
Thatcher, R W; North, D; Biver, C
There are two inter-related categories of EEG measurement: 1, EEG currents or power and; 2, EEG network properties such as coherence and phase delays. The purpose of this study was to compare the ability of these two different categories of EEG measurement to predict performance on the Weschler Intelligence test (WISC-R). Resting eyes closed EEG was recorded from 19 scalp locations with a linked ears reference from 442 subjects aged 5-52 years. The Weschler Intelligence test was administered to the same subjects but not while the EEG was recorded. Subjects were divided into high IQ (> or = 120) and low IQ ( EEG coherence > EEG amplitude asymmetry > absolute power > relative power and power ratios. The strongest correlations to IQ were short EEG phase delays in the frontal lobes and long phase delays in the posterior cortical regions, reduced coherence and increased absolute power. The findings are consistent with increased neural efficiency and increased brain complexity as positively related to intelligence, and with frontal lobe synchronization of neural resources as a significant contributing factor to EEG and intelligence correlations. Quantitative EEG predictions of intelligence provide medium to strong effect size estimates of cognitive functioning while simultaneously revealing a deeper understanding of the neurophysiological substrates of intelligence.
Grant, Arthur C.; Abdel-Baki, Samah G.; Omurtag, Ahmet; Sinert, Richard; Chari, Geetha; Malhotra, Schweta; Weedon, Jeremy; Fenton, Andre A.; Zehtabchi, Shahriar
Measuring the diagnostic accuracy (DA) of an EEG device is unconventional and complicated by imperfect interrater reliability. We sought to compare the DA of a miniature, wireless, battery-powered EEG device (“microEEG”) to a reference EEG machine in emergency department (ED) patients with altered mental status (AMS). 225 ED patients with AMS underwent 3 EEGs. EEG1 (Nicolet Monitor, “reference”) and EEG2 (microEEG) were recorded simultaneously with EEG cup electrodes using a signal splitter. ...
Melnik, Andrew; Legkov, Petr; Izdebski, Krzysztof; Kärcher, Silke M.; Hairston, W. David; Ferris, Daniel P.; König, Peter
Lab-based electroencephalography (EEG) techniques have matured over decades of research and can produce high-quality scientific data. It is often assumed that the specific choice of EEG system has limited impact on the data and does not add variance to the results. However, many low cost and mobile EEG systems are now available, and there is some doubt as to the how EEG data vary across these newer systems. We sought to determine how variance across systems compares to variance across subjects or repeated sessions. We tested four EEG systems: two standard research-grade systems, one system designed for mobile use with dry electrodes, and an affordable mobile system with a lower channel count. We recorded four subjects three times with each of the four EEG systems. This setup allowed us to assess the influence of all three factors on the variance of data. Subjects performed a battery of six short standard EEG paradigms based on event-related potentials (ERPs) and steady-state visually evoked potential (SSVEP). Results demonstrated that subjects account for 32% of the variance, systems for 9% of the variance, and repeated sessions for each subject-system combination for 1% of the variance. In most lab-based EEG research, the number of subjects per study typically ranges from 10 to 20, and error of uncertainty in estimates of the mean (like ERP) will improve by the square root of the number of subjects. As a result, the variance due to EEG system (9%) is of the same order of magnitude as variance due to subjects (32%/sqrt(16) = 8%) with a pool of 16 subjects. The two standard research-grade EEG systems had no significantly different means from each other across all paradigms. However, the two other EEG systems demonstrated different mean values from one or both of the two standard research-grade EEG systems in at least half of the paradigms. In addition to providing specific estimates of the variability across EEG systems, subjects, and repeated sessions, we also
Melnik, Andrew; Legkov, Petr; Izdebski, Krzysztof; Kärcher, Silke M; Hairston, W David; Ferris, Daniel P; König, Peter
Lab-based electroencephalography (EEG) techniques have matured over decades of research and can produce high-quality scientific data. It is often assumed that the specific choice of EEG system has limited impact on the data and does not add variance to the results. However, many low cost and mobile EEG systems are now available, and there is some doubt as to the how EEG data vary across these newer systems. We sought to determine how variance across systems compares to variance across subjects or repeated sessions. We tested four EEG systems: two standard research-grade systems, one system designed for mobile use with dry electrodes, and an affordable mobile system with a lower channel count. We recorded four subjects three times with each of the four EEG systems. This setup allowed us to assess the influence of all three factors on the variance of data. Subjects performed a battery of six short standard EEG paradigms based on event-related potentials (ERPs) and steady-state visually evoked potential (SSVEP). Results demonstrated that subjects account for 32% of the variance, systems for 9% of the variance, and repeated sessions for each subject-system combination for 1% of the variance. In most lab-based EEG research, the number of subjects per study typically ranges from 10 to 20, and error of uncertainty in estimates of the mean (like ERP) will improve by the square root of the number of subjects. As a result, the variance due to EEG system (9%) is of the same order of magnitude as variance due to subjects (32%/sqrt(16) = 8%) with a pool of 16 subjects. The two standard research-grade EEG systems had no significantly different means from each other across all paradigms. However, the two other EEG systems demonstrated different mean values from one or both of the two standard research-grade EEG systems in at least half of the paradigms. In addition to providing specific estimates of the variability across EEG systems, subjects, and repeated sessions, we also
Tangwiriyasakul, Chayanin; Verhagen, R.; Rutten, Wim; van Putten, Michel Johannes Antonius Maria
Introduction: To design a neurofeedback system (NF system) for clinical purposes (e.g. stroke rehabilitation) using imaging-observation of motor movements. Event-Related Desynchronization (ERD) of the mu rhythm (8-13 Hz) is vital to indicate the engagement between the patient’s brain and the NF
Farquhar, J.D.R.; Hill, N.J.
Detecting event related potentials (ERPs) from single trials is critical to the operation of many stimulus-driven brain computer interface (BCI) systems. The low strength of the ERP signal compared to the noise (due to artifacts and BCI irrelevant brain processes) makes this a challenging signal
Domahs, Ulrike; Kehrein, Wolfgang; Knaus, Johannes; Wiese, Richard; Schlesewsky, Matthias
Flow are violations of phonological constraints processed in word comprehension? The present article reports the results of ail event-related potentials (ERP) Study oil a phonological constraint of German that disallows identical segments within it syllable or word (CC(i)VC(i)). We examined three
Berger, Natalie I.; Coch, Donna
Texted English is a hybrid, technology-based language derived from standard English modified to facilitate ease of communication via instant and text messaging. We compared semantic processing of texted and standard English sentences by recording event-related potentials in a classic semantic incongruity paradigm designed to elicit an N400 effect.…
Bruin, KJ; Kenemans, JL; Verbaten, MN; Van der Heijden, AHC
The goal of this study was to investigate habituation processes in the brain, and in particular, to identify the brain structures involved in these processes. Therefore, event-related potentials (ERPs) were recorded in response to a series of repeated, task-irrelevant, salient stimuli presented
S.J.E. Langeslag (Sandra); B.M. Jansma (Bernadette); I.H.A. Franken (Ingmar); J.W. van Strien (Jan)
textabstractIn event-related potential (ERPs) studies, emotional stimuli usually elicit an enhanced late positive potential (LPP), which is assumed to reflect motivated attention. However, whether a stimulus elicits emotional responses may depend on the individual's state, such as experiencing
Klaver, P; Smid, HGOM; Heinze, HJ
Behavioral measures and event-related potentials (ERPs) were recorded from 12 subjects while performing three delayed matching-to-sample tasks. The task instructions indicated whether stimulus locations, shapes or conjunctions of locations and shapes had to be memorized and matched against a probe.
Baumann, Stefan; Schumacher, Petra B.
The paper reports on a perception experiment in German that investigated the neuro-cognitive processing of information structural concepts and their prosodic marking using event-related brain potentials (ERPs). Experimental conditions controlled the information status (given vs. new) of referring and non-referring target expressions (nouns vs.…
J.W. van Strien (Jan); L.A. Isbell (Lynne A.)
textabstractStudies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to
Kohls, Gregor; Peltzer, Judith; Schulte-Ruther, Martin; Kamp-Becker, Inge; Remschmidt, Helmut; Herpertz-Dahlmann, Beate; Konrad, Kerstin
Social motivation deficit theories suggest that children with autism do not properly anticipate and appreciate the pleasure of social stimuli. In this study, we investigated event-related brain potentials evoked by cues that triggered social versus monetary reward anticipation in children with autism. Children with autism showed attenuated P3…
Lemons, Christopher J.; Key, Alexandra P. F.; Fuchs, Douglas; Yoder, Paul J.; Fuchs, Lynn S.; Compton, Donald L.; Williams, Susan M.; Bouton, Bobette
The purpose of this study was to determine if event-related potential (ERP) data collected during three reading-related tasks (Letter Sound Matching, Nonword Rhyming, and Nonword Reading) could be used to predict short-term reading growth on a curriculum-based measure of word identification fluency over 19 weeks in a sample of 29 first-grade…
Dillon, Daniel G.; Cooper, Julie J.; Grent-'t-Jong, Tineke; Woldorff, Marty G.; LaBar, Kevin S.
Event-related potential (ERP) studies have shown that emotional stimuli elicit greater amplitude late positive-polarity potentials (LPPs) than neutral stimuli. This effect has been attributed to arousal, but emotional stimuli are also more semantically coherent than uncategorized neutral stimuli. ERPs were recorded during encoding of positive,…
Perfetti, Charles A.; Wlotko, Edward W.; Hart, Lesley A.
Adults learned the meanings of rare words (e.g., gloaming) and then made meaning judgments on pairs of words. The 1st word was a trained rare word, an untrained rare word, or an untrained familiar word. Event-related potentials distinguished trained rare words from both untrained rare and familiar words, first at 140 ms and again at 400-600 ms…
Domahs, U.; Kehrein, W.; Knaus, J.; Wiese, R.; Schlesewsky, M.
How are violations of phonological constraints processed in word comprehension? The present article reports the results of an event-related potentials (ERP) study on a phonological constraint of German that disallows identical segments within a syllable or word (CC iVCi). We examined three types of
Li, X.; Hagoort, P.; Yang, Y.
In an event-related potential experiment with Chinese discourses as material, we investigated how and when accentuation influences spoken discourse comprehension in relation to the different information states of the critical words. These words could either provide new or old information. It was
Zempleni, Monika-Zita; Renken, Remco; Hoeks, John C. J.; Hoogduin, Johannes M.; Stowe, Laurie A.
Lexical semantic ambiguity is the phenomenon when a word has multiple meanings (e.g. 'bank'). The aim of this event-related functional MRI study was to identify those brain areas, which are involved in contextually driven ambiguity resolution. Ambiguous words were selected which have a most
Yu, Luodi; Fan, Yuebo; Deng, Zhizhou; Huang, Dan; Wang, Suiping; Zhang, Yang
The present study investigated pitch processing in Mandarin-speaking children with autism using event-related potential measures. Two experiments were designed to test how acoustic, phonetic and semantic properties of the stimuli contributed to the neural responses for pitch change detection and involuntary attentional orienting. In comparison…
Sambeth, A.; Maes, J.H.R.; Quian Quiroga, R.; Coenen, A.M.L.
The present study compared the effects of repeated stimulus presentations on the event-related potential (ERP) of humans and rats. Both species were presented with a total of 100 auditory stimuli, divided into four blocks of 25 stimuli. By means of wavelet denoising, single-trial ERPs were
Rollins, Leslie; Riggins, Tracy
The aim of the present study was to investigate developmental changes in encoding processes between 6-year-old children and adults using event-related potentials (ERPs). Although episodic memory ("EM") effects have been reported in both children and adults at retrieval and subsequent memory effects have been established in adults, no…
Kok, A.; de Looren de Jong, H.
Event-related potentials were recorded in response to visual stimuli in 2 reaction tasks in which 12 right-handed male undergraduates were instructed to react immediately to the stimuli, or to delay their response for 2 sec. There were 4 types of stimuli: frequent-degraded, frequent-undegraded,
Peer, J.M. van; Roelofs, K.; Rotteveel, M.; Dijk, J.G. van; Spinhoven, P.; Ridderinkhof, K.R.
We investigated the effects of cortisol administration (50 mg) on approach and avoidance tendencies in low and high trait avoidant healthy young men. Event-related brain potentials (ERPs) were measured during a reaction time task, in which participants evaluated the emotional expression of
Batty, Magali; Meaux, Emilie; Wittemeyer, Kerstin; Roge, Bernadette; Taylor, Margot J.
Social deficits are one of the most striking manifestations of autism spectrum disorders (ASDs). Among these social deficits, the recognition and understanding of emotional facial expressions has been widely reported to be affected in ASDs. We investigated emotional face processing in children with and without autism using event-related potentials…
Klaver, Peter; Talsma, D.; Wijers, Albertus; Heinze, Hans-Jochen; Mulder, Gijsbertus
EVENT-RELATED potentials (ERPs) were recorded as 12 subjects performed a delayed matching to sample task. We presented two bilateral abstract shapes and cued spatially which had to be memorized for a subsequent matching task: left, right or both. During memorization a posterior slow negative ERP
Klaver, P.; Fell, J.; Weis, S.; Greiff, A. de; Ruhlmann, J.; Reul, J.; Elger, C.E.; Fernandez, G.S.E.
Our event-related functional MRI (efMRI) study investigates whether visual advance information (AI) affects rather perceptual or central response-related processing areas. Twelve subjects were required to make a go/no-go decision to a conjunction of a specific color and motion direction. The stimuli
Boonstra, T.W.; Daffertshofer, A.; Beek, P.J.
The influence of sleep deprivation (SD) on event-related fields and the distribution of power over the scalp of MEG imaged brain activity was studied during acoustically paced rhythmic force production. At the behavioral level, SD resulted in a reduction of the lag (negative asynchrony) between
Brodeur, Mathieu B.; Debruille, J. Bruno; Renoult, Louis; Prevost, Marie; Dionne-Dostie, Emmanuelle; Buchy, Lisa; Lepage, Martin
The present study was carried out to examine how the event-related potentials to fragmentation predict recognition success. Stimuli were abstract meaningless figures that were either complete or fragmented to various extents but still recoverable. Stimuli were first encoded as part of a symmetry discrimination task. In a subsequent recognition…
Du, Jing; Li, Jianming; Wang, Ying; Jiang, Qianjin; Livesley, W. John; Jang, Kerry L.; Wang, Kai; Wang, Wei
Some studies of the event-related potentials demonstrated a reduction of the voluntary component P3 (P300 or P3b) in youngsters with the attention deficit/hyperactivity disorder (ADHD) or in conduct disorders (CD), and a reduction of the automatic processing component, mismatch negativity, in patients with both ADHD and CD (ADHD+CD). Recently, a…
Lahera, G; Pedrera, A; Cabañes, L; Fernandez-Lorente, J; Simal, P; Montes, J M; Saiz-Ruiz, J
Auditory P300 event-related potential (ERP) and performance on Sustained Attention were evaluated in 24 euthymic bipolar patients and 38 healthy volunteers. There were no significant differences between groups, and performance in sustained attention had no significant influence in the P300 responses. P300 response might be driven by the presence of mood symptoms.
Pollak, Seth D.; Cicchetti, Dante; Klorman, Rafael; Brumaghim, Joan T.
Recorded cognitive event-related potentials from maltreated and nonmaltreated children during presentations of happy, angry, or neutral facial expressions. Found that for nonmaltreated children, the average amplitude of P300 was comparable for responses to happy and neutral expressions. Maltreated children displayed larger P300 amplitude to…
Meyler, Ann; Breznitz, Zvia
The authors examined the processing of phonological and orthographic word representations among 17 dyslexic and 16 normal college-level readers using Event-Related Potential measures. They focused on 2 early components--the P200 and the P300. The results revealed P200 and P300 components of lower amplitude and later latency among dyslexic readers…
Jessen, Anna; Fleischhauer, Elisabeth; Clahsen, Harald
This study reports developmental changes in morphological encoding across late childhood. We examined event-related brain potentials (ERPs) during the silent production of regularly vs. irregularly inflected verb forms (viz. "-t" vs. "-n" participles of German) in groups of eight- to ten-year-olds, eleven- to…
Steinhauer, Karsten; White, Erin J.; Drury, John E.
The ways in which age of acquisition (AoA) may affect (morpho)syntax in second language acquisition (SLA) are discussed. We suggest that event-related brain potentials (ERPs) provide an appropriate online measure to test some such effects. ERP findings of the past decade are reviewed with a focus on recent and ongoing research. It is concluded…
Zou, Yuan; Nathan, Viswam; Jafari, Roozbeh
Electroencephalography (EEG) is the recording of electrical activity produced by the firing of neurons within the brain. These activities can be decoded by signal processing techniques. However, EEG recordings are always contaminated with artifacts which hinder the decoding process. Therefore, identifying and removing artifacts is an important step. Researchers often clean EEG recordings with assistance from independent component analysis (ICA), since it can decompose EEG recordings into a number of artifact-related and event-related potential (ERP)-related independent components. However, existing ICA-based artifact identification strategies mostly restrict themselves to a subset of artifacts, e.g., identifying eye movement artifacts only, and have not been shown to reliably identify artifacts caused by nonbiological origins like high-impedance electrodes. In this paper, we propose an automatic algorithm for the identification of general artifacts. The proposed algorithm consists of two parts: 1) an event-related feature-based clustering algorithm used to identify artifacts which have physiological origins; and 2) the electrode-scalp impedance information employed for identifying nonbiological artifacts. The results on EEG data collected from ten subjects show that our algorithm can effectively detect, separate, and remove both physiological and nonbiological artifacts. Qualitative evaluation of the reconstructed EEG signals demonstrates that our proposed method can effectively enhance the signal quality, especially the quality of ERPs, even for those that barely display ERPs in the raw EEG. The performance results also show that our proposed method can effectively identify artifacts and subsequently enhance the classification accuracies compared to four commonly used automatic artifact removal methods.
Glickman, Matthew R.; Tang, Akaysha (University of New Mexico, Albuquerque, NM)
The motivating vision behind Sandia's MENTOR/PAL LDRD project has been that of systems which use real-time psychophysiological data to support and enhance human performance, both individually and of groups. Relevant and significant psychophysiological data being a necessary prerequisite to such systems, this LDRD has focused on identifying and refining such signals. The project has focused in particular on EEG (electroencephalogram) data as a promising candidate signal because it (potentially) provides a broad window on brain activity with relatively low cost and logistical constraints. We report here on two analyses performed on EEG data collected in this project using the SOBI (Second Order Blind Identification) algorithm to identify two independent sources of brain activity: one in the frontal lobe and one in the occipital. The first study looks at directional influences between the two components, while the second study looks at inferring gender based upon the frontal component.
Electroencephalographic data recorded on the human scalp can be modeled as a linear mixture of underlying dipolar source generators. The characterization of such generators is the aim of several families of signal processing methods. In this HDR we consider in several details three of such families, namely 1) EEG distributed inverse solutions, 2) diagonalization methods, including spatial filtering and blind source separation and 3) Riemannian geometry. We highlight our contributions in each ...
Předmětem této bakalářské práce je seznámení se signálem EEG. Jsou zde rozebrány jeho vlastnosti, použití a způsoby zpracování. Hlavní část se zabývá segmentací EEG signálu. Dvě metody segmentace jsou realizovány v programu Matlab, a to adaptivní segmentace na základě míry diference střední amplitudy a míry diference střední frekvence a adaptivní segmentace na základě míry diference odhadnuté z rychlé Fourierovy transformace. Funkčnost algoritmu je ověřena na reálných EEG signálech. Subjec...
Tato bakalářská práce se zabývá analýzou spánkových EEG, která je provedena pomocí výpočtu vybraných parametrů z časové a frekvenční oblasti. Parametry se počítají z jednotlivých úseků EEG signálů, které odpovídají jednotlivým spánkovým fázím. Na základě analýzy se rozhodne, které parametry EEG jsou vhodné pro automatickou detekci fází a která metoda je vhodnější pro hodnocení dat v hypnogramu. K analýze byl použit program MATLAB, ve kterém byla daná data porovnána. This thesis deals with ...
Full Text Available The electroencephalogram (EEG signal represents a subject’s specific brain activity patterns and is considered as an ideal biometric given its superior forgery prevention. However, the accuracy and stability of the current EEG-based person authentication systems are still unsatisfactory in practical application. In this paper, a multi-task EEG-based person authentication system combining eye blinking is proposed, which can achieve high precision and robustness. Firstly, we design a novel EEG-based biometric evoked paradigm using self- or non-self-face rapid serial visual presentation (RSVP. The designed paradigm could obtain a distinct and stable biometric trait from EEG with a lower time cost. Secondly, the event-related potential (ERP features and morphological features are extracted from EEG signals and eye blinking signals, respectively. Thirdly, convolutional neural network and back propagation neural network are severally designed to gain the score estimation of EEG features and eye blinking features. Finally, a score fusion technology based on least square method is proposed to get the final estimation score. The performance of multi-task authentication system is improved significantly compared to the system using EEG only, with an increasing average accuracy from 92.4% to 97.6%. Moreover, open-set authentication tests for additional imposters and permanence tests for users are conducted to simulate the practical scenarios, which have never been employed in previous EEG-based person authentication systems. A mean false accepted rate (FAR of 3.90% and a mean false rejected rate (FRR of 3.87% are accomplished in open-set authentication tests and permanence tests, respectively, which illustrate the open-set authentication and permanence capability of our systems.
Blokland, Arjan; Prickaerts, Jos; van Duinen, Marlies; Sambeth, Anke
It has been shown to be difficult to predict whether cognition-enhancing effects of drugs in animal studies have the same effect in humans. Various issues in translating findings from animal to human studies can be identified. Here we discuss whether EEG could be considered as a possible tool to translate the effects of cognition enhancers across species. Three different aspects of EEG measures are evaluated: frequency bands, event-related potentials, and coherence analysis. On basis of the comparison of these measures between species, and effects of drugs that improve or impair memory performance (mainly cholinergic drugs), it appears that event-related potentials and coherence analyses could be considered as potential translational tools to study cognition-enhancing drug effects in rodents and animals. Copyright © 2015 Elsevier B.V. All rights reserved.
Lobo, Isabela; Portugal, Liana Catarina; Figueira, Ivan; Volchan, Eliane; David, Isabel; Garcia Pereira, Mirtes; de Oliveira, Leticia
Considering the Research Domain Criteria (RDoC) framework, it is crucial to investigate posttraumatic stress disorder (PTSD) as a spectrum that ranges from normal to pathological. This dimensional approach is especially important to aid early PTSD detection and to guide better treatment options. In recent years, electroencephalography (EEG) has been used to investigate PTSD; however, reviews regarding EEG data related to PTSD are lacking, especially considering the dimensional approach. This systematic review examined the literature regarding EEG alterations in trauma-exposed people with posttraumatic stress symptoms (PTSS) to identify putative EEG biomarkers of PTSS severity. A systematic review of EEG studies of trauma-exposed participants with PTSS that reported dimensional analyses (e.g., correlations or regressions) between PTSS and EEG measures was performed. The literature search yielded 1178 references, of which 34 studies were eligible for inclusion. Despite variability among the reviewed studies, the PTSS severity was often associated with P2, P3-family event-related potentials (ERPs) and alpha rhythms. The search was limited to articles published in English; no information about non-published studies or studies reported in other languages was obtained. Another limitation was the heterogeneity of studies, which made meta-analysis challenging. EEG provides promising candidates to act as biomarkers, although further studies are required to confirm the findings. Thus, EEG, in addition to being cheaper and easier to implement than other central techniques, has the potential to reveal biomarkers of PTSS severity. Copyright © 2015 Elsevier B.V. All rights reserved.
Kamiyama, Keiko S; Abla, Dilshat; Iwanaga, Koichi; Okanoya, Kazuo
We examined the integrative process between emotional facial expressions and musical excerpts by using an affective priming paradigm. Happy or sad musical stimuli were presented after happy or sad facial images during electroencephalography (EEG) recordings. We asked participants to judge the affective congruency of the presented face-music pairs. The congruency of emotionally congruent pairs was judged more rapidly than that of incongruent pairs. In addition, the EEG data showed that incongruent musical targets elicited a larger N400 component than congruent pairs. Furthermore, these effects occurred in nonmusicians as well as musicians. In sum, emotional integrative processing of face-music pairs was facilitated in congruent music targets and inhibited in incongruent music targets; this process was not significantly modulated by individual musical experience. This is the first study on musical stimuli primed by facial expressions to demonstrate that the N400 component reflects the affective priming effect. Copyright © 2012 Elsevier Ltd. All rights reserved.
Jones, E A; Giger-Mateeva, V I; Reits, D; Riemslag, F C; Liberov, B; Spekrijse, H
The P300 complex was derived from the electroencephalogram (EEG) as subjects mentally counted infrequent large checkerboard visual stimuli, presented randomly among frequent small checkerboard stimuli. Use of low contrast (10%) stimuli and four midline scalp electrodes, facilitated separation of cognitive and sensory components and enabled the P300 complex to be resolved into three distinct components--N200, P3a, and P3b. In 20 healthy adult subjects normative data were established and the P3a and P3b components were shown to depend on cognitive function. In 19 age-matched cirrhotic patients without overt hepatic encephalopathy (HE) the EEG and visual evoked potentials (VEPs) were normal, but latencies of P3a and/or P3b were prolonged in 9. Prolonged latencies were not associated with an abnormal number connection test. Ten additional age-matched cirrhotic patients without overt HE, who were alcohol, drug, and caffeine free, were randomized to receive flumazenil (1 mg) and placebo intravenously, double-blind. After flumazenil or placebo, latencies of P3a and P3b and psychometric test results did not change significantly. These findings suggest that in cirrhotic patients without overt HE (i) impaired cognitive sensory function may occur in the absence of abnormalities of a standard psychometric test, the EEG, or VEPs, and (ii) increased latencies of P3a and P3b may constitute a component of subclinical HE, which is not mediated by increased brain levels of central benzodiazepine receptor agonist ligands.
Aldea, Roxana; Lazăr, Anca Mihaela
The main objective is to high-light the P300 potential on certain electroencephalographic signals. P300 occurs at a relatively well defined time in relation to a stimulus and it represents a signal with a specified band frequency. The electroencephalographic (EEG) was recorded with 4 wet electrodes by means of g.MOBIlab+ module, a g.tec acquisition system. The multiresolution wavelet transform was chosen to extract the P300 potential from the EEG signal because it provides information on both time and frequency domains. The multiresolution wavelet transform decomposes the signal in sub-bands and it helps to highlight the P300 potential. The spectrum of the P300 potential is around 3Hz. For the multiresolution wavelet decomposition this corresponds to coefficients of approximation of order 4 according to 0 to 60 Hz band of the original EEG signal. The representation of these coefficients emphasizes a better detection of P300 potential then in the original signal. It is shown to be a more appropriate method than the direct analysis of the signal because it works with lower dimensional signals. This method of detection of the P300 potential can be used successfully in the implementation of a Brain Computer Interface (BCI).
Meares, Russell; Melkonian, Dmitriy; Gordon, Evian; Williams, Leanne
P3a and P3b event-related brain potentials to auditory stimuli were recorded for 17 unmedicated patients with borderline personality disorder, 17 matched healthy controls and 100 healthy control participants spanning five decades. Using high-resolution fragmentary decomposition for single-trial event-related potential analysis, distinctive disturbances in P3a in borderline personality disorder patients were found: abnormally enhanced amplitude, failure to habituate and a loss of temporal locking with P3b. Normative age dependencies from 100 controls suggest that natural age-related decline in P3a amplitude is reduced in borderline personality disorder patients and is likely to indicate failure of frontal maturation. On the basis of the theories of Hughlings Jackson, this conceptualization of borderline personality disorder is consistent with an aetiological model of borderline personality disorder.
Wiegand, Iris; Müller, Hermann J.; Finke, Kathrin
measures with lateralized event-related potentials of younger and older adults performing a compound-search task, in which the target-defining dimension of a pop-out target (color/shape) and the response-critical target feature (vertical/horizontal stripes) varied independently across trials. Slower......Attentional decline plays a major role in cognitive changes with aging. However, which specific aspects of attention contribute to this decline is as yet little understood. To identify the contributions of various potential sources of age decrements in visual search, we combined response time...... responses in older participants were associated with age differences in all analyzed event-related potentials from perception to response, indicating that behavioral slowing originates from multiple stages within the information-processing stream. Furthermore, analyses of carry-over effects from one trial...
Francois, Clément; Schön, Daniele
To learn a new language, it is necessary for the learner to succeed in segmenting the continuous stream of sounds into significant units. Previous behavioral studies have shown that it is possible to segment a language or musical stream based only on probabilities of occurrence between adjacent syllables/tones. Here we used a sung language and tested participants' learning of both linguistic and musical structures while recording electroencephalography. Although behavioral results showed learning of the linguistic structure only, event-related potential results for both dimensions showed a negative component sensitive to the degree of familiarity of items. We discuss this component as an index of lexical search, also pointing to the greater sensitivity of the event-related potentials compared to the behavioral responses.
Full Text Available Event-related potentials are an informative method for measuring the extent of information processing in the brain. The voltage deflections in an ERP waveform reflect the processing of sensory information as well as higher-level processing that involves selective attention, memory, semantic comprehension, and other types of cognitive activity. ERPs provide a non-invasive method of studying, with exceptional temporal resolution, cognitive processes in the human brain. ERPs are extracted from scalp-recorded electroencephalography by a series of signal processing steps. The present tutorial will highlight several of the analysis techniques required to obtain event-related potentials. Some methodological issues that may be encountered will also be discussed.
Leiser, Steven C; Dunlop, John; Bowlby, Mark R; Devilbiss, David M
Electroencephalography (EEG) and related methodologies offer the promise of predicting the likelihood that novel therapies and compounds will exhibit clinical efficacy early in preclinical development. These analyses, including quantitative EEG (e.g. brain mapping) and evoked/event-related potentials (EP/ERP), can provide a physiological endpoint that may be used to facilitate drug discovery, optimize lead or candidate compound selection, as well as afford patient stratification and Go/No-Go decisions in clinical trials. Currently, the degree to which these different methodologies hold promise for translatability between preclinical models and the clinic have not been well summarized. To address this need, we review well-established and emerging EEG analytic approaches that are currently being integrated into drug discovery programs throughout preclinical development and clinical research. Furthermore, we present the use of EEG in the drug development process in the context of a number of major central nervous system disorders including Alzheimer's disease, schizophrenia, depression, attention deficit hyperactivity disorder, and pain. Lastly, we discuss the requirements necessary to consider EEG technologies as a biomarker. Many of these analyses show considerable translatability between species and are used to predict clinical efficacy from preclinical data. Nonetheless, the next challenge faced is the selection and validation of EEG endpoints that provide a set of robust and translatable biomarkers bridging preclinical and clinical programs. 2010 Elsevier Inc. All rights reserved.
Dahal, Nabaraj; (Nanda Nandagopal, D.; Cocks, Bernadine; Vijayalakshmi, Ramasamy; Dasari, Naga; Gaertner, Paul
Objective. The objective of our current study was to look for the EEG correlates that can reveal the engaged state of the brain while undertaking cognitive tasks. Specifically, we aimed to identify EEG features that could detect audio distraction during simulated driving. Approach. Time varying autoregressive (TVAR) analysis using Kalman smoother was carried out on short time epochs of EEG data collected from participants as they undertook two simulated driving tasks. TVAR coefficients were then used to construct all pole model enabling the identification of EEG features that could differentiate normal driving from audio distracted driving. Main results. Pole analysis of the TVAR model led to the visualization of event related synchronization/desynchronization (ERS/ERD) patterns in the form of pole displacements in pole plots of the temporal EEG channels in the z plane enabling the differentiation of the two driving conditions. ERS in the EEG data has been demonstrated during audio distraction as an associated phenomenon. Significance. Visualizing the ERD/ERS phenomenon in terms of pole displacement is a novel approach. Although ERS/ERD has previously been demonstrated as reliable when applied to motor related tasks, it is believed to be the first time that it has been applied to investigate human cognitive phenomena such as attention and distraction. Results confirmed that distracted/non-distracted driving states can be identified using this approach supporting its applicability to cognition research.
Sha Sha Song; Guang Jie Zhao
The emotional and psychological activities associated with the visual perception of macroscopic and microscopic structure patterns of wood were investigated. The macroscopic and microscopic structure patterns of 18 different timber tree species of northeast China were selected as the research objects, and these were divided into eight categories for event-related potential analysis. The 30 effective subjects’ tasks were to watch the wood structure stimuli patterns and evaluate them on a 7-poi...
Full Text Available Abstract Background Attention-Deficit/Hyperactivity Disorder (ADHD is a prevalent, complex disorder which is characterized by symptoms of inattention, hyperactivity, and impulsivity. Convergent evidence from neurobiological studies of ADHD identifies dysfunction in fronto-striatal-cerebellar circuitry as the source of behavioural deficits. Recent studies have shown that regions governing basic sensory processing, such as the somatosensory cortex, show abnormalities in those with ADHD suggesting that these processes may also be compromised. Methods We used event-related magnetoencephalography (MEG to examine patterns of cortical rhythms in the primary (SI and secondary (SII somatosensory cortices in response to median nerve stimulation, in 9 adults with ADHD and 10 healthy controls. Stimuli were brief (0.2 ms non-painful electrical pulses presented to the median nerve in two counterbalanced conditions: unpredictable and predictable stimulus presentation. We measured changes in strength, synchronicity, and frequency of cortical rhythms. Results Healthy comparison group showed strong event-related desynchrony and synchrony in SI and SII. By contrast, those with ADHD showed significantly weaker event-related desynchrony and event-related synchrony in the alpha (8–12 Hz and beta (15–30 Hz bands, respectively. This was most striking during random presentation of median nerve stimulation. Adults with ADHD showed significantly shorter duration of beta rebound in both SI and SII except for when the onset of the stimulus event could be predicted. In this case, the rhythmicity of SI (but not SII in the ADHD group did not differ from that of controls. Conclusion Our findings suggest that somatosensory processing is altered in individuals with ADHD. MEG constitutes a promising approach to profiling patterns of neural activity during the processing of sensory input (e.g., detection of a tactile stimulus, stimulus predictability and facilitating our
Claudio Portella; Sergio Machado; Oscar Arias-Carrión; Sack, Alexander T.; Julio Guilherme Silva; Marco Orsini; Marco Antonio Araujo Leite; Adriana Cardoso Silva; Nardi, Antonio E.; Mauricio Cagy; Roberto Piedade; Pedro Ribeiro
The brain is capable of elaborating and executing different stages of information processing. However, exactly how these stages are processed in the brain remains largely unknown. This study aimed to analyze the possible correlation between early and late stages of information processing by assessing the latency to, and amplitude of, early and late event-related potential (ERP) components, including P200, N200, premotor potential (PMP) and P300, in healthy participants in the context of a vis...
Stevenson, Ryan A.; Bushmakin, Maxim; Kim, Sunah; Wallace, Mark T.; Puce, Aina; James, Thomas W
In recent years, it has become evident that neural responses previously considered to be unisensory can be modulated by sensory input from other modalities. In this regard, visual neural activity elicited to viewing a face is strongly influenced by concurrent incoming auditory information, particularly speech. Here, we applied an additive-factors paradigm aimed at quantifying the impact that auditory speech has on visual event-related potentials (ERPs) elicited to visual speech. These multise...
Babiloni, Claudio; Marzano, Nicola; Soricelli, Andrea; Cordone, Susanna; Millán-Calenti, José Carlos; Del Percio, Claudio; Buján, Ana
This article reviews three experiments on event-related potentials (ERPs) testing the hypothesis that primary visual consciousness (stimulus self-report) is related to enhanced cortical neural synchronization as a function of stimulus features. ERP peak latency and sources were compared between “seen” trials and “not seen” trials, respectively related and unrelated to the primary visual consciousness. Three salient features of visual stimuli were considered (visuospatial, emotional face expre...
Paniz Tavakoli; Ken Campbell
Event-related potentials are an informative method for measuring the extent of information processing in the brain. The voltage deflections in an ERP waveform reflect the processing of sensory information as well as higher-level processing that involves selective attention, memory, semantic comprehension, and other types of cognitive activity. ERPs provide a non-invasive method of studying, with exceptional temporal resolution, cognitive processes in the human brain. ERPs are extracted from s...
Kramer, Arthur F.; Donchin, Emanuel; Wickens, Christopher D.
Over the past decade considerable strides were made in explicating the antecedant conditions necessary for the elicitation, and the modulation of the amplitude and latency, of a number of components of the event-related brain potential (ERP). The focus of this report is on P300. The degree to which the psychophysiological measures contribute to issues in two real-world domains (communication devices for the motor impaired and the assessment of mental workload of aircraft pilots) are examined.
Titlic, Marina; Mise, Nikolina Ivica; Pintaric, Irena; Rogosic, Veljko; Vanjaka-Rogosic, Lucija; Mihalj, Mario; Jurinovic, Pavao; Katic, Ana Curkovic;; Andjelinovic, Maja
Objective: Recording of event-related potentials by using oddball paradigm of auditory P300 has yielded conflicting results in migraine. The aim of this study was to demonstrate that migraine patients have reduced P300 amplitude and prolonged P300 latency, suggesting alterations of the cognitive-evaluative component. Methods: We recruited 29 migraine patients (24 females; median age 40 years) and 29 healthy age- and gender-matched participants. Participants were subjected to the same testing ...
Versace, Francesco; Bradley, Margaret M.; Lang, Peter J.
Dense array event-related potentials (ERPs) and memory performance were assessed following rapid serial visual presentation (RSVP) of emotional and neutral pictures. Despite the extremely brief presentation, emotionally arousing pictures prompted an enhanced negative voltage over occipital sensors, compared to neutral pictures, replicating previous encoding effects. Emotionally arousing pictures were also remembered better in a subsequent recognition test, with higher hit rates and better dis...
Gaudreault, Pierre-Olivier; Gagnon, Jean-François; Montplaisir, Jacques; Vendette, Mélanie; Postuma, Ronald B; Gagnon, Katia; Gosselin, Nadia
Rapid eye movement sleep behavior disorder is found in 33-46% of patients with Parkinson's disease and was shown to be associated with cognitive deficits. Our goal was to improve our understanding of the role of this sleep disorder in cerebral dysfunction occurring in Parkinson's disease using a visual cognitive task and event-related potentials. Sixteen patients with Parkinson's disease and rapid eye movement sleep behavior disorder, 15 patients with Parkinson's disease without rapid eye movement sleep behavior disorder and 16 healthy control subjects were included. The amplitude and latency of event-related potentials were compared between groups. No group differences were found for reaction times or accuracy. A Group effect was found for P2 wave amplitude; patients with rapid eye movement sleep behavior disorder had increased P2 in comparison with the control group (p disorder were associated with abnormal visual P2 component of event-related potentials. Although patients with Parkinson's disease alone were not significantly different from patients with combined Parkinson's disease and rapid eye movement sleep behavior disorder, their P2 amplitudes were not sufficiently abnormal to differ from that of control subjects. This study confirms that rapid eye movement sleep behavior disorder accentuates cerebral dysfunctions in Parkinson's disease. Copyright © 2012 Elsevier Ltd. All rights reserved.
Yang, Chengqing; Zhang, Tianhong; Li, Zezhi; Heeramun-Aubeeluck, Anisha; Liu, Na; Huang, Nan; Zhang, Jie; He, Leiying; Li, Hui; Tang, Yingying; Chen, Fazhan; Wang, Jijun; Lu, Zheng
This study aimed to explore the characteristics of event-related potentials induced by facial emotion recognition in patients with first-episode schizophrenia and in their siblings. In this case-control study, 30 first-episode schizophrenia patients, 26 siblings, and 30 healthy controls were enrolled. They completed facial emotion recognition tasks from the Ekman Standard Faces Database as an induction for evoked potentials. Evoked potential data were obtained using a 64-channel electroencephalography system. Average evoked potential waveforms were computed from epochs for each stimulus type. The amplitudes and latency of the event-related potentials for P100 (positive potential 100 ms after stimulus onset), N170 (negative potential 170 ms after stimulus onset), and N250 (fronto-central peak) were investigated at O1, O2, P7, and P8 electrode locations. There were significant differences between the groups for P100 amplitude (F = 11.526, P schizophrenia group at the O1, O2, P7, and P8 electrode positions. There were no significant differences between the siblings of schizophrenia patients and the healthy controls. Patients with schizophrenia showed abnormalities in P100 amplitude, but similar results were not observed in their siblings. These results provide evidence of dysfunctional event-related potential patterns underlying facial emotion processing in patients with schizophrenia. P100 may be a characteristic index of schizophrenia.
Zhai, Jiahuan; Li, Ting; Zhang, Zhongxing; Gong, Hui
Functional near-infrared brain imaging (fNIRI) and event-related potential (ERP) were used simultaneous to detect the prefrontal cortex (PFC) which is considered to execute cognitive control of the subjects while performing the Chinese characters color-word matching Stroop task with event-related design. The fNIRI instrument is a portable system operating at three wavelengths (735nm & 805nm &850nm) with continuous-wave. The event-related potentials were acquired by Neuroscan system. The locations of optodes corresponding to the electrodes were defined four areas symmetrically. In nine native Chinese-speaking fit volunteers, fNIRI measured the hemodynamic parameters (involving oxy-/deoxy- hemoglobin) changes when the characteristic waveforms (N500/P600) were recorded by ERP. The interference effect was obvious as a longer reaction time for incongruent than congruent and neutral stimulus. The responses of hemodynamic and electrophysiology were also stronger during incongruent compared to congruent and neutral trials, and these results are similar to those obtained with fNIRI or ERP separately. There are high correlations, even linear relationship, in the two kinds of signals. In conclusion, the multi-modality approach combining of fNIRI and ERP is feasible and could obtain more cognitive function information with hemodynamic and electrophysiology signals. It also provides a perspective to prove the neurovascular coupling mechanism.
Full Text Available Bachground and Aim: The involvement of central auditory nervous system is relatively prevalent in patients suffering from multiple sclerosis (MS. To understand cortex function and to investigate cognitive impairment, event related potential is considered as a valuable tool. This study was aimed to compare the amplitude and latency of the event related potentials of P300 in MS patients and normal individuals.Methods: This cross sectional study was conducted on 21 MS patients and 27 normal cases aged 18-50 years. Auditory P300 was recorded with oddball paradigm, using two tone burst stimuli (1000 and 2000.Results: In MS patients, mean latencies were significantly longer (p<0.001 and mean amplitude were significantly lower (p<0.001, in both males and females. Sex did not affect P300 latencies and amplitudes significantly.Conclusion: MS patients show some degree of event related potential abnormalities. Combination of auditory P300 and neuropsychological tests may be useful to investigate cognitive impairment in MS patients.
Jansen, Marije; White, Thomas P.; Mullinger, Karen J.; Liddle, Elizabeth B.; Gowland, Penny A.; Francis, Susan T.; Bowtell, Richard; Liddle, Peter F.
The simultaneous acquisition and subsequent analysis of EEG and fMRI data is challenging owing to increased noise levels in the EEG data. A common method to integrate data from these two modalities is to use aspects of the EEG data, such as the amplitudes of event-related potentials (ERP) or oscillatory EEG activity, to predict fluctuations in the fMRI data. However, this relies on the acquisition of high quality datasets to ensure that only the correlates of neuronal activity are being studied. In this study, we investigate the effects of head-motion-related artefacts in the EEG signal on the predicted T2*-weighted signal variation. We apply our analyses to two independent datasets: 1) four participants were asked to move their feet in the scanner to generate small head movements, and 2) four participants performed an episodic memory task. We created T2*-weighted signal predictors from indicators of abrupt head motion using derivatives of the realignment parameters, from visually detected artefacts in the EEG as well as from three EEG frequency bands (theta, alpha and beta). In both datasets, we found little correlation between the T2*-weighted signal and EEG predictors that were not convolved with the canonical haemodynamic response function (cHRF). However, all convolved EEG predictors strongly correlated with the T2*-weighted signal variation in various regions including the bilateral superior temporal cortex, supplementary motor area, medial parietal cortex and cerebellum. The finding that movement onset spikes in the EEG predict T2*-weighted signal intensity only when the time course of movements is convolved with the cHRF, suggests that the correlated signal might reflect a BOLD response to neural activity associated with head movement. Furthermore, the observation that broad-spectral EEG spikes tend to occur at the same time as abrupt head movements, together with the finding that abrupt movements and EEG spikes show similar correlations with the T2
Sanchez-Lopez, Javier; Silva-Pereyra, Juan; Fernandez, Thalia
Background. Research on sports has revealed that behavioral responses and event-related brain potentials (ERP) are better in expert than in novice athletes for sport-related tasks. Focused attention is essential for optimal athletic performance across different sports but mainly in combat disciplines. During combat, long periods of focused attention (i.e., sustained attention) are required for a good performance. Few investigations have reported effects of expertise on brain electrical activity and its neural generators during sport-unrelated attention tasks. The aim of the present study was to assess the effect of expertise (i.e., skilled and novice martial arts athletes) analyzing the ERP during a sustained attention task (Continuous Performance Task; CPT) and the cortical three-dimensional distribution of current density, using the sLORETA technique. Methods. CPT consisted in an oddball-type paradigm presentation of five stimuli (different pointing arrows) where only one of them (an arrow pointing up right) required a motor response (i.e., target). CPT was administered to skilled and novice martial arts athletes while EEG were recorded. Amplitude ERP data from target and non-target stimuli were compared between groups. Subsequently, current source analysis for each ERP component was performed on each subject. sLORETA images were compared by condition and group using Statistical Non-Parametric Mapping analysis. Results. Skilled athletes showed significant amplitude differences between target and non-target conditions in early ERP components (P100 and P200) as opposed to the novice group; however, skilled athletes showed no significant effect of condition in N200 but novices did show a significant effect. Current source analysis showed greater differences in activations in skilled compared with novice athletes between conditions in the frontal (mainly in the Superior Frontal Gyrus and Medial Frontal Gyrus) and limbic (mainly in the Anterior Cingulate Gyrus) lobes
Full Text Available Background. Research on sports has revealed that behavioral responses and event-related brain potentials (ERP are better in expert than in novice athletes for sport-related tasks. Focused attention is essential for optimal athletic performance across different sports but mainly in combat disciplines. During combat, long periods of focused attention (i.e., sustained attention are required for a good performance. Few investigations have reported effects of expertise on brain electrical activity and its neural generators during sport-unrelated attention tasks. The aim of the present study was to assess the effect of expertise (i.e., skilled and novice martial arts athletes analyzing the ERP during a sustained attention task (Continuous Performance Task; CPT and the cortical three-dimensional distribution of current density, using the sLORETA technique. Methods. CPT consisted in an oddball-type paradigm presentation of five stimuli (different pointing arrows where only one of them (an arrow pointing up right required a motor response (i.e., target. CPT was administered to skilled and novice martial arts athletes while EEG were recorded. Amplitude ERP data from target and non-target stimuli were compared between groups. Subsequently, current source analysis for each ERP component was performed on each subject. sLORETA images were compared by condition and group using Statistical Non-Parametric Mapping analysis. Results. Skilled athletes showed significant amplitude differences between target and non-target conditions in early ERP components (P100 and P200 as opposed to the novice group; however, skilled athletes showed no significant effect of condition in N200 but novices did show a significant effect. Current source analysis showed greater differences in activations in skilled compared with novice athletes between conditions in the frontal (mainly in the Superior Frontal Gyrus and Medial Frontal Gyrus and limbic (mainly in the Anterior Cingulate
Huber-Huber, Christoph; Ditye, Thomas; Marchante Fernández, María; Ansorge, Ulrich
According to the pre-motor theory of attention, attention is shifted to a saccade's landing position before the saccade is executed. Such pre-saccadic attention shifts are usually studied in psychophysical dual-task conditions, with a target-discrimination task before saccade onset. Here, we present a novel approach to investigate pre-saccadic attention shifts with the help of event-related potentials (ERPs). Participants executed one or two saccades to color-defined targets while ERPs and eye-movements were recorded. In single-target blocks participants executed a single saccade. In two-targets blocks participants made either a single saccade to one of the targets, or two successive saccades to both targets. Importantly, in two-targets blocks, targets could appear on the same or on opposite sides of the vertical midline. This allowed us to study contra-to-ipsilateral ERP differences (such as the N2pc or PCN) that reflect attention shifts to the targets, prior to saccade onset and during saccades. If pre-saccadic attention shifts to saccade target locations are necessary for saccade execution and if searched-for saccade targets capture attention, there should be enhanced attentional competition (1) between two targets compared to single targets; (2) between two opposite-sides targets compared to two same-side targets; and (3) in two saccades rather than one saccade conditions: More attentional competition was expected to delay saccade latency and to weaken pre-saccadic laterality effects in ERPs. Hypotheses were tested by means of temporally aligned ERPs that were simultaneously time-locked to stimulus onsets, saccade onsets, and saccade offsets. Predictions (1) and (2) were partly and fully confirmed, respectively, but no evidence was found for (3). We explain the implications of our results for the role of attention during saccade preparation, and we point out how temporally aligned ERPs compare to ICA-based electroencephalogram (EEG) artifact correction
Vardi, Yoram; Sprecher, Elliot; Gruenwald, Ilan; Yarnitsky, David; Gartman, Irena; Granovsky, Yelena
There is a need for an objective technique to assess the degree of hypoactive sexual desire disorder (HSDD). Recently, we described such a methodology (event-related potential technique [ERP]) based on recording of p300 electroencephalography (EEG) waves elicited by auditory stimuli during synchronous exposure to erotic films. To compare sexual interest of sexually healthy women to females with sexual dysfunction (FSD) using ERP, and to explore whether FSD women with and without HSDD would respond differently to two different types of erotic stimuli-films containing (I) or not containing (NI) sexual intercourse scenes. Twenty-two women with FSD, of which nine had HSDD only, and 30 sexually healthy women were assessed by the Female Sexual Functioning Index. ERP methodology was performed applying erotic NI or I films. Significant differences in percent of auditory p300 amplitude reduction (PR) in response to erotic stimuli within and between all three groups for each film type. PRs to each film type were similar in sexually healthy women (60.6% +/- 40.3 (NI) and 51.7% +/- 32.3 [I]), while in women with FSD, reduction was greater when viewing the NI vs. I erotic films (71.4% +/- 41.0 vs. 37.7% +/- 45.7; P = 0.0099). This difference was mainly due to the greater PR of the subgroup with HSDD in response to NI vs. I films (77.7% +/- 46.7 vs. 17.0% +/- 50.3) than in the FSD women without HSDD group or the sexually healthy women (67.5% +/- 38.7 vs. 50.4% +/- 39.4 respectively), P = 0.0084. For comparisons, we used the mixed-model one-way analysis of variance. Differences in neurophysiological response patterns between sexually healthy vs. sexually dysfunctional females may point to a specific inverse discrimination ability for sexually relevant information in the subgroup of women with HSDD. These findings suggest that the p300 ERP technique could be used as an objective quantitative tool for libido assessment in sexually dysfunctional women.
Brunner, C; Allison, B Z; Altstätter, C; Neuper, C
Brain-computer interface (BCI) systems rely on the direct measurement of brain signals, such as event-related desynchronization (ERD), steady state visual evoked potentials (SSVEPs), P300s, or slow cortical potentials. Unfortunately, none of these BCI approaches work for all users. This study compares two conventional BCI approaches (ERD and SSVEP) within subjects, and also evaluates a novel hybrid BCI based on a combination of these signals. We recorded EEG data from 12 subjects across three conditions. In the first condition, subjects imagined moving both hands or both feet (ERD). In the second condition, subjects focused on one of the two oscillating visual stimuli (SSVEP). In the third condition, subjects simultaneously performed both tasks. We used logarithmic band power features at sites and frequencies consistent with ERD and SSVEP activity, and subjects received real-time feedback based on their performance. Subjects also completed brief questionnaires. All subjects could simultaneously perform the movement and visual task in the hybrid condition even though most subjects had little or no training. All subjects showed both SSVEP and ERD activity during the hybrid task, consistent with the activity in both single tasks. Subjects generally considered the hybrid condition moderately more difficult, but all of them were able to complete the hybrid task. Results support the hypothesis that subjects who do not have strong ERD activity might be more effective with an SSVEP BCI, and suggest that SSVEP BCIs work for more subjects. A simultaneous hybrid BCI is feasible, although the current hybrid approach, which involves combining ERD and SSVEP in a two-choice task to improve accuracy, is not significantly better than a comparable SSVEP BCI. Switching to an SSVEP BCI could increase reliability in subjects who have trouble producing the EEG activity necessary to use an ERD BCI. Subjects who are proficient in both BCI approaches might be able to combine these
Full Text Available In humans, the ability to withhold manual motor responses seems to rely on a right-lateralized frontal–basal ganglia–thalamic network, including the pre-supplementary motor area and the inferior frontal gyrus. These areas should drive subthalamic nuclei to implement movement inhibition via the hyperdirect pathway. The output of this network is expected to influence those cortical areas underlying limb movement preparation and initiation, i.e. premotor (PMA and primary motor (M1 cortices. Electroencephalographic (EEG studies have shown an enhancement of the N200/P300 complex in the event-related potentials (ERPs when a planned reaching movement is successfully stopped after the presentation of an infrequent stop-signal. PMA and M1 have been suggested as possible neural sources of this ERP complex but, due to the limited spatial resolution of scalp EEG, it is not yet clear which cortical areas contribute to its generation. To elucidate the role of motor cortices, we recorded epicortical ERPs from the lateral surface of the fronto-temporal lobes of five pharmacoresistant epileptic patients performing a reaching version of the countermanding task while undergoing presurgical monitoring. We consistently found a stereotyped ERP complex on a single-trial level when a movement was successfully cancelled. These ERPs were selectively expressed in M1, PMA and Brodmann's area (BA 9 and their onsets preceded the end of the stop process, suggesting a causal involvement in this executive function. Such ERPs also occurred in unsuccessful-stop trials, that is, when subjects moved despite the occurrence of a stop-signal, mostly when they had long reaction times. These findings support the hypothesis that motor cortices are the final target of the inhibitory command elaborated by the frontal–basal ganglia–thalamic network.
Lopez-Gordo, M A; Grima Murcia, M D; Padilla, Pablo; Pelayo, F; Fernandez, E
Clinical processing of event-related potentials (ERPs) requires a precise synchrony between the stimulation and the acquisition units that are guaranteed by means of a physical link between them. This precise synchrony is needed since temporal misalignments during trial averaging can lead to high deviations of peak times, thus causing error in diagnosis or inefficiency in classification in brain-computer interfaces (BCIs). Out of the laboratory, mobile EEG systems and BCI headsets are not provided with the physical link, thus being inadequate for acquisition of ERPs. In this study, we propose a method for the asynchronous detection of trials onset from raw EEG without physical links. We validate it with a BCI application based on the dichotic listening task. The user goal was to attend the cued auditory message and to report three keywords contained in it while ignoring the other message. The BCI goal was to detect the attended message from the analysis of auditory ERPs. The rate of successful onset detection in both synchronous (using the real onset) and asynchronous (blind detection of trial onset from raw EEG) was 73% with a synchronization error of less than 1[Formula: see text]ms. The level of synchronization provided by this proposal would allow home-based acquisition of ERPs with low cost BCI headsets and any media player unit without physical links between them.
Full Text Available This proof-of-concept study investigated whether a time-frequency EEG approach could be used to examine vection (i.e., illusions of self-motion. In the main experiment, we compared the event-related spectral perturbation (ERSP data of 10 observers during and directly after repeated exposures to two different types of optic flow display (each was 35° wide by 29° high and provided 20 s of motion stimulation. Displays consisted of either a vection display (which simulated constant velocity forward self-motion in depth or a control display (a spatially scrambled version of the vection display. ERSP data were decomposed using time-frequency Principal Components Analysis (t-f PCA. We found an increase in 10 Hz alpha activity, peaking some 14 s after display motion commenced, which was positively associated with stronger vection ratings. This followed decreases in beta activity, and was also followed by a decrease in delta activity; these decreases in EEG amplitudes were negatively related to the intensity of the vection experience. After display motion ceased, a series of increases in the alpha band also correlated with vection intensity, and appear to reflect vection- and/or motion-aftereffects, as well as later cognitive preparation for reporting the strength of the vection experience. Overall, these findings provide support for the notion that EEG can be used to provide objective markers of changes in both vection status (i.e., vection/no vection and vection strength.
Ng, Kwun Kei; Penney, Trevor B
Humans, and other animals, are able to easily learn the durations of events and the temporal relationships among them in spite of the absence of a dedicated sensory organ for time. This chapter summarizes the investigation of timing and time perception using scalp-recorded electroencephalography (EEG), a non-invasive technique that measures brain electrical potentials on a millisecond time scale. Over the past several decades, much has been learned about interval timing through the examination of the characteristic features of averaged EEG signals (i.e., event-related potentials, ERPs) elicited in timing paradigms. For example, the mismatch negativity (MMN) and omission potential (OP) have been used to study implicit and explicit timing, respectively, the P300 has been used to investigate temporal memory updating, and the contingent negative variation (CNV) has been used as an index of temporal decision making. In sum, EEG measures provide biomarkers of temporal processing that allow researchers to probe the cognitive and neural substrates underlying time perception.
Haufe, Stefan; Treder, Matthias S.; Gugler, Manfred F.; Sagebaum, Max; Curio, Gabriel; Blankertz, Benjamin
Emergency braking assistance has the potential to prevent a large number of car crashes. State-of-the-art systems operate in two stages. Basic safety measures are adopted once external sensors indicate a potential upcoming crash. If further activity at the brake pedal is detected, the system automatically performs emergency braking. Here, we present the results of a driving simulator study indicating that the driver's intention to perform emergency braking can be detected based on muscle activation and cerebral activity prior to the behavioural response. Identical levels of predictive accuracy were attained using electroencephalography (EEG), which worked more quickly than electromyography (EMG), and using EMG, which worked more quickly than pedal dynamics. A simulated assistance system using EEG and EMG was found to detect emergency brakings 130 ms earlier than a system relying only on pedal responses. At 100 km h-1 driving speed, this amounts to reducing the braking distance by 3.66 m. This result motivates a neuroergonomic approach to driving assistance. Our EEG analysis yielded a characteristic event-related potential signature that comprised components related to the sensory registration of a critical traffic situation, mental evaluation of the sensory percept and motor preparation. While all these components should occur often during normal driving, we conjecture that it is their characteristic spatio-temporal superposition in emergency braking situations that leads to the considerable prediction performance we observed.
Bocharov, Andrey V; Knyazev, Gennady G; Savostyanov, Alexander N
Depression is one of the most prevalent mental illnesses and is associated with changes in emotion processing. The aim of this study was to determine the influence of depressive symptoms on EEG oscillatory dynamics accompanying implicit processing of angry and happy facial expressions in 46 healthy subjects. The Beck Depression Inventory was used to assess the presence of depressive symptoms in normal subjects. During the experiment, they were told to categorize the gender of angry, neutral, or happy faces presented to them, while high-resolution EEG was recorded. Analysis of the event-related spectral perturbations and the analysis of dipoles were carried out on EEG recordings using the EEGLAB toolbox. High depression (HD) and low depression (LD) groups did not differ on error rate and reaction time during categorization of gender. The perception of happy faces was accompanied by higher theta synchronization in the LD than the HD group. In contrast, theta synchronization was higher in the HD than the LD group during perception of angry faces. These findings imply that even at preclinical stages, HD scorers evidence increased emotional arousal to negative and decreased emotional arousal to positive stimuli during implicit emotion processing. Copyright © 2017 Elsevier Masson SAS. All rights reserved.
Lopez-Gordo, M. A.; Sanchez-Morillo, D.; Valle, F. Pelayo
Electroencephalography (EEG) emerged in the second decade of the 20th century as a technique for recording the neurophysiological response. Since then, there has been little variation in the physical principles that sustain the signal acquisition probes, otherwise called electrodes. Currently, new advances in technology have brought new unexpected fields of applications apart from the clinical, for which new aspects such as usability and gel-free operation are first order priorities. Thanks to new advances in materials and integrated electronic systems technologies, a new generation of dry electrodes has been developed to fulfill the need. In this manuscript, we review current approaches to develop dry EEG electrodes for clinical and other applications, including information about measurement methods and evaluation reports. We conclude that, although a broad and non-homogeneous diversity of approaches has been evaluated without a consensus in procedures and methodology, their performances are not far from those obtained with wet electrodes, which are considered the gold standard, thus enabling the former to be a useful tool in a variety of novel applications. PMID:25046013
Morris, David Jackson; Steinmetzger, Kurt; Tøndering, John
The modulation of auditory event-related potentials (ERP) by attention generally results in larger amplitudes when stimuli are attended. We measured the P1-N1-P2 acoustic change complex elicited with synthetic overt (second formant, F2 = 1000 Hz) and subtle (F2 = 100 Hz) diphthongs, while subjects....... Multivariate analysis of ERP components from the rising F2 changes showed main effects of attention on P2 amplitude and latency, and N1-P2 amplitude. P2 amplitude decreased by 40% between the attend and ignore conditions, and by 60% between the attend and divert conditions. The effect of diphthong magnitude...
Tagai, Keiko; Shimakura, Hitomi; Isobe, Hiroko; Nittono, Hiroshi
The effects of makeup on attractiveness have been evaluated using mainly subjective measures. In this study, event-related brain potentials (ERPs) were recorded from a total of 45 Japanese women (n = 23 and n = 22 for Experiment 1 and 2, respectively) to examine the neural processing of faces with no makeup, light makeup, and heavy makeup. To have the participants look at each face carefully, an identity judgement task was used: they were asked to judge whether the two faces presented in succ...
Wang, Pei; Yang, Ya-Ping; Tan, Chen-Hao; Zhao, Xiang-Xia; Liu, Yong-He; Lin, Chong-De
In this study, a priming Stroop paradigm was used to determine whether stereotype activation is unintentional. Priming conditions (priming/no-priming) and the relationship between priming and target (consistent/inconsistent/no-relation) were the independent variables; accuracy, reaction time and N400 amplitude were used as dependent variables. The reaction time revealed that stereotype activation is, to some extent, unintentional. Furthermore, the event-related potenial (ERP) results showed that N400 amplitude was larger for inconsistent conditions than for consistent conditions. This result supported the notion that stereotype activation is an unintentional and automatic process. © 2015 International Union of Psychological Science.
Full Text Available Nicola Luigi Bragazzi,1,2 Giovanni Del Puente21School of Public Health, Department of Health Sciences (DISSAL, University of Genoa, Genoa, Italy; 2DINOGMI, Department of Neuroscience, Rehabilitation, Ophtalmology, Genetics, Maternal and Child Health, Section of Psychiatry, University of Genoa, Genoa, Italy Dr Salvatore Campanella has recently advocated the urgent need to incorporate cognitive event-related potentials (ERPs for a proper diagnosis, treatment, and prognosis of psychiatric disorders, on the basis of four working hypotheses, which are theoretically solid and experimentally supported.1View original paper by Campanella S.
Juul, Rasmus V; Foster, David J R; Upton, Richard N
The purpose of the study was to investigate placebo and buprenorphine effects on event-related potentials (ERPs) in experimental pain and the potential benefit of population pharmacodynamic modelling in data analysis. Nineteen healthy volunteers received transdermal placebo and buprenorphine......-effects modelling implemented in NONMEM (V7.2.0.). Pharmacodynamic models were developed to adequately describe both placebo and buprenorphine ERP data. Models predicted significant placebo effects, but did not predict significant effects related to buprenorphine concentration. Models revealed that ERPs varied both...
Wilson, John A; Nordal, Helge J
Coma is a dynamic condition that may have various causes. Important changes may take place rapidly, often with consequences for treatment. The purpose of this article is to provide a brief overview of EEG patterns in comas with various causes, and indicate how EEG contributes in an assessment of the prognosis for coma patients. The article is based on many years of clinical and research-based experience of EEG used for patients in coma. A self-built reference database was supplemented by searches for relevant articles in PubMed. EEG reveals immediate changes in coma, and can provide early information on cause and prognosis. It is the only diagnostic tool for detecting a non-convulsive epileptic status. Locked-in- syndrome may be overseen without EEG. Repeated EEG scans increase diagnostic certainty and make it possible to monitor the development of coma. EEG reflects brain function continuously and therefore holds a key place in the assessment and treatment of coma.
Giraudet, Louise; St-Louis, Marie-Eve; Scannella, Sébastien; Causse, Mickaël
An analysis of airplane accidents reveals that pilots sometimes purely fail to react to critical auditory alerts. This inability of an auditory stimulus to reach consciousness has been coined under the term of inattentional deafness. Recent data from literature tends to show that tasks involving high cognitive load consume most of the attentional capacities, leaving little or none remaining for processing any unexpected information. In addition, there is a growing body of evidence for a shared attentional capacity between vision and hearing. In this context, the abundant information in modern cockpits is likely to produce inattentional deafness. We investigated this hypothesis by combining electroencephalographic (EEG) measurements with an ecological aviation task performed under contextual variation of the cognitive load (high or low), including an alarm detection task. Two different audio tones were played: standard tones and deviant tones. Participants were instructed to ignore standard tones and to report deviant tones using a response pad. More than 31% of the deviant tones were not detected in the high load condition. Analysis of the EEG measurements showed a drastic diminution of the auditory P300 amplitude concomitant with this behavioral effect, whereas the N100 component was not affected. We suggest that these behavioral and electrophysiological results provide new insights on explaining the trend of pilots' failure to react to critical auditory information. Relevant applications concern prevention of alarms omission, mental workload measurements and enhanced warning designs.
Michel, V; Mazzola, L; Lemesle, M; Vercueil, L
Long-term EEG in adults includes three modalities: sleep deprived-EEG lasting 1 to 3 hours, 24 hours ambulatory-EEG and continuous prolonged video-EEG lasting from several hours to several days. The main indications of long-term EEG are: syndromic classification of epilepsy; search for interictal discharges when epilepsy is suspected or for the purpose of therapeutic evaluation; positive diagnosis of paroxysmal clinical events; and pre-surgical evaluation of drug-resistant epilepsy. Sleep deprived-EEG and ambulatory-EEG are indicated to detect interictal discharges in order to validate a syndromic classification of epilepsy when standard EEG is negative. These exams can help in evaluating treatment efficacy, especially when clinical evaluation is difficult. Long-term video EEG is indicated for drug-resistant epilepsy, to analyze electro-clinical correlations in a pre-surgical evaluation context, and to refine a positive diagnosis when paroxysmal clinical events are frequent. Copyright © 2015. Published by Elsevier SAS.
Full Text Available Electroencephalography (EEG is considered the output of a brain and it is a bioelectrical signal with multiscale and nonlinear properties. Motor Imagery EEG (MI-EEG not only has a close correlation with the human imagination and movement intention but also contains a large amount of physiological or disease information. As a result, it has been fully studied in the field of rehabilitation. To correctly interpret and accurately extract the features of MI-EEG signals, many nonlinear dynamic methods based on entropy, such as Approximate Entropy (ApEn, Sample Entropy (SampEn, Fuzzy Entropy (FE, and Permutation Entropy (PE, have been proposed and exploited continuously in recent years. However, these entropy-based methods can only measure the complexity of MI-EEG based on a single scale and therefore fail to account for the multiscale property inherent in MI-EEG. To solve this problem, Multiscale Sample Entropy (MSE, Multiscale Permutation Entropy (MPE, and Multiscale Fuzzy Entropy (MFE are developed by introducing scale factor. However, MFE has not been widely used in analysis of MI-EEG, and the same parameter values are employed when the MFE method is used to calculate the fuzzy entropy values on multiple scales. Actually, each coarse-grained MI-EEG carries the characteristic information of the original signal on different scale factors. It is necessary to optimize MFE parameters to discover more feature information. In this paper, the parameters of MFE are optimized independently for each scale factor, and the improved MFE (IMFE is applied to the feature extraction of MI-EEG. Based on the event-related desynchronization (ERD/event-related synchronization (ERS phenomenon, IMFE features from multi channels are fused organically to construct the feature vector. Experiments are conducted on a public dataset by using Support Vector Machine (SVM as a classifier. The experiment results of 10-fold cross-validation show that the proposed method yields
Electroencephalogy ( EEG ) Feedback In Decision- Making The goal of this project is to investigate whether Electroencephalogy ( EEG ) can provide useful...feedback when training rapid decision-making. More specifically, EEG will allow us to provide online feedback about the neural decision processes...Electroencephalogy ( EEG ) Feedback In Decision-Making Report Title The goal of this project is to investigate whether Electroencephalogy ( EEG ) can provide useful
Meledin, Irina; Abu Tailakh, Muhammad; Gilat, Shlomo; Yogev, Hagai; Golan, Agneta; Novack, Victor; Shany, Eilon
To compare amplitude-integrated EEG (aEEG) and conventional EEG (EEG) activity in premature neonates. Biweekly aEEG and EEG were simultaneously recorded in a cohort of infants born less than 34 weeks gestation. aEEG recordings were visually assessed for lower and upper border amplitude and bandwidth. EEG recordings were compressed for visual evaluation of continuity and assessed using a signal processing software for interburst intervals (IBI) and frequencies' amplitude. Ten-minute segments of aEEG and EEG indices were compared using regression analysis. A total of 189 recordings from 67 infants were made, from which 1697 aEEG/EEG pairs of 10-minute segments were assessed. Good concordance was found for visual assessment of continuity between the 2 methods. EEG IBI, alpha and theta frequencies' amplitudes were negatively correlated to the aEEG lower border while conceptional age (CA) was positively correlated to aEEG lower border ( P EEG to aEEG. aEEG recordings in high-risk premature neonates reflect reliably EEG background information related to continuity and amplitude.
Silvoni, S; Konicar, L; Prats-Sedano, M A; Garcia-Cossio, E; Genna, C; Volpato, C; Cavinato, M; Paggiaro, A; Veser, S; De Massari, D; Birbaumer, N
We investigated neurophysiological brain responses elicited by a tactile event-related potential paradigm in a sample of ALS patients. Underlying cognitive processes and neurophysiological signatures for brain-computer interface (BCI) are addressed. We stimulated the palm of the hand in a group of fourteen ALS patients and a control group of ten healthy participants and recorded electroencephalographic signals in eyes-closed condition. Target and non-target brain responses were analyzed and classified offline. Classification errors served as the basis for neurophysiological brain response sub-grouping. A combined behavioral and quantitative neurophysiological analysis of sub-grouped data showed neither significant between-group differences, nor significant correlations between classification performance and the ALS patients' clinical state. Taking sequential effects of stimuli presentation into account, analyses revealed mean classification errors of 19.4% and 24.3% in healthy participants and ALS patients respectively. Neurophysiological correlates of tactile stimuli presentation are not altered by ALS. Tactile event-related potentials can be used to monitor attention level and task performance in ALS and may constitute a viable basis for future BCIs. Implications for brain-computer interface implementation of the proposed method for patients in critical conditions, such as the late stage of ALS and the (completely) locked-in state, are discussed. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Pasaye, E H; Gutiérrez, R A; Alcauter, S; Mercadillo, R E; Aguilar-Castañeda, E; De Iturbe, M; Romero-Romo, J; Barrios, F A
The phantom limb phenomenon has been used in amputee patients as a paradigm to study plasticity, mainly of the sensorimotor cortex. Nevertheless, most functional studies have been done in upper limb amputee patients using magnetoencephalography and functional magnetic resonance image imaging (fMRI). In addition, the actual experience of phantom limb sensation has not been widely used to study the neural mechanism of the human brain as a conscious knowledge of the phantom limb perception like the integration of the body image in amputee patients. fMRI studies of patients with lower limb amputation have recently been published, but none of these used an event-related design to try to observe only the stimulus application, correlating images with the subject's indication of phantom perception and discarding images with no phantom perception. In this work, we used the event-related fMRI design in two right-handed patients with identical right, transfemoral amputations, performing the same sensitive stimulation in a 3.0 T MR scanner. For comparison, we applied the same paradigm to six control subjects to compare the resulting functional maps. We found areas with statistical significance in the sensorimotor cortex contralateral to the site of stimulation, in the parietal lobe in Brodmann areas 3 in both cases (Patients and Control Subjects), but we also found activation in the Brodmann areas 6, 40, and 5 with stimulation of the stump. We observed a specific activation of the frontoparietal circuit during phantom limb perception in both amputee patients.
Ohbayashi, Wakana; Kakigi, Ryusuke; Nakata, Hiroki
Exposure to auditory white noise has been shown to facilitate human cognitive function. This phenomenon is termed stochastic resonance, and a moderate amount of auditory noise has been suggested to benefit individuals in hypodopaminergic states. The present study investigated the effects of white noise on the N140 and P300 components of event-related potentials in somatosensory Go/No-go paradigms. A Go or No-go stimulus was presented to the second or fifth digit of the left hand, respectively, at the same probability. Participants performed somatosensory Go/No-go paradigms while hearing three different white noise levels (45, 55, and 65 dB conditions). The peak amplitudes of Go-P300 and No-go-P300 in ERP waveforms were significantly larger under 55 dB than 45 and 65 dB conditions. White noise did not affect the peak latency of N140 or P300, or the peak amplitude of N140. Behavioral data for the reaction time, SD of reaction time, and error rates showed the absence of an effect by white noise. This is the first event-related potential study to show that exposure to auditory white noise at 55 dB enhanced the amplitude of P300 during Go/No-go paradigms, reflecting changes in the neural activation of response execution and inhibition processing.
Ma, Qingguo; Pei, Guanxiong; Wang, Kai
The framing effect is the phenomenon in which different descriptions of an identical problem can result in different choices. The influence of negative emotions on the framing effect and its neurocognitive basis are important issues, especially in the domain of saving lives, which is essential and highly risky. In each trial of our experiment, the emotion stimulus is presented to the participants, followed by the decision-making stimulus, which comprises certain and risky options with the same expected value. Each pair of options is positively or negatively framed. The behavioral results indicate a significant interactive effect between negative emotion and frame; thus, the risk preference under the positive frame can be enhanced by negative emotions, whereas this finding is not true under the negative frame. The event-related potential analysis indicates that choosing certain options under the positive frame with negative emotion priming generates smaller P2 and P3 amplitudes and a larger N2 amplitude than with neutral emotion priming. The event-related potential findings indicate that individuals can detect risk faster and experience more conflict and increased decision difficulty if they choose certain options under the positive frame with negative priming compared with neutral priming.
Wang, Xiaoyi; Huang, Yujing; Ma, Qingguo; Li, Nan
Using event-related potential measures, the present study investigated the affective responses to aesthetic experience. To differentiate the objective aesthetic value from subjective aesthetic evaluation, an amended oddball task was used in which pendant pictures were presented as frequent nontarget stimuli, whereas the landscape pictures were presented as a rare target. The pendant pictures were chosen from the largest online store in China and divided into beautiful and less beautiful conditions by the sales ranking. A positive component, P2, was recorded for each condition on the participants' frontal, central and parietal scalp areas. Less beautiful pendants elicited greater amplitudes of P2 than the beautiful ones. This indicates that emotion arousal seems to occur at the early stage of processing of aesthetics and can be detected by the P2 component, implying that the event-related potential methodology may be a more sensitive measure of the beauty-related attention bias. From the perspective of artwork design and marketing, our finding also shows that P2 can potentially be used as a reference measure in consumer aesthetic experience.
Andreas A. Ioannides
Full Text Available How the brain works is nowadays synonymous with how different parts of the brain work together and the derivation of mathematical descriptions for the functional connectivity patterns that can be objectively derived from data of different neuroimaging techniques. In most cases static networks are studied, often relying on resting state recordings. Here, we present a quantitative study of dynamic reconfiguration of connectivity for event-related experiments. Our motivation is the development of a methodology that can be used for personalized monitoring of brain activity. In line with this motivation, we use data with visual stimuli from a typical subject that participated in different experiments that were previously analyzed with traditional methods. The earlier studies identified well-defined changes in specific brain areas at specific latencies related to attention, properties of stimuli, and tasks demands. Using a recently introduced methodology, we track the event-related changes in network organization, at source space level, thus providing a more global and complete view of the stages of processing associated with the regional changes in activity. The results suggest the time evolving modularity as an additional brain code that is accessible with noninvasive means and hence available for personalized monitoring and clinical applications.
Becker, Frank; Reinvang, Ivar
To investigate changes in brain activation related to tone and speech sound processing during aphasia rehabilitation. Longitudinal study investigating patients with stroke, subarachnoid hemorrhage and traumatic brain injury 3 and 7 months post-injury. Eight patients with aphasia, reflecting a wide range of auditory comprehension impairment. Token test and Norwegian Basic Aphasia Assessment were used to measure auditory comprehension function. Brain event-related potentials were recorded in passive paradigms with harmonically rich tones and syllables in order to obtain the mismatch negativity component that reflects automatic stimulus discrimination. In an active syllable discrimination paradigm, stimulus feature integration (N1), attended stimulus discrimination and classification (N2), and target detection (P3) were studied. Auditory comprehension scores improved approximately 10% during the observation period. Ipsilesional frontal P3- and N2-amplitude increased significantly. A significant shift in topographical distribution from the contralesional to the ipsilesional hemisphere was observed for the N2 component. The study of individual waveforms indicates inter-individual differences in reorganization after brain injury. Hemispherical distribution of brain activation correlating with speech sound processing in aphasia can change during the first months after brain injury. Event-related potentials are a potentially useful method for detecting individual activation patterns relevant to recovery in aphasia rehabilitation.
Lee, Ja Y; Lindquist, Kristen A; Nam, Chang S
There is debate about whether emotional granularity, the tendency to label emotions in a nuanced and specific manner, is merely a product of labeling abilities, or a systematic difference in the experience of emotion during emotionally evocative events. According to the Conceptual Act Theory of Emotion (CAT) (Barrett, 2006), emotional granularity is due to the latter and is a product of on-going temporal differences in how individuals categorize and thus make meaning of their affective states. To address this question, the present study investigated the effects of individual differences in emotional granularity on electroencephalography-based brain activity during the experience of emotion in response to affective images. Event-related potentials (ERP) and event-related desynchronization and synchronization (ERD/ERS) analysis techniques were used. We found that ERP responses during the very early (60-90 ms), middle (270-300 ms), and later (540-570 ms) moments of stimulus presentation were associated with individuals' level of granularity. We also observed that highly granular individuals, compared to lowly granular individuals, exhibited relatively stable desynchronization of alpha power (8-12 Hz) and synchronization of gamma power (30-50 Hz) during the 3 s of stimulus presentation. Overall, our results suggest that emotional granularity is related to differences in neural processing throughout emotional experiences and that high granularity could be associated with access to executive control resources and a more habitual processing of affective stimuli, or a kind of "emotional complexity." Implications for models of emotion are also discussed.
Groen, Yvonne; Wijers, Albertus A.; Mulder, Lambertus J. M.; Waggeveld, Brenda; Minderaa, Ruud B.; Althaus, Monika
Objective: Performance monitoring was investigated in typically developing (TD) children, children with Autistic Spectrum Disorder (ASD), and Methylphenidate (Mph)-treated and medication-free children with Attention Deficit Hyperactivity Disorder (ADHD). Methods: Subjects performed a feedback-based
Kamil Konrad Imbir
Full Text Available This paper presents behavioral and event-related potential (ERP correlates of emotional word processing during a lexical decision task (LDT. We showed that valence and origin (two distinct affective properties of stimuli help to account for the ERP correlates of LDT. The origin of emotion is a factor derived from the emotion duality model. This model distinguishes between the automatic and controlled elicitation of emotional states. The subjects’ task was to discriminate words from pseudo-words. The stimulus words were carefully selected to differ with respect to valence and origin whilst being matched with respect to arousal, concreteness, length and frequency in natural language. Pseudo-words were matched to words with respect to length. The subjects were 32 individuals aged from 19 to 26 years who were invited to participate in an EEG study of lexical decision making. They evaluated a list of words and pseudo-words. We found that valence modulated the amplitude of the FN400 component (290-375ms at centro-frontal (Fz, Cz region, whereas origin modulated the amplitude of the component in the LPC latency range (375-670ms. The results indicate that the origin of stimuli should be taken into consideration while deliberating on the processing of emotional words.
Howe, Aaron S; Bani-Fatemi, Ali; De Luca, Vincenzo
The present meta-analysis investigated the clinical utility of the auditory P300 latency event-related potential in differentiating patients with Alzheimer's disease (AD), patients with mild cognitive impairment (MCI), and unaffected controls. Effect size estimates were computed from mean P300 latency measurements at midline electrodes between patients and unaffected controls using the random effects restricted maximum likelihood model. The effects of clinical and ERP/EEG methological variables were assessed in a moderator analysis. P300 latency was found to be significantly prolonged in patients with AD (and MCI) compared to unaffected controls. Shortened P300 latencies were observed when comparing patients with MCI to patients with AD. Clinically relevant differences in P300 latency effect sizes were associated with mean age, interstimulus interval, stimulus difference, target frequency, reference electrode, and sampling rate. The meta-analytic findings provide robust statistical evidence for the use of the auditory P300 latency subcomponent as a biological marker of prodromal AD. Copyright © 2014 Elsevier Inc. All rights reserved.
Delorme, Arnaud; Palmer, Jason; Onton, Julie; Oostenveld, Robert; Makeig, Scott
Independent component analysis (ICA) and blind source separation (BSS) methods are increasingly used to separate individual brain and non-brain source signals mixed by volume conduction in electroencephalographic (EEG...
Mousikou, Petroula; Mahajan, Yatin; de Lissa, Peter; Thie, Johnson; McArthur, Genevieve
Background. Auditory event-related potentials (ERPs) have proved useful in investigating the role of auditory processing in cognitive disorders such as developmental dyslexia, specific language impairment (SLI), attention deficit hyperactivity disorder (ADHD), schizophrenia, and autism. However, laboratory recordings of auditory ERPs can be lengthy, uncomfortable, or threatening for some participants – particularly children. Recently, a commercial gaming electroencephalography (EEG) system has been developed that is portable, inexpensive, and easy to set up. In this study we tested if auditory ERPs measured using a gaming EEG system (Emotiv EPOC®, www.emotiv.com) were equivalent to those measured by a widely-used, laboratory-based, research EEG system (Neuroscan). Methods. We simultaneously recorded EEGs with the research and gaming EEG systems, whilst presenting 21 adults with 566 standard (1000 Hz) and 100 deviant (1200 Hz) tones under passive (non-attended) and active (attended) conditions. The onset of each tone was marked in the EEGs using a parallel port pulse (Neuroscan) or a stimulus-generated electrical pulse injected into the O1 and O2 channels (Emotiv EPOC®). These markers were used to calculate research and gaming EEG system late auditory ERPs (P1, N1, P2, N2, and P3 peaks) and the mismatch negativity (MMN) in active and passive listening conditions for each participant. Results. Analyses were restricted to frontal sites as these are most commonly reported in auditory ERP research. Intra-class correlations (ICCs) indicated that the morphology of the research and gaming EEG system late auditory ERP waveforms were similar across all participants, but that the research and gaming EEG system MMN waveforms were only similar for participants with non-noisy MMN waveforms (N = 11 out of 21). Peak amplitude and latency measures revealed no significant differences between the size or the timing of the auditory P1, N1, P2, N2, P3, and MMN peaks. Conclusions
Badcock, Nicholas A; Mousikou, Petroula; Mahajan, Yatin; de Lissa, Peter; Thie, Johnson; McArthur, Genevieve
Background. Auditory event-related potentials (ERPs) have proved useful in investigating the role of auditory processing in cognitive disorders such as developmental dyslexia, specific language impairment (SLI), attention deficit hyperactivity disorder (ADHD), schizophrenia, and autism. However, laboratory recordings of auditory ERPs can be lengthy, uncomfortable, or threatening for some participants - particularly children. Recently, a commercial gaming electroencephalography (EEG) system has been developed that is portable, inexpensive, and easy to set up. In this study we tested if auditory ERPs measured using a gaming EEG system (Emotiv EPOC(®), www.emotiv.com) were equivalent to those measured by a widely-used, laboratory-based, research EEG system (Neuroscan). Methods. We simultaneously recorded EEGs with the research and gaming EEG systems, whilst presenting 21 adults with 566 standard (1000 Hz) and 100 deviant (1200 Hz) tones under passive (non-attended) and active (attended) conditions. The onset of each tone was marked in the EEGs using a parallel port pulse (Neuroscan) or a stimulus-generated electrical pulse injected into the O1 and O2 channels (Emotiv EPOC(®)). These markers were used to calculate research and gaming EEG system late auditory ERPs (P1, N1, P2, N2, and P3 peaks) and the mismatch negativity (MMN) in active and passive listening conditions for each participant. Results. Analyses were restricted to frontal sites as these are most commonly reported in auditory ERP research. Intra-class correlations (ICCs) indicated that the morphology of the research and gaming EEG system late auditory ERP waveforms were similar across all participants, but that the research and gaming EEG system MMN waveforms were only similar for participants with non-noisy MMN waveforms (N = 11 out of 21). Peak amplitude and latency measures revealed no significant differences between the size or the timing of the auditory P1, N1, P2, N2, P3, and MMN peaks
Nicholas A. Badcock
Full Text Available Background. Auditory event-related potentials (ERPs have proved useful in investigating the role of auditory processing in cognitive disorders such as developmental dyslexia, specific language impairment (SLI, attention deficit hyperactivity disorder (ADHD, schizophrenia, and autism. However, laboratory recordings of auditory ERPs can be lengthy, uncomfortable, or threatening for some participants – particularly children. Recently, a commercial gaming electroencephalography (EEG system has been developed that is portable, inexpensive, and easy to set up. In this study we tested if auditory ERPs measured using a gaming EEG system (Emotiv EPOC®, www.emotiv.com were equivalent to those measured by a widely-used, laboratory-based, research EEG system (Neuroscan.Methods. We simultaneously recorded EEGs with the research and gaming EEG systems, whilst presenting 21 adults with 566 standard (1000 Hz and 100 deviant (1200 Hz tones under passive (non-attended and active (attended conditions. The onset of each tone was marked in the EEGs using a parallel port pulse (Neuroscan or a stimulus-generated electrical pulse injected into the O1 and O2 channels (Emotiv EPOC®. These markers were used to calculate research and gaming EEG system late auditory ERPs (P1, N1, P2, N2, and P3 peaks and the mismatch negativity (MMN in active and passive listening conditions for each participant.Results. Analyses were restricted to frontal sites as these are most commonly reported in auditory ERP research. Intra-class correlations (ICCs indicated that the morphology of the research and gaming EEG system late auditory ERP waveforms were similar across all participants, but that the research and gaming EEG system MMN waveforms were only similar for participants with non-noisy MMN waveforms (N = 11 out of 21. Peak amplitude and latency measures revealed no significant differences between the size or the timing of the auditory P1, N1, P2, N2, P3, and MMN peaks
Borowska Marta; Białobłocka Natalia
This paper reports on a multiresolution analysis of EEG signals. The dominant frequency components of signals with and without observed epileptic discharges were compared. The study showed that there were significant differences in dominant frequency between the signals with epileptic discharges and the signals without discharges. This gives the ability to identify epilepsy during EEG examination. The frequency of the signals coming from the frontal, central, parietal and occipital channels a...
Wang, Grace Y; Kydd, Robert; Russell, Bruce R
Methadone has been used to treat opiate dependence since the mid-1960s. Despite its clinical effectiveness there is evidence from neuropsychological studies demonstrating that its long-term use might have negative effects on cognition. Nevertheless, it remains uncertain whether the observed cognitive impairments in patients undertaking methadone maintenance treatment (MMT) are solely attributable to the pharmacological effects of methadone, as suggested by some researchers. Determining the effects of MMT on neuropsychological function using electroencephalography (EEG) combined with event-related potentials (ERP) has been used infrequently. However EEG and ERP provide a means of closely examining information processing to determine whether MMT induces any deficits. The purpose of this review was to investigate whether psychophysiological evidence supports cognitive impairment in association with MMT by focusing on research using EEG and ERPs. The findings of EEG studies to date appear not support the notion that cognitive impairments are attributable to the specific pharmacological effects of methadone suggested by some neuropsychological studies. However, due to the methodological deficits and limited number of the studies, any conclusion based on the findings of the existing EEG studies should be avoided.
Dong, Li; Li, Fali; Liu, Qiang; Wen, Xin; Lai, Yongxiu; Xu, Peng; Yao, Dezhong
Reference electrode standardization technique (REST) has been increasingly acknowledged and applied as a re-reference technique to transform an actual multi-channels recordings to approximately zero reference ones in electroencephalography/event-related potentials (EEG/ERPs) community around the world in recent years. However, a more easy-to-use toolbox for re-referencing scalp EEG data to zero reference is still lacking. Here, we have therefore developed two open-source MATLAB toolboxes for REST of scalp EEG. One version of REST is closely integrated into EEGLAB, which is a popular MATLAB toolbox for processing the EEG data; and another is a batch version to make it more convenient and efficient for experienced users. Both of them are designed to provide an easy-to-use for novice researchers and flexibility for experienced researchers. All versions of the REST toolboxes can be freely downloaded at http://www.neuro.uestc.edu.cn/rest/Down.html, and the detailed information including publications, comments and documents on REST can also be found from this website. An example of usage is given with comparative results of REST and average reference. We hope these user-friendly REST toolboxes could make the relatively novel technique of REST easier to study, especially for applications in various EEG studies.
Barry, Robert J; De Blasio, Frances; Rushby, Jacqueline A; Clarke, Adam R
We examined relationships between the phase of narrow-band electroencephalographic (EEG) activity at stimulus onset and the resultant event-related potentials (ERPs) in an equiprobable auditory Go/NoGo task with a fixed SOA, in the context of a novel conceptualisation of orthogonal phase effects (cortical negativity vs. positivity, negative driving vs. positive driving, waxing vs. waning). ERP responses to each stimulus type were analysed. Prestimulus narrow-band EEG activity (in 1Hz bands from 1 to 13Hz) at Cz was assessed for each trial using FFT decomposition of the EEG data. For each frequency, the cycle at stimulus onset was used to sort trials into four phases, for which ERPs were derived from the raw EEG activity at 9 central sites. The occurrence of preferred phase-defined brain states was confirmed at a number of frequencies, crossing the traditional frequency bands. As expected, these did not differ between Go and NoGo stimuli. These preferred states were associated with more efficient processing of the stimulus, as reflected in differences in latency and amplitude of the N1 and P3 ERP components. The present results, although derived in a different paradigm by EEG decomposition methods different from those used previously, confirm the existence of preferred brain states and their impact on the efficiency of brain dynamics involved in perceptual and cognitive processing. Copyright © 2010 Elsevier B.V. All rights reserved.
Kuziek, Jonathan W P; Shienh, Axita; Mathewson, Kyle E
Electroencephalography (EEG) experiments are typically performed in controlled laboratory settings to minimise noise and produce reliable measurements. These controlled conditions also reduce the applicability of the obtained results to more varied environments and may limit their relevance to everyday situations. Advances in computer portability may increase the mobility and applicability of EEG results while decreasing costs. In this experiment we show that stimulus presentation using a Raspberry Pi 2 computer provides a low cost, reliable alternative to a traditional desktop PC in the administration of EEG experimental tasks. Significant and reliable MMN and P3 activity, typical event-related potentials (ERPs) associated with an auditory oddball paradigm, were measured while experiments were administered using the Raspberry Pi 2. While latency differences in ERP triggering were observed between systems, these differences reduced power only marginally, likely due to the reduced processing power of the Raspberry Pi 2. An auditory oddball task administered using the Raspberry Pi 2 produced similar ERPs to those derived from a desktop PC in a laboratory setting. Despite temporal differences and slight increases in trials needed for similar statistical power, the Raspberry Pi 2 can be used to design and present auditory experiments comparable to a PC. Our results show that the Raspberry Pi 2 is a low cost alternative to the desktop PC when administering EEG experiments and, due to its small size and low power consumption, will enable mobile EEG experiments unconstrained by a traditional laboratory setting. Copyright © 2016 Elsevier B.V. All rights reserved.
Iwahashi, M; Katayama, Y; Ueno, S; Iramina, K
When the odd stimulation is presented, the positive component of electroencephalograph is induced at around 300 ms after the odd stimulation. This positive component is called P300. Many studies suggest that P300 may result from the summation of activity from multiple generators located in widespread cortical and subcortical areas. However, there is still no conclusive indication of the sources of P300. In this paper, we focus on the left supramaginal gyrus as one of the sources of P300. We investigated the temporal aspect of this area using TMS (transcranial magnetic stimulation). We investigated the relationship between the latency of the P300 and an effect of TMS when the left supramarginal gyrus was stimulated by TMS. In our previous study, we reported a method of removing stimulus artifact during TMS with Sample-and-Hold circuit and electroencephalogram (EEG) activity evoked by TMS could be measured successfully. In addition to this method, independent component analysis (ICA) was also applied to recorded EEG data in order to remove the stimulus artifact by off-line analysis. By using these methods, short latency (P300 was delayed around 50 ms. Difference of the peak latency between the control measurement and the case of TMS applying at 150 ms was not significant. However, the differences of the peak latency of the control measurement and the peak latency of the measurement in the cases of TMS applying at 200 ms and 250 ms was significant (p<0.05). We considered that this delay was due to inhibiting to recognize the target stimulation.
This thesis describes the design, microfabrication, and testing of an active scalp EEG (electroencephalograph) electrode that has several distinct advantages over existing technologies. These advantages are: (1) no electrolyte used, (2) no skin preparation, (3) significantly reduced sensor size, and (4) compatibility with EEG monitoring systems. The active electrode array is an integrated system made of an array of capacitive sensors with local integrated circuitry housed in a package with batteries to power the circuitry. This level of integration was required to achieve the functional performance obtained by the electrode. The electrode consists of a silicon sensor substrate fabricated at UCD and a custom circuit substrate fabricated at Orbit Semiconductors, using a 2 μm analog CMOS technology. The circuitry was designed for low 1/f noise. One side of the sensor substrate holds four capacitive sensors with rm Si_3N _4 as the dielectric material. The opposite side holds aluminum pads for bonding to the circuit substrate. A via hole technology was developed to make electrical contact to both sides of the sensor substrate. The via holes are 200 μm square openings etched through the silicon by a reactive ion etching (RIE) process using an rm SF_6/O_2 gas mixture, oxidized, and then filled with sputtered aluminum for contacts through the substrate. The via holes have an aspect ratio of 2:1 (length of opening to depth of hole). Silicon RIE etch rates of up to 18 mu/hr were obtained under optimum conditions, using a 0.8 μm aluminum mask. The circuit and sensor substrates were bonded with silver adhesive, and wire bonding was used to make electrical contacts between the substrates. The two substrates were then integrated in a custom package for testing. The electrode was tested on an electrical test bench and on human subjects in four modalities of EEG activity, namely: (1) spontaneous EEG, (2) sensory event-related potentials, (3) brain stem potentials, and (4
Coch, Donna; Maron, Leeza; Wolf, Maryanne; Holcomb, Phillip J
In an investigation of the N400 component, event-related potentials (ERPs) elicited by 4 types of word stimuli (real words, pseudowords, random letter strings, and false fonts) and 3 types of picture stimuli (real pictures, pseudopictures, and picture parts) presented in separate lists were recorded from 10- and 11-year-old children. All types of word stimuli elicited an anteriorly distributed negativity peaking at about 400 msec (antN400). Words and pseudowords elicited similar ERPs, whereas ERPs to letter strings differed from those to both pseudowords and false fonts. All types of picture stimuli elicited dual anterior negativities (N350 and N430). Real pictures and pseudopictures elicited similar ERPs, whereas pseudopictures and picture parts elicited asymmetrical processing. The results are discussed in terms of increased sensitivity to and dependence on context in children.
Braverman, Ami; Berger, Andrea; Meiran, Nachshon
According to "hierarchical" multi-step theories, response selection is preceded by a decision regarding which task rule should be executed. Other theories assume a "flat" single-step architecture in which task information and stimulus information are simultaneously considered. Using task switching, the authors independently manipulated two kinds of conflict: task conflict (with information that potentially triggers the relevant or the competing task rule/identity) and response conflict (with information that potentially triggers the relevant or the competing response code/motor response). Event related potentials indicated that the task conflict effect began before the response conflict effect and carried on in parallel with it. These results are more in line with the hierarchical view. Copyright © 2014 Elsevier Inc. All rights reserved.
Cohen, Jeremiah Y; Heitz, Richard P; Schall, Jeffrey D; Woodman, Geoffrey F
Despite nearly a century of electrophysiological studies recording extracranially from humans and intracranially from monkeys, the neural generators of nearly all human event-related potentials (ERPs) have not been definitively localized. We recorded an attention-related ERP component, known as the N2pc, simultaneously with intracranial spikes and local field potentials (LFPs) in macaques to test the hypothesis that an attentional-control structure, the frontal eye field (FEF), contributed to the generation of the macaque homologue of the N2pc (m-N2pc). While macaques performed a difficult visual search task, the search target was selected earliest by spikes from single FEF neurons, later by FEF LFPs, and latest by the m-N2pc. This neurochronometric comparison provides an empirical bridge connecting macaque and human experiments and a step toward localizing the neural generator of this important attention-related ERP component.
Kuipers, Jan Rouke; Thierry, Guillaume
A number of studies have shown that from an early age, bilinguals outperform their monolingual peers on executive control tasks. We previously found that bilingual children and adults also display greater attention to unexpected language switches within speech. Here, we investigated the effect of a bilingual upbringing on speech perception in one language. We recorded monolingual and bilingual toddlers' event-related potentials (ERPs) to spoken words preceded by pictures. Words matching the picture prime elicited an early frontal positivity in bilingual participants only, whereas later ERP amplitudes associated with semantic processing did not differ between groups. These results add to the growing body of evidence that bilingualism increases overall attention during speech perception whilst semantic integration is unaffected. Copyright © 2015 The Authors. Published by Elsevier Inc. All rights reserved.
Full Text Available Using a crossmodal priming paradigm, this study investigated how the brain bound the spatial and semantic features in multisensory processing. The visual stimuli (pictures of animals were presented after the auditory stimuli (sounds of animals, and the stimuli from different modalities may match spatially (or semantically or not. Participants were required to detect the head orientation of the visual target (an oddball paradigm. The event-related potentials (ERPs to the visual stimuli was enhanced by spatial attention (150–170 ms irrespectively of semantic information. The early crossmodal attention effect for the visual stimuli was more negative in the spatial-congruent condition than in the spatial-incongruent condition. By contrast, the later effects of spatial ERPs were significant only for the semantic- congruent condition (250–300 ms. These findings indicated that spatial attention modulated early visual processing, and semantic and spatial features were simultaneously used to orient attention and modulate later processing stages.
Zhou, Linshu; Jiang, Cunmei; Wu, Yingying; Yang, Yufang
This study on event-related brain potential investigated whether music can convey the concept of movement. Using a semantic priming paradigm, natural musical excerpts were presented to non-musicians, followed by semantically congruent or incongruent pictures that depicted objects either in motion or at rest. The priming effects were tested in object decision and implicit recognition tasks to distinguish the effects of automatic conceptual activation from response competition. Results showed that in both tasks, pictures that were incongruent to preceding musical excerpts elicited larger N400 than congruent pictures, suggesting that music can prime the representations of movement concepts. Results of the multiple regression analysis showed that movement expression could be well predicted by specific acoustic and musical features, indicating the associations between music per se and the processing of iconic musical meaning. Copyright © 2015 Elsevier Ltd. All rights reserved.
Kipp, Kerstin H; Mecklinger, Axel; Brunnemann, Nicole; Shamdeen, Mohammed G; Meng-Hentschel, Juliane; Gortner, Ludwig
Prematurity may cause hippocampal compromise. Therefore, hippocampus-dependent memory processes (recollection-based retrieval) may be more impaired than hippocampus-independent processes (familiarity-based retrieval). The memory of 18 children born preterm with reduced hippocampal volumes, without neonatal complications (weeks of gestation < 34, weight < 1,600 g), and 15 controls (8-10 years) was tested using an item recognition task. While groups were equal in memory performance, dissociation was found: The event-related potential (ERP) correlate of familiarity was intact in the preterm group, whereas the correlate of recollection was attenuated. A follow-up experiment ruled out that this was due to general cognitive deficits. Furthermore, gestational age correlated with the ERP index of recollection. Thus, recognition memory in preterm children may be characterized by a compensation of attenuated recollection by familiarity. © 2014 The Authors. Child Development © 2014 Society for Research in Child Development, Inc.
Hämäläinen, Jarmo A; Guttorm, Tomi K; Richardson, Ulla; Alku, Paavo; Lyytinen, Heikki; Leppänen, Paavo H T
Identifying children at risk for reading problems or dyslexia at kindergarten age could improve support for beginning readers. Brain event-related potentials (ERPs) were measured for temporally complex pseudowords and corresponding non-speech stimuli from 6.5-year-old children who participated in behavioral literacy tests again at 9 years in the second grade. Children who had reading problems at school age had larger N250 responses to speech and non-speech stimuli particularly at the left hemisphere. The brain responses also correlated with reading skills. The results suggest that atypical auditory and speech processing are a neural-level risk factor for future reading problems. [Supplementary material is available for this article. Go to the publisher's online edition of Developmental Neuropsychology for the following free supplemental resources: Sound files used in the experiments. Three speech sounds and corresponding non-speech sounds with short, intermediate, and long gaps].
Green, Jessica J; McDonald, John J
We conducted two audiovisual experiments to determine whether event-related potential (ERP) components elicited by attention-directing cues reflect supramodal attentional control. Symbolic visual cues were used to direct attention prior to auditory targets in Experiment 1, and symbolic auditory cues were used to direct attention prior to visual targets in Experiment 2. Different patterns of cue ERPs were found in the two experiments. A frontal negativity called the ADAN was absent in Experiment 2, which indicates that this component does not reflect supramodal attentional control. A posterior positivity called the LDAP was observed in both experiments but was focused more posteriorly over the occipital scalp in Experiment 2. This component appears to reflect multiple processes, including visual processes involved in location marking and target preparation as well as supramodal processes involved in attentional control.
Sole Puig, Maria; Pallarés, Josep Marco; Perez Zapata, Laura; Puigcerver, Laura; Cañete, Josep; Supèr, Hans
Neural mechanisms of attention allow selective sensory information processing. Top-down deployment of visual-spatial attention is conveyed by cortical feedback connections from frontal regions to lower sensory areas modulating late stimulus responses. A recent study reported the occurrence of small eye vergence during orienting top-down attention. Here we assessed a possible link between vergence and attention by comparing visual event related potentials (vERPs) to a cue stimulus that induced attention to shift towards the target location to the vERPs to a no-cue stimulus that did not trigger orienting attention. The results replicate the findings of eye vergence responses during orienting attention and show that the strength and time of eye vergence coincide with the onset and strength of the vERPs when subjects oriented attention. Our findings therefore support the idea that eye vergence relates to and possibly has a role in attentional selection.
Maria Sole Puig
Full Text Available Neural mechanisms of attention allow selective sensory information processing. Top-down deployment of visual-spatial attention is conveyed by cortical feedback connections from frontal regions to lower sensory areas modulating late stimulus responses. A recent study reported the occurrence of small eye vergence during orienting top-down attention. Here we assessed a possible link between vergence and attention by comparing visual event related potentials (vERPs to a cue stimulus that induced attention to shift towards the target location to the vERPs to a no-cue stimulus that did not trigger orienting attention. The results replicate the findings of eye vergence responses during orienting attention and show that the strength and time of eye vergence coincide with the onset and strength of the vERPs when subjects oriented attention. Our findings therefore support the idea that eye vergence relates to and possibly has a role in attentional selection.
Lamti, Hachem A; Gorce, Philippe; Ben Khelifa, Mohamed Moncef; Alimi, Adel M
The goal of this study is to investigate the influence of mental fatigue on the event related potential P300 features (maximum pick, minimum amplitude, latency and period) during virtual wheelchair navigation. For this purpose, an experimental environment was set up based on customizable environmental parameters (luminosity, number of obstacles and obstacles velocities). A correlation study between P300 and fatigue ratings was conducted. Finally, the best correlated features supplied three classification algorithms which are MLP (Multi Layer Perceptron), Linear Discriminate Analysis and Support Vector Machine. The results showed that the maximum feature over visual and temporal regions as well as period feature over frontal, fronto-central and visual regions were correlated with mental fatigue levels. In the other hand, minimum amplitude and latency features didn't show any correlation. Among classification techniques, MLP showed the best performance although the differences between classification techniques are minimal. Those findings can help us in order to design suitable mental fatigue based wheelchair control.
Gondan, Matthias; Röder, B.
not contain common activity: This activity would be subtracted twice from one ERP and would, therefore, contaminate the result. In the present study, ERPs to unimodal, bimodal, and trimodal auditory, visual, and tactile stimuli (T) were recorded. We demonstrate that (T + TAV) - (TA + TV) is equivalent to AV......Event-related potentials (ERPs) can be used in multisensory research to determine the point in time when different senses start to interact, for example, the auditory and the visual system. For this purpose, the ERP to bimodal stimuli (AV) is often compared to the sum of the ERPs to auditory (A......) and visual (V) stimuli: AV - (A + V). If the result is non-zero, this is interpreted as an indicator for multisensory interactions. Using this method, several studies have demonstrated auditory-visual interactions as early as 50 ms after stimulus onset. The subtraction requires that A, V, and AV do...
Full Text Available Behavioral studies demonstrate that the timing of receiving gains or losses affects decision-making, a phenomenon known as temporal discounting, as participants are inclined to prefer immediate rewards over delayed ones and vice versa for losses. The present study used the event-related potential (ERP technique with a simple gambling task to investigate how delayed rewards and losses affected the brain activity in outcome evaluations made by 20 young adults. Statistical analysis revealed a larger feedback related negativity (FRN effect between loss and gain following immediate outcomes than following future outcomes. In addition, delay impacted FRN only in gain conditions, with delayed winning eliciting a more negative FRN than immediatewinning. These results suggest that temporal discounting and sign effect could be encoded in the FRN in the early stage of outcome evaluation.
Iwanami, Akira; Okajima, Yuka; Ota, Haruhisa; Tani, Masayuki; Yamada, Takashi; Yamagata, Bun; Hashimoto, Ryuichiro; Kanai, Chieko; Takashio, Osamu; Inamoto, Atsuko; Ono, Taisei; Takayama, Yukiko; Kato, Nobumasa
In the present study, we investigated auditory event-related potentials in adults with Asperger disorder and normal controls using an auditory oddball task and a novelty oddball task. Task performance and the latencies of P300 evoked by both target and novel stimuli in the two tasks did not differ between the two groups. Analysis of variance revealed that there was a significant interaction effect between group and electrode site on the mean amplitude of the P300 evoked by novel stimuli, which indicated that there was an altered distribution of the P300 in persons with Asperger disorder. In contrast, there was no significant interaction effect on the mean P300 amplitude elicited by target stimuli. Considering that P300 comprises two main subcomponents, frontal-central-dominant P3a and parietal-dominant P3b, our results suggested that persons with Asperger disorder have enhanced amplitude of P3a, which indicated activated prefrontal function in this task.
Lemons, Christopher J; Key, Alexandra P F; Fuchs, Douglas; Yoder, Paul J; Fuchs, Lynn S; Compton, Donald L; Williams, Susan M; Bouton, Bobette
The purpose of this study was to determine if event-related potential (ERP) data collected during three reading-related tasks (Letter Sound Matching, Nonword Rhyming, and Nonword Reading) could be used to predict short-term reading growth on a curriculum-based measure of word identification fluency over 19 weeks in a sample of 29 first-grade children. Results indicate that ERP responses to the Letter Sound Matching task were predictive of reading change and remained so after controlling for two previously validated behavioral predictors of reading, Rapid Letter Naming and Segmenting. ERP data for the other tasks were not correlated with reading change. The potential for cognitive neuroscience to enhance current methods of indexing responsiveness in a response-to-intervention (RTI) model is discussed.
Yu, Luodi; Fan, Yuebo; Deng, Zhizhou; Huang, Dan; Wang, Suiping; Zhang, Yang
The present study investigated pitch processing in Mandarin-speaking children with autism using event-related potential measures. Two experiments were designed to test how acoustic, phonetic and semantic properties of the stimuli contributed to the neural responses for pitch change detection and involuntary attentional orienting. In comparison with age-matched (6-12 years) typically developing controls (16 participants in Experiment 1, 18 in Experiment 2), children with autism (18 participants in Experiment 1, 16 in Experiment 2) showed enhanced neural discriminatory sensitivity in the nonspeech conditions but not for speech stimuli. The results indicate domain specificity of enhanced pitch processing in autism, which may interfere with lexical tone acquisition and language development for children who speak a tonal language.
Nieuwland, Mante S; Martin, Andrea E; Carreiras, Manuel
The animacy distinction is deeply rooted in the language faculty. A key example is differential object marking, the phenomenon where animate sentential objects receive specific marking. We used event-related potentials to examine the neural processing consequences of case-marking violations on animate and inanimate direct objects in Spanish. Inanimate objects with incorrect prepositional case marker 'a' ('al suelo') elicited a P600 effect compared to unmarked objects, consistent with previous literature. However, animate objects without the required prepositional case marker ('el obispo') only elicited an N400 effect compared to marked objects. This novel finding, an exclusive N400 modulation by a straightforward grammatical rule violation, does not follow from extant neurocognitive models of sentence processing, and mirrors unexpected "semantic P600" effects for thematically problematic sentences. These results may reflect animacy asymmetry in competition for argument prominence: following the article, thematic interpretation difficulties are elicited only by unexpectedly animate objects. Copyright © 2013 Elsevier Inc. All rights reserved.
Choi, Sungmook; Kim, Jingu; Ryu, Kwangmin
Although much is known about how contextualized and decontextualized learning affects explicit lexical knowledge, how these learning conditions contribute to implicit lexical knowledge remains unclear. To address this problem, Korean high school students were instructed to learn 30 English words by reading meaningful passages (i.e., in context) and another 30 English words using a wordlist (i.e., out of context). Five weeks later, implicit lexical knowledge was gauged by reaction time and the N400 event-related brain potential component, and explicit lexical knowledge was assessed with an explicit behavioral measure. Results showed that neither learning type was superior to the other in terms of implicit lexical knowledge acquisition, whereas learning words out of context was more effective than learning words in context for establishing explicit lexical knowledge. These results suggest that the presence or absence of context may lead to dissociation in the development of implicit and explicit lexical knowledge. Copyright © 2014 Elsevier Ltd. All rights reserved.
Bradley, Margaret M.; Lang, Peter J.
Dense array event-related potentials (ERPs) and memory performance were assessed following rapid serial visual presentation (RSVP) of emotional and neutral pictures. Despite the extremely brief presentation, emotionally arousing pictures prompted an enhanced negative voltage over occipital sensors, compared to neutral pictures, replicating previous encoding effects. Emotionally arousing pictures were also remembered better in a subsequent recognition test, with higher hit rates and better discrimination performance. ERPs measured during the recognition test showed both an early (250–350 ms) frontally distributed difference between hits and correct rejections, and a later (400–500 ms), more centrally distributed difference, consistent with effects of recognition on ERPs typically found using slower presentation rates. The data are consistent with the hypothesis that features of affective pictures pop out during rapid serial visual presentation, prompting better memory performance. PMID:20628736
Full Text Available Acupuncture can be used to treat various nervous system diseases. Here, 168 vascular dementia patients were orally administered donepezil hydrochloride alone (5 mg/day, once a day for 56 days, or combined with acupuncture at Shenting (DU24, Tianzhu (BL10, Sishencong (Extra, Yintang (Extra, Renzhong (DU26, Neiguan (PC6, Shenmen (HT7, Fengchi (GB20, Wangu (GB12 and Baihui (DU20 (once a day for 56 days. Compared with donepezil hydrochloride alone, P300 event related potential latency was shorter with an increased amplitude in patients treated with donepezil hydrochloride and acupuncture. Mini-Mental State Examination score was also higher. Moreover, these differences in P300 latency were identified within different infarcted regions in patients treated with donepezil hydrochloride and acupuncture. These findings indicate that acupuncture combined with donepezil hydrochloride noticeably improves cognitive function in patients with vascular dementia, and exerts neuroprotective effects against vascular dementia.
Wang, Lili; Fu, Shimin; Feng, Chunliang; Luo, Wenbo; Zhu, Xiangru; Luo, Yue-jia
To investigate whether the non-conscious processing of fearful faces exist in unattended condition, event-related potentials (ERPs) were recorded in a facial expression detection task. Participants were asked to discriminate the facial expressions (fearful or neutral) at the attended location. Unattended faces were associated with a response that was either congruent or in conflict with the response to the attended face. ERP results showed that the trials with response conflict between attended and unattended faces enhanced the amplitude of the P3 component when the neutral face was presented at attended location and the fearful face was presented at the unattended location. Our findings imply that the non-conscious fearful faces can be processed in the unattended condition. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Takahashi, Mitsuru; Gouko, Manabu; Ito, Koji
Stroke patients have some motor deficits, but they can regain their motor abilities by rehabilitation. In the aspect of rehabilitation, voluntary movement is very important. We propose a system which can make a closed loop in brain for stroke patients like voluntary movement. Event Related Desynchronization (ERD) is used to extract patients' motor intention, and then Functional Electrical Stimulation (FES) stimuls their paralyzed muscles. In many Brain Computer Interface (BCI) researches, subjects are trained for several months or years to do the task, because of the difficulty to extract clear ERD without training. Thinking about applying for stroke patients, motor imagery training should be shorter, because of the brain plasticity. We did a pilot study about the effect of visual feedback training for three days with healthy subjects. The result indicated that ERD could be clearly extracted in three days, but the training effect differs in each subjects.
Godleski, Stephanie A; Ostrov, Jamie M; Houston, Rebecca J; Schlienz, Nicolas J
This exploratory study investigates how hostile attribution biases for relationally provocative situations may be related to neurocognitive processing using the P300 event-related potential. Participants were 112 (45 women) emerging adults enrolled in a large, public university in upstate New York. Participants completed self-report measures on relational aggression and hostile attribution biases and performed an auditory perseveration task to elicit the P300. It was found that hostile attribution biases for relational provocation situations was associated with a larger P300 amplitude above and beyond the role of hostile attribution biases for instrumental situations, relational aggression, and gender. Larger P300 amplitude is interpreted to reflect greater allocation of cognitive resources or enhanced "attending" to salient stimuli. Implications for methodological approaches to studying aggression and hostile attribution biases and for theory are discussed, as well as implications for the fields of developmental psychology and psychopathology. Copyright 2010 Elsevier B.V. All rights reserved.
Gibbons, Henning; Rammsayer, Thomas H; Stahl, Jutta
Event-related potential correlates of positive priming (PP) and negative priming (NP) were investigated in order to further elucidate the cognitive mechanisms involved. Thirty-six participants performed both an identity- and a location-based priming task. Repeating the target stimulus/location from the immediately preceding display produced behavioral PP. With localization, but not with identification, behavioral NP was observed when the target stimulus/location matched the preceding distractor stimulus/location. Smaller P300 amplitude accompanied identity-based PP, suggesting persisting target-specific activation. The lateralized readiness potential, an index of correct/incorrect response activation, indicated persisting central motor activation as another source of PP. Both location-based PP and NP were accompanied by reduced P1/N1 and P300 amplitudes, pointing to the involvement of inhibition of return in location-based priming. The results support the view that multiple brain processes underlie behavioral priming.
Zhu, Weina; Zhang, Junjun; Ding, Xiaojun; Zhou, Changle; Ma, Yuanye; Xu, Dan
To compare the effects of music from different cultural environments (Guqin: Chinese music; piano: Western music) on crossmodal selective attention, behavioral and event-related potential (ERP) data in a standard two-stimulus visual oddball task were recorded from Chinese subjects in three conditions: silence, Guqin music or piano music background. Visual task data were then compared with auditory task data collected previously. In contrast with the results of the auditory task, the early (N1) and late (P300) stages exhibited no differences between Guqin and piano backgrounds during the visual task. Taking our previous study and this study together, we can conclude that: although the cultural-familiar music influenced selective attention both in the early and late stages, these effects appeared only within a sensory modality (auditory) but not in cross-sensory modalities (visual). Thus, the musical cultural factor is more obvious in intramodal than in crossmodal selective attention.
Wang, Enguo; Qin, Shutao; Chang, MengYan; Zhu, Xiangru
This study reports the neurophysiological and behavioral correlates of digital memory encoding features in Chinese individuals with and without dyscalculia. Eighteen children with dyscalculia (ages 11.5-13.5) and 18 matched controls were tested, and their event-related potentials (ERPs) were digitally recorded simultaneously with behavioral measures. The results showed that both groups had a significant Dm effect, and this effect was greater in the control group. In the 300-400-ms, 400-500-ms, and 600-700-ms processing stages, both groups showed significant differences of digital memory encoding in the frontal, central, and parietal regions. In the 500-600-ms period, the Dm effect in the control group was significantly greater than that in the dyscalculia group only in the parietal region. These results suggest that individuals with dyscalculia exhibit impaired digital memory encoding and deficits in psychological resource allocation. Copyright © 2014 Elsevier Ltd. All rights reserved.
Bourisly, Ali K; Pothen, Annie
The primary objective of this study was to further characterize the role of sex, if any, in event-related potentials (ERPs). More specifically, we aimed to investigate sex sensitivity with respect to the P300 ERP. Each female and male study participant underwent an oddball paradigm electroencephalography ERP session. ERP data were subjected to preprocessing and postprocessing, as well as statistical analysis. The results of the study showed that men had larger P300 amplitudes on average for both low-probability and high-probability stimuli compared with women (PP300 latencies on average than did women (PP300 ERP, which may be because of men eliciting higher response inhibition compared with women.
Full Text Available Event-related potentials (ERPs are important clinical and research instruments in neuropsychiatry, particularly due to their strategic role for the investigation of brain function. These techniques are often underutilized in the evaluation of neurological and psychiatric disorders, but ERPs are noninvasive instruments that directly reflect cortical neuronal activity. Previous studies using the P300, P3a, and MMN components of the ERP to study dementing illness are reviewed. The results suggest that particularly the P300 brain potential is sensitive to Alzheimer's disease processes during its early stages, and that easily performed stimulus discrimination tasks are the clinically most useful. Finally, these data suggest that the P300 ERP can aid in the diagnosis of dementia and may help in the assessment of early Alzheimer's disease.
Liu, Qiang; Wang, Xiu-Juan; Zhang, Zhe-Cheng; Xue, Rong; Li, Ping; Li, Bo
Acupuncture can be used to treat various nervous system diseases. Here, 168 vascular dementia patients were orally administered donepezil hydrochloride alone (5 mg/day, once a day for 56 days), or combined with acupuncture at Shenting (DU24), Tianzhu (BL10), Sishencong (Extra), Yintang (Extra), Renzhong (DU26), Neiguan (PC6), Shenmen (HT7), Fengchi (GB20), Wangu (GB12) and Baihui (DU20) (once a day for 56 days). Compared with donepezil hydrochloride alone, P300 event related potential latency was shorter with an increased amplitude in patients treated with donepezil hydrochloride and acupuncture. Mini-Mental State Examination score was also higher. Moreover, these differences in P300 latency were identified within different infarcted regions in patients treated with donepezil hydrochloride and acupuncture. These findings indicate that acupuncture combined with donepezil hydrochloride noticeably improves cognitive function in patients with vascular dementia, and exerts neuroprotective effects against vascular dementia.
Tanaka, Motoshi; Honma, Tomohiro; Inoue, Hiroshi; Niiyama, Yoshitsugu; Takahashi, Toru; Kumagai, Masanori; Akiyama, Yoshinobu
In order to study the application of event-related potential (ERP) for performing objective evaluation of food, the ERP was measured when subjectively judging the appearance of food by three-grade scale with the opinion “like”, “favorite” and “more favorite”. Sushi and cooked rice were selected as typical foods. Five pictures of each food that the subjects liked were chosen before measurements, and then were used in opinion tests. As a result, the P300 component of the ERP was detected, and the P300 area (surrounded by ERP waveform from the latency 250 to 500ms) became larger when the subjects judged as “more favorite”, which indicates the feasibility of evaluation of food using the ERP.
Versace, Francesco; Bradley, Margaret M; Lang, Peter J
Dense array event-related potentials (ERPs) and memory performance were assessed following rapid serial visual presentation (RSVP) of emotional and neutral pictures. Despite the extremely brief presentation, emotionally arousing pictures prompted an enhanced negative voltage over occipital sensors, compared to neutral pictures, replicating previous encoding effects. Emotionally arousing pictures were also remembered better in a subsequent recognition test, with higher hit rates and better discrimination performance. ERPs measured during the recognition test showed both an early (250-350 ms) frontally distributed difference between hits and correct rejections, and a later (400-500 ms), more centrally distributed difference, consistent with effects of recognition on ERPs typically found using slower presentation rates. The data are consistent with the hypothesis that features of affective pictures pop out during rapid serial visual presentation, prompting better memory performance.
Domínguez, Alberto; Alija, Maira; Cuetos, Fernando; de Vega, Mauel
Behavioral measures in visual priming tasks show opposite effects for syllables and morphemes, which indicate that they are processed by two independent systems. We used event related potentials (ERPs) to explore two priming situations in Spanish: prefix related words (reacción-REFORMA [reaction-reform]), in which prime and target words shared a first syllable that was also a prefix, and syllable related words (regalo-REFORMA [gift-reform.]), in which the shared first syllable was a pseudoprefix in the prime word. Prefix related pairs, unlike syllable related pairs, evoked a very early positivity in reaction to the target (at 150-250ms window), suggesting that the prefix information is immediately available, at a prelexical stage. By contrast, syllable related pairs showed a larger N400 effect. This late negativity may be caused by lateral inhibition among lexical candidates activated in the lexicon by the prime's first syllable.
Full Text Available Previous studies have found that the amplitude of the early event-related potential (ERP components evoked by faces, such as N170 and P2, changes systematically as a function of noise added to the stimuli. This change has been linked to an increased perceptual processing demand and to enhanced difficulty in perceptual decision making about faces. However, to date it has not yet been tested whether noise manipulation affects the neural correlates of decisions about face and non-face stimuli similarly. To this end, we measured the event-related potentials for faces and cars at three different phase noise levels. Subjects performed the same two-alternative age-discrimination task on stimuli chosen from young-old morphing continua that were created from faces as well as cars and were calibrated to lead to similar performances at each noise-level. Adding phase noise to the stimuli reduced performance and enhanced response latency for the two categories to the same extent. Parallel to that, phase noise reduced the amplitude and prolonged the latency of the face-specific N170 component. The amplitude of the P1 showed category-specific noise dependence: it was enhanced over the right hemisphere for cars and over the left hemisphere for faces as a result of adding phase noise to the stimuli, but remained stable across noise levels for cars over the left and for faces over the right hemisphere. Moreover, noise modulation altered the category-selectivity of the N170, while the P2 ERP component, typically associated with task decision difficulty, was larger for the more noisy stimuli regardless of stimulus category. Our results suggest that the category-specificity of noise-induced modulations of ERP responses starts at around 100 ms post-stimulus.
Tamayo-Orrego, Lukas; Osorio Forero, Alejandro; Quintero Giraldo, Lina Paola; Parra Sánchez, José Hernán; Varela, Vilma; Restrepo, Francia
To better understand the neurophysiological substrates in attention deficit/hyperactivity disorder (ADHD), a study was performed on of event-related potentials (ERPs) in Colombian patients with inattentive and combined ADHD. A case-control, cross-sectional study was designed. The sample was composed of 180 subjects between 5 and 15 years of age (mean, 9.25±2.6), from local schools in Manizales. The sample was divided equally in ADHD or control groups and the subjects were paired by age and gender. The diagnosis was made using the DSM-IV-TR criteria, the Conners and WISC-III test, a psychiatric interview (MINIKID), and a medical evaluation. ERPs were recorded in a visual and auditory passive oddball paradigm. Latency and amplitude of N100, N200 and P300 components for common and rare stimuli were used for statistical comparisons. ADHD subjects show differences in the N200 amplitude and P300 latency in the auditory task. The N200 amplitude was reduced in response to visual stimuli. ADHD subjects with combined symptoms show a delayed P300 in response to auditory stimuli, whereas inattentive subjects exhibited differences in the amplitude of N100 and N200. Combined ADHD patients showed longer N100 latency and smaller N200-P300 amplitude compared to inattentive ADHD subjects. The results show differences in the event-related potentials between combined and inattentive ADHD subjects. Copyright © 2014 Asociación Colombiana de Psiquiatría. Publicado por Elsevier España. All rights reserved.
Locquet, Médéa; Honvo, Germain; Rabenda, Véronique; Van Hees, Thierry; Petermans, Jean; Reginster, Jean-Yves; Bruyère, Olivier
Older adults often resort to self-medication to relieve symptoms of their current illnesses; however, the risks of this practice are multiplied in old age. In particular, this age group is more vulnerable to adverse drug events because of the physiological changes that occur due to senescence. The aim of the study was to obtain an overview of the adverse health events related to self-medication among subjects aged 60 years and over through a systematic review of the literature. A study of relevant articles was conducted among databases (MEDLINE, PsycINFO, and EBM Reviews-Cochrane Database of Systematic Reviews). Eligibility criteria were established and applied by two investigators to include suitable studies. The results and outcomes of interest were detailed in a descriptive report. The electronic search identified 4096 references, and the full texts of 74 were reviewed, of which four were retained in the analysis: three had a cross-sectional design and one prospectively followed elderly subjects. The first study showed a 26.7% prevalence of adverse drug reactions (ADRs) among elders, the second study found a 75% prevalence of side effects, and, finally, a prospective study showed an ADR incidence of 4.5% among self-medicated elders. These studies showed that adverse health events related to self-medication are relatively frequently reported. They also highlighted that analgesics and anti-inflammatory drugs are the most self-medicated products, while vitamins and dietary supplements also appear to be frequently self-administered, but by older individuals. Studies on self-medication in the elderly and its adverse health effects are clearly lacking. There is a need to perform prospective studies on this topic to gain a clear understanding of the extent of this problem and to enhance the awareness of health professionals to better inform seniors.
Lee, Ja Y.; Lindquist, Kristen A.; Nam, Chang S.
There is debate about whether emotional granularity, the tendency to label emotions in a nuanced and specific manner, is merely a product of labeling abilities, or a systematic difference in the experience of emotion during emotionally evocative events. According to the Conceptual Act Theory of Emotion (CAT) (Barrett, 2006), emotional granularity is due to the latter and is a product of on-going temporal differences in how individuals categorize and thus make meaning of their affective states. To address this question, the present study investigated the effects of individual differences in emotional granularity on electroencephalography-based brain activity during the experience of emotion in response to affective images. Event-related potentials (ERP) and event-related desynchronization and synchronization (ERD/ERS) analysis techniques were used. We found that ERP responses during the very early (60–90 ms), middle (270–300 ms), and later (540–570 ms) moments of stimulus presentation were associated with individuals’ level of granularity. We also observed that highly granular individuals, compared to lowly granular individuals, exhibited relatively stable desynchronization of alpha power (8–12 Hz) and synchronization of gamma power (30–50 Hz) during the 3 s of stimulus presentation. Overall, our results suggest that emotional granularity is related to differences in neural processing throughout emotional experiences and that high granularity could be associated with access to executive control resources and a more habitual processing of affective stimuli, or a kind of “emotional complexity.” Implications for models of emotion are also discussed. PMID:28392761
Haifeng, Jiang; Wenxu, Zhuang; Hong, Cheng; Chuanwei, Li; Jiang, Du; Haiming, Sun; Zhikang, Chen; Din, Xu; Jijun, Wang; Min, Zhao
Substance use and abuse are characterized by biases in the attentional processing of substance-related stimuli. There are no event related potential (ERP)-based studies of attentional bias for substance-related cues among methamphetamine (MA) dependent patients. The study aimed to measure changes in P300 event-related potentials elicited by MA-related words in MA-dependent individuals at baseline and after 3 and 6 months of abstinence, examining the relationship of ERP changes to craving. 26 MA-dependent patients (14 male) newly enrolled in two compulsory treatment centers in China and 29 healthy controls (15 male) were included in this study. At baseline (2-3 weeks in treatment) and after 3 and 6 months of abstinence from MA use, we obtained ERP data during a Stroop color-matching task using MA-related and neutral words. Self-reported craving was measured by a Visual Analog Scale (VAS). Increased P300 amplitudes elicited by MA-related words were observed over left-anterior electrode sites. Abnormal P300 amplitudes declined to the normal levels of healthy controls at the end of 3 months of abstinence, and the decrease was maintained up to the end of 6 months of abstinence. The behavioral data did not show similar changes. The positive relationship between the changes of VAS scores for MA craving and the changes of P300 amplitudes over left anterior electrode sites elicited by MA-related words within the first 3 months was significant. These findings highlight the potential use of ERP as an objective index to track changes in subjective MA craving among abstinent MA-dependent patients. Copyright © 2015. Published by Elsevier Inc.
Teche, Stefania P; Rovaris, Diego L; Aguiar, Bianca W; Hauck, Simone; Vitola, Eduardo S; Bau, Claiton H D; Freitas, Lucia H; Grevet, Eugenio H
The exposition to traumatic events related to urban violence is epidemic in Brazil, with rate of 80% in the general population, and is becoming a major cause of post-traumatic stress disorder (PTSD). The objective of the study was to compare serum levels of pro-inflammatory interleukin-6 (IL-6) and anti-inflammatory interleukin-10 (IL-10) in PTSD and resilient individuals. We hypothesized that resilient individuals present an attenuated pro-inflammatory and enhanced anti-inflammatory state. We conducted a case-control study comparing 30 resilient individuals and 30 PTSD patients exposed to traumatic events related to urban violence. The groups were evaluated using Self-Report Questionnaire (SRQ-20), Mini-International Neuropsychiatric Interview (MINI) and the Davidson Trauma Scale. For all individuals, blood samples were collected to determine IL-6, IL-10 and cortisol serum levels. All samples were frozen at -80°C until the assay and were analyzed with the same immunoassay kit and in duplicates. The resilient group presented higher IL-10 levels than PTSD patients [mean (CI95%); 1.03 (0.52-2.08) pg/mL vs. 0.29 (0.20-0.43) pg/mL; P=0.002]. There were no differences in terms of IL-6 or cortisol levels. The results provided evidence for increased levels of IL-10 in resilient individuals when compared to PTSD patients, probably conferring them a better anti-inflammatory response after exposition. Copyright © 2017 Elsevier Ireland Ltd. All rights reserved.
Gong, Jinnan; Luo, Cheng; Chang, Xuebin; Zhang, Rui; Klugah-Brown, Benjamin; Guo, Lanjin; Xu, Peng; Yao, Dezhong
The rhythm of electroencephalogram (EEG) depends on the neuroanatomical-based parameters such as white matter (WM) connectivity. However, the impacts of these parameters on the specific characteristics of EEG have not been clearly understood. Previous studies demonstrated that, these parameters contribute the inter-subject differences of EEG during performance of specific task such as motor imagery (MI). Though researchers have worked on this phenomenon, the idea is yet to be understood in terms of the mechanism that underlies such differences. Here, to tackle this issue, we began our investigations by first examining the structural features related to scalp EEG characteristics, which are event-related desynchronizations (ERDs), during MI using diffusion MRI. Twenty-four right-handed subjects were recruited to accomplish MI tasks and MRI scans. Based on the high spatial resolution of the structural and diffusion images, the motor-related WM links, such as basal ganglia (BG)-primary somatosensory cortex (SM1) pathway and supplementary motor area (SMA)-SM1 connection, were reconstructed by using probabilistic white matter tractography. Subsequently, the relationships of WM characteristics with EEG signals were investigated. These analyses demonstrated that WM pathway characteristics, including the connectivity strength and the positional characteristics of WM connectivity on SM1 (defined by the gyrus-sulcus ratio of connectivity, GSR), have a significant impact on ERDs when doing MI. Interestingly, the high GSR of WM connections between SM1 and BG were linked to the better ERDs. These results therefore, indicated that the connectivity in the gyrus of SM1 interacted with MI network which played the critical role for the scalp EEG signal extraction of MI to a great extent. The study provided the coupling mechanism between structural and dynamic physiological features of human brain, which would also contribute to understanding individual differences of EEG in MI
Qin, S.; Piekema, C.; Petersson, K.M.; Han, B.; Luo, J.; Fernandez, G.
Using event-related functional magnetic resonance imaging, we identified brain regions involved in storing associations of events discontinuous in time into long-term memory. Participants were scanned while memorizing item-triplets including simultaneous and discontinuous associations. Subsequent
Wang, Changming; Xiong, Shi; Hu, Xiaoping; Yao, Li; Zhang, Jiacai
Categorization of images containing visual objects can be successfully recognized using single-trial electroencephalograph (EEG) measured when subjects view images. Previous studies have shown that task-related information contained in event-related potential (ERP) components could discriminate two or three categories of object images. In this study, we investigated whether four categories of objects (human faces, buildings, cats and cars) could be mutually discriminated using single-trial EEG data. Here, the EEG waveforms acquired while subjects were viewing four categories of object images were segmented into several ERP components (P1, N1, P2a and P2b), and then Fisher linear discriminant analysis (Fisher-LDA) was used to classify EEG features extracted from ERP components. Firstly, we compared the classification results using features from single ERP components, and identified that the N1 component achieved the highest classification accuracies. Secondly, we discriminated four categories of objects using combining features from multiple ERP components, and showed that combination of ERP components improved four-category classification accuracies by utilizing the complementarity of discriminative information in ERP components. These findings confirmed that four categories of object images could be discriminated with single-trial EEG and could direct us to select effective EEG features for classifying visual objects.
Olbrich, Sebastian; van Dinteren, Rik; Arns, Martijn
Personalized medicine in psychiatry is in need of biomarkers that resemble central nervous system function at the level of neuronal activity. Electroencephalography (EEG) during sleep or resting-state conditions and event-related potentials (ERPs) have not only been used to discriminate patients from healthy subjects, but also for the prediction of treatment outcome in various psychiatric diseases, yielding information about tailored therapy approaches for an individual. This review focuses on baseline EEG markers for two psychiatric conditions, namely major depressive disorder and attention deficit hyperactivity disorder. It covers potential biomarkers from EEG sleep research and vigilance regulation, paroxysmal EEG patterns and epileptiform discharges, quantitative EEG features within the EEG main frequency bands, connectivity markers and ERP components that might help to identify favourable treatment outcome. Further, the various markers are discussed in the context of their potential clinical value and as research domain criteria, before giving an outline for future studies that are needed to pave the way to an electrophysiological biomarker-based personalized medicine. © 2016 S. Karger AG, Basel.
Macdonald, Margaret; Campbell, Kenneth
Unexpected physical increases in the intensity of a frequently occurring "standard" auditory stimulus are experienced as obtrusive. This could either be because of a physical change, the increase in intensity of the "deviant" stimulus, or a psychological change, the violation of the expectancy for the occurrence of the lower intensity standard stimulus. Two experiments were run in which event-related potentials (ERPs) were recorded to determine whether "psychological" increments (violation of an expectancy for a lower intensity) would be processed differently than psychological decrements (violation of an expectancy for a higher intensity). Event-related potentials (ERPs) were recorded while subjects were presented with auditory tones that alternated between low and high intensity. The subjects ignored the auditory stimuli while watching a video. Deviants were created by repeating the same stimulus. In the first experiment, pairs of stimuli alternating in intensity, were presented in separate increment (H-L...H-L...H-H...H-L, in which H = 80 dB SPL and L = 60 dB SPL) and decrement conditions (L-H...L-H...L-L... L-H, in which H = 90 dB SPL and L = 80 dB SPL). The paradigm employed in the second experiment consisted of an alternating intensity pattern (H-L-H-L-H-H-H-L) or (H-L-H-L-L-L-H-L). Importantly, the stimulus prior to the deviant (the standard) and the actual deviants in both increment and decrement conditions in both experiments were physically identical (80 dB SPL tones). The repetition of the lower intensity tone therefore acted as a psychological rather than a physical decrement (a higher intensity tone was expected) while the repetition of the higher intensity tone acted as a psychological increment (a lower intensity tone was expected). The psychological increments in both experiments elicited a larger amplitude mismatch negativity (MMN) than the decrements. Thus, regardless of whether an acoustic change signals a physical increase in intensity or
Full Text Available Although the influence of stereotype threat (ST on working self-concepts has been highlighted in recent years, its neural underpinnings are unclear. Notably, the aging ST, which largely influences older adults’ cognitive ability, mental and physical health, did not receive much attention. In order to investigate these issues, electroencephalogram (EEG data were obtained from older adults during a modified Stroop task using neutral words, positive and negative self-concept words in aging ST vs. neutral control conditions. Results showed longer reaction times (RTs for identifying colors of words under the aging ST compared to the neutral condition. More importantly, the negative self-concept elicited more positive late P300 amplitudes and enhanced theta band activities compared to the positive self-concept or neutral words under the aging ST condition, whereas no difference was found between these self-concepts and neutral words in the control condition. Furthermore, the aging ST induced smaller theta band synchronization and enhanced alpha band synchronization compared to the control condition. Moreover, we also observed valence differences in self-concepts where the negative self-concept words reduced early P150/N170 complex relative to neutral words. These findings suggest that priming ST could activate negative self-concepts as current working self-concept, and that this influence occurred during a late neural time course.
Zhang, Baoshan; Lin, Yao; Gao, Qianyun; Zawisza, Magdalena; Kang, Qian; Chen, Xuhai
Although the influence of stereotype threat (ST) on working self-concepts has been highlighted in recent years, its neural underpinnings are unclear. Notably, the aging ST, which largely influences older adults’ cognitive ability, mental and physical health, did not receive much attention. In order to investigate these issues, electroencephalogram (EEG) data were obtained from older adults during a modified Stroop task using neutral words, positive and negative self-concept words in aging ST vs. neutral control conditions. Results showed longer reaction times (RTs) for identifying colors of words under the aging ST compared to the neutral condition. More importantly, the negative self-concept elicited more positive late P300 amplitudes and enhanced theta band activities compared to the positive self-concept or neutral words under the aging ST condition, whereas no difference was found between these self-concepts and neutral words in the control condition. Furthermore, the aging ST induced smaller theta band synchronization and enhanced alpha band synchronization compared to the control condition. Moreover, we also observed valence differences in self-concepts where the negative self-concept words reduced early P150/N170 complex relative to neutral words. These findings suggest that priming ST could activate negative self-concepts as current working self-concept, and that this influence occurred during a late neural time course. PMID:28747885
Language impairments are a well established finding in patients with schizophrenia and in individuals at-risk for psychosis. A growing body of research has revealed shared risk factors between individuals with psychotic-like experiences (PLEs) from the general population and patients with schizophrenia. In particular, adolescents with PLEs have been shown to be at an increased risk for later psychosis. However, to date there has been little information published on electrophysiological correlates of language comprehension in this at-risk group. A 64 channel EEG recorded electrical activity while 37 (16 At-Risk; 21 Controls) participants completed the British Picture Vocabulary Scale (BPVS-II) receptive vocabulary task. The P300 component was examined as a function of language comprehension. The at-risk group were impaired behaviourally on receptive language and were characterised by a reduction in P300 amplitude relative to the control group. The results of this study reveal electrophysiological evidence for receptive language deficits in adolescents with PLEs, suggesting that the earliest neurobiological changes underlying psychosis may be apparent in the adolescent period.
Murphy, Jennifer; Blanchard, Mathieu M; Rawdon, Caroline; Kavanagh, Fergal; Kelleher, Ian; Clarke, Mary C; Roche, Richard A P; Cannon, Mary
Language impairments are a well established finding in patients with schizophrenia and in individuals at-risk for psychosis. A growing body of research has revealed shared risk factors between individuals with psychotic-like experiences (PLEs) from the general population and patients with schizophrenia. In particular, adolescents with PLEs have been shown to be at an increased risk for later psychosis. However, to date there has been little information published on electrophysiological correlates of language comprehension in this at-risk group. A 64 channel EEG recorded electrical activity while 37 (16 At-Risk; 21 Controls) participants completed the British Picture Vocabulary Scale (BPVS-II) receptive vocabulary task. The P300 component was examined as a function of language comprehension. The at-risk group were impaired behaviourally on receptive language and were characterised by a reduction in P300 amplitude relative to the control group. The results of this study reveal electrophysiological evidence for receptive language deficits in adolescents with PLEs, suggesting that the earliest neurobiological changes underlying psychosis may be apparent in the adolescent period. Copyright © 2012 Elsevier B.V. All rights reserved.
Stock, Ann-Kathrin; Popescu, Florin; Neuhaus, Andres H; Beste, Christian
Much research has been devoted to investigating response inhibition and the neuronal processes constituting this essential cognitive faculty. However, the nexus between cognitive subprocesses, behavior, and electrophysiological processes remains associative in nature. We therefore investigated whether neurophysiological correlates of inhibition subprocesses merely correlate with behavioral performance or actually provide information expedient to the prediction of behavior on a single-subject level. Tackling this question, we used different data-driven classification approaches in a sample of n = 262 healthy young subjects who completed a standard Go/Nogo task while an EEG was recorded. On the basis of median-split response inhibition performance, subjects were classified as "accurate/slow" and "less accurate/fast." Even though these behavioral group differences were associated with significant amplitude variations in classical electrophysiological correlates of response inhibition (i.e., N2 and P3), they were not predictive for group membership on a single-subject level. Instead, amplitude differences in the Go-P2 originating in the precuneus (BA7) were shown to predict group membership on a single-subject level with up to 64% accuracy. These findings strongly suggest that the behavioral outcome of response inhibition greatly depends on the amount of cognitive resources allocated to early stages of stimulus-response activation during responding. This suggests that research should focus more on early processing steps during responding when trying to understand the origin of interindividual differences in response inhibition processes. Copyright © 2016 the American Physiological Society.
Agapov, S. N.; V. A. Bulanov; Zakharov, A. V.; Sergeeva, M. S.
Since it was first used in 1926, EEG has been one of the most useful instruments of neuroscience. In order to start using EEG data we need not only EEG apparatus, but also some analytical tools and skills to understand what our data mean. This article describes several classical analytical tools and also new one which appeared only several years ago. We hope it will be useful for those researchers who have only started working in the field of cognitive EEG.
Janssen, Tieme Willem Pieter; Bink, Marleen; Geladé, Katleen; van Mourik, Rosa; Maras, Athanasios; Oosterlaan, Jaap
Electroencephalographic (EEG) neurofeedback (NF) is considered a nonpharmacological alternative for medication in attention-deficit/hyperactivity disorder (ADHD). Comparisons of the behavioral efficacy of NF and medication have produced inconsistent results. EEG measures can provide insight into treatment mechanisms, but have received little consideration. In this randomized controlled trial (RCT), effects of NF were compared with methylphenidate (MPH), and physical activity (PA) in children with ADHD on event-related potential (ERP) indices of response inhibition, which are involved in ADHD psychopathology. Using a multicenter three way parallel group RCT design, 112 children with a Diagnostic and Statistical Manual of Mental Disorders, 4th ed. (DSM-IV) (American Psychiatric Association 1994 ) diagnosis of ADHD, between 7 and 13 years of age, were initially included. NF training consisted of 30 sessions of theta/beta training at Cz over a 10 week period. PA training was a semiactive control group, matched in frequency and duration. MPH was titrated using a double-blind placebo controlled procedure in 6 weeks, followed by a stable dose for 4 weeks. ERP measures of response inhibition, N2 and P3, were available for 81 children at pre- and postintervention (n = 32 NF, n = 25 MPH, n = 24 PA). Only the medication group showed a specific increase in P3 amplitude compared with NF (partial eta-squared [ηp(2) ] = 0.121) and PA (ηp(2) = 0.283), which was related to improved response inhibition. Source localization of medication effects on P3 amplitude indicated increased activation primarily in thalamic and striatal nuclei. This is the first study that simultaneously compared NF with stimulant treatment and a semiactive control group. Only stimulant treatment demonstrated specific improvements in brain function related to response inhibition. These results are in line with recent doubts on the efficacy and specificity of NF as treatment for ADHD. Train
Full Text Available Self-referential emotion refers to the process of evaluating emotional stimuli with respect to the self. Processes indicative of a self-positivity bias are reflected in electroencephalogram (EEG signals at ~400 ms when the task does not require a discrimination of self from other. However, when distinguishing between self-referential and other-referential emotions is required, previous studies have shown inconsistent temporal dynamics of EEG signals in slightly different tasks. Based on the observation of early self–other discrimination, we hypothesized that self would be rapidly activated in the early stage to modulate emotional processing in the late stage during an implicit self-referential emotion. To test this hypothesis, we employed an implicit task in which participants were asked to judge the order of Chinese characters of trait adjectives preceded by a self (“I” or other pronoun (“He” or “She”. This study aimed to explore the difference of social-related emotional evaluation from self-reference; the other pronoun was not defined to a specific person, rather it referred to the general concept. Sixteen healthy Chinese subjects participated in the experiment. Event-related potentials (ERPs showed that there were self-other discrimination effects in the N1 (80–110 ms and P1 (170–200 ms components in the anterior brain. The emotional valence was discriminated in the later component of N2 (220–250 ms. The interaction between self-reference and emotional valence occurred during the late positive potential (LPP; 400–500 ms. Moreover, there was a positive correlation between response time (RT and N1 in the self-reference condition based on the positive-negative contrast, suggesting a modulatory effect of the self-positivity bias. The results indicate that self-reference emerges earlier than emotion and then combines with emotional processing in an implicit task. The findings extend the view that the self plays a highly
Hinojosa, José A; Albert, Jacobo; Fernández-Folgueiras, Uxía; Santaniello, Gerardo; López-Bachiller, Cristina; Sebastián, Manuel; Sánchez-Carmona, Alberto J; Pozo, Miguel A
Previous research on emotion in language has mainly concerned the impact of emotional information on several aspects of lexico-semantic analyses of single words. However, affective influences on morphosyntactic processing are less understood. In the present study, we focused on the impact of negative valence in the processing of gender agreement relations. Event-related potentials (ERPs) were recorded while participants read three-word phrases and performed a syntactic judgment task. Negative and neutral adjectives could agree or disagree in gender with the preceding noun. At an electrophysiological level, the amplitude of a left anterior negativity (LAN) to gender agreement mismatches decreased in negative words, relative to neutral words. The behavioral data suggested that LAN amplitudes might be indexing the processing costs associated with the detection of gender agreement errors, since the detection of gender mismatches resulted in faster and more accurate responses than did the detection of correct gender agreement relations. According to this view, it seems that negative content facilitated the processes implicated in the early detection of gender agreement mismatches. However, gender agreement violations in negative words triggered processes involved in the reanalysis and repair of the syntactic structure, as reflected in larger P600 amplitudes to incorrect than to correct phrases, irrespective of their emotional valence.
Coch, Donna; Sanders, Lisa D; Neville, Helen J
In a dichotic listening paradigm, event-related potentials (ERPs) were recorded to linguistic and nonlinguistic probe stimuli embedded in 2 different narrative contexts as they were either attended or unattended. In adults, the typical N1 attention effect was observed for both types of probes: Probes superimposed on the attended narrative elicited an enhanced negativity compared to the same probes when unattended. Overall, this sustained attention effect was greater over medial and left lateral sites, but was more posteriorly distributed and of longer duration for linguistic as compared to nonlinguistic probes. In contrast, in 6- to 8-year-old children the ERPs were morphologically dissimilar to those elicited in adults and children displayed a greater positivity to both types of probe stimuli when embedded in the attended as compared to the unattended narrative. Although both adults and children showed attention effects beginning at about 100 msec, only adults displayed left-lateralized attention effects and a distinct, posterior distribution for linguistic probes. These results suggest that the attentional networks indexed by this task continue to develop beyond the age of 8 years.
Full Text Available New paradigms are required in Brain-Computer Interface (BCI systems for the needs and expectations of healthy people. To solve this issue, we explore the emerging field of cooperative BCIs, which involves several users in a single BCI system. Contrary to classical BCIs that are dependent on the unique subject’s will, cooperative BCIs are used for problem solving tasks where several people shall be engaged by sharing a common goal. Similarly as combining trials over time improves performance, combining trials across subjects can significantly improve performance compared with when only a single user is involved. Yet, cooperative BCIs may only be used in particular settings, and new paradigms must be proposed to efficiently use this approach. The possible benefits of using several subjects are addressed, and compared with current single-subject BCI paradigms. To show the advantages of a cooperative BCI, we evaluate the performance of combining decisions across subjects with data from an event-related potentials (ERP based experiment where each subject observed the same sequence of visual stimuli. Furthermore, we show that it is possible to achieve a mean AUC superior to 0.95 with 10 subjects and 3 electrodes on each subject, or with 4 subjects and 6 electrodes on each subject. Several emerging challenges and possible applications are proposed to highlight how cooperative BCIs could be efficiently used with current technologies and leverage BCI applications.
Obermeier, Christian; Kotz, Sonja A; Jessen, Sarah; Raettig, Tim; von Koppenfels, Martin; Menninghaus, Winfried
Rhetorical theory suggests that rhythmic and metrical features of language substantially contribute to persuading, moving, and pleasing an audience. A potential explanation of these effects is offered by "cognitive fluency theory," which stipulates that recurring patterns (e.g., meter) enhance perceptual fluency and can lead to greater aesthetic appreciation. In this article, we explore these two assertions by investigating the effects of meter and rhyme in the reception of poetry by means of event-related brain potentials (ERPs). Participants listened to four versions of lyrical stanzas that varied in terms of meter and rhyme, and rated the stanzas for rhythmicity and aesthetic liking. The behavioral and ERP results were in accord with enhanced liking and rhythmicity ratings for metered and rhyming stanzas. The metered and rhyming stanzas elicited smaller N400/P600 ERP responses than their nonmetered, nonrhyming, or nonmetered and nonrhyming counterparts. In addition, the N400 and P600 effects for the lyrical stanzas correlated with aesthetic liking effects (metered-nonmetered), implying that modulation of the N400 and P600 has a direct bearing on the aesthetic appreciation of lyrical stanzas. We suggest that these effects are indicative of perceptual-fluency-enhanced aesthetic liking, as postulated by cognitive fluency theory.
Kanou, Naoyuki; Sakuma, Kenji; Nakashima, Kenji
Amyotrophic Lateral Sclerosis(ALS) patients are unable to successfully communicate their desires, although their mentality is normal, and so, the necessity of Communication Aids(CA) for ALS patients is realized. Therefore, the authors are focused on Event-Related Potential(ERP) which is elicited primarily for the target by visual and auditory stimuli. P200, N200 and P300 are components of ERP. These are potentials that are elicited when the subject focuses attention on stimuli that appears infrequently. ALS patient participated in two experiments. In the first experiment, a target word out of five words on a computer display was specified. The five words were linked to an each electric appliance, allowing the ALS patient to switch on a target appliance by ERP. In the second experiment, a target word in a 5×5 matrix was specified by measure of ERP. The rows and columns of the matrix were reversed randomly. The word on a crossing point of rows and columns including the target word, was specified as the target word. The rate of correct judgment in the first and second experiments were 100% in N200 and 96% in P200. For practical use of this system, it is very important to determine suitable communication algorithms for each patient by performing these experiments evaluating the results.
Borgström, Kristina; Torkildsen, Janne von Koss; Lindgren, Magnus
What role does attention to different object properties play in early vocabulary development? This longitudinal study using event-related potentials in combination with behavioral measures investigated 20- and 24-month-olds' (n = 38; n = 34; overlapping n = 24) ability to use object shape and object part information in word-object mapping. The N400 component was used to measure semantic priming by images containing shape or detail information. At 20 months, the N400 to words primed by object shape varied in topography and amplitude depending on vocabulary size, and these differences predicted productive vocabulary size at 24 months. At 24 months, when most of the children had vocabularies of several hundred words, the relation between vocabulary size and the N400 effect in a shape context was weaker. Detached object parts did not function as word primes regardless of age or vocabulary size, although the part-objects were identified behaviorally. The behavioral measure, however, also showed relatively poor recognition of the part-objects compared to the shape-objects. These three findings provide new support for the link between shape recognition and early vocabulary development. PMID:25762957
Full Text Available Patients with classic galactosemia, an inborn error of metabolism, have speech and language production impairments. Past research primarily focused on speech (motor problems, but these cannot solely explain the language impairments. Which specific deficits contribute to the impairments in language production is not yet known. Deficits in semantic and syntactic planning are plausible and require further investigation. In the present study, we examined syntactic encoding while patients and matched controls overtly described scenes of moving objects using either separate words (minimal syntactic planning or sentences (sentence-level syntactic planning. The design of the paradigm also allowed tapping into local noun phrase- and more global sentence-level syntactic planning. Simultaneously, we recorded event-related potentials (ERPs. The patients needed more time to prepare and finish the utterances and made more errors. The patient ERPs had a very similar morphology to that of healthy controls, indicating overall comparable neural processing. Most importantly, the ERPs diverged from those of controls in several functionally informative time windows, ranging from very early (90-150 ms post scene onset to relatively late (1820-2020 ms post scene onset. These time windows can be associated with different linguistic encoding stages. The ERP results form the first neuroscientific evidence for language production impairments in patients with galactosemia in lexical and syntactic planning stages, i.e., prior to the linguistic output phase. These findings hence shed new light on the language impairments in this disease.
Timmers, Inge; Jansma, Bernadette M; Rubio-Gozalbo, M Estela
Patients with classic galactosemia, an inborn error of metabolism, have speech and language production impairments. Past research primarily focused on speech (motor) problems, but these cannot solely explain the language impairments. Which specific deficits contribute to the impairments in language production is not yet known. Deficits in semantic and syntactic planning are plausible and require further investigation. In the present study, we examined syntactic encoding while patients and matched controls overtly described scenes of moving objects using either separate words (minimal syntactic planning) or sentences (sentence-level syntactic planning). The design of the paradigm also allowed tapping into local noun phrase- and more global sentence-level syntactic planning. Simultaneously, we recorded event-related potentials (ERPs). The patients needed more time to prepare and finish the utterances and made more errors. The patient ERPs had a very similar morphology to that of healthy controls, indicating overall comparable neural processing. Most importantly, the ERPs diverged from those of controls in several functionally informative time windows, ranging from very early (90-150 ms post scene onset) to relatively late (1820-2020 ms post scene onset). These time windows can be associated with different linguistic encoding stages. The ERP results form the first neuroscientific evidence for language production impairments in patients with galactosemia in lexical and syntactic planning stages, i.e., prior to the linguistic output phase. These findings hence shed new light on the language impairments in this disease.
Full Text Available Joint time-frequency representations offer a rich representation of event related potentials (ERPs that cannot be obtained through individual time or frequency domain analysis. This representation, however, comes at the expense of increased data volume and the difficulty of interpreting the resulting representations. Therefore, methods that can reduce the large amount of time-frequency data to experimentally relevant components are essential. In this paper, we present a method that reduces the large volume of ERP time-frequency data into a few significant time-frequency parameters. The proposed method is based on applying the widely used matching pursuit (MP approach, with a Gabor dictionary, to principal components extracted from the time-frequency domain. The proposed PCA-Gabor decomposition is compared with other time-frequency data reduction methods such as the time-frequency PCA approach alone and standard matching pursuit methods using a Gabor dictionary for both simulated and biological data. The results show that the proposed PCA-Gabor approach performs better than either the PCA alone or the standard MP data reduction methods, by using the smallest amount of ERP data variance to produce the strongest statistical separation between experimental conditions.
Dowens, Margaret Gillon; Guo, Taomei; Guo, Jingjing; Barber, Horacio; Carreiras, Manuel
Traditionally, age of acquisition (AoA) has been considered the single most important factor in second language (L2) acquisition and processing, particularly in the area of syntax processing. However, there is now growing evidence of the importance of other factors, such as the level of proficiency attained and the degree of overlap or similarity between the first language (L1) and L2 structures and possibility of transfer of features and/or processing routines. However, the relative importance of these factors and the nature of L1-L2 transfer are still unclear. To shed light on these issues, we recorded the electrical brain activity of a group of Chinese proficient late learners of Spanish, using the Event Related Potentials technique, while they read Spanish sentences containing violations of number and grammatical gender agreement (adjective-noun agreement and article-noun agreement). Unlike Spanish, Mandarin Chinese is an isolating language in which morphosyntactic features such as gender and number are not computed and so the ERP results from this group can help to clarify the role of L1-L2 transfer in morpho-syntax processing routines. The results included P600 effects for both gender and number agreement violations, with no differences between these disagreement conditions. These results are taken to support second language acquisition models which stress the roles of proficiency and L1-L2 transfer in L2 syntax processing. Copyright © 2011 Elsevier Ltd. All rights reserved.
Singh, Nilkamal; Telles, Shirley
Evoked potentials (EPs) are a relatively noninvasive method to assess the integrity of sensory pathways. As the neural generators for most of the components are relatively well worked out, EPs have been used to understand the changes occurring during meditation. Event-related potentials (ERPs) yield useful information about the response to tasks, usually assessing attention. A brief review of the literature yielded eleven studies on EPs and seventeen on ERPs from 1978 to 2014. The EP studies covered short, mid, and long latency EPs, using both auditory and visual modalities. ERP studies reported the effects of meditation on tasks such as the auditory oddball paradigm, the attentional blink task, mismatched negativity, and affective picture viewing among others. Both EP and ERPs were recorded in several meditations detailed in the review. Maximum changes occurred in mid latency (auditory) EPs suggesting that maximum changes occur in the corresponding neural generators in the thalamus, thalamic radiations, and primary auditory cortical areas. ERP studies showed meditation can increase attention and enhance efficiency of brain resource allocation with greater emotional control. PMID:26137479
Carreiras, Manuel; Vergara, Marta; Barber, Horacio
A number of behavioral studies have suggested that syllables might play an important role in visual word recognition in some languages. We report two event-related potential (ERP) experiments using a new paradigm showing that syllabic units modulate early ERP components. In Experiment 1, words and pseudowords were presented visually and colored so that there was a match or a mismatch between the syllable boundaries and the color boundaries. The results showed color-syllable congruency effects in the time window of the P200. Lexicality modulated the N400 amplitude, but no effects of this variable were obtained at the P200 window. In Experiment 2, high- and low-frequency words and pseudowords were presented in the congruent and incongruent conditions. The results again showed congruency effects at the P200 for low-frequency words and pseudowords, but not for high-frequency words. Lexicality and lexical frequency effects showed up at the N400 component. The results suggest a dissociation between syllabic and lexical effects with important consequences for models of visual word recognition.
Full Text Available Recent findings indicated that both P300 and alpha event-related desynchronization (α-ERD were associated, and similarly involved in cognitive brain functioning, e.g., attention allocation and memory updating. However, an explicit causal influence between the neural generators of P300 and α-ERD has not yet been investigated. In the present study, using an oddball task paradigm, we assessed the task effect (target vs. non-target on P300 and α-ERD elicited by stimuli of four sensory modalities, i.e., audition, vision, somatosensory, and pain, estimated their respective neural generators, and investigated the information flow among their neural generators using time-varying effective connectivity in the target condition. Across sensory modalities, the scalp topographies of P300 and α-ERD were similar and respectively maximal at parietal and occipital regions in the target condition. Source analysis revealed that P300 and α-ERD were mainly generated from posterior cingulate cortex and occipital lobe respectively. As revealed by time-varying effective connectivity, the cortical information was consistently flowed from α-ERD sources to P300 sources in the target condition for all four sensory modalities. All these findings showed that P300 in the target condition is modulated by the changes of α-ERD, which would be useful to explore neural mechanism of cognitive information processing in the human brain.
Stevenson, Ryan A; Bushmakin, Maxim; Kim, Sunah; Wallace, Mark T; Puce, Aina; James, Thomas W
In recent years, it has become evident that neural responses previously considered to be unisensory can be modulated by sensory input from other modalities. In this regard, visual neural activity elicited to viewing a face is strongly influenced by concurrent incoming auditory information, particularly speech. Here, we applied an additive-factors paradigm aimed at quantifying the impact that auditory speech has on visual event-related potentials (ERPs) elicited to visual speech. These multisensory interactions were measured across parametrically varied stimulus salience, quantified in terms of signal to noise, to provide novel insights into the neural mechanisms of audiovisual speech perception. First, we measured a monotonic increase of the amplitude of the visual P1-N1-P2 ERP complex during a spoken-word recognition task with increases in stimulus salience. ERP component amplitudes varied directly with stimulus salience for visual, audiovisual, and summed unisensory recordings. Second, we measured changes in multisensory gain across salience levels. During audiovisual speech, the P1 and P1-N1 components exhibited less multisensory gain relative to the summed unisensory components with reduced salience, while N1-P2 amplitude exhibited greater multisensory gain as salience was reduced, consistent with the principle of inverse effectiveness. The amplitude interactions were correlated with behavioral measures of multisensory gain across salience levels as measured by response times, suggesting that change in multisensory gain associated with unisensory salience modulations reflects an increased efficiency of visual speech processing.
Full Text Available An interaction between orofacial somatosensation and the perception of speech was demonstrated in recent psychophysical studies (Ito et al. 2009; Ito and Ostry 2009. To explore further the neural mechanisms of the speech-related somatosensory-auditory interaction, we assessed to what extent multisensory evoked potentials reflect multisensory interaction during speech perception. We also examined the dynamic modulation of multisensory integration resulting from relative timing differences between the onsets of the two sensory stimuli. We recorded event-related potentials from 64 scalp sites in response to somatosensory stimulation alone, auditory stimulation alone, and combined somatosensory and auditory stimulation. In the multisensory condition, the timing of the two stimuli was either simultaneous or offset by 90 ms (lead and lag. We found evidence of multisensory interaction with the amplitude of the multisensory evoked potential reliably different than the sum of the two unisensory potentials around the first peak of multisensory response (100–200 ms. The magnitude of the evoked potential difference varied as a function of the relative timing between the stimuli in the interval from 170 to 200 ms following somatosensory stimulation. The results demonstrate clear multisensory convergence and suggest a dynamic modulation of multisensory interaction during speech.
Leynes, P Andrew; Mok, Brittany A
The influence of encoding focus on source memory was investigated using event-related potentials (ERPs). Encoding was focused on the self (self-focus) or on the speaker (other-focus) while hearing words spoken in a male or female voice. Examination of the behavioral and ERP evidence suggests that encoding focus alters the amount of diagnostic recollection. Self-focus encoding produced more positive encoding ERPs, led to greater old/new recognition, and elicited a greater Late Positive Component (LPC; the putative neural correlate of recollection) during the source test. Other-focus encoding led to greater source memory and a smaller LPC amplitude. Collectively, the results suggest that encoding focus alters the information bound in the memory trace that leads to varying levels of source-diagnostic features. Drawing attention to the speaker facilitates binding of source-diagnostic features (i.e., voice), whereas self-focus encoding facilitates binding a host of non-diagnostic features. The results have important implications for situations that depend on encoding processes, such as false memory or classroom learning, and they provide evidence that the LPC tracks recollected details but not necessarily diagnostic recollection. Copyright © 2017 Elsevier Inc. All rights reserved.
Yang, Xiaohong; Chen, Xuhai; Chen, Shuang; Xu, Xiaoying; Yang, Yufang
This study investigated whether semantic integration in discourse context could be influenced by topic structure using event-related brain potentials. Participants read discourses in which the last sentence contained a critical word that was either congruent or incongruent with the topic established in the first sentence. The intervening sentences between the first and the last sentence of the discourse either maintained or shifted the original topic. Results showed that incongruent words in topic-maintained discourses elicited an N400 effect that was broadly distributed over the scalp while those in topic-shifted discourses elicited an N400 effect that was lateralized to the right hemisphere and localized over central and posterior areas. Moreover, a late positivity effect was only elicited by incongruent words in topic-shifted discourses, but not in topic-maintained discourses. This suggests an important role for discourse structure in semantic integration, such that compared with topic-maintained discourses, the complexity of discourse structure in topic-shifted condition reduces the initial stage of semantic integration and enhances the later stage in which a mental representation is updated.
Hannah, Samuel D; Shedden, Judith M; Brooks, Lee R; Grundy, John G
In this paper, we use behavioural methods and event-related potentials (ERPs) to explore the relations between informational and instantiated features, as well as the relation between feature abstraction and rule type. Participants are trained to categorize two species of fictitious animals and then identify perceptually novel exemplars. Critically, two groups are given a perfectly predictive counting rule that, according to Hannah and Brooks (2009. Featuring familiarity: How a familiar feature instantiation influences categorization. Canadian Journal of Experimental Psychology/Revue Canadienne de Psychologie Expérimentale, 63, 263-275. Retrieved from http://doi.org/10.1037/a0017919), should orient them to using abstract informational features when categorizing the novel transfer items. A third group is taught a feature list rule, which should orient them to using detailed instantiated features. One counting-rule group were taught their rule before any exposure to the actual stimuli, and the other immediately after training, having learned the instantiations first. The feature-list group were also taught their rule after training. The ERP results suggest that at test, the two counting-rule groups processed items differently, despite their identical rule. This not only supports the distinction that informational and instantiated features are qualitatively different feature representations, but also implies that rules can readily operate over concrete inputs, in contradiction to traditional approaches that assume that rules necessarily act on abstract inputs.
Ventouras, E; Moatsos, M; Papageorgiou, C; Rabavilas, A; Uzunoglu, N
The analysis of the P600 component of Event-related Potentials (ERPs) has attracted attention due to its relation to covert cognitive mechanisms, in connection to memory processes. The component may often be low-amplitude, compared to other components such as the P300. Independent component analysis (ICA) techniques have been successfully applied in ERP processing, in the framework of blind source separation (BSS) for unmixing recorded potentials into a sum of temporally independent and spatially fixed components. In the present work ICA was used for reconstructing averaged ERPs in the time window of the P600 component, selecting a subset of independent components' projections to the original electrode recording positions. The selection is based on two empirical criteria, selecting the projection that reconstructs a P600 nearest temporally to the original P600, or selecting the projection combination - up to a preselected maximum number of combined projections providing maximum reconstructed P600 amplitude. The techniques are tested on ERPs recorded from healthy subjects and psychiatric patients, notably improving the differentiation of the two groups, based on either the amplitude or the latency of the reconstructed P600 component, in comparison to results achieved using the original ERPs.
Zurrón, Montserrat; Pouso, María; Lindín, Mónica; Galdo, Santiago; Díaz, Fernando
Event-Related Potentials (ERPs) elicited by congruent and incongruent colour-word stimuli of a Stroop paradigm, in a task in which participants were required to judge the congruence/incongruence of the two dimensions of the stimuli, were recorded in order to study the timing of the semantic conflict. The reaction time to colour-word incongruent stimuli was significantly longer than the reaction time to congruent stimuli (the Stroop effect). A temporal Principal Components Analysis was applied to the data to identify the ERP components. Three positive components were identified in the 300-600 ms interval in response to the congruent and incongruent stimuli: First P3, P3b and PSW. The factor scores corresponding to the First P3 and P3b components were significantly smaller for the incongruent stimuli than for the congruent stimuli. No differences between stimuli were observed in the factor scores corresponding to the PSW or in the ERP latencies. We conclude that the temporal locus of the semantic conflict, which intervenes in generating the Stroop effect, may occur within the time interval in which the First P3 and P3b components are identified, i.e. at approximately 300-450 ms post-stimulus. We suggest that the semantic conflict delays the start of the response selection process, which explains the longer reaction time to incongruent stimuli.
Werheid, Katja; Schacht, Annekathrin; Sommer, Werner
Facial attractiveness is of high importance for human interaction and communication, and everyday experience suggests that the mere aspect of a face elicits spontaneous appraisal of attractiveness. However, little is known about the time course of brain responses related to this process. In the present study, event-related brain potentials were recorded during attractiveness classification of facial portraits that were standardized with respect to facial expression. The faces were either preceded by another face of high or low attractiveness or by an affectively neutral object. Attractive as opposed to non-attractive target faces elicited an early posterior negativity (EPN; approximately 250 ms) and a late parietal positivity (LPC; 400-600 ms), which were not modulated by affectively congruent prime faces. Elevated LPC activity had previously been shown in response to attractive versus non-attractive faces, possibly reflecting task-related evaluative processes. An enhanced EPN had been reported for faces with emotional compared to neutral emotional expression, and related to facilitated selection of emotional information. Extending these findings, our study is the first to report an attractiveness-related ERP modulation prior to the LPC, suggesting that appraising facial attractiveness starts already at processing stages associated with stimulus selection.
Gosselin, Nadia; Saluja, Rajeet Singh; Chen, Jen-Kai; Bottari, Carolina; Johnston, Karen; Ptito, Alain
The high incidence of concussions in contact sports and their impact on brain functions are a major cause for concern. To improve our understanding of brain functioning after sports-related concussion, advanced functional assessment techniques, namely event-related potentials (ERPs) and functional magnetic resonance imaging (fMRI), have been recently used in research studies. Contrary to neuropsychological tests that measure verbal and/or motor responses, ERPs and fMRI assess the neural activities associated with cognitive/behavioral demands, and thus provide access to better comprehension of brain functioning. In fact, ERPs have excellent temporal resolution, and fMRI identifies the involved structures during a task. This article describes ERP and fMRI techniques and reviews the results obtained with these tools in sports-related concussion. Although these techniques are not yet readily available, they offer a unique clinical approach, particularly for complex cases (ie, athletes with multiple concussions, chronic symptoms) and objective measures that provide valuable information to guide management and return-to-play decision making.
Lih Lee, Wee; Tan, Tele; Falkmer, Torbjörn; Leung, Yee Hong
Objective. In recent years, ICA has been one of the more popular methods for extracting event-related potential (ERP) at the single-trial level. It is a blind source separation technique that allows the extraction of an ERP without making strong assumptions on the temporal and spatial characteristics of an ERP. However, the problem with traditional ICA is that the extraction is not direct and is time-consuming due to the need for source selection processing. In this paper, the application of an one-unit ICA-with-Reference (ICA-R), a constrained ICA method, is proposed. Approach. In cases where the time-region of the desired ERP is known a priori, this time information is utilized to generate a reference signal, which is then used for guiding the one-unit ICA-R to extract the source signal of the desired ERP directly. Main results. Our results showed that, as compared to traditional ICA, ICA-R is a more effective method for analysing ERP because it avoids manual source selection and it requires less computation thus resulting in faster ERP extraction. Significance. In addition to that, since the method is automated, it reduces the risks of any subjective bias in the ERP analysis. It is also a potential tool for extracting the ERP in online application.
Fosi, Tangunu; Werner, Klaus; Boyd, Stewart G; De Haan, Michelle; Scott, Rod C; Neville, Brian G
To investigate acoustic auditory processing in patients with recent infantile spasms (IS). Patients (n = 22; 12 female; median age 8 months; range 5-11 months) had normal preceding development, brain magnetic resonance imaging (MRI), and neurometabolic testing (West syndrome of unknown cause, uWS). Controls were healthy babies (n = 22; 11 female; median age 6 months; range 3-12 months). Event-related potentials (ERPs) and psychometry (Bayley Scales of Infant Development, Second Edition, BSID-II) took place at a month following IS remission. Following a repeated pure tone, uWS patients showed less suppression of the N100 at the mid-temporal electrodes (p = 0.006), and a prolonged response latency (p = 0.019). Their novelty P300 amplitude over the mid-temporal electrodes was halved (p = 0.001). The peak of the novelty P300 to environmental broadband sounds emerged later over the left temporal lobe in patients (p = 0.015), the lag correlating with duration of spasms (r = 0.547, p = 0.015). BSID-II scores were lower in patients (p < 0.001), with no correlation to ERP. Complex acoustic information is processed poorly following IS. This would impair language. Treatment did not reverse this phenomenon, but may have limited its severity. The data are most consistent with altered connectivity of the cortical acoustic processing areas induced by IS. Wiley Periodicals, Inc. © 2017 International League Against Epilepsy.
Jin, Jia; Yu, Liping; Ma, Qingguo
Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW) task and a boring watch-stop task (WS) to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model.
Suárez-Pellicioni, M; Núñez-Peña, M I; Colomé, A
This study uses event-related brain potentials to investigate the difficulties that high math anxious individuals face when processing dramatically incorrect solutions to simple arithmetical problems. To this end, thirteen high math-anxious (HMA) and thirteen low math-anxious (LMA) individuals were presented with simple addition problems in a verification task. The proposed solution could be correct, incorrect but very close to the correct one (small-split), or dramatically incorrect (large-split). The two groups did not differ in mathematical ability or trait anxiety. We reproduced previous results for flawed scores suggesting HMA difficulties in processing large-split solutions. Moreover, large-split solutions elicited a late positive component (P600/P3b) which was more enhanced and delayed in the HMA group. Our study proposes that the pattern of flawed scores found by previous studies (and that we replicate) has to do with HMA individuals'difficulties in inhibiting an extended processing of irrelevant information (large-split solutions). Copyright © 2013 Elsevier B.V. All rights reserved.
Zulay Rosario Lugo
Full Text Available Event-related potentials (ERP have been proposed to improve the differential diagnosis of non-responsive patients. We investigated the potential of the P300 as a reliable marker of conscious processing in patients with locked-in syndrome (LIS. Eleven chronic LIS patients and ten healthy subjects (HS listened to a complex-tone auditory oddball paradigm, first in a passive condition (listen to the sounds and then in an active condition (counting the deviant tones. Seven out of nine HS displayed a P300 waveform in the passive condition and all in the active condition. HS showed statistically significant changes in peak and area amplitude between conditions. Three out of seven LIS patients showed the P3 waveform in the passive condition and 5 of 7 in the active condition. No changes in peak amplitude and only a significant difference at one electrode in area amplitude were observed in this group between conditions. We conclude that, in spite of keeping full consciousness and intact or nearly intact cortical functions, compared to HS, LIS patients present less reliable results when testing with ERP, specifically in the passive condition. We thus strongly recommend applying ERP paradigms in an active condition when evaluating consciousness in non-responsive patients.
Full Text Available Functional neuroimaging of covert perceptual and cognitive processes can inform the diagnoses and prognoses of patients with disorders of consciousness, such as the vegetative and minimally conscious states (VS;MCS. Here we report an event-related potential (ERP paradigm for detecting a hierarchy of auditory processes in a group of healthy individuals and patients with disorders of consciousness. Simple cortical responses to sounds were observed in all 16 patients; 7/16 (44% patients exhibited markers of the differential processing of speech and noise; and 1 patient produced evidence of the semantic processing of speech (i.e. the N400 effect. In several patients, the level of auditory processing that was evident from ERPs was higher than the abilities that were evident from behavioural assessment, indicating a greater sensitivity of ERPs in some cases. However, there were no differences in auditory processing between VS and MCS patient groups, indicating a lack of diagnostic specificity for this paradigm. Reliably detecting semantic processing by means of the N400 effect in passively listening single-subjects is a challenge. Multiple assessment methods are needed in order to fully characterise the abilities of patients with disorders of consciousness.
Tang, Alva; Santesso, Diane L; Segalowitz, Sidney J; Schmidt, Louis A
Shyness and sociability are independent personality dimensions, each with distinct behavioral and psychophysiological correlates that are conserved across development, culture, and phylogeny. However, relatively little is known regarding how shyness and sociability are instantiated in the brain, particularly during childhood and during the processing of nonsocial stimuli. Using a three-stimulus auditory oddball task, we examined whether variations in shyness and sociability were related to the N200 and P300 event-related potential (ERP) brain responses to processing task-relevant, novel, and standard auditory tones in 53 typically developing 10-year-old children. ERP amplitudes were measured at four midline scalp sites: Fz, FCz, Cz, and Pz. We found that increases in shyness were correlated with increases in target P300 amplitudes across all four head sites, increases in standard P300 amplitudes, and decreases in target P300 latencies in anterior sites. No relations were found for sociability and P300 responses. We also found that P300 amplitude in the frontal region to standard tones mediated the relation between conflicted shyness (i.e., high shyness and high sociability) and emotional instability. These results suggest that shyness and sociability are distinguishable on neurocognitive measures and that these neurocognitive measures may be putative mechanisms in understanding risk for emotional instability and a broad range of dysregulated behavioral problems observed in individuals characterized by conflicted shyness. Copyright © 2015 Elsevier Inc. All rights reserved.
Tang, Alva; Santesso, Diane L; Segalowitz, Sidney J; Schulkin, Jay; Schmidt, Louis A
Shyness and sociability are orthogonal personality dimensions, but little is known about how the two traits are instantiated in the brain and body. Using a 3-stimulus auditory oddball task, we examined whether shyness and sociability were distinguishable on P300 event-related potentials (ERPs) in processing task-relevant, novel, and standard auditory tones in 48 young adults. ERP amplitudes were measured at four midline scalp sites (Fz, FCz, Cz, Pz). We found that shyness, but not sociability, was related to reduced frontal novelty P300 amplitudes and to high emotionality. We also found that low baseline salivary cortisol levels mediated the relation between: (a) high shyness and reduced frontal P300 amplitudes to novel tones, and (b) high shyness and high scores of emotionality. We speculate that low baseline cortisol may serve as a putative mechanism influencing central attentional states of avoidance to threat and novelty and emotional arousal in adults who are shy. Copyright © 2016 Elsevier B.V. All rights reserved.
Wang, Jing; Han, Weiwei
Consumer neuroscience can provide useful insights into the neural foundations of consumer decisions, such as perceived quality. One of the applications is to guide attribute configuration of products to fit consumers' expectations on the basis of individual preferences. In this study, we required 20 participants to decide whether to buy the product provided in the stimuli and to respond as soon as possible. According to their reports of expectations after the experiment, we subdivided the stimuli into two conditions. Condition 1 contained the stimuli that fit individual preferences, whereas Condition 2 contained the other stimuli. An essential component of event-related potentials (ERPs), the P300, was elicited in the two conditions and distributed over almost all parietal and occipital regions. Products in Condition 1 induced a higher P300 amplitude than those in Condition 2. The results show that evaluating product attributes is a cognitive process that modulates attention in the aforementioned regions. When participants evaluate the alternatives, categorical processing occurred on the basis of similarity judgment. The situation in Condition 1 produced a similarity overlap between the product and the expectation and resulted in a higher P300. Otherwise, there was no overlap, leading to a smaller P300. Hence, the P300 may be a useful neural endogenous indicator for measuring consumers' evaluations of products in marketing research.
Leynes, P Andrew; Crawford, Jarret T; Radebaugh, Anne M; Taranto, Elizabeth
Source memory for the speaker's voice (male or female) was investigated when semantic knowledge (gender stereotypes) could and could not inform the episodic source judgment while event-related potentials (ERPs) were recorded. Source accuracy was greater and response times were faster when stereotypes could predict the speaker's voice at test. Recollection supported source judgments in both conditions as indicated by significant parietal "old/new" ERP effects (500-800ms). Prototypical late ERP effects (the right frontal "old/new" effect and the late posterior negativity, LPN) were evident when source judgment was based solely on episodic memory. However, these two late ERP effects were diminished and a novel, frontal-negative ERP with left-central topography was observed when stereotypes aided source judgments. This pattern of ERP activity likely reflects activation of left frontal or left temporal lobes when semantic knowledge, in the form of a gender stereotype, is accessed to inform the episodic source judgment. Copyright © 2012 Elsevier B.V. All rights reserved.
Tagai, Keiko; Shimakura, Hitomi; Isobe, Hiroko; Nittono, Hiroshi
The effects of makeup on attractiveness have been evaluated using mainly subjective measures. In this study, event-related brain potentials (ERPs) were recorded from a total of 45 Japanese women (n = 23 and n = 22 for Experiment 1 and 2, respectively) to examine the neural processing of faces with no makeup, light makeup, and heavy makeup. To have the participants look at each face carefully, an identity judgement task was used: they were asked to judge whether the two faces presented in succession were of the same person or not. The ERP waveforms in response to the first faces were analyzed. In two experiments with different stimulus probabilities, the amplitudes of N170 and vertex positive potential (VPP) were smaller for faces with light makeup than for faces with heavy makeup or no makeup. The P1 amplitude did not differ between facial types. In a subsequent rating phase, faces with light makeup were rated as more attractive than faces with heavy makeup and no makeup. The results suggest that the processing fluency of faces with light makeup is one of the reasons why light makeup is preferred to heavy makeup and no makeup in daily life.
Farwell, L A; Martinerie, J M; Bashore, T R; Rapp, P E; Goddard, P H
A fundamentally important problem for cognitive psychophysiologists is selection of the appropriate off-line digital filter to extract signal from noise in the event-related brain potential (ERP) recorded at the scalp. Investigators in the field typically use a type of finite impulse response (FIR) filter known as moving average or boxcar filter to achieve this end. However, this type of filter can produce significant amplitude diminution and distortion of the shape of the ERP waveform. Thus, there is a need to identify more appropriate filters. In this paper, we compare the performance of another type of FIR filter that, unlike the boxcar filter, is designed with an optimizing algorithm that reduces signal distortion and maximizes signal extraction (referred to here as an optimal FIR filter). We applied several different filters of both types to ERP data containing the P300 component. This comparison revealed that boxcar filters reduced the contribution of high-frequency noise to the ERP but in so doing produced a substantial attenuation of P300 amplitude and, in some cases, substantial distortions of the shape of the waveform, resulting in significant errors in latency estimation. In contrast, the optimal FIR filters preserved P300 amplitude, morphology, and latency and also eliminated high-frequency noise more effectively than did the boxcar filters. The implications of these results for data acquisition and analysis are discussed.
Marmolejo-Ramos, Fernando; Hellemans, Kim; Comeau, Amy; Heenan, Adam; Faulkner, Andrew; Abizaid, Alfonso; D'Angiulli, Amedeo
Although food and affective pictures share similar emotional and motivational characteristics, the relationship between the neuronal responses to these stimuli is unclear. Particularly, it is not known whether perceiving and imagining food and affective stimuli elicit similar event-related potential (ERP) patterns. In this study, two ERP correlates, the early posterior negativity (EPN) and the late positive potential (LPP) for perceived and imagined emotional and food photographs were investigated. Thirteen healthy volunteers were exposed to a set of food photos, as well as unpleasant, pleasant, and neutral photos from the International Affective Picture System. In each trial, participants were first asked to view a photo (perception condition), and then to create a visual mental image of it and to rate its vividness (imagery condition). The results showed that during perception, brain regions corresponding to sensorimotor and parietal motivational (defensive and appetitive) systems were activated to different extents, producing a graded pattern of EPN and LPP responses specific to the photo content - more prominent for unpleasant than pleasant and food content. Also, an EPN signature occurred in both conditions for unpleasant content, suggesting that, compared to food or pleasant content, unpleasant content may be attended to more intensely during perception and may be represented more distinctly during imagery. Finally, compared to LLP activation during perception, as well as imagery and perception of all other content, LPP activation was significantly reduced during imagery of unpleasant photos, suggesting inhibition of unwanted memories. Results are framed within a neurocognitive working model of embodied emotions.
Timmers, Inge; Gentile, Francesco; Rubio-Gozalbo, M Estela; Jansma, Bernadette M
During sentence production, linguistic information (semantics, syntax, phonology) of words is retrieved and assembled into a meaningful utterance. There is still debate on how we assemble single words into more complex syntactic structures such as noun phrases or sentences. In the present study, event-related potentials (ERPs) were used to investigate the time course of syntactic planning. Thirty-three volunteers described visually animated scenes using naming formats varying in syntactic complexity: from simple words ('W', e.g., "triangle", "red", "square", "green", "to fly towards"), to noun phrases ('NP', e.g., "the red triangle", "the green square", "to fly towards"), to a sentence ('S', e.g., "The red triangle flies towards the green square."). Behaviourally, we observed an increase in errors and corrections with increasing syntactic complexity, indicating a successful experimental manipulation. In the ERPs following scene onset, syntactic complexity variations were found in a P300-like component ('S'/'NP'>'W') and a fronto-central negativity (linear increase with syntactic complexity). In addition, the scene could display two actions - unpredictable for the participant, as the disambiguation occurred only later in the animation. Time-locked to the moment of visual disambiguation of the action and thus the verb, we observed another P300 component ('S'>'NP'/'W'). The data show for the first time evidence of sensitivity to syntactic planning within the P300 time window, time-locked to visual events critical of syntactic planning. We discuss the findings in the light of current syntactic planning views.
Liu, T; Liu, X; Xiao, T; Shi, J
The relationship between recognition memory and cognitive control is an important research topic. The current study investigated how conflict control influences an individual's emotional memory. During the encoding phase, participants were required to judge the affective valence of a Chinese Chengyu word (either positive or negative) in a modified Simon paradigm and to remember the word. Half of the words were presented in the congruent condition and the other half were displayed in the incongruent condition. During the retrieval phase, participants were instructed to make an 'old/new judgment' and decide whether the word had been presented previously. Electrophysiological responses were recorded using the event-related potential (ERP) technique. The behavioral results of retrieval processes showed that participants remembered more positive than negative words when they were encoded in the congruent condition. The electrophysiological results revealed that the retrieval of words encoded in the incongruent condition elicited less negative frontal negativity (FN) and early posterior negativity (EPN) amplitudes than those encoded in the congruent condition. The retrieval of words encoded in the incongruent condition induced greater late positive complex (LPC) amplitudes, relative to those encoded in the congruent condition on the left hemisphere. It was also observed that the recognition of positive words induced faster LPC responses than negative words when they were encoded in the incongruent condition. The present electrophysiological study illustrates that emotional memory processes may be affected by conflict control. Copyright © 2015 IBRO. Published by Elsevier Ltd. All rights reserved.
Maurice J C M Magnée
Full Text Available Successful integration of various simultaneously perceived perceptual signals is crucial for social behavior. Recent findings indicate that this multisensory integration (MSI can be modulated by attention. Theories of Autism Spectrum Disorders (ASDs suggest that MSI is affected in this population while it remains unclear to what extent this is related to impairments in attentional capacity. In the present study Event-related potentials (ERPs following emotionally congruent and incongruent face-voice pairs were measured in 23 high-functioning, adult ASD individuals and 24 age- and IQ-matched controls. MSI was studied while the attention of the participants was manipulated. ERPs were measured at typical auditory and visual processing peaks, namely, P2 and N170. While controls showed MSI during divided attention and easy selective attention tasks, individuals with ASD showed MSI during easy selective attention tasks only. It was concluded that individuals with ASD are able to process multisensory emotional stimuli, but this is differently modulated by attention mechanisms in these participants, especially those associated with divided attention. This atypical interaction between attention and MSI is also relevant to treatment strategies, with training of multisensory attentional control possibly being more beneficial than conventional sensory integration therapy.
Alain, Claude; Tremblay, Kelly
The perception of complex acoustic signals such as speech and music depends on the interaction between peripheral and central auditory processing. As information travels from the cochlea to primary and associative auditory cortices, the incoming sound is subjected to increasingly more detailed and refined analysis. These various levels of analyses are thought to include low-level automatic processes that detect, discriminate and group sounds that are similar in physical attributes such as frequency, intensity, and location as well as higher-level schema-driven processes that reflect listeners' experience and knowledge of the auditory environment. In this review, we describe studies that have used event-related brain potentials in investigating the processing of complex acoustic signals (e.g., speech, music). In particular, we examine the role of hearing loss on the neural representation of sound and how cognitive factors and learning can help compensate for perceptual difficulties. The notion of auditory scene analysis is used as a conceptual framework for interpreting and studying the perception of sound.
Alonso-Prieto, Esther; Oruç, Ipek; Rubino, Cristina; Zhu, Maria; Handy, Todd; Barton, Jason J S
Face perception models propose that different facial attributes are processed by anatomically distinct neural pathways that partially overlap. Whether these attributes interact functionally is an open question. Our goal was to determine if there are interactions between age and ethnicity processing and, if so, at what temporal epoch these interactions are evident. We monitored event-related potentials on electroencephalography while subjects categorized faces by age or ethnicity in two conditions: a baseline in which the other of these two properties not being categorized was held constant and an interference condition in which it also varied, as modelled after the Garner interference paradigm. We found that, when participants were categorizing faces by age, variations in ethnicity increased the amplitude of the right face-selective N170 component. When subjects were categorizing faces by ethnicity, variations in age did not alter the N170. We concluded that there is an asymmetric pattern of influence between age and ethnicity on early face-specific stages of visual processing, which has parallels with behavioural evidence of asymmetric interactions between identity and expression processing of faces.
Liu, Yanling; Teng, Zhaojun; Lan, Haiying; Zhang, Xin; Yao, Dezhong
Previous research has shown that exposure to violent video games increases aggression, whereas exposure to prosocial video games can reduce aggressive behavior. However, little is known about the neural correlates of these behavioral effects. This work is the first to investigate the electrophysiological features of the relationship between playing a prosocial video game and inhibition of aggressive behavior. Forty-nine subjects played either a prosocial or a neutral video game for 20 min, then participated in an event-related potential (ERP) experiment based on an oddball paradigm and designed to test electrophysiological responses to prosocial and violent words. Finally, subjects completed a competitive reaction time task (CRTT) which based on Taylor's Aggression Paradigm and contains reaction time and noise intensity chosen as a measure of aggressive behavior. The results show that the prosocial video game group (compared to the neutral video game group) displayed smaller P300 amplitudes, were more accurate in distinguishing violent words, and were less aggressive as evaluated by the CRTT of noise intensity chosen. A mediation analysis shows that the P300 amplitude evoked by violent words partially mediates the relationship between type of video game and subsequent aggressive behavior. The results support theories based on the General Learning Model. We provide converging behavioral and neural evidence that exposure to prosocial media may reduce aggression. PMID:26257620
Anthony J Angwin
Full Text Available Event-related potentials (ERPs were recorded to investigate lexical ambiguity resolution during sentence processing in 16 people with Parkinson's disease (PD and 16 healthy controls. Sentences were presented word-by-word on computer screen, and participants were required to decide if a subsequent target word was related to the meaning of the sentence. The task consisted of related, unrelated and ambiguous trials. For the ambiguous trials, the sentence ended with an ambiguous word and the target was related to one of the meanings of that word, but not the one captured by the sentence context (e.g., 'He dug with the spade', Target 'ACE'. Both groups demonstrated slower reaction times and lower accuracy for the ambiguous condition relative to the unrelated condition, however accuracy was impacted by the ambiguous condition to a larger extent in the PD group. These results suggested that PD patients experience increased difficulties with contextual ambiguity resolution. The ERP results did not reflect increased ambiguity resolution difficulties in PD, as a similar N400 effect was evident for the unrelated and ambiguous condition in both groups. However, the magnitude of the N400 for these conditions was correlated with a measure of inhibition in the PD group, but not the control group. The ERP results suggest that semantic processing may be more compromised in PD patients with increased response inhibition deficits.
Gibb, Brandon E; Pollak, Seth D; Hajcak, Greg; Owens, Max
Although a number of studies have reported that children of depressed, compared to nondepressed, parents exhibit biased attention to sad facial stimuli, the direction of this bias remains unclear; some studies find evidence of preferential attention toward sad faces whereas others find evidence of attention avoidance. In the current study, we used event-related potentials (ERPs) to assess children's attention to emotional stimuli using a spatial cueing task. Across all indices of attention bias (N2pc and sustained posterior contralateral negativity [SPCN] time locked to face onset, P3b time locked to probe onset, reaction times [RTs] to probes), children of mothers with a history of major depressive disorder (MDD) during the child's life exhibited less attention to sad faces than children of never depressed mothers. For two of these indices (SPCN and RTs), the attention biases for the offspring of depressed mothers was not specific to sadness and was observed for all emotional expressions. Group differences in the ERP indices were maintained when controlling for the influence of mothers' and children's current symptoms of depression and anxiety, mothers' history of anxiety disorders, and children's history of MDD and anxiety disorders, suggesting that the results are specific to mothers' history of MDD. (PsycINFO Database Record (c) 2016 APA, all rights reserved).
Wangler, Susanne; Gevensleben, Holger; Albrecht, Björn; Studer, Petra; Rothenberger, Aribert; Moll, Gunther H; Heinrich, Hartmut
In a randomized controlled trial, we could demonstrate clinical efficacy of neurofeedback (NF) training for children with ADHD (Gevensleben et al., 2009a). The present investigation aimed at learning more about the neuronal mechanisms of NF training. Children with ADHD either completed a NF training or a computerized attention skills training (ratio 3:2). NF training consisted of one block of theta/beta training and one block of slow cortical potential (SCP) training, each comprising 18 training units. At three times (pre-training, between the two training blocks and at post-training), event-related potentials (ERP) were recorded during the Attention Network Test. ERP analysis focused on the P3, reflecting inter alia attentional resources for stimulus evaluation, and the contingent negative variation (CNV), primarily related to cognitive preparation. After NF training, an increase of the CNV in cue trials could be observed, which was specific for the SCP training. A larger pre-training CNV was associated with a larger reduction of ADHD symptomatology for SCP training. CNV effects reflect neuronal circuits underlying resource allocation during cognitive preparation. These distinct ERP effects are closely related to a successful NF training in children with ADHD. In future studies, neurophysiological recordings could help to optimize and individualize NF training. The findings contribute to a better understanding of the mechanisms underlying NF training in children with ADHD. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Lin, Ming-Huang; Wang, Ching-yi; Cheng, Shih-kuen; Cheng, Shih-hung
This study investigates how semantic networks represent different artistic furniture. Event-related potentials (ERPs) were recorded while participants made style-match judgments for table and chair sets. All of the tables were in the Normal style, whereas the chairs were in the Normal, Minimal, ReadyMade, or Deconstruction styles. The Normal and Minimal chairs had the same rates of "match" responses, which were both higher than the rates for the ReadyMade and Deconstruction chairs. Compared with Normal chairs, the ERPs elicited by both ReadyMade chairs and Deconstruction chairs exhibited reliable N400 effects, which suggests that these two design styles were unlike the Normal design style. However, Minimal chairs evoked ERPs that were similar to the ERPs of Normal chairs. Furthermore, the N400 effects elicited by ReadyMade and Deconstruction chairs showed different scalp distributions. These findings reveal that semantic networks represent different design styles for items of the same category. Copyright © 2011 Elsevier B.V. All rights reserved.
Elsner, Birgit; Jeschonek, Susanna; Pauen, Sabina
Event-related potentials (ERPs) to single visual stimuli were recorded in 7-month-old infants. In a three-stimulus oddball paradigm, infants watched one frequently occurring standard stimulus (either an animal or a furniture item) and two infrequently occurring oddball stimuli, presenting one exemplar from the same and one from the different superordinate category as compared to the standard stimulus. Additionally, visual attributes of the stimuli were controlled to investigate whether infants focus on category membership or on perceptual similarity when processing the stimuli. Infant ERPs indicated encoding of the standard stimulus and discriminating it from the two oddball stimuli by larger Nc peak amplitude and late-slow-wave activity for the infrequent stimuli. Moreover, larger Nc latency and positive-slow-wave activity indicated increased processing for the different-category as compared to the same-category oddball. Thus, 7-month-olds seem to encode single stimuli not only by surface perceptual features, but they also regard information of category membership, leading to facilitated processing of the oddball that belongs to the same domain as the standard stimulus. Copyright © 2012 Elsevier Ltd. All rights reserved.
Van Strien, Jan W.; Isbell, Lynne A.
Studies of event-related potentials in humans have established larger early posterior negativity (EPN) in response to pictures depicting snakes than to pictures depicting other creatures. Ethological research has recently shown that macaques and wild vervet monkeys respond strongly to partially exposed snake models and scale patterns on the snake skin. Here, we examined whether snake skin patterns and partially exposed snakes elicit a larger EPN in humans. In Task 1, we employed pictures with close-ups of snake skins, lizard skins, and bird plumage. In task 2, we employed pictures of partially exposed snakes, lizards, and birds. Participants watched a random rapid serial visual presentation of these pictures. The EPN was scored as the mean activity (225–300 ms after picture onset) at occipital and parieto-occipital electrodes. Consistent with previous studies, and with the Snake Detection Theory, the EPN was significantly larger for snake skin pictures than for lizard skin and bird plumage pictures, and for lizard skin pictures than for bird plumage pictures. Likewise, the EPN was larger for partially exposed snakes than for partially exposed lizards and birds. The results suggest that the EPN snake effect is partly driven by snake skin scale patterns which are otherwise rare in nature. PMID:28387376
Troup, Lucy J.; Bastidas, Stephanie; Nguyen, Maia T.; Andrzejewski, Jeremy A.; Bowers, Matthew; Nomi, Jason S.
The effect of cannabis on emotional processing was investigated using event-related potential paradigms (ERPs). ERPs associated with emotional processing of cannabis users, and non-using controls, were recorded and compared during an implicit and explicit emotional expression recognition and empathy task. Comparisons in P3 component mean amplitudes were made between cannabis users and controls. Results showed a significant decrease in the P3 amplitude in cannabis users compared to controls. Specifically, cannabis users showed reduced P3 amplitudes for implicit compared to explicit processing over centro-parietal sites which reversed, and was enhanced, at fronto-central sites. Cannabis users also showed a decreased P3 to happy faces, with an increase to angry faces, compared to controls. These effects appear to increase with those participants that self-reported the highest levels of cannabis consumption. Those cannabis users with the greatest consumption rates showed the largest P3 deficits for explicit processing and negative emotions. These data suggest that there is a complex relationship between cannabis consumption and emotion processing that appears to be modulated by attention. PMID:26926868
Cahn, B Rael; Polich, John
A three-stimulus auditory oddball series was presented to experienced Vipassana meditators during meditation and a control thought period to elicit event-related brain potentials (ERPs) in the two different mental states. The stimuli consisted of a frequent standard tone (500 Hz), an infrequent oddball tone (1000 Hz), and an infrequent distracter (white noise), with all stimuli passively presented through headphones and no task imposed. The strongest meditation compared to control state effects occurred for the distracter stimuli: N1 amplitude from the distracter was reduced frontally during meditation; P2 amplitude from both the distracter and oddball stimuli were somewhat reduced during meditation; P3a amplitude from the distracter was reduced during meditation. The meditation-induced reduction in P3a amplitude was strongest in participants reporting more hours of daily meditation practice and was not evident in participants reporting drowsiness during their experimental meditative session. The findings suggest that meditation state can decrease the amplitude of neurophysiologic processes that subserve attentional engagement elicited by unexpected and distracting stimuli. Consistent with the aim of Vipassana meditation to reduce cognitive and emotional reactivity, the state effect of reduced P3a amplitude to distracting stimuli reflects decreased automated reactivity and evaluative processing of task irrelevant attention-demanding stimuli.
del Re, Elisabetta C.; Spencer, Kevin M.; Oribe, Naoya; Mesholam-Gately, Raquelle I.; Goldstein, Jill; Shenton, Martha E.; Petryshen, Tracey; Seidman, Larry J.; McCarley, Robert W.; Niznikiewicz, Margaret A.
The clinical high risk (CHR) period is a phase denoting a risk for overt psychosis during which subacute symptoms often appear, and cognitive functions may deteriorate. To compare biological indices during this phase with those during first episode schizophrenia, we cross-sectionally examined sex- and age-matched clinical high risk (CHR, n=21), first episode schizophrenia patients (FESZ, n=20) and matched healthy controls (HC, n=25) on oddball and novelty paradigms and assessed the N100, P200, P3a and P3b as indices of perceptual, attentional and working memory processes. To our knowledge, this is the only such comparison using all of these event-related potentials (ERPs) in two paradigms. We hypothesized that the ERPs would differentiate between the three groups and allow prediction of a diagnostic group. The majority of ERPs were significantly affected in CHR and FESZ compared with controls, with similar effect sizes. Nonetheless, in logistic regression, only the P3a and N100 distinguished CHR and FESZ from healthy controls, suggesting that ERPs not associated with an overt task might be more sensitive to prediction of group membership. PMID:25557063
Delplanque, Sylvain; Silvert, Laetitia; Hot, Pascal; Sequeira, Henrique
In natural situations, unpredictable events processing often interacts with the ongoing cognitive activities. In a similar manner, the insertion of deviant unpredictable stimuli into a classical oddball task evokes both the P3a and P3b event-related potentials (ERPs) components that are, respectively, thought to index reallocation of attentional resources or inhibitory process and memory updating mechanism. This study aims at characterising the influence of the emotional arousal and valence of a deviant and unpredictable non-target stimulus on these components. ERPs were recorded from 28 sites during a visual three-stimulus oddball paradigm. Unpleasant, neutral and pleasant pictures served as non-target unpredictable items and subjects were asked to realize a perceptually difficult standard/target discrimination task. A temporal principal component analysis (PCA) allowed us to show that non-target pictures elicited both a P3a and a P3b. Moreover, the P3b component was modulated by the emotional arousal and the valence of the pictures. Thus, the memory updating process may be modulated by the affective arousal and valence of unpredictable disturbing stimuli, even if the task does not require any explicit emotional categorization.
The topographic pattern and latency of the P2 component of the somatosensory evoked potential elicited by painful electrical stimulation of the sural nerve was compared to the P3a event-related potential evoked by an infrequent task-irrelevant (deviant) innocuous sural nerve stimulus presented as part of the deviant-odd ball paradigm. Conditions typically used to record the sural nerve pain-evoked P2 (multiple stimulus levels, short fixed inter-stimulus intervals, and the subjects engaged in a pain rating task) did not elicit a P3a. The P3a was elicited when the painful stimuli were presented at a long and variable inter-stimulus interval. When present, the P3a occurred immediately following P2. These findings demonstrate that P2 is not a pain-evoked P3a. Rather, the response properties and latency of P2 present the possibility that it indexes a stimulus evaluation process where the sensory input is compared to an environmental template maintained by working memory.
Greer, Joanna M. H.; Hamilton, Colin; Riby, Leigh M.
The primary aim of the current study was to employ event-related potentials (ERPs) methodology to disentangle the mechanisms related to inhibitory control in older adults with Williams syndrome (WS). Eleven older adults with WS (mean age 42), 16 typically developing adults (mean age 42) and 13 typically developing children (mean age 12) participated in the study. ERPs were recorded during a three-stimulus visual oddball task, during which participants were required to make a response to a rare target stimulus embedded in a train of frequent non-target stimuli. A task-irrelevant infrequent stimulus was also present at randomised intervals during the session. The P3a latency data response related to task-irrelevant stimulus processing was delayed in WS. In addition, the early perceptual N2 amplitude was attenuated. These data are indicative of compromised early monitoring of perceptual input, accompanied by appropriate orientation of responses to task-irrelevant stimuli. However, the P3a delay suggests inefficient evaluation of the task-irrelevant stimuli. These data are discussed in terms of deficits in the disengagement of attentional processes, and the regulation of monitoring processes required for successful inhibition. PMID:28187205
Ballesteros, Antonio, E-mail: Antonio.Ballesteros-Avila@ec.europa.eu [JRC-IET: Institute for Energy and Transport of the Joint Research Centre of the European Commission, Postbus 2, NL-1755 ZG Petten (Netherlands); Sanda, Radian; Peinador, Miguel; Zerger, Benoit [JRC-IET: Institute for Energy and Transport of the Joint Research Centre of the European Commission, Postbus 2, NL-1755 ZG Petten (Netherlands); Negri, Patrice [IRSN: Institut de Radioprotection et de Sûreté Nucléaire (France); Wenke, Rainer [GRS: Gesellschaft für Anlagen- und Reaktorsicherheit (GRS) mbH (Germany)
Highlights: • The important role of Operating Experience Feedback is emphasised. • Events relating to cracks and leaks in the reactor coolant pressure boundary are analysed. • A methodology for event investigation is described. • Some illustrative results of the analysis of events for specific components are presented. - Abstract: The presence of cracks and leaks in the reactor coolant pressure boundary may jeopardise the safe operation of nuclear power plants. Analysis of cracks and leaks related events is an important task for the prevention of their recurrence, which should be performed in the context of activities on Operating Experience Feedback. In response to this concern, the EU Clearinghouse operated by the JRC-IET supports and develops technical and scientific work to disseminate the lessons learned from past operating experience. In particular, concerning cracks and leaks, the studies carried out in collaboration with IRSN and GRS have allowed to identify the most sensitive areas to degradation in the plant primary system and to elaborate recommendations for upgrading the maintenance, ageing management and inspection programmes. An overview of the methodology used in the analysis of cracks and leaks related events is presented in this paper, together with the relevant results obtained in the study.
Liu, Yanling; Teng, Zhaojun; Lan, Haiying; Zhang, Xin; Yao, Dezhong
Previous research has shown that exposure to violent video games increases aggression, whereas exposure to prosocial video games can reduce aggressive behavior. However, little is known about the neural correlates of these behavioral effects. This work is the first to investigate the electrophysiological features of the relationship between playing a prosocial video game and inhibition of aggressive behavior. Forty-nine subjects played either a prosocial or a neutral video game for 20 min, then participated in an event-related potential (ERP) experiment based on an oddball paradigm and designed to test electrophysiological responses to prosocial and violent words. Finally, subjects completed a competitive reaction time task (CRTT) which based on Taylor's Aggression Paradigm and contains reaction time and noise intensity chosen as a measure of aggressive behavior. The results show that the prosocial video game group (compared to the neutral video game group) displayed smaller P300 amplitudes, were more accurate in distinguishing violent words, and were less aggressive as evaluated by the CRTT of noise intensity chosen. A mediation analysis shows that the P300 amplitude evoked by violent words partially mediates the relationship between type of video game and subsequent aggressive behavior. The results support theories based on the General Learning Model. We provide converging behavioral and neural evidence that exposure to prosocial media may reduce aggression.
Olofsson, Jonas K; Gospic, Katarina; Petrovic, Predrag; Ingvar, Martin; Wiens, Stefan
Little is known about how rapid electrocortical responses (event-related potentials; ERPs) to affective pictures are modulated by benzodiazepine agonists. The present study investigated effects of oxazepam (20 mg p.o.) on behavioral measures and ERPs associated with affective picture processing during perception and recognition memory retrieval. Forty-three healthy young adults were given oxazepam or placebo treatment under a double-blind experimental procedure. Affective pictures (negatively arousing or neutral) elicited ERP responses and participants rated pictures for emotionality (during incidental encoding) and recognition. Oxazepam did not affect perceptual (P1, P2) or emotional (early posterior negativity and late parietal positivity) ERPs or ratings during perception. However, oxazepam impaired recognition performance and decreased positive mid-frontal ERP component at 420-450 ms for old vs. new pictures. The memory impairment was retained at the delayed memory test. Oxazepam does not selectively influence electrocortical or perceptual indexes of emotional perception or emotional memory. Rather, it blocks memory consolidation independent of valence category. These findings indicate that ERPs can be of use in assessing effects of benzodiazepines on memory-related processes.
Jin, Hua; Xu, Guiping; Zhang, John X; Gao, Hongwei; Ye, Zuoer; Wang, Pin; Lin, Huiyan; Mo, Lei; Lin, Chong-De
The ability to predict the trajectory of a ball based on the opponent's body kinematics has been shown to be critical to high-performing athletes in many sports. However, little is known about the neural correlates underlying such superior ability in action anticipation. The present event-related potential study compared brain responses from professional badminton players and non-player controls when they watched video clips of badminton games and predicted a ball's landing position. Replicating literature findings, the players made significantly more accurate judgments than the controls and showed better action anticipation. Correspondingly, they showed enlarged amplitudes of two ERP components, a P300 peaking around 350ms post-stimulus with a parietal scalp distribution and a P2 peaking around 250ms with a posterior-occipital distribution. The P300 effect was interpreted to reflect primed access and/or directing of attention to game-related memory representations in the players facilitating their online judgment of related actions. The P2 effect was suggested to reflect some generic learning effects. The results identify clear neural responses that differentiate between different levels of action anticipation associated with sports expertise. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Portella, Claudio; Machado, Sergio; Arias-Carrión, Oscar; Sack, Alexander T.; Silva, Julio Guilherme; Orsini, Marco; Leite, Marco Antonio Araujo; Silva, Adriana Cardoso; Nardi, Antonio E.; Cagy, Mauricio; Piedade, Roberto; Ribeiro, Pedro
The brain is capable of elaborating and executing different stages of information processing. However, exactly how these stages are processed in the brain remains largely unknown. This study aimed to analyze the possible correlation between early and late stages of information processing by assessing the latency to, and amplitude of, early and late event-related potential (ERP) components, including P200, N200, premotor potential (PMP) and P300, in healthy participants in the context of a visual oddball paradigm. We found a moderate positive correlation among the latency of P200 (electrode O2), N200 (electrode O2), PMP (electrode C3), P300 (electrode PZ) and the reaction time (RT). In addition, moderate negative correlation between the amplitude of P200 and the latencies of N200 (electrode O2), PMP (electrode C3), P300 (electrode PZ) was found. Therefore, we propose that if the secondary processing of visual input (P200 latency) occurs faster, the following will also happen sooner: discrimination and classification process of this input (N200 latency), motor response processing (PMP latency), reorganization of attention and working memory update (P300 latency), and RT. N200, PMP, and P300 latencies are also anticipated when higher activation level of occipital areas involved in the secondary processing of visual input rise (P200 amplitude). PMID:23355929
Zendel, Benjamin Rich; de Boysson, Chloé; Mellah, Samira; Démonet, Jean-François; Belleville, Sylvie
Attentional control declines in older adults and is paralleled by changes in event-related brain potentials (ERPs). The N200 is associated with attentional control, thus training-related improvements in attentional control should be paralleled by enhancements to the N200. Older participants were randomly assigned to 1 of 3 groups, which focused on training different levels of attentional control: (1) single-task training (single), where participants trained on 2 tasks in isolation; (2) fixed divided attention training (fixed), where participants trained on 2 tasks simultaneously; and (3) variable divided attention training (variable), where participants trained on 2 tasks simultaneously but were instructed to alternatively prioritize each of the 2 tasks. After training, the amplitude of the N200 wave increased in dual-task conditions for the variable group, and this enhancement was correlated with improved dual-task performance. Participants in the variable group also had the greatest improvement in the ability to modulate their allocation of attention in accordance with task instructions to the less salient and less complex of the 2 tasks. Training older adults to modulate their division of attention between tasks improves neural functions associated with attentional control of the trained tasks. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.
Wang, Cuicui; Jin, Jia; Vieito, João Paulo; Ma, Qingguo
Using event-related potentials, this study investigated how financial herding or antiherding affected the valuation of subsequent outcomes. For each trial, subjects decided whether to buy the stock according to its net money flow information which could be used to reflect the strength of buying power or selling power of the stock. The return on investment (ROI) as feedback included the increase or decrease percentage after subjects' responses. Results showed that, compared with herding, antiherding induced larger discrepancies of FRN and P300 amplitude between positive ROI and negative ROI, indicating that individuals under antiherding condition had stronger motivation and paid more attention in the evaluation process of ROI. Moreover, only for positive ROI, the amplitudes of FRN and P300 were modulated by two kinds of behaviors. We suggested that individuals making antiherd decisions were more confident with their own ability and choices, which reduced the positive outcome prediction error and gave more mental resources to evaluate positive outcome. However, negative outcomes evoked no different motivational meaning and negative emotion for individuals between herding and antiherding. The study may provide new insights into neurocognitive processes of herding and antiherding in financial market.
Wilding, E L; Fraser, C S; Herron, J E
Event-related potentials (ERPs) were acquired during two experiments in order to determine boundary conditions for when recollection of colour information can be controlled strategically. In initial encoding phases, participants saw an equal number of words presented in red or green. In subsequent retrieval phases, all words were shown in white. Participants were asked to endorse old words that had been shown at encoding in one colour (targets), and to reject new test words as well as old words shown in the alternate colour (non-targets). Study and test lists were longer in Experiment 1, and as a result, the accuracy of memory judgments was superior in Experiment 2. The left-parietal ERP old/new effect--the electrophysiological signature of recollection--was reliable for targets in both experiments, and reliable for non-targets in Experiment 1 only. These findings are consistent with the view that participants were able to restrict recollection to targets in Experiment 2, while recollecting information about targets as well as non-targets in Experiment 1. The fact that this selective strategy was implemented in Experiment 2 despite the close correspondence between the kinds of information associated with targets and non-targets indicates that participants were able to exert considerable control over the conditions under which recollection of task-relevant information occurred.
Full Text Available The neural correlates of rejection in bargaining situations when proposing a fair or unfair offer are not yet well understood. We measured neural responses to rejection and acceptance of monetary offers with event-related potentials (ERPs in mid-adolescents (14-17 years and early adults (19-24 years. Participants played multiple rounds of the Ultimatum Game as proposers, dividing coins between themselves and a second player (responder by making a choice between an unfair distribution (7 coins for proposer and 3 for responder; 7/3 and one of two alternatives: a fair distribution (5/5 or a hyperfair distribution (3/7. Participants mostly made fair offers (5/5 when the alternative was unfair (7/3, but made mostly unfair offers (7/3 when the alternative was hyperfair (3/7. When participants' fair offers (5/5; alternative was 7/3 were rejected this was associated with a larger Medial Frontal Negativity (MFN compared to acceptance of fair offers and rejection of unfair offers (7/3; alternative was 3/7. Also, the MFN was smaller after acceptance of unfair offers (7/3 compared to rejection. These neural responses did not differ between adults and mid-adolescents, suggesting that the MFN reacts as a neural alarm system to social prediction errors which is already prevalent during adolescence.
Hansson, M; Gänsler, T; Salomonsson, G
This paper deals with estimation of the waveform of a single event-related potential, sERP. An additive noise model is used for the measured signal and the SNR of the disturbed sERP is approximately 0 dB. The sERP is described by a series expansion where the basis functions are damped sinusoids. The fundamental basis function is estimated by the least squares Prony method, derived for colored noise. The performance of the Prony method for different forms of the power density spectrum of the noise is investigated. A white noise approximation can be used at a low signal-to-noise (SNR). The basis functions change slowly but the waveform of the sERP may vary from one stimulus to another, thus we average a small number of correlation functions in order to increase the SNR. The method is evaluated by using measurements from four subjects and the results confirm the variability of the sERP.
Ma, Yujun; Wang, Enguo; Yuan, Tian; Zhao, Guo Xiang
As the reading process is inseparable from working memory, inhibition, and other higher cognitive processes, the deep cognitive processing defects that are associated with dyslexia may be due to defective distraction inhibition systems. In this study, we used event-related potential technology to explore the source of negative priming effects in children with developmental dyslexia and in a group of healthy children for comparison. We found that the changes in the average response times in the negative priming and control conditions were consistent across the two groups, while the negative priming effects differed significantly between the groups. The magnitude of the negative priming effect was significantly different between the two groups, with the magnitude being significantly higher in the control group than it was in the developmental dyslexia group. These results indicate that there are deficits in distraction inhibition in children with developmental dyslexia. In terms of the time course of processing, inhibition deficits in the dyslexia group appeared during early-stage cognition selection and lasted through the response selection phase. Regarding the cerebral cortex locations, early-stage cognition selection was mainly located in the parietal region, while late-stage response selection was mainly located in the frontal and central regions. The results of our study may help further our understanding of the intrinsic causes of developmental dyslexia. Copyright © 2016 Elsevier Ltd. All rights reserved.
López Zunini, Rocío A; Knoefel, Frank; Lord, Courtney; Dzuali, Fiatsogbe; Breau, Michael; Sweet, Lisa; Goubran, Rafik; Taler, Vanessa
Persons with Mild Cognitive Impairment (MCI) can experience deficits in working memory. In the present study, we investigated working memory in persons with MCI and cognitively healthy older adults using event-related potentials (ERPs). Participants performed an n-back working memory task with baseline (0-back), low load (1-back), and high load (2-back) working memory conditions. MCI participants' performance was less accurate than that of healthy older adults in both the 1-back and 2-back conditions, and reaction times were longer in MCI than control participants in the 0-back, 1-back and 2-back conditions. ERP analyses revealed delayed P200 and N200 latencies and smaller P300 amplitudes in MCI relative to control participants in the 0-back, 1-back and 2-back conditions. Deterioration in working memory performance concomitant with marked electrophysiological alterations suggests that persons with MCI exhibit deficits in several cognitive processes that include early attention, stimulus discrimination and classification, and updating and manipulation of information held in working memory. Copyright © 2016 Elsevier B.V. All rights reserved.
Full Text Available Establishing associations between pieces of information is related to the medial temporal lobe (MTL. However, it remains unclear how emotions affect memory for associations and, consequently, MTL activity. Thus, this event-related fMRI study attempted to identify neural correlates of the influence of positive and negative emotions on associative memory. Twenty-five participants were instructed to memorize 90 pairs of standardized pictures during a scanned encoding phase. Each pair was composed of a scene and an unrelated object. Trials were neutral, positive, or negative as a function of the emotional valence of the scene. At the behavioral level, participants exhibited better memory retrieval for both emotional conditions relative to neutral trials. Within the right MTL, a functional dissociation was observed, with entorhinal activation elicited by emotional associations, posterior parahippocampal activation elicited by neutral associations, and hippocampal activation elicited by both emotional and neutral associations. In addition, emotional associations induced greater activation than neutral trials in the right amygdala. This fMRI study shows that emotions are associated with the performance improvement of associative memory, by enhancing activity in the right amygdala and the right entorhinal cortex. It also provides evidence for a rostrocaudal specialization within the MTL regarding the emotional valence of associations.
Kao, Ming-Hung; Mandal, Abhyuday; Lazar, Nicole; Stufken, John
In this article, we propose an efficient approach to find optimal experimental designs for event-related functional magnetic resonance imaging (ER-fMRI). We consider multiple objectives, including estimating the hemodynamic response function (HRF), detecting activation, circumventing psychological confounds and fulfilling customized requirements. Taking into account these goals, we formulate a family of multi-objective design criteria and develop a genetic-algorithm-based technique to search for optimal designs. Our proposed technique incorporates existing knowledge about the performance of fMRI designs, and its usefulness is shown through simulations. Although our approach also works for other linear combinations of parameters, we primarily focus on the case when the interest lies either in the individual stimulus effects or in pairwise contrasts between stimulus types. Under either of these popular cases, our algorithm outperforms the previous approaches. We also find designs yielding higher estimation efficiencies than m-sequences. When the underlying model is with white noise and a constant nuisance parameter, the stimulus frequencies of the designs we obtained are in good agreement with the optimal stimulus frequencies derived by Liu and Frank, 2004, NeuroImage 21: 387-400. In addition, our approach is built upon a rigorous model formulation.
Muller-Gass, Alexandra; Campbell, Kenneth
The minimum time interval between two stimuli that can be reliably detected is called the gap detection threshold. The present study examines whether an unconscious state, natural sleep affects the gap detection threshold. Event-related potentials were recorded in 10 young adults while awake and during all-night sleep to provide an objective estimate of this threshold. These subjects were presented with 2, 4, 8 or 16ms gaps occurring in 1.5 duration white noise. During wakefulness, a significant N1 was elicited for the 8 and 16ms gaps. N1 was difficult to observe during stage N2 sleep, even for the longest gap. A large P2 was however elicited and was significant for the 8 and 16ms gaps. Also, a later, very large N350 was elicited by the 16ms gap. An N1 and P2 was significant only for the 16ms gap during REM sleep. ERPs to gaps occurring in noise segments can therefore be successfully elicited during natural sleep. The gap detection threshold is similar in the waking and sleeping states. Crown Copyright © 2014. Published by Elsevier Ireland Ltd. All rights reserved.
Munsters, N M; van Ravenswaaij, H; van den Boomen, C; Kemner, C
Reliable measures are required to draw meaningful conclusions regarding developmental changes in longitudinal studies. Little is known, however, about the test-retest reliability of face-sensitive event related potentials (ERPs), a frequently used neural measure in infants. The aim of the current study is to investigate the test-retest reliability of ERPs typically evoked by faces in 9-10 month-old infants. The infants (N=31) were presented with neutral, fearful and happy faces that contained only the lower or higher spatial frequency information. They were tested twice within two weeks. The present results show that the test-retest reliability of the face-sensitive ERP components is moderate (P400 and Nc) to substantial (N290). However, there is low test-retest reliability for the effects of the specific experimental manipulations (i.e. emotion and spatial frequency) on the face-sensitive ERPs. To conclude, in infants the face-sensitive ERP components (i.e. N290, P400 and Nc) show adequate test-retest reliability, but not the effects of emotion and spatial frequency on these ERP components. We propose that further research focuses on investigating elements that might increase the test-retest reliability, as adequate test-retest reliability is necessary to draw meaningful conclusions on individual developmental trajectories of the face-sensitive ERPs in infants. Copyright © 2017 The Authors. Published by Elsevier Ltd.. All rights reserved.
Rushby, Jacqueline A; Barry, Robert J; Johnstone, Stuart S
Twenty undergraduate students participated in an elaborative learning test to evaluate the relationship between electrical brain activity and subsequently recalled and not-recalled words. Data collected from the midline (Fz, Cz, Pz) and lateral scalp sites (F3, F4, C3, C4, P3, P4) were analysed. The difference between event-related potentials (ERPs) elicited by subsequently recalled and not-recalled words, the ERP memory effect, was evaluated for each portion (primacy, plateau and recency) of the serial-position curve (SPC). We compared peak amplitudes for the P1, N1, P2, N400, P3 and frontal positive slow wave (FPSW) components. The electrophysiological data support the hypothesis that different mechanisms underlie primacy and recency effects during free recall paradigms. There was no support for the hypothesis that an association arises between memory and the FPSW when subjects utilise elaborative learning strategies. The P2 component predicted subsequent recall at the primacy portion of the SPC, and P1 predicted recall at the primacy and plateau portions of the curve. The findings suggest that the early positive components of the ERP (i.e. P1 and P2) are useful indices of the differential stimulus processing during elaborative learning which predicts later recall. Copyright 2002 Elsevier Science B.V.
Azizian, Allen; Polich, John
The occurrence of primacy versus recency effects in free recall is suggested to reflect either two distinct memory systems, or the operation of a single system that is modulated by allocation of attention and less vulnerable to interference. Behavioral and event-related brain potential (ERPs) measures were used to investigate the encoding substrates of the serial position curve and subsequent recall in young adults. Participants were instructed to remember lists of words consisting of 12 common nouns each presented once every 1.5 sec, with a recall signal following the last word to indicate that all remembered items should be written on paper. This procedure was repeated for 20 different word lists. Both performance and late ERP amplitudes reflected classic recall serial position effects. Greater recall and larger late positive component amplitudes were obtained for the primacy and recency items, with less recall and smaller amplitudes for the middle words. The late positive component was larger for recalled compared to unrecalled primacy items, but it did not differ between memory performance outcomes for the recency items. The close relationship between the enhanced amplitude and primacy retrieval supports the view that this positive component reflects one of a process series related to attentional gradient and encoding of events for storage in memory. Recency effects appear to index operations determined by the anticipation of the last stimulus presentation, which occurred for both recalled and unrecalled memory items. Theoretical implications are discussed. PMID:17892393
Slotnick, Scott D
Functional magnetic resonance imaging (fMRI) is currently the standard method of evaluating brain function in the field of Cognitive Neuroscience, in part because fMRI data acquisition and analysis techniques are readily available. Because fMRI has excellent spatial resolution but poor temporal resolution, this method can only be used to identify the spatial location of brain activity associated with a given cognitive process (and reveals virtually nothing about the time course of brain activity). By contrast, event-related potential (ERP) recording, a method that is used much less frequently than fMRI, has excellent temporal resolution and thus can track rapid temporal modulations in neural activity. Unfortunately, ERPs are under utilized in Cognitive Neuroscience because data acquisition techniques are not readily available and low density ERP recording has poor spatial resolution. In an effort to foster the increased use of ERPs in Cognitive Neuroscience, the present article details key techniques involved in high density ERP data acquisition. Critically, high density ERPs offer the promise of excellent temporal resolution and good spatial resolution (or excellent spatial resolution if coupled with fMRI), which is necessary to capture the spatial-temporal dynamics of human brain function.
Moreno, Sylvain; Wodniecka, Zofia; Tays, William; Alain, Claude; Bialystok, Ellen
Bilinguals and musicians exhibit behavioral advantages on tasks with high demands on executive functioning, particularly inhibitory control, but the brain mechanisms supporting these differences are unclear. Of key interest is whether these forms of experience influence cognition through similar or distinct information processing mechanisms. Here, we recorded event-related potentials (ERPs) in three groups - bilinguals, musicians, and controls - who completed a visual go-nogo task that involved the withholding of key presses to rare targets. Participants in each group achieved similar accuracy rates and responses times but the analysis of cortical responses revealed significant differences in ERP waveforms. Success in withholding a prepotent response was associated with enhanced stimulus-locked N2 and P3 wave amplitude relative to go trials. For nogo trials, there were altered timing-specific ERP differences and graded amplitude differences observed in the neural responses across groups. Specifically, musicians showed an enhanced early P2 response accompanied by reduced N2 amplitude whereas bilinguals showed increased N2 amplitude coupled with an increased late positivity wave relative to controls. These findings demonstrate that bilingualism and music training have differential effects on the brain networks supporting executive control over behavior.
Sarah J. Hart
Full Text Available Although emotionally salient stimuli influence higher order information processing, the relative vulnerability of specific stages of cognitive processing to modulation by emotional input remains elusive. To test the temporal dynamics of emotional interference during executive function, we recorded event-related potentials while participants performed an effortful anticipation task with aversive emotional and neutral distracters. Participants were presented with a modified delayed Stroop task that dissociated the anticipation of an easier or more difficult task (instructional cues to attend to word versus color from the response to the Stroop stimulus, while aversive and neutral pictures were displayed during the delay period. Our results indicated a relative decrease in the amplitude of the contingent negative variation (CNV during aversive trials that was greater during the early anticipatory phase than during the later response preparation phase, and greater during (the more difficult color than word trials. During the initial stage of cue processing, there was also significant interaction between emotion and anticipatory difficulty on N1 amplitude, where emotional stimuli led to significantly enhanced negativity during color cues relative to word cues. These results suggest that earlier processes of orientation and effortful anticipation may reflect executive engagement that is influenced by emotional interference while later phases of response preparation may be modulated by emotional interference regardless of anticipatory difficulty.
Lenk, Steffen; Bluschke, Annet; Beste, Christian; Iannilli, Emilia; Rößner, Veit; Hummel, Thomas; Bender, Stephan
This study examined whether the memory encoding and short term maintenance of olfactory stimuli is associated with neurophysiological activation patterns which parallel those described for sensory modalities such as vision and auditory. We examined olfactory event-related potentials in an olfactory change detection task in twenty-four healthy adults and compared the measured activation to that found during passive olfactory stimulation. During the early olfactory post-processing phase, we found a sustained negativity over bilateral frontotemporal areas in the passive perception condition which was enhanced in the active memory task. There was no significant lateralization in either experimental condition. During the maintenance interval at the end of the delay period, we still found sustained activation over bilateral frontotemporal areas which was more negative in trials with correct - as compared to incorrect - behavioural responses. This was complemented by a general significantly stronger frontocentral activation. Summarizing, we were able to show that olfactory short term memory involves a parallel sequence of activation as found in other sensory modalities. In addition to olfactory-specific frontotemporal activations in the memory encoding phase, we found slow cortical potentials over frontocentral areas during the memory maintenance phase indicating the activation of a supramodal memory maintenance system. These findings could represent the neurophysiological underpinning of the 'olfactory flacon', the olfactory counter-part to the visual sketchpad and phonological loop embedded in Baddeley's working memory model. Copyright © 2014 Elsevier Inc. All rights reserved.
Riečanský, Igor; Tomova, Livia; Katina, Stanislav; Bauer, Herbert; Fischmeister, Florian Ph S; Lamm, Claus
Rotation of a visual image in mind is associated with a slow posterior negative deflection of the event-related potential (ERP), termed rotation-related negativity (RRN). Retention of a visual image in short-term memory is also associated with a slow posterior negative ERP, termed negative slow wave (NSW). We tested whether short-term memory retention, indexed by the NSW, contributes to the RRN. ERPs were recorded in the same subjects in two tasks, a mental rotation task, eliciting the RRN, and a visual short-term memory task, eliciting the NSW. Over both right and left parietal scalp, no association was found between the NSW and the RRN amplitudes. Furthermore, adjusting for the effect of the NSW had no influence on a significant association between the RRN amplitude and response time, an index of mental rotation performance. Our data indicate that the RRN reflects manipulation of a visual image but not its retention in short-term memory. Copyright © 2013 Elsevier Inc. All rights reserved.
Zhang, Yan; Wei, Bin; Zhao, Peiqiong; Zheng, Minxiao; Zhang, Lili
High rates of agreement in the judgment of facial attractiveness suggest universal principles of beauty. This study investigated gender differences in recognition memory processing of female facial attractiveness. Thirty-four Chinese heterosexual participants (17 females, 17 males) aged 18-24 years (mean age 21.63 ± 1.51 years) participated in the experiment which used event-related potentials (ERPs) based on a study-test paradigm. The behavioral data results showed that both men and women had significantly higher accuracy rates for attractive faces than for unattractive faces, but men reacted faster to unattractive faces. Gender differences on ERPs showed that attractive faces elicited larger early components such as P1, N170, and P2 in men than in women. The results indicated that the effects of recognition bias during memory processing modulated by female facial attractiveness are greater for men than women. Behavioral and ERP evidences indicate that men and women differ in their attentional adhesion to attractive female faces; different mating-related motives may guide the selective processing of attractive men and women. These findings establish a contribution of gender differences on female facial attractiveness during memory processing from an evolutionary perspective.
Full Text Available Abstract Background We developed an electroencephalogram-based brain computer interface system to modulate functional electrical stimulation (FES to the affected tibialis anterior muscle in a stroke patient. The intensity of FES current increased in a stepwise manner when the event-related desynchronization (ERD reflecting motor intent was continuously detected from the primary cortical motor area. Methods We tested the feasibility of the ERD-modulated FES system in comparison with FES without ERD modulation. The stroke patient who presented with severe hemiparesis attempted to perform dorsiflexion of the paralyzed ankle during which FES was applied either with or without ERD modulation. Results After 20 minutes of training, the range of movement at the ankle joint and the electromyography amplitude of the affected tibialis anterior muscle were significantly increased following the ERD-modulated FES compared with the FES alone. Conclusions The proposed rehabilitation technique using ERD-modulated FES for stroke patients was feasible. The system holds potentials to improve the limb function and to benefit stroke patients.
Hsu, Chun-Hsien; Tsai, Jie-Li; Lee, Chia-Ying; Tzeng, Ovid J-L
In this study, event-related potentials (ERPs) were used to trace the temporal dynamics of phonological consistency and phonetic combinability in the reading of Chinese phonograms. The data showed a significant consistency-by-combinability interaction at N170. High phonetic combinability characters elicited greater negativity at N170 than did low phonetic combinability characters, and the combinability effect was only found in the reading of high consistency characters. The results support the phonological mapping hypothesis of the reading-related N170 effect and suggest that the earlier stages of visual word recognition are shaped by the mapping of orthography to phonology even in Chinese. Moreover, our data revealed both consistency and combinability effects at P200 and N400, accounted for by the two-stage framework for visual word recognition. That is, characters with high combinability or high consistency facilitated the earlier stages of orthographic or phonological processing which were due to increased activation at the perceptual level; consequently, less positive P200 was demonstrated. In the later stages, high combinability or high consistency characters were associated with a larger semantic neighborhood, which increased semantic competition and exaggerated the N400 effect. These data support the assumption of radical-based inputs proposed by the lexical constituent model. However, the phonetic consistency effects found at N170 and P200 cannot be reconciled with the current framework of the lexical constituent model. A possible revision will be discussed.
The author analyzed the role of consciousness in emotional face comprehension. The author recorded psychophysiological measures of event-related potentials (ERPs), elicited by supraliminal and subliminal stimuli when participants viewed emotional facial expressions of 4 emotions or neutral stimuli. The author analyzed an ERP emotion-specific effect (N200 peak variation; temporal interval was 180-300 ms poststimulus) in terms of peak amplitude and latency variables. The results indicated 4 important findings. First, there was an emotional-specific ERP deflection only for emotional stimuli, not for neutral stimuli. Second, the unaware information processing was quite similar to that of aware in terms of peak morphology, but not in terms of latency. In fact, unconscious stimulation produced a more delayed peak variation than did conscious stimulation. Third, valence of facial stimulus (positive or negative) was supraliminally and subliminally decoded because it was showed by differences of peak deflection between negative high arousing (fear and anger) and low arousing (happiness, sadness, and neutral) stimuli. Finally, the author found a more posterior distribution of ERP as a function of emotional content of the stimulus. Cortical lateralization (right or left) was not correlated to conscious or unconscious stimulation. The author discussed the functional significance of her results in terms of supraliminal and subliminal conditions.
Takayoshi, Hiroyuki; Onoda, Keiichi; Yamaguchi, Shuhei
Apathy is a mental state of diminished motivation. Although the reward system as the foundation of the motivation in the human brain has been studied extensively with neuroimaging techniques, the electrophysiological correlates of motivation and apathy have not been fully explored. Thus, in 14 healthy volunteers, we examined whether event-related evoked potentials (ERP) obtained during a simple number discrimination task with/without rewards reflected apathy tendency and a reward-dependent tendency, which were assessed separately using the apathy scale and the temperament and character inventory (TCI). Participants were asked to judge the size of a number, and received feedback based on their performance in each trial. The P3 amplitudes related to the feedback stimuli increased only in the reward condition. Furthermore, the P2 amplitudes related to the negative feedback stimuli in the reward condition had a positive correlation with the reward-dependent tendency in TCI, whereas the P3 amplitudes related to the positive feedback stimuli had a negative correlation with the apathy score. Our result suggests that the P2 and P3 ERPs to reward-related feedback stimuli are modulated in a distinctive manner by the motivational reward dependence and apathy tendency, and thus the current paradigm may be useful for investigating the brain activity associated with motivation.
Wu, Qiuyan; Deng, Yuan
In the current study, we explored the effects of ERPs (event-related potentials), related to the cross-modal transfer from visual input to phonological retrieval. Using Chinese single-character words, participants were asked to make orthographic (intra-modal) and phonological (cross-modal) responses to visually presented words. By comparing the cross-modal and intra-modal tasks, we found that both tasks evoke similar activity in the early stage of lexical processing, showing the same pattern of N2 effect (a negative component peaking around 220 ms) and P2 effect (a positive component peaking around 270 ms). However, the effect of the task was significant in the 300-700 ms time window, consisting of a frontal-based N400 effect and a parietal based late positive component (LPC) effect. These findings suggest that the frontal-based N400 is associated with orthography-to-phonology mapping in Chinese, and the LPC reflects greater requirement of maintaining retrieved information in working memory for the cross-modal processing. Copyright © 2011 Elsevier Ireland Ltd. All rights reserved.
Pinheiro, Ana P; del Re, Elisabetta; Nestor, Paul G; McCarley, Robert W; Gonçalves, Óscar F; Niznikiewicz, Margaret
Recent evidence suggests that affect acts as modulator of cognitive processes and in particular that induced mood has an effect on the way semantic memory is used on-line. We used event-related potentials (ERPs) to examine affective modulation of semantic information processing under three different moods: neutral, positive and negative. Fifteen subjects read 324 pairs of sentences, after mood induction procedure with 30 pictures of neutral, 30 pictures of positive and 30 pictures of neutral valence: 108 sentences were read in each mood induction condition. Sentences ended with three word types: expected words, within-category violations, and between-category violations. N400 amplitude was measured to the three word types under each mood induction condition. Under neutral mood, a congruency (more negative N400 amplitude for unexpected relative to expected endings) and a category effect (more negative N400 amplitude for between- than to within-category violations) were observed. Also, results showed differences in N400 amplitude for both within- and between-category violations as a function of mood: while positive mood tended to facilitate the integration of unexpected but related items, negative mood made their integration as difficult as unexpected and unrelated items. These findings suggest the differential impact of mood on access to long-term semantic memory during sentence comprehension.
Borgström, Kristina; Torkildsen, Janne von Koss; Lindgren, Magnus
What role does attention to different object properties play in early vocabulary development? This longitudinal study using event-related potentials in combination with behavioral measures investigated 20- and 24-month-olds' (n = 38; n = 34; overlapping n = 24) ability to use object shape and object part information in word-object mapping. The N400 component was used to measure semantic priming by images containing shape or detail information. At 20 months, the N400 to words primed by object shape varied in topography and amplitude depending on vocabulary size, and these differences predicted productive vocabulary size at 24 months. At 24 months, when most of the children had vocabularies of several hundred words, the relation between vocabulary size and the N400 effect in a shape context was weaker. Detached object parts did not function as word primes regardless of age or vocabulary size, although the part-objects were identified behaviorally. The behavioral measure, however, also showed relatively poor recognition of the part-objects compared to the shape-objects. These three findings provide new support for the link between shape recognition and early vocabulary development.
Full Text Available What role does attention to different object properties play in early vocabulary development? This longitudinal study using event-related potentials in combination with behavioral measures investigated 20- and 24-month-olds’ (n = 38; n = 34; overlapping n = 24 ability to use object shape and object part information in word-object mapping. The N400 component was used to measure semantic priming by images containing shape or detail information. At 20 months, the N400 to words primed by object shape varied in topography and amplitude depending on vocabulary size, and these differences predicted productive vocabulary size at 24 months. At 24 months, when most of the children had vocabularies of several hundred words, the relation between vocabulary size and the N400 effect in a shape context was weaker. Detached object parts did not function as word primes regardless of age or vocabulary size, although the part-objects were identified behaviorally. The behavioral measure, however, also showed relatively poor recognition of the part-objects compared to the shape-objects. These three findings provide new support for the link between shape recognition and early vocabulary development.
Rodríguez-Gómez, Pablo; Sánchez-Carmona, Alberto; Smith, Cybelle; Pozo, Miguel A; Hinojosa, José A; Moreno, Eva M
Previous event-related potential studies have demonstrated the online generation of inferences during reading for comprehension tasks. The present study contrasted the brainwave patterns of activity to the fulfilment or violation of various types of inferences (causal, emotional, locative). Relative to inference congruent sentence endings, a typical centro-parietal N400 was elicited for the violation of causal and locative inferences. This N400 effect was initially absent for emotional inferences, most likely due to their lower cloze probability. Between 500 and 750ms, a larger frontal positivity (pN400FP) was elicited by inference incongruent sentence endings in the causal condition. In emotional sentences, both inference congruent and incongruent endings exerted this frontally distributed late positivity. For the violation of locative inferences, the larger positivity was only marginally significant over left posterior scalp locations. Thus, not all inference eliciting sentences evoked a similar pattern of ERP responses. We interpret and discuss our results in line with recent views on what the N400, the P600 and the pN400FP brainwave potentials index. Copyright © 2016 Elsevier Ltd. All rights reserved.
Lucy J Troup
Full Text Available The effect of cannabis on emotional processing was investigated using event-related potential paradigms (ERPs. ERPs associated with emotional processing of cannabis users, and non-using controls, were recorded and compared during an implicit and explicit emotional expression recognition and empathy task. Comparisons in P3 component mean amplitudes were made between cannabis users and controls. Results showed a significant decrease in the P3 amplitude in cannabis users compared to controls. Specifically, cannabis users showed reduced P3 amplitudes for implicit compared to explicit processing over centro-parietal sites which reversed, and was enhanced, at fronto-central sites. Cannabis users also showed a decreased P3 to happy faces, with an increase to angry faces, compared to controls. These effects appear to increase with those participants that self-reported the highest levels of cannabis consumption. Those cannabis users with the greatest consumption rates showed the largest P3 deficits for explicit processing and negative emotions. These data suggest that there is a complex relationship between cannabis consumption and emotion processing that appears to be modulated by attention.
Domahs, Ulrike; Kehrein, Wolfgang; Knaus, Johannes; Wiesel, Richard; Schlesewsky, Matthias
How are violations of phonological constraints processed in word comprehension? The present article reports the results of an event-related potentials (ERP) study on a phonological constraint of German that disallows identical segments within a syllable or word (CC(i)VC(i)). We examined three types of monosyllabic late positive CCVC words: (a) existing words [see text], (b) wellformed novel words [see text] and component (c) illformed novel words [see text] as instances of Obligatory Contour Principle non-word (OCP) violations. Wellformed and illformed novel words evoked an N400 effect processing in comparison to existing words. In addition, illformed words produced an enhanced late posterior positivity effect compared to wellformed novel words. obligatory contour Our findings support the well-known observation that novel words evoke principle higher costs in lexical integration (reflected by N400 effects). Crucially, modulations of a late positive component (LPC) show that violations of phonological phonotactic constraints influence later stages of cognitive processing even constraints when stimuli have already been detected as non-existing. Thus, the comparison of electrophysiological effects evoked by the two types of non-existing words reveals the stages at which phonologically based structural wellformedness comes into play during word processing.
Raz, Sivan; Dan, Orrie; Arad, Hen; Zysberg, Leehu
The present study was aimed at identifying potential behavioral and neural correlates of emotional intelligence (EI) by using scalp-recorded Event-Related Potentials (ERPs). EI levels were defined according to both self-report questionnaire and a performance-based test. We identified ERP correlates of emotional processing by comparing ERPs elicited in trials using pleasant, neutral and unpleasant pictures. The effects of these emotion-inducing pictures were then compared across groups with low and high EI levels. Behavioral results revealed a significant valence×EI group interaction effect since valence ratings were lower for unpleasant pictures and higher for pleasant pictures in the high EI group compared with the low EI group. The groups did not differ with respect to neutral picture ratings. The ERP results indicate that participants with high EI exhibited significantly greater mean amplitudes of the P2 (200-300ms post-stimulus) and P3 (310-450ms post-stimulus) ERP components in response to emotional and neutral pictures, at posterior-parietal as well as at frontal scalp locations. This may suggest greater recruitment of resources to process all emotional and non-emotional stimuli at early and late processing stages among individuals with higher EI. The present study also underscores the usefulness of ERP methodology as a sensitive measure for the study of emotional stimuli processing in the research field of EI. Copyright © 2013 Elsevier B.V. All rights reserved.
Ibáñez, Agustín; Toro, Pablo; Cornejo, Carlos; Urquina, Hugo; Hurquina, Hugo; Manes, Facundo; Weisbrod, Matthias; Schröder, Johannes
Human communication in a natural context implies the dynamic coordination of contextual clues, paralinguistic information and literal as well as figurative language use. In the present study we constructed a paradigm with four types of video clips: literal and metaphorical expressions accompanied by congruent and incongruent gesture actions. Participants were instructed to classify the gesture accompanying the expression as congruent or incongruent by pressing two different keys while electrophysiological activity was being recorded. We compared behavioral measures and event related potential (ERP) differences triggered by the gesture stroke onset. Accuracy data showed that incongruent metaphorical expressions were more difficult to classify. Reaction times were modulated by incongruent gestures, by metaphorical expressions and by a gesture-expression interaction. No behavioral differences were found between the literal and metaphorical expressions when the gesture was congruent. N400-like and LPC-like (late positive complex) components from metaphorical expressions produced greater negativity. The N400-like modulation of metaphorical expressions showed a greater difference between congruent and incongruent categories over the left anterior region, compared with the literal expressions. More importantly, the literal congruent as well as the metaphorical congruent categories did not show any difference. Accuracy, reaction times and ERPs provide convergent support for a greater contextual sensitivity of the metaphorical expressions. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.
Full Text Available Previous research has shown that exposure to violent video games increases aggression, whereas exposure to prosocial video games can reduce aggressive behavior. However, little is known about the neural correlates of these behavioral effects. This work is the first to investigate the electrophysiological features of the relationship between playing a prosocial video game and inhibition of aggressive behavior. Forty-nine subjects played either a prosocial or a neutral video game for 20 minutes, then participated in an event-related potential (ERP experiment based on an oddball paradigm and designed to test electrophysiological responses to prosocial and violent words. Finally, subjects completed a competitive reaction time task (CRTT, which is based on Taylor’s Aggression Paradigm and measures both reaction time and noise intensity preference as indices of aggressive behavior. The results show that the prosocial video game group (compared to the neutral video game group displayed smaller P300 amplitudes, were more accurate in distinguishing violent words, and were less aggressive as evaluated by the CRTT (noise intensity preference. A mediation analysis shows that the P300 amplitude evoked by violent words partially mediates the relationship between type of video game and subsequent aggressive behavior. The results support theories based on the General Learning Model. We provide converging behavioral and neural evidence that exposure to prosocial media may reduce aggression.
Full Text Available Recent research has shown that neurophysiological activation during action planning depends on the orientation to initial or final action goals for precision grips. However, the neural signature for a distinct class of grasping, power grips, is still unknown. The aim of the present study was to differentiate between cerebral activity, by means of event-related potentials (ERPs, and its temporal organization during power grips executed with an emphasis on either the initial or final parts of movement sequences. In a grasp and transportation task, visual cues emphasized either the grip (the immediate goal or the target location (the final goal. ERPs differed between immediate and final goal-cued conditions, suggesting different means of operation dependent on goal-relatedness. Differences in mean amplitude occurred earlier for power grips than for recently reported precision grips time-locked to grasping over parieto-occipital areas. Time-locked to final object placement, differences occurred within a similar time window for power and precision grips over frontal areas. These results suggest that a parieto-frontal network of activation is of crucial importance for grasp planning and execution. Our results indicate that power grip preparation and execution for goal-related actions are controlled by similar neural mechanisms as have been observed during precision grips, but with a distinct temporal pattern.
Taha, Haitham; Khateb, Asaid
The Arabic alphabetical orthographic system has various unique features that include the existence of emphatic phonemic letters. These represent several pairs of letters that share a phonological similarity and use the same parts of the articulation system. The phonological and articulatory similarities between these letters lead to spelling errors where the subject tends to produce a pseudohomophone (PHw) instead of the correct word. Here, we investigated whether or not the unique orthographic features of the written Arabic words modulate early orthographic processes. For this purpose, we analyzed event-related potentials (ERPs) collected from adult skilled readers during an orthographic decision task on real words and their corresponding PHw. The subjects' reaction times (RTs) were faster in words than in PHw. ERPs analysis revealed significant response differences between words and the PHw starting during the N170 and extending to the P2 component, with no difference during processing steps devoted to phonological and lexico-semantic processing. Amplitude and latency differences were found also during the P6 component which peaked earlier for words and where source localization indicated the involvement of the classical left language areas. Our findings replicate some of the previous findings on PHw processing and extend them to involve early orthographical processes. PMID:24348367
Sakamoto, Kiwako; Nakata, Hiroki; Yumoto, Masato; Sadato, Norihiro; Kakigi, Ryusuke
The purpose of the present study was to investigate the effect of mastication on Go/No-go decisional processing using event-related potentials (ERPs). Thirteen normal subjects underwent seven sessions of a somatosensory Go/No-go paradigm for approximately 4min; Pre, and Post 1, 2, 3, 4, 5, and 6. The Control condition included the same seven sessions. The RT and standard deviation were recorded, and the peak amplitude and latency of the N140 and P300 components were analyzed. The RT was significantly shorter in Mastication than in Control at Post 1-3 and 4-6. The peak latency of N140 was earlier in Mastication than in Control at Post 4-6. The latency of N140 was shortened by repeated sessions in Mastication, but not by those in Control. The peak latency of P300 was significantly shorter in Mastication than in Control at Post 4-6. The peak latency of P300 was significantly longer in Control with repeated sessions, but not in Mastication. These results suggest that mastication may influence response execution processing in Go trials, as well as response inhibition processing in No-go trials. Mastication accelerated Go/No-go decisional processing in the human brain. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Full Text Available The selection of task-relevant information requires both the focalization of attention on the task and resistance to interference from irrelevant stimuli. A previous study using the P3 component of the event-related potentials suggested that a reduced ability to resist interference could be responsible for attention disorders at early stages of Parkinson's disease (PD, with a possible role of the dorsolateral prefrontal cortex (DLPFC.Our objective was to better determine the origin of this impairment, by studying an earlier ERP component, the N2, and its subcomponents, as they reflect early inhibition processes and as they are known to have sources in the anterior cingulate cortex (ACC, which is involved together with the DLPFC in inhibition processes. Fifteen early-stage PD patients and 15 healthy controls (HCs performed a three-stimulus visual oddball paradigm, consisting in detecting target inputs amongst standard stimuli, while resisting interference from distracter ones. A 128-channel electroencephalogram was recorded during this task and the generators of the N2 subcomponents were identified using standardized weighted low-resolution electromagnetic tomography (swLORETA.PD patients displayed fewer N2 generators than HCs in both the DLPFC and the ACC, for all types of stimuli. In contrast to controls, PD patients did not show any differences between their generators for different N2 subcomponents.Our data suggest that impaired inhibition in PD results from dysfunction of the DLPFC and the ACC during the early stages of attentional processes.
Full Text Available Internet addiction disorder (IAD is associated with deficits in social communication and avoidance of social contact. It has been hypothesized that people with IAD may have an impaired capacity for empathy. The purpose of the current study was to examine the processing of empathy for others’ pain in IADs. Event-related potentials produced in response to pictures showing others in painful and non-painful situations were recorded in 16 IAD subjects and 16 healthy controls (HCs. The N1, P2, N2, P3, and late positive potential components were compared between the two groups. Robust picture × group interactions were observed for N2 and P3. The painful pictures elicited larger N2 and P3 amplitudes than the non-painful pictures did only in the HC group but not in the IAD group. The results of this study suggest that both of the early automatic and of the later cognitive processes of pain empathy may be impaired in IADs. This study provides psychophysical evidence of empathy deficits in association with IAD. Further studies combining multidimensional measurements of empathy are needed to confirm these findings.
Xuan, Dong; Wang, Suhong; Yang, Yilin; Meng, Ping; Xu, Feng; Yang, Wen; Sheng, Wei; Yang, Yuxia
In this study, we investigated the age difference in numeral recognition and calculation in one group of school-aged children (n = 38) and one of undergraduate students (n = 26) using the event-related potential (ERP) methods. Consistent with previous reports, the age difference was significant in behavioral results. Both numeral recognition and calculation elicited a negativity peaking at about 170-280 ms (N2) and a positivity peaking at 200-470 ms (pSW) in raw ERPs, and a difference potential (dN3) between 360 and 450 ms. The difference between the two age groups indicated that more attention resources were devoted to arithmetical tasks in school-aged children, and that school-aged children and undergraduate students appear to use different strategies to solve arithmetical problems. The analysis of frontal negativity suggested that numeral recognition and mental calculation impose greater load on working memory and executive function in schoolchildren than in undergraduate students. The topography data determined that the parietal regions were responsible for arithmetical function in humans, and there was an age-related difference in the area of cerebral activation.
Leen eVan Beek
Full Text Available This study used for the first time event-related potentials (ERPs to examine the well-known arithmetic problem size effect in children. The electrophysiological correlates of this problem size effect have been well documented in adults, but such information in children is lacking. In the present study, 22 typically developing 12-year-olds were asked to solve single-digit addition problems of small (sum ≤ 10 and large problem size (sum > 10 and to speak the solution into a voice key while ERPs were recorded. Children displayed similar early and late components compared to previous adult studies on the problem size effect. There was no effect of problem size on the early components P1, N1 and P2. The peak amplitude of the N2 component showed more negative potentials on left and right anterior electrodes for large additions compared to small additions, which might reflect differences in attentional and working memory resources between large and small problems. The mean amplitude of the late positivity component (LPC, which follows the N2, was significantly larger for large than for small additions at right parieto-occipital electrodes, in line with previous adult data. The ERPs of the problem size effect during arithmetic might be a useful neural marker for future studies on fact retrieval impairments in children with mathematical difficulties.
Danckert, James; Ferber, Susanne; Goodale, Melvyn A
Exposure to prisms has long been used to explore the control of visually guided actions primarily because adaptation requires the recalibration of misaligned reference frames due to perturbed visual input (i.e. eye-in-head and hand-centered reference frames must be realigned). To date, the only neuroimaging study to explore the direct effects of prisms on pointing used positron emission tomography and found increased activation only in right parietal cortex. We used event-related functional MRI to examine the effects of prisms on visuomanual pointing. Results demonstrated changes in activity in the anterior cingulate, the anterior intraparietal region and in a medial region of the right cerebellum. Specifically, activity in these regions was higher for the first few pointing trials made while viewing targets through prisms when directly contrasted to the last few trials. These results highlight that a more extensive network of cortical and cerebellar regions is involved in recalibrating visuomotor commands in the face of perturbed visual input.
Münte, Thomas F; Joppich, Gregor; Däuper, Jan; Schrader, Christoph; Dengler, Reinhard; Heldmann, Marcus
The generation of random sequences is considered to tax executive functions and has been reported to be impaired in Parkinson's disease (PD) previously. To assess the neurophysiological markers of random number generation in PD. Event-related potentials (ERP) were recorded in 12 PD patients and 12 age-matched normal controls (NC) while either engaging in random number generation (RNG) by pressing the number keys on a computer keyboard in a random sequence or in ordered number generation (ONG) necessitating key presses in the canonical order. Key presses were paced by an external auditory stimulus at a rate of 1 tone every 1800 ms. As a secondary task subjects had to monitor the tone-sequence for a particular target tone to which the number "0" key had to be pressed. This target tone occurred randomly and infrequently, thus creating a secondary oddball task. Behaviorally, PD patients showed an increased tendency to count in steps of one as well as a tendency towards repetition avoidance. Electrophysiologically, the amplitude of the P3 component of the ERP to the target tone of the secondary task was reduced during RNG in PD but not in NC. The behavioral findings indicate less random behavior in PD while the ERP findings suggest that this impairment comes about, because attentional resources are depleted in PD.
Full Text Available Bilinguals and musicians exhibit behavioral advantages on tasks with high demands on executive functioning, particularly inhibitory control, but the brain mechanisms supporting these differences are unclear. Of key interest is whether these forms of experience influence cognition through similar or distinct information processing mechanisms. Here, we recorded event-related potentials (ERPs in three groups - bilinguals, musicians, and controls - who completed a visual go-nogo task that involved the withholding of key presses to rare targets. Participants in each group achieved similar accuracy rates and responses times but the analysis of cortical responses revealed significant differences in ERP waveforms. Success in withholding a prepotent response was associated with enhanced stimulus-locked N2 and P3 wave amplitude relative to go trials. For nogo trials, there were altered timing-specific ERP differences and graded amplitude differences observed in the neural responses across groups. Specifically, musicians showed an enhanced early P2 response accompanied by reduced N2 amplitude whereas bilinguals showed increased N2 amplitude coupled with an increased late positivity wave relative to controls. These findings demonstrate that bilingualism and music training have differential effects on the brain networks supporting executive control over behavior.
Fukushima, T; Ikeda, T; Uyama, E; Uchino, M; Okabe, H; Ando, M
Auditory and visual cognitive event-related potentials (ERPs) were investigated in 14 patients with HTLV-1 associated myelopathy (HAM) and in 36 normal controls. In the HAM patients, the latencies of P300 and N200 by the auditory tone method were significantly delayed, and N100 by the auditory click method was significantly delayed in latency. No abnormal ERP components were observed with visual methods. While these auditory abnormal ERPs were present in the HAM patients, there was no evidence of visual abnormal ERPs. Abnormal lesions on the white matter were evident at magnetic resonance imaging (MRI) in 6 (75%) of 8 patients. There was no correlation between MRI lesions and the abnormalities of ERPs, but there was a significant correlation between bifrontal index on MRI and P300 amplitudes at Cz and Pz sites by auditory tone method. In one patient, atrophy of bilateral parietal lobes was seen on MRI and P300 latencies delayed using various methods. Therefore, the possibility that electrophysiological cognitive impairment in patients with HAM is related to brain atrophy rather than to white matter lesions requires attention.
Auditory event-related potentials (ERP) and sensomotor reaction time (RT) were investigated in divers during decompression from hyperbaric trimix conditions in order to assess the auditory information processing of the divers. Two passive series, 30 low (800 Hz) and 30 high (1200 Hz) tones were presented as well as one simple reaction task (SRT) and one choice reaction task (CRT) series. In both task series, the subjects were instructed to press the button as quickly as possible with the right-hand thumb after a low tone was heard. The individual analyses of the decompression period ERPs and RT data were compared with the pre-diving results for the series. Despite the interindividual differences, the sensomotor reactions were retarded during the decompression period, most clearly in the CRT. A prolongation of the N2 and P3 latency in this series gives grounds to accept that a cognitive slowing takes part in the longer reaction times during decompression. The slowing of the auditory information processing during decompression manifests with task manipulation difficulties.
Full Text Available Previous studies have found quantity of exposure, i.e., frequency of exposure (Horst et al., 1998; Webb, 2008; Pellicer-Sánchez and Schmitt, 2010, is important for second language (L2 contextual word learning. Besides this factor, context constraint and L2 proficiency level have also been found to affect contextual word learning (Pulido, 2003; Tekmen and Daloglu, 2006; Elgort et al., 2015; Ma et al., 2015. In the present study, we adopted the event-related potential (ERP technique and chose high constraint sentences as reading materials to further explore the effects of quantity of exposure and proficiency on L2 contextual word learning. Participants were Chinese learners of English with different English proficiency levels. For each novel word, there were four high constraint sentences with the critical word at the end of the sentence. Learners read sentences and made semantic relatedness judgment afterwards, with ERPs recorded. Results showed that in the high constraint condition where each pseudoword was embedded in four sentences with consistent meaning, N400 amplitude upon this pseudoword decreased significantly as learners read the first two sentences. High proficiency learners responded faster in the semantic relatedness judgment task. These results suggest that in high quality sentence contexts, L2 learners could rapidly acquire word meaning without multiple exposures, and L2 proficiency facilitated this learning process.
Full Text Available People have different motivations to get along with others in different sociality mental modes (i.e., communal mode and market mode, which might affect social decision-making. The present study examined how these two types of sociality mental modes affect the processing of advice-giving using the event-related potentials (ERPs. After primed with the communal mode and market mode, participants were instructed to decide whether or not give an advice (profitable or damnous to a stranger without any feedback. The behavioral results showed that participants preferred to give the profitable advice to the stranger more slowly compared with the damnous advice, but this difference was only observed in the market mode condition. The ERP results indicated that participants demonstrated more negative N1 amplitude for the damnous advice compared with the profitable advice, and larger P300 was elicited in the market mode relative to both the communal mode and the control group. More importantly, participants in the market mode demonstrated larger P300 for the profitable advice than the damnous advice, whereas this difference was not observed at the communal mode and the control group. These findings are consistent with the dual-process system during decision-making and suggest that market mode may lead to deliberate calculation for costs and benefits when giving the profitable advice to others.
Full Text Available Background and Aim: Following an early visual deprivation, the neural network involved in processing auditory spatial information undergoes a profound reorganization. In order to investigate this process, event-related potentials provide accurate information about time course neural activation as well as perception and cognitive processes. In this study, the latency and amplitude of auditory P300 were compared in sighted and early blind individuals in age range of 18-25 years old.Methods: In this cross-sectional study, auditory P300 potential was measured in conventional oddball paradigm by using two tone burst stimuli (1000 and 2000 Hz on 40 sighted subjects and 19 early blind subjects with mean age 20.94 years old.Results: The mean latency of P300 in early blind subjects was significantly smaller than sighted subjects (p=0.00.( There was no significant difference in amplitude between two groups (p>0.05.Conclusion: Reduced latency of P300 in early blind subjects in comparison to sighted subjects probably indicates the rate of automatic processing and information categorization is faster in early blind subjects because of sensory compensation. It seems that neural plasticity increases the rate of auditory processing and attention in early blind subjects.
Full Text Available Human intrinsic motivation is of great importance in human behavior. However, although researchers have focused on this topic for decades, its neural basis was still unclear. The current study employed event-related potentials to investigate the neural disparity between an interesting stop-watch (SW task and a boring watch-stop task (WS to understand the neural mechanisms of intrinsic motivation. Our data showed that, in the cue priming stage, the cue of the SW task elicited smaller N2 amplitude than that of the WS task. Furthermore, in the outcome feedback stage, the outcome of the SW task induced smaller FRN amplitude and larger P300 amplitude than that of the WS task. These results suggested that human intrinsic motivation did exist and that it can be detected at the neural level. Furthermore, intrinsic motivation could be quantitatively indexed by the amplitude of ERP components, such as N2, FRN, and P300, in the cue priming stage or feedback stage. Quantitative measurements would also be convenient for intrinsic motivation to be added as a candidate social factor in the construction of a machine learning model.
Krause, C M; Lang, H; Laine, M; Kuusisto, M; Pörn, B
Event-Related Desynchronization (ERD) and Synchronization (ERS) were studied in 20 normal subjects during a Sternberg-type auditory memory-scanning paradigm. Half of the subjects performed the experiment with vowels and the other half with tones as stimuli. The stimuli consisted of 100 msec long synthesized vowels and 100 msec long tones produced by eight different synthesized instruments. In this paradigm each trial started with the presentation of a visual warning signal, after which a four-stimulus set was presented for memorization whether after a probe stimulus was presented and identified by the subject as belonging or not belonging to the memorized set. The ERD/ERS of the lower (8-10 Hz) and upper (10-12 Hz) alpha frequency bands differed in their reactivity to stimulus type; the differences between the two frequency bands reached statistical significance only in the case of vowels. The presentation of the memory set elicited ERS which was more pronounced in the 10-12 Hz frequency band and greater for vowels than for tones. On the other hand, the presentation of the probe elicited ERD which was greater for vowels than for tones, especially in the upper alpha frequency band. The results of this exploratory study suggest that ERD is closely related to memory process and that the ERD/ERS-technique might provide a valuable tool for future research encompassing more complex auditory stimulation like speech and music.
Full Text Available Recent studies demonstrate that syntactic processing can be affected by emotional information and that subliminal emotional information can also affect cognitive processes. In this study, we explore whether unconscious emotional information may also impact syntactic processing. In an Event-Related brain Potential (ERP study, positive, neutral and negative subliminal adjectives were inserted within neutral sentences, just before the presentation of the supraliminal adjective. They could either be correct (50% or contain a morphosyntactic violation (number or gender disagreements. Larger error rates were observed for incorrect sentences than for correct ones, in contrast to most studies using supraliminal information. Strikingly, emotional adjectives affected the conscious syntactic processing of sentences containing morphosyntactic anomalies. The neutral condition elicited left anterior negativity (LAN followed by a P600 component. However, a lack of anterior negativity and an early P600 onset for the negative condition were found, probably as a result of the negative subliminal correct adjective capturing early syntactic resources. Positive masked adjectives in turn prompted an N400 component in response to morphosyntactic violations, probably reflecting the induction of a heuristic processing mode involving access to lexico-semantic information to solve agreement anomalies. Our results add to recent evidence on the impact of emotional information on syntactic processing, while showing that this can occur even when the reader is unaware of the emotional stimuli.
Ray, Koushik; Chatterjee, Abhirup; Panjwani, Usha; Kumar, Sanjeev; Sahu, Surajit; Ghosh, Sayan; Thakur, Lalan; Anand, Jag Parvesh
The efficacy of modafinil as a countermeasure in the reduction of cognitive decline following 24 h of sleep deprivation (SD) on subjective sleepiness scales, event-related potential (ERP) P300, and contingent negative variation (CNV) was evaluated. Eleven healthy males, age 25-30 years participated. The experiment was performed in five sessions on different days between 7 and 8a.m. Session 1, baseline recordings; Session 2, after one night's SD; Session 3, 48 h of recovery from SD; Session 4, after 1 week of Session 1, following one night's SD along with modafinil (400mg/day); Session 5, 48 h of recovery after SD+modafinil. Subjective sleepiness scores increased significantly after SD as compared to baseline (PP300 peak latencies of ERP following SD (PP300 peak latencies after SD (PP300 amplitudes and CNV N100, M200 peak latencies and M100, M200 amplitudes were observed. The results strongly suggest that modafinil in a dose of 400mg/day, reduces the subjective sleepiness and cognitive decline following 24 h of SD. Copyright © 2012 Elsevier Inc. All rights reserved.
Heinrich, Sven P; Marhöfer, David; Bach, Michael
An objective assessment of sensory and sensuo-cognitive function, based on physiological signals rather than on the behavioral response of a patient, is often advisable, albeit challenging. Evoked potentials are frequently used as an objective measure, but usually fail to detect defects beyond primary sensory areas, including those of psychogenic origin. Here we assess whether the event-related P300 component may be used to measure "cognitive" visual acuity. A visual oddball paradigm was used to elicit P300 responses in subjects with normal or artificially blurred vision. Probe stimuli consisted of infrequently presented gratings with spatial frequencies in the range of 2.2-16.2 cycles per degree, which could be either target or non-target stimuli depending on their orientation. Frequent stimuli were homogeneously grey fields. Without blur, rare stimuli of all spatial frequencies produced reliable P300 responses. Blur abolished the P300 to fine gratings consistently in 10 of 11 subjects. The drop in P300 amplitude was steep, rather than gradual, between visible and invisible gratings. The P300 is sensitive to identify the resolution threshold and thus may serve as a tool for estimating acuity in cases of visual impairments. The study presents a tool for the objective assessment of acuity in cases of higher-level visual impairments. The concept can most likely be extended to other sensory modalities. 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.
Yang, Shuo; Qiao, Yanyun; Wang, Lei; Hao, Pengru
Mental fatigue caused by continuous cognitive tasks represents one of the most worrying modern health problems. Event Related Potential (ERP) P300 is thought to be associated with cognitive function. This study aimed at characterizing the neural activity correlated with the attentional processes and exploring a novelty method which combine the magnetic stimulation and acupoint to relieve mental fatigue caused by continuous cognitive tasks. P300 (P3a and P3b) were extracted at three points: when subjects felt relaxed, at the point of mental fatigue, and after the subjects were stimulated at acupoints. The amplitudes and latencies of P3a and P3b were analyzed statistically. Among the four features (P3a amplitude, P3a latency, P3b amplitude, and P3b latency), only P3b amplitude was found to have a significant difference between the resting state and the mental fatigue state. And P3b amplitude significantly increased after magnetic stimulation at the acupoints. Subjects experiencing mental fatigue demonstrated a significant decrease in P3b amplitude in the parietal region, suggesting attenuation of resource allocation for selective attention. P3b amplitude significantly increased after magnetic stimulation at acupoints indicating that this strategy can be used to improve selective attention and relieve mental fatigue.
Kim, Sung Min; Choi, Jeong Woo; Lee, Chany; Lee, Byeong Uk; Koo, Yong Seo; Kim, Kyung Hwan; Jung, Ki-Young
The aim of this study was to investigate whether there is a working memory (WM) deficit in restless legs syndrome (RLS) patients, by studying the Sternberg WM task of event-related potential (ERP). Thirteen drug-naive RLS patients and 13 healthy age-matched controls with no sleep disturbances participated in the present study. P300 ERP was recorded during Sternberg WM task using digits as mnemonic items. P300 amplitudes and reaction times were compared between groups (RLS vs. control) considering brain regions (frontal, central, and parietal) and memory load sizes (two, three, and four) as within-subject factors. Clinical and sleep-related variables were correlated with P300 amplitude. The reaction time in RLS patients was significantly longer than controls over all memory load sizes. The P300 amplitude at parietal regions in RLS patients was significantly lower than in controls regardless of memory load sizes, which was significantly negatively correlated with duration of RLS history in RLS patients. Our study suggests that patients with severe RLS have WM deficits. Furthermore, negative correlation of P300 amplitudes with the duration of RLS illness suggests that cerebral cortical dysfunction in RLS patients results from repeated RLS symptom attacks. Copyright © 2014 Elsevier B.V. All rights reserved.
Titlic, Marina; Mise, Nikolina Ivica; Pintaric, Irena; Rogosic, Veljko; Vanjaka-Rogosic, Lucija; Mihalj, Mario; Jurinovic, Pavao; Katic, Ana Curkovic; Andjelinovic, Maja
Recording of event-related potentials by using oddball paradigm of auditory P300 has yielded conflicting results in migraine. The aim of this study was to demonstrate that migraine patients have reduced P300 amplitude and prolonged P300 latency, suggesting alterations of the cognitive-evaluative component. We recruited 29 migraine patients (24 females; median age 40 years) and 29 healthy age- and gender-matched participants. Participants were subjected to the same testing procedures of auditory P300 by discrimination the target auditory stimulus from the frequent stimulus, and analyzing P300 target/frequent stimulus amplitudes, and P300 target/frequent stimulus latencies. Patients with migraine don't have prolonged P300 target stimulus latency, but have a longer P300 frequent stimulus latency for 17.5ms. Out of 29 participants with migraine 8 had pathological P300 target stimulus amplitude, and 19 had pathological P300 frequent stimulus amplitude. People with migraine have altered the P300 which indicates the presence of cognitive dysfunction in these patients and importance of early diagnosis and intervention to preventing any deterioration in cognitive functions.
Pogarell, Oliver; Padberg, Frank; Karch, Susanne; Segmiller, Felix; Juckel, Georg; Mulert, Christoph; Hegerl, Ulrich; Tatsch, Klaus; Koch, Walter
The P300 is a cortically generated event related potential (ERP) widely used in neurophysiological research since it is related to cognitive functions and central information processing. Intracerebral recordings and functional neuroimaging studies have demonstrated that this potential is generated by various brain regions including frontal, temporal and parietal cortices. Regarding the neurochemical background, clinical and genetic investigations suggest that dopaminergic neurons could be involved in the generation of the P300. However, there is no direct evidence in vivo that P300 amplitudes and latencies are related to dopaminergic parameters. The aim of this study was to further elucidate dopaminergic aspects of the P300 ERP by combining neurophysiological and nuclear medicine assessments in vivo. Patients with a major depressive episode underwent both P300 recordings and dynamic [¹²³I] IBZM SPECT for the evaluation of striatal dopamine D₂/D₃-receptor availability. There were statistically significant positive correlations of the striatal dopamine D₂/D₃-receptor status with P300 amplitudes and significant negative correlations with P300 latencies. Using this combined approach, the study presents direct evidence in vivo that the central dopaminergic system might play an important role in the generation of the P300 and that central dopaminergic activity could be involved in the modulation of P300 parameters. This association might be of relevance for the interpretation of P300 studies in psychiatric disorders. 2011 Elsevier Ireland Ltd. All rights reserved.
Full Text Available Disturbances of thyroid function are often accompanied by cognitive and affective disorders. Assessment of cognitive status in the patients with subclinical hypothyroidism represents a possibility for early diagnostics of cognitive impairment and timely introduction of necessary pharmacotherapy treatment. The aim of this study was to quantify whether there are P3 event related potential (ERP deviations as electrophysiological markers of cognitive activity in patients with subclinical hypothyroidism. P300 potentials were examined in thirty patients with subclinical hypothyroidism and in 30 healthy subjects of the control group. P300 was recorded using the classic auditory oddball paradigm, with 20% of target and 80% of non-target stimuli. The results analysis showed a significantly longer latency P300 and reduced amplitude P300 in subjects with subclinical hypothyroidism compared to euthyroid subjects. There is also a statistically significant negative correlation between the results of a mini mental state examination and the P300 latency at Fz electrode (r= -0.47, p <0.01 and Cz electrode (r= -0.43, p =0.017. P300 ERP is important in the evaluation of patients with subclinical hypothyroidism, due to the sensitivity in the detection cognitive disorders.
Xiong, Peng; Zeng, Yong; Zhu, Zuxin; Tan, Deyong; Xu, Fei; Lu, Jin; Wan, Jing; Ma, Mingxing
Nerve growth factor (NGF) plays a crucial role in central nervous system neuron plasticity. Low levels of serum NGF in schizophrenic patients suggest that the neurotrophin contributes to the pathogenesis of the disease. NGF is also thought to alter characteristics of event-related brain potential (ERP) components. The auditory-evoked P300 ERP component, considered an index of brain activity, has reduced amplitude in acute and chronic schizophrenia. This study evaluated the relationship among serum NGF levels, P300 characteristics, and Positive and Negative Symptom Scale (PANSS) scores in first episode, neuroleptic naive schizophrenic patients (N=30) and healthy controls (N=28). Serum NGF was measured by ELISA and P300 elicited using auditory oddball paradigm. Compared to control subjects, schizophrenic patients had significantly reduced serum NGF (pP300 amplitudes at Fz (p=0.003). Additionally, there was a positive correlation between serum NGF serum and P300 amplitude at Fz. No correlation was found between serum NGF or P300 characteristics and PANSS scores. These results suggest that the effects of NGF in schizophrenia are related not only to regulation of neurodevelopment, but also to the electrophysiological characteristics of nerve growth factor. Copyright (c) 2010 Elsevier B.V. All rights reserved.
Wickens, C. D.; Heffley, E. F.; Kramer, A. F.; Donchin, E.
The advantages of employing the event-related brain potential (ERP) in the assessment of allocation of attention in dynamic environments are discussed. Three experiments are presented in which the P300 component of the ERP is demonstrated to be a useful index of subjects' locus of attention. The first two experiments were concerned with the allocation of attention during discrete and continuous visual monitoring tasks. The results indicated that a P300 was elicited only by stimuli to which the subject had to attend in order to perform successfully the task. The third experiment was conducted to assess the sensitivity of P300 to the manner in which attention is allocated to different aspects of a display during the performance of a 3-dimensional target acquisition task. The amplitude of the P300 was found to reflect differences between two levels of workload, as well as the task relevance of the stimuli. The results of the experiments are discussed in terms of their utility in the evaluation of the design of man-machine systems as well as in the study of the allocation of attention in operational environments.
Xu, Kepeng; Li, Shifeng; Ren, Deyun; Xia, Ruixue; Xue, Hong; Zhou, Aibao; Xu, Yan
A growing number of studies have demonstrated preferential processing of self-related information. However, previous research has been limited in examining the distinction between processes related to the self and those related to the non-self, it remains unclear how self-related information with differing levels of importance is processed within the self. The present study examined how the importance of self-related content affects the neural activity involved in self-referential processing. The behavioral results showed that the participants had faster responses to more important self-related content. The event-related potential (ERP) results showed that early attention resources were diverted to the identification of highly important self-related content compared with minimally important self-related content, as reflected by the enhanced P200. Furthermore, the N200 amplitude for highly important self-related content was smaller than for moderately important self-related content which, in turn, were smaller than minimally important self-related content. Moreover, the P300 amplitudes were modulated by the degree of importance of self-related content, whereby a higher importance of self-related content led to larger P300 amplitudes. Taken together, these findings demonstrate an effect of the degree of importance of the self-related content at both behavioral and neurophysiological levels.
Full Text Available A growing number of studies have demonstrated preferential processing of self-related information. However, previous research has been limited in examining the distinction between processes related to the self and those related to the non-self, it remains unclear how self-related information with differing levels of importance is processed within the self. The present study examined how the importance of self-related content affects the neural activity involved in self-referential processing. The behavioral results showed that the participants had faster responses to more important self-related content. The event-related potential (ERP results showed that early attention resources were diverted to the identification of highly important self-related content compared with minimally important self-related content, as reflected by the enhanced P200. Furthermore, the N200 amplitude for highly important self-related content was smaller than for moderately important self-related content which, in turn, were smaller than minimally important self-related content. Moreover, the P300 amplitudes were modulated by the degree of importance of self-related content, whereby a higher importance of self-related content led to larger P300 amplitudes. Taken together, these findings demonstrate an effect of the degree of importance of the self-related content at both behavioral and neurophysiological levels.
Thakur, Lalan; Ray, Koushik; Anand, J P; Panjwani, Usha
The P300 wave is an event related potential (ERP) elicited by infrequent, task-relevant stimuli and appeared at about 300 ms, represents higher cognitive function of information processing, working memory or stimulus categorization. Hypobaric hypoxia deteriorates the cognitive function during the short term stay (days to few weeks) at high altitude. The present study was carried out to evaluate the P300 responses during long duration stay (1 month and 6 months) at high altitude (HA, 4115 m) in a sample of Indian lowlanders. The study was carried out on 18 healthy male volunteers at sea level (SL). The volunteers were stage inducted to 4115 m altitude in the Eastern Himalayas. The P300 was recorded after 1 and 6 months of their stay at HA. The latencies of peaks N100, P200 and N200 waves did not show any significant changes after 1 and 6 months of stay at HA as compared to SL. The P300 latency was significantly delayed after 1 month and further delayed after 6 month of residence at 4115 m. The P200 and P300 amplitudes did not show any changes. The increase in P300 latency indicated that long duration of stay at high altitude slows the stimulus evaluation processes. The observations suggest that hypoxia causes slowing of the signal processing at HA. The magnitude of the effects of hypobaric hypoxia may be dependent upon the duration of residence at high altitude.
Kishore, Krishna; Ray, Koushik; Anand, J P; Thakur, Lalan; Kumar, Sanjeev; Panjwani, Usha
The efficacy of tyrosine, a catecholamine precursor, as a countermeasure in the reduction of cognitive decline during heat exposure (HE) using event-related potential P300, and contingent negative variation (CNV) was evaluated. Ten healthy males, age 20-30years participated in the study. Volunteers received placebo or tyrosine (6.5g) 90min prior to HE (1.5h in 45°C+30% RH). P300 latency was significantly increased (p<0.01) during exposure with placebo, which was reduced significantly (p<0.01) after tyrosine supplementation. There was an increase in CNV M100 latency (p<0.05) and reaction time (p<0.01) and decrease in M100 amplitude (p<0.01) during HE with placebo, which returns to near normal level with the tyrosine administration. A significantly higher plasma norepinephrine (p<0.05), dopamine and epinephrine levels were detected in tyrosine supplemented group post heat exposure. HE increases the brain catecholamine activity thereby reduces the plasma norepinephrine and dopamine level leading to a reduction in cognitive performances. Tyrosine supplementation increases the catecholamine level and reduces the impairment of cognitive performance during HE. Copyright © 2013 Elsevier Inc. All rights reserved.
Yang, Wen; Li, Mei
The event related potential (ERP-P300) is useful to determine cognitive disturbances. This study examined the changes of ERP-P300 following different dosages of topiramate (TPM) treatment in children with epilepsy in order to investigate the effect of different dosages of TPM on cognitive function. Thirty cases of benign childhood epilepsy with centrotemporal spikes (BECTS) were first administered with TPM at a dosage of 2 mg/kg/d for 6 months. Afterwards they received another 6 months of TPM treatment at a dosage of 5 mg/kg/d. ERP-P300 was tested before and after different dosages of TPM treatment. There were no significant differences in the latency and amplitude of ERP-P300 before and after 6 months low dosages of TPM treatment. However, the latency was more prolonged and the amplitude was reduced in the ERP-P300 testing after 6 months high dosage of TMP treatment (Prelated to its dosage in children with epilepsy.
Full Text Available The brain is capable of elaborating and executing different stages of information processing. However, exactly how these stages are processed in the brain remains largely unknown. This study aimed to analyze the possible correlation between early and late stages of information processing by assessing the latency to, and amplitude of, early and late event-related potential (ERP components, including P200, N200, premotor potential (PMP and P300, in healthy participants in the context of a visual oddball paradigm. We found a moderate positive correlation among the latency of P200 (electrode O2, N200 (electrode O2, PMP (electrode C3, P300 (electrode PZ and the reaction time (RT. In addition, moderate negative correlation between the amplitude of P200 and the latencies of N200 (electrode O2, PMP (electrode C3, P300 (electrode PZ was found. Therefore, we propose that if the secondary processing of visual input (P200 latency occurs faster, the following will also happen sooner: discrimination and classification process of this input (N200 latency, motor response processing (PMP latency, reorganization of attention and working memory update (P300 latency, and RT. N200, PMP, and P300 latencies are also anticipated when higher activation level of occipital areas involved in the secondary processing of visual input rise (P200 amplitude.
Zhong, Jun; Liu, Yongfang; Zhang, Entao; Luo, Junlong; Chen, Jie
Individuals may pay more attention to information about envied targets. Thus, we further investigate the neural correlates underlying the cognitive processing of envy-related stimuli. Participants read information about target persons characterized by two domains: levels of possession and self-relevance of comparison. Event-related potentials (ERPs) were then recorded for three target names (high-envy, moderate-envy, and low-envy) while participants performed a three-stimulus oddball task. The results showed that high- and moderate-envy target names elicited larger P300 amplitudes than did low-envy target names. Specifically, high-envy target names elicited larger P300 amplitudes than did low-envy target names at the left, central, and right sites; in contrast, moderate-envy target names elicited larger P300 amplitudes than did low-envy target names only at central sites. P300 amplitudes did not differ between high- and moderate-envy target names. Thus, we extend previous behavioral findings by showing that people preferentially attend toward envy-related stimuli, as reflected by enhanced P300 amplitudes. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.
Full Text Available Introduction:Previous studies have highlighted the advantage of audio–visual oddball tasks (instead of unimodal ones in order to electrophysiologically index subclinical behavioral differences. Since alexithymia is highly prevalent in the general population, we investigated whether the use of various bimodal tasks could elicit emotional effects in low- versus high-alexithymic scorers. Methods:Fifty students (33 females were split into groups based on low and high scores on the Toronto Alexithymia Scale. During event-related potential recordings, they were exposed to three kinds of audio–visual oddball tasks: neutral (geometrical forms and bips, animal (dog and cock with their respective shouts, or emotional (faces and voices stimuli. In each condition, participants were asked to quickly detect deviant events occurring amongst a train of frequent matching stimuli (e.g., push a button when a sad face–voice pair appeared amongst a train of neutral face–voice pairs. P100, N100, and P300 components were analyzed: P100 refers to visual perceptive processing, N100 to auditory ones, and the P300 relates to response-related stages. Results:High-alexithymic scorers presented a particular pattern of results when processing the emotional stimulations, reflected in early ERP components by increased P100 and N100 amplitudes in the emotional oddball tasks (P100: pConclusions:Our findings suggest that high-alexithymic scorers require heightened early attentional resources when confronted with emotional stimuli.
Demestre, J; Meltzer, S; García-Albea, J E; Vigil, A
Event-related brain potentials (ERPs) were recorded during spoken language comprehension to study the on-line effects of gender agreement violations in controlled infinitival complements. Spanish sentences were constructed in which the complement clause contained a predicate adjective marked for syntactic gender. By manipulating the gender of the antecedent (i.e., the controller) of the implicit subject while holding constant the gender of the adjective, pairs of grammatical and ungrammatical sentences were created. The detection of such a gender agreement violation would indicate that the parser had established the coreference relation between the null subject and its antecedent. The results showed a complex biphasic ERP (i.e., an early negativity with prominence at anterior and central sites, followed by a centroparietal positivity) in the violating condition as compared to the non-violating conditions. The brain reacts to NP-adjective gender agreement violations within a few hundred milliseconds of their occurrence. The data imply that the parser has properly coindexed the null subject of an infinitive clause with its antecedent.
Full Text Available Primary Progressive Aphasia (PPA is a rare and insidious language impairment that worsens over time. It belongs to the group of fronto–temporal dementias. This study was aimed at assessing the role of speed of cognitive abilities, such as word recognition, in PPA. The design is a single-case, longitudinal study. A male patient suffering from PPA was enrolled and 15 healthy older adults were the control group. An event-related electrical potential connected with word recognition, namely the N400, was delayed by 200 msec at baseline compared to healthy controls and progressively deteriorated. One year later, the delay was greater and two years later the potential had disappeared. Reduced speed of processing is an early pathological factor that negatively affecting higher cognitive functions in APP. Event–related electrical potentials are recommended in the field of aphasia and cognitive decline. They permit observation of a speed decline in higher cognitive abilities, when pathological changes at a central level begin and language comprehension seems to be unaffected.
Full Text Available Searching for points of interest (POI in large-volume imagery is a challenging problem with few good solutions. In this work, a neural engineering approach called rapid image triage (RIT which could offer about a ten-fold speed up in POI searching is developed. It is essentially a cortically-coupled computer vision technique, whereby the user is presented bursts of images at a speed of 6–15 images per second and then neural signals called event-related potential (ERP is used as the ‘cue’ for user seeing images of high relevance likelihood. Compared to past efforts, the implemented system has several unique features: (1 it applies overlapping frames in image chip preparation, to ensure rapid image triage performance; (2 a novel common spatial-temporal pattern (CSTP algorithm that makes use of both spatial and temporal patterns of ERP topography is proposed for high-accuracy single-trial ERP detection; (3 a weighted version of probabilistic support-vector-machine (SVM is used to address the inherent unbalanced nature of single-trial ERP detection for RIT. High accuracy, fast learning, and real-time capability of the developed system shown on 20 subjects demonstrate the feasibility of a brainmachine integrated rapid image triage system for fast detection of POI from large-volume imagery.
Li, Feng; Li, Jiang; McKenzie, Frederic; Zhang, Guangfan; Wang, Wei; Pepe, Aaron; Xu, Roger; Schnell, Thomas; Anderson, Nick; Heitkamp, Dean
In this paper, we present methods to analyze and improve an EEG-based engagement assessment approach, consisting of data preprocessing, feature extraction and engagement state classification. During data preprocessing, spikes, baseline drift and saturation caused by recording devices in EEG signals are identified and eliminated, and a wavelet based method is utilized to remove ocular and muscular artifacts in the EEG recordings. In feature extraction, power spectrum densities with 1 Hz bin are calculated as features, and these features are analyzed using the Fisher score and the one way ANOVA method. In the classification step, a committee classifier is trained based on the extracted features to assess engagement status. Finally, experiment results showed that there exist significant differences in the extracted features among different subjects, and we have implemented a feature normalization procedure to mitigate the differences and significantly improved the engagement assessment performance.
A DISTINGUISH METHOD OF EPILEPTIC EEG AND DEGLUTITION EEG BASED ON CHAOTIC NOISE-REDUCTION* Guanghua Ouyang, Chunyan Li, Guotai Jiang College of Life...EEG and deglutition EEG’s nonnoise trajectory and distinguishing these two waveforms is presented. The main aim of this paper is to introduce the...different parameters of dipole, a method of distinguishing epileptic EEG and deglutition EEG using the measurement of nonlinear dynamics is obtained. Key
Janssen, T.W.P.; Bink, M.; Gelade, K.; van Mourik, R.; Maras, A.; Oosterlaan, J.
Objective: Electroencephalographic (EEG) neurofeedback (NF) is considered a nonpharmacological alternative for medication in attention-deficit/hyperactivity disorder (ADHD). Comparisons of the behavioral efficacy of NF and medication have produced inconsistent results. EEG measures can provide
Omurtag, Ahmet; Baki, Samah G Abdel; Chari, Geetha; Cracco, Roger Q; Zehtabchi, Shahriar; Fenton, Andr? A; Grant, Arthur C.
Background We describe and characterize the performance of microEEG compared to that of a commercially available and widely used clinical EEG machine. microEEG is a portable, battery-operated, wireless EEG device, developed by Bio-Signal Group to overcome the obstacles to routine use of EEG in emergency departments (EDs). Methods The microEEG was used to obtain EEGs from healthy volunteers in the EEG laboratory and ED. The standard system was used to obtain EEGs from healthy volunteers in the...
Full Text Available This paper reports on a multiresolution analysis of EEG signals. The dominant frequency components of signals with and without observed epileptic discharges were compared. The study showed that there were significant differences in dominant frequency between the signals with epileptic discharges and the signals without discharges. This gives the ability to identify epilepsy during EEG examination. The frequency of the signals coming from the frontal, central, parietal and occipital channels are similar. Multiresolution analysis can be used to describe the activity of brain waves and to try to predict epileptic seizures, thereby contributing to precise medical diagnoses.
Martel, Adrien; Dähne, Sven; Blankertz, Benjamin
Objective. The present study addressed the question whether neurophysiological signals exhibit characteristic modulations preceding a miss in a covert vigilant attention task which mimics a natural environment in which critical stimuli may appear in the periphery of the visual field. Approach. Subjective, behavioural and encephalographic (EEG) data of 12 participants performing a modified Mackworth Clock task were obtained and analysed offline. The stimulus consisted of a pointer performing regular ticks in a clockwise sequence across 42 dots arranged in a circle. Participants were requested to covertly attend to the pointer and press a response button as quickly as possible in the event of a jump, a rare and random event. Main results. Significant increases in response latencies and decreases in the detection rates were found as a function of time-on-task, a characteristic effect of sustained attention tasks known as the vigilance decrement. Subjective sleepiness showed a significant increase over the duration of the experiment. Increased activity in the α-frequency range (8-14 Hz) was observed emerging and gradually accumulating 10 s before a missed target. Additionally, a significant gradual attenuation of the P3 event-related component was found to antecede misses by 5 s. Significance. The results corroborate recent findings that behavioural errors are presaged by specific neurophysiological activity and demonstrate that lapses of attention can be predicted in a covert setting up to 10 s in advance reinforcing the prospective use of brain-computer interface (BCI) technology for the detection of waning vigilance in real-world scenarios. Combining these findings with real-time single-trial analysis from BCI may pave the way for cognitive states monitoring systems able to determine the current, and predict the near-future development of the brain's attentional processes.
Thiery, Thomas; Lajnef, Tarek; Jerbi, Karim; Arguin, Martin; Aubin, Mercedes; Jolicoeur, Pierre
Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP) components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. In this study, we used a modified Posner cueing task with an endogenous cue to determine the degree to which information in the EEG signal can be used to track visual spatial attention in presentation sequences lasting 200 ms. We used a machine learning classification method to evaluate how well EEG signals discriminate between four different locations of the focus of attention. We then used a multi-class support vector machine (SVM) and a leave-one-out cross-validation framework to evaluate the decoding accuracy (DA). We found that ERP-based features from occipital and parietal regions showed a statistically significant valid prediction of the location of the focus of visuospatial attention (DA = 57%, p < .001, chance-level 25%). The mean distance between the predicted and the true focus of attention was 0.62 letter positions, which represented a mean error of 0.55 degrees of visual angle. In addition, ERP responses also successfully predicted whether spatial attention was allocated or not to a given location with an accuracy of 79% (p < .001). These findings are discussed in terms of their implications for visuospatial attention decoding and future paths for research are proposed. PMID:27529476
Thiery, Thomas; Lajnef, Tarek; Jerbi, Karim; Arguin, Martin; Aubin, Mercedes; Jolicoeur, Pierre
Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP) components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. In this study, we used a modified Posner cueing task with an endogenous cue to determine the degree to which information in the EEG signal can be used to track visual spatial attention in presentation sequences lasting 200 ms. We used a machine learning classification method to evaluate how well EEG signals discriminate between four different locations of the focus of attention. We then used a multi-class support vector machine (SVM) and a leave-one-out cross-validation framework to evaluate the decoding accuracy (DA). We found that ERP-based features from occipital and parietal regions showed a statistically significant valid prediction of the location of the focus of visuospatial attention (DA = 57%, p < .001, chance-level 25%). The mean distance between the predicted and the true focus of attention was 0.62 letter positions, which represented a mean error of 0.55 degrees of visual angle. In addition, ERP responses also successfully predicted whether spatial attention was allocated or not to a given location with an accuracy of 79% (p < .001). These findings are discussed in terms of their implications for visuospatial attention decoding and future paths for research are proposed.
Full Text Available Visuospatial attention can be deployed to different locations in space independently of ocular fixation, and studies have shown that event-related potential (ERP components can effectively index whether such covert visuospatial attention is deployed to the left or right visual field. However, it is not clear whether we may obtain a more precise spatial localization of the focus of attention based on the EEG signals during central fixation. In this study, we used a modified Posner cueing task with an endogenous cue to determine the degree to which information in the EEG signal can be used to track visual spatial attention in presentation sequences lasting 200 ms. We used a machine learning classification method to evaluate how well EEG signals discriminate between four different locations of the focus of attention. We then used a multi-class support vector machine (SVM and a leave-one-out cross-validation framework to evaluate the decoding accuracy (DA. We found that ERP-based features from occipital and parietal regions showed a statistically significant valid prediction of the location of the focus of visuospatial attention (DA = 57%, p < .001, chance-level 25%. The mean distance between the predicted and the true focus of attention was 0.62 letter positions, which represented a mean error of 0.55 degrees of visual angle. In addition, ERP responses also successfully predicted whether spatial attention was allocated or not to a given location with an accuracy of 79% (p < .001. These findings are discussed in terms of their implications for visuospatial attention decoding and future paths for research are proposed.
Li, Yuezhi; Wang, Li-Qun; Hu, Yong
To assess the effects of stimulus context on the P300 component, an eight-orientation Landolt ring task was introduced. As the stimulus context of this task differs from the traditional two-stimulus oddball paradigm, the purpose here was to apply EEG/fMRI integration to investigate the localization and activities of the P300 generators involved with this task. Ten healthy subjects performed the visual P300 task while fMRI and 64-channel ERP data were acquired. The voltage topographical maps of the P300 component were calculated and analyzed for the main activation foci. Furthermore, constraints from fMRI were used to identify the source activities of visual P300 ERP. Analysis of the hemodynamic response to the visual target stimuli revealed a distributed network of neural sources in the bilateral parietal lobules, middle and inferior frontal gyrus, precentral and postcentral cortex, and anterior cingulate gyrus. The analysis particularly showed preponderant activations of the bilateral superior parietal lobules. In this target detection design, two distinct P300 peaks were observed in the dipole waveforms, the bilateral prefrontal and the right inferior parietal dipole waveforms displayed the higher peak at short latency, while the four parietal, the anterior cingulate, and the temporal dipole waveforms had the higher peak at long latency. Compared with the classical oddball paradigm, the amplitude decreased in this study, which might be related to its particular stimulus context. The source technique was utilized to yield a realistic 11-dipole model and distinguish the anatomical generators of early and late components of the P300 response.
Ueno, Tomoyuki; Hada, Yasushi; Shimizu, Yukiyo; Yamada, Thoru
The somatosensory event-related potential N140 is thought to be related to selective attention. This study aimed to compare the somatosensory event-related potential N140 in healthy subjects to that in patients with stroke to determine whether N140 and attentiveness are associated in patients with stroke with or without hemispatial agnosia. Normal somatosensory event-related potential N140 values were determined using data from ten healthy subjects. Fifteen patients with stroke were divided into two groups based on the presence of hemispatial neglect. Somatosensory event-related potential N140 components were compared between the two groups. Stimulation of the affected limb in the hemispatial agnosia group resulted in significantly longer N140 latency at the contralateral vs. the ipsilateral electrode. This was the inverse of the relationship observed in normal subjects, with stimulation of the intact side in patients with hemispatial agnosia, and with stimulation of both the intact and affected sides in patients without agnosia. In the hemispatial agnosia group, the peak latency of N140 following stimulation of the affected side was significantly longer than it was following stimulation of the intact side and when compared to that in patients without agnosia. In addition, abnormal N140 peak latencies were observed at the Cz and ipsilateral electrodes in patients with hemispatial agnosia following stimulation of the intact side. These findings suggest that somatosensory event-related potential N140 is independently generated in each hemisphere and may reflect cognitive attention.
Boudreaux, Edwin D; Moon, Simon; Baumann, Brigitte M; Camargo, Carlos A; O'Hea, Erin; Ziedonis, Douglas M
Experiencing a serious consequence related to one's health behavior may motivate behavior change. This study sought to examine how causal attribution, perceived illness severity, and fear secondary to an acute health event relate to intentions to quit smoking. Using a cross-sectional survey design, adult emergency department patients who smoked provided demographic data and ratings of nicotine dependence, causal attribution, perceived illness severity, event-related fear, and intentions to quit smoking. A linear regression analysis was used to examine the relations between the independent variables and quit intentions. We enrolled 186 participants. After adjusting for nicotine dependence, smoking-related causal attribution and event-related fear were associated with intentions to quit (β = 0.26, p < 0.01 and β = 0.21, p < 0.01, respectively). Perceived illness severity was correlated with event-related fear (r = 0.46, p < 0.001) but was not associated with intentions to quit (β = -0.08, p = 0.32). While causal attribution and event-related fear were modestly associated with quit intentions, perceived illness severity was not. Longitudinal studies are needed to better explicate the relation between these variables and behavior change milestones.
Aloise, Fabio; Aricò, Pietro; Schettini, Francesca; Salinari, Serenella; Mattia, Donatella; Cincotti, Febo
In this study a gaze independent event related potential (ERP)-based brain computer interface (BCI) for communication purpose was combined with an asynchronous classifier endowed with dynamical stopping feature. The aim was to evaluate if and how the performance of such asynchronous system could be negatively affected in terms of communication efficiency and robustness to false positives during the intentional no-control state. The proposed system was validated with the participation of 9 healthy subjects. A comparison was performed between asynchronous and synchronous classification technique outputs while users were controlling the same gaze independent BCI interface. The performance of both classification techniques were assessed both off-line and on-line by means of the efficiency metric introduced by Bianchi et al. (2007). This latter metric allows to set a different misclassification cost for wrong classifications and abstentions. Robustness was evaluated as the rate of false positives occurring during voluntary no-control states. The asynchronous classifier did not exhibited significantly higher accuracy or lower error rate with respect to the synchronous classifier (accuracy: 74.66% versus 87.96%, error rate: 7.11% versus 12.04% respectively). However, the on-line and off-line analysis revealed that the communication efficiency was significantly improved (pinterface is a promising solution to be further explored in order to increase the general usability of ERP-based BCI systems designed for severely disabled people with an impairment of the voluntary control of eye movements. In fact, the asynchronous classifier can improve communication efficiency automatically adapting the number of stimulus repetitions to the current user's state and suspending the control if he/she does not intend to select an item. Copyright © 2013 Elsevier B.V. All rights reserved.
Full Text Available How we compute time is not fully understood. Questions include whether an automatic brain mechanism is engaged in temporally regular environmental structure in order to anticipate events, and whether this can be dissociated from task-related processes, including response preparation, selection and execution. To investigate these issues, a passive temporal oddball task requiring neither time-based motor response nor explicit decision was specifically designed and delivered to participants during high-density, event-related potentials recording. Participants were presented with pairs of audiovisual stimuli (S1 and S2 interspersed with an Inter-Stimulus Interval (ISI that was manipulated according to an oddball probabilistic distribution. In the standard condition (70% of trials, the ISI lasted 1,500 ms, while in the two alternative, deviant conditions (15% each, it lasted 2,500 and 3,000 ms. The passive over-exposition to the standard ISI drove participants to automatically and progressively create an implicit temporal expectation of S2 onset, reflected by the time course of the Contingent Negative Variation response, which always peaked in correspondence to the point of S2 maximum expectation and afterwards inverted in polarity towards the baseline. Brain source analysis of S1- and ISI-related ERP activity revealed activation of sensorial cortical areas and the supplementary motor area (SMA, respectively. In particular, since the SMA time course synchronised with standard ISI, we suggest that this area is the major cortical generator of the temporal CNV reflecting an automatic, action-independent mechanism underlying temporal expectancy.
Pamela D Butler
Full Text Available Perceptual organization, which refers to the ability to integrate fragments of stimuli to form a representation of a whole edge, part, or object, is impaired in schizophrenia. A contour integration paradigm, involving detection of a set of Gabor patches forming an oval contour pointing to the right or left embedded in a field of randomly oriented Gabors, has been developed for use in clinical trials of schizophrenia. The purpose of the present study was to assess contributions of early and later stages of processing to deficits in contour integration, as well as to develop an event-related potential (ERP analog of this task. Twenty-one patients with schizophrenia and 28 controls participated. The Gabor elements forming the contours were given a low or high degree of orientational jitter, making it either easy or difficult to identify the direction in which the contour was pointing. ERP results showed greater negative peaks at ~165 (N1 component and ~270 ms for the low-jitter versus the high-jitter contours, with a much greater difference between jitter conditions at 270 ms. This later ERP component was previously termed Ncl for closure negativity. Source localization identified the Ncl in the lateral occipital object recognition area. Patients showed a significant decrease in the Ncl, but not N1, compared to controls, and this was associated with impaired behavioral ability to identify contours. In addition, an earlier negative peak was found at ~120 ms (termed N120 that differentiated jitter conditions, had a dorsal stream source, and differed between patients and controls. Patients also showed a deficit in the dorsal stream sensory P1 component. These results are in accord with impairments in distributed circuitry contributing to perceptual organization deficits and provide an ERP analog to the behavioral contour integration task.
Meaux, Emilie; Hernandez, Nadia; Carteau-Martin, Isabelle; Martineau, Joëlle; Barthélémy, Catherine; Bonnet-Brilhault, Frédérique; Batty, Magali
Although the wide neural network and specific processes related to faces have been revealed, the process by which face-processing ability develops remains unclear. An interest in faces appears early in infancy, and developmental findings to date have suggested a long maturation process of the mechanisms involved in face processing. These developmental changes may be supported by the acquisition of more efficient strategies to process faces (theory of expertise) and by the maturation of the face neural network identified in adults. This study aimed to clarify the link between event-related potential (ERP) development in response to faces and the behavioral changes in the way faces are scanned throughout childhood. Twenty-six young children (4-10 years of age) were included in two experimental paradigms, the first exploring ERPs during face processing, the second investigating the visual exploration of faces using an eye-tracking system. The results confirmed significant age-related changes in visual ERPs (P1, N170 and P2). Moreover, an increased interest in the eye region and an attentional shift from the mouth to the eyes were also revealed. The proportion of early fixations on the eye region was correlated with N170 and P2 characteristics, highlighting a link between the development of ERPs and gaze behavior. We suggest that these overall developmental dynamics may be sustained by a gradual, experience-dependent specialization in face processing (i.e. acquisition of face expertise), which produces a more automatic and efficient network associated with effortless identification of faces, and allows the emergence of human-specific social and communication skills. © 2014 Federation of European Neuroscience Societies and John Wiley & Sons Ltd.
Liu, Tongran; Xiao, Tong; Li, Xiaoyan; Shi, Jiannong
The relationship between human fluid intelligence and social-emotional abilities has been a topic of considerable interest. The current study investigated whether adolescents with different intellectual levels had different automatic neural processing of facial expressions. Two groups of adolescent males were enrolled: a high IQ group and an average IQ group. Age and parental socioeconomic status were matched between the two groups. Participants counted the numbers of the central cross changes while paired facial expressions were presented bilaterally in an oddball paradigm. There were two experimental conditions: a happy condition, in which neutral expressions were standard stimuli (p = 0.8) and happy expressions were deviant stimuli (p = 0.2), and a fearful condition, in which neutral expressions were standard stimuli (p = 0.8) and fearful expressions were deviant stimuli (p = 0.2). Participants were required to concentrate on the primary task of counting the central cross changes and to ignore the expressions to ensure that facial expression processing was automatic. Event-related potentials (ERPs) were obtained during the tasks. The visual mismatch negativity (vMMN) components were analyzed to index the automatic neural processing of facial expressions. For the early vMMN (50-130 ms), the high IQ group showed more negative vMMN amplitudes than the average IQ group in the happy condition. For the late vMMN (320-450 ms), the high IQ group had greater vMMN responses than the average IQ group over frontal and occipito-temporal areas in the fearful condition, and the average IQ group evoked larger vMMN amplitudes than the high IQ group over occipito-temporal areas in the happy condition. The present study elucidated the close relationships between fluid intelligence and pre-attentive change detection on social-emotional information.
Zhang, Songyan; Du, Xue; Wu, Xin; Wei, Dongtao; Zhang, Meng; Qiu, Jiang
Event-related brain potentials (ERPs) were used to examine the electrophysiological correlates of the visual illusion effect in the Müller-Lyer illusion tasks. The participants were presented with the context of a horizontal line with two symmetric inward-pointing arrowheads or outward-pointing arrowheads, and then, they were asked to indicate whether they perceived an increase or a decrease in the line length. The behavioral results showed that there were significant differences among the four types of tasks, which meant that participants could understand different mean illusion magnitudes. The ERP results showed that both the illusion-45 and the illusion-135 elicited a more negative ERP deflection (N180-280) than did the illusion-225 and illusion-315 between 180 and 280 ms. In addition, the strong illusion stimuli elicited a more positive ERP deflection (P280-450) than did the weak illusion stimuli between 280 and 450 ms after the onset of the stimuli. Dipole source analysis of the difference wave (illusion-135-illusion-225) indicated that one generator localized in the left lateral occipital cortex and the difference wave (illusion-45-illusion-135) indicated that one generator localized in the left lingual gyrus. Our results led us to conclude that the ERP deflection in the different illusory strength might be related to the theory of attention resource distribution or because of the inverse optics problem. Then, the early visual areas lateral occipital cortex and the lingual gyrus near to the visual cortex could contribute to integrated processing in the illusory contours and top-down control processing because of the visual experiences.
Ma, Qingguo; Jin, Jia; Yuan, Ruixian; Zhang, Wuke
Fans of celebrities commonly exist in modern society. Researchers from social science have been concerned with this problem for years. Furthermore, such researchers have attempted to measure people’s involvement with celebrities in various ways. However, no study measured the degree of addiction to a specific celebrity at the neurological level. Therefore, the current study employed visually evoked event related potentials (ERPs) to examine people’s attitude toward celebrities by comparing different brain activities of fans and non-fans when they were shown a set of photos. These photos include a specific celebrity, a familiar person, a stranger and a butterfly. Furthermore, to examine the validity of the detected neural index, we also investigated the correlation between brain activity and the score of the Celebrity Attitude Scale (CAS), which was a questionnaire used to explore people’s attitude toward celebrities at behavioral level. Two groups of subjects were asked to complete an implicit task, i.e., to press a button when a picture of a butterfly appeared. Results revealed that fans showed significant positive N2 and P300 deflection when viewing the photos of their favorite celebrity, whereas in the non-fan group, the subjects only showed larger P300 amplitude as a response to the celebrity’s photos. Furthermore, a positive correlation between P300 amplitude elicited by the stimuli of a celebrity face and CAS scores was also observed. These findings indicated fan attitude to a specific celebrity can also be observed at the neurological level and suggested the potential utility of using ERP component as an index of fandom involvement. PMID:26057891
Spielmann, Mona Isabel; Schröger, Erich; Kotz, Sonja A; Bendixen, Alexandra
Sounds emitted by different sources arrive at our ears as a mixture that must be disentangled before meaningful information can be retrieved. It is still a matter of debate whether this decomposition happens automatically or requires the listener's attention. These opposite positions partly stem from different methodological approaches to the problem. We propose an integrative approach that combines the logic of previous measurements targeting either auditory stream segregation (interpreting a mixture as coming from two separate sources) or integration (interpreting a mixture as originating from only one source). By means of combined behavioral and event-related potential (ERP) measures, our paradigm has the potential to measure stream segregation and integration at the same time, providing the opportunity to obtain positive evidence of either one. This reduces the reliance on zero findings (i.e., the occurrence of stream integration in a given condition can be demonstrated directly, rather than indirectly based on the absence of empirical evidence for stream segregation, and vice versa). With this two-way approach, we systematically manipulate attention devoted to the auditory stimuli (by varying their task relevance) and to their underlying structure (by delivering perceptual tasks that require segregated or integrated percepts). ERP results based on the mismatch negativity (MMN) show no evidence for a modulation of stream integration by attention, while stream segregation results were less clear due to overlapping attention-related components in the MMN latency range. We suggest future studies combining the proposed two-way approach with some improvements in the ERP measurement of sequential stream segregation.
Wang, Lin-Jie; Wei, Jin-he; Zhang, Dan; Dong, Wei-jun; Guo, Jian-ping; Hu, Mao-qi
To explore the dynamic change of the late attentional selection process under linearly varied vestibular stimuli using event-related potentials (ERPs) technique. Thirty-three subjects participated in the experiment. They were exposed to vestibular stimulation of constant angular velocity rotation (10 degrees/s) and four levels of constant angular acceleration rotation, the acceleration was 0.6 degrees/s2, 0.8 degrees/s2, 1.0 degrees/s2, 1.2 degrees/s2 respectively. The same auditory go/no-go cognitive task was done during the stimulation. The task involved verbally given Chinese digit number from two to nine with 1000 ms random interval. Subjects were asked to push the button for the odd numbers (target) and withhold to the even numbers (non-target). Compared with control and different level of constant angular acceleration rotation, the N2 amplitude of non-target ERPs (NT-ERPs) decreased significantly over anterior-central scalp during 10 degrees/s constant rotation, but the N2 amplitude of target ERPs (T-ERPs) reduced significantly only at F4, F(Z) and T4 sites. The P3 latency of T-ERPs decreased significantly in 10 degrees/s constant rotation in contrast with control. Under four different acceleration level, the P3 latency of T-ERPs was relatively longer in 0.8 degrees/s2 and 1.0 degrees/s2, but shorter in 0.6 degrees/s2 and 1.2 degrees/s2. Constant angular velocity rotation had an activating effect on late attentional selection process. In contrast to the activation effect of constant angular velocity rotation, constant angular acceleration had an inhibition effect on the cognitive processes and this inhibition effect may have several levels.
Boyum, James H; Atwell, Thomas D; Schmit, Grant D; Poterucha, John J; Schleck, Cathy D; Harmsen, W Scott; Kamath, Patrick S
To determine the incidence of major adverse events related to a large volume of image-guided liver biopsies performed at our institution over a 12-year period and to identify risk factors for major bleeding events. A retrospective analysis of an internally maintained biopsy registry was performed. The analysis revealed that 6613 image-guided liver biopsies were performed in 5987 adult patients between December 7, 2001, and December 31, 2013. Liver biopsies were performed using real-time ultrasound guidance and a spring-loaded biopsy device, with rare exceptions. Adverse events considered major and included in this study were hematoma, infection, pneumothorax, hemothorax, and death. Using data from the biopsy registry, we evaluated statistically significant risk factors (Pliver biopsy, including coagulation status, biopsy technique, and medications. A total of 49 acute and delayed major adverse events (0.7%) occurred after 6613 liver biopsy events. The incidence of hematoma requiring transfusion and/or angiographic intervention was 0.5% (34 of 6613). The incidence of infection was 0.1% (8 of 6613), and that of hemothorax was 0.06% (4 of 6613). No patient (0%) incurred a pneumothorax after biopsy. Three patients (0.05%) died within 30 days of liver biopsy, 1 being directly related to biopsy. Thirty-eight of 46 major adverse events (83%) presented acutely (within 24 hours). More than 2 biopsy passes, platelets 50,000/μL or less, and female sex were statistically significant risk factors for postbiopsy hemorrhage. Image-guided liver biopsy performed by subspecialized interventionalists at a tertiary medical center is safe when the platelet count is greater than 50,000/μL. With appreciation of specific risk factors, safety outcomes of this procedure can be optimized in both general and specialized centers. Copyright © 2016 Mayo Foundation for Medical Education and Research. Published by Elsevier Inc. All rights reserved.
Wynn, Jonathan K; Mathis, Kristopher I; Ford, Judith; Breitmeyer, Bruno G; Green, Michael F
Schizophrenia patients exhibit deficits on visual processing tasks, including visual backward masking, and these impairments are related to deficits in higher-level processes. In the current study we used electroencephalography techniques to examine successive stages and pathways of visual processing in a specialized masking paradigm, four-dot masking, which involves masking by object substitution. Seventy-six schizophrenia patients and 66 healthy controls had event-related potentials (ERPs) recorded during four-dot masking. Target visibility was manipulated by changing stimulus onset asynchrony (SOA) between the target and mask, such that performance decreased with increasing SOA. Three SOAs were used: 0, 50, and 100 ms. The P100 and N100 perceptual ERPs were examined. Additionally, the visual awareness negativity (VAN) to correct vs. incorrect responses, an index of reentrant processing, was examined for SOAs 50 and 100 ms. Results showed that patients performed worse than controls on the behavioral task across all SOAs. The ERP results revealed that patients had significantly smaller P100 and N100 amplitudes, though there was no effect of SOA on either component in either group. In healthy controls, but not patients, N100 amplitude correlated significantly with behavioral performance at SOAs where masking occurred, such that higher accuracy correlated with a larger N100. Healthy controls, but not patients, exhibited a larger VAN to correct vs. incorrect responses. The results indicate that the N100 appears to be related to attentional effort in the task in controls, but not patients. Considering that the VAN is thought to reflect reentrant processing, one interpretation of the findings is that patients' lack of VAN response and poorer performance may be related to dysfunctional reentrant processing.
Ding, Yi; Guo, Fu; Zhang, Xuefeng; Qu, Qingxing; Liu, Weilin
The capacity of product form to arouse user's behavioural intention plays a decisive role in further user experience, even in purchase decision, while traditional methods rarely give a fully understanding of user experience evoked by product form, especially the feeling of anticipated use of product. Behavioural intention aroused by product form designs has not yet been investigated electrophysiologically. Hence event related potentials (ERPs) were applied to explore the process of behavioural intention when users browsed different smart phone form designs with brand and price not taken into account for mainly studying the brain activity evoked by variety of product forms. Smart phone pictures with different anticipated user experience were displayed with equiprobability randomly. Participants were asked to click the left mouse button when certain picture gave them a feeling of behavioural intention to interact with. The brain signal of each participant was recorded by Curry 7.0. The results show that pictures with an ability to arouse participants' behavioural intention for further experience can evoke enhanced N300 and LPPs (late positive potentials) in central-parietal, parietal and occipital regions. The scalp topography shows that central-parietal, parietal and occipital regions are more activated. The results indicate that the discrepancy of ERPs can reflect the neural activities of behavioural intention formed or not. Moreover, amplitude of ERPs occurred in corresponding brain areas can be used to measure user experience. The exploring of neural correlated with behavioural intention provide an accurate measurement method of user's perception and help marketers to know which product can arouse users' behavioural intention, maybe taken as an evaluating indicator of product design. Copyright © 2016 Elsevier Ltd and The Ergonomics Society. All rights reserved.
Full Text Available Background. The study of the attentional system remains a challenge for current neuroscience. The Attention Network Test (ANT was designed to study simultaneously three different attentional networks (alerting, orienting and executive based in subtraction of different experimental conditions. However, some studies recommend caution with these calculations due to the interactions between the attentional networks. In particular, it is highly relevant that several interpretations about attentional impairment have arisen from these calculations in diverse pathologies. Event Related Potentials (ERPs and neural source analysis can be applied to disentangle the relationships between these attentional networks not specifically shown by behavioural measures. Results. This study shows that there is a basic level of alerting (tonic alerting in the no cue condition, represented by a slow negative trend in the ERP trace prior to the onset of the target stimuli. A progressive increase in the CNV amplitude related to the amount of information provided by the cue conditions is also shown. Neural source analysis reveals specific modulations of the CNV related to a task-related expectancy presented in the no cue condition; a late modulation triggered by the central cue condition and probably representing a generic motor preparation; and an early and late modulation for spatial cue condition suggesting specific motor and sensory preactivation. Finally, the first component in the information processing of the target stimuli modulated by the interaction between orienting network and the executive system can be represented by N1. Conclusions. The ANT is useful as a paradigm to study specific attentional mechanisms and their interactions. However, calculation of network effects is based in subtractions with non-comparable experimental conditions, as evidenced by the present data, which can induce misinterpretations in the study of the attentional capacity in human
Park, Hame; Kim, June Sic; Chung, Chun Kee
A primate study reported the existence of neurons from the dorso-lateral prefrontal cortex which fired prior to executing categorical action sequences. The authors suggested these activities may represent abstract level information. Here, we aimed to find the neurophysiological representation of planning categorical action sequences at the population level in healthy humans. Previous human studies have shown beta-band event-related desynchronization (ERD) during action planning in humans. Some of these studies showed different levels of ERD according to different types of action preparation. Especially, the literature suggests that variations in cognitive factors rather than physical factors (force, direction, etc) modulate the level of beta-ERD. We hypothesized that the level of beta-band power will differ according to planning of different categorical sequences. We measured magnetoencephalography (MEG) from 22 subjects performing 11 four-sequence actions--each consisting of one or two of three simple actions--in 3 categories; 'Paired (ooxx)', 'Alternative (oxox)' and 'Repetitive (oooo)' ('o' and 'x' each denoting one of three simple actions). Time-frequency representations were calculated for each category during the planning period, and the corresponding beta-power time-courses were compared. We found beta-ERD during the planning period for all subjects, mostly in the contralateral fronto-parietal areas shortly after visual cue onset. Power increase (transient rebound) followed ERD in 20 out of 22 subjects. Amplitudes differed among categories in 20 subjects for both ERD and transient rebound. In 18 out of 20 subjects 'Repetitive' category showed the largest ERD and rebound. The current result suggests that beta-ERD in the contralateral frontal/motor/parietal areas during planning is differentiated by the category of action sequences.
David A Wolk
Full Text Available Episodic memory loss is the hallmark cognitive dysfunction associated with Alzheimer’s Disease (AD. Amnestic Mild Cognitive Impairment (a-MCI frequently represents a transitional stage between normal aging and early AD. A better understanding of the qualitative features of memory loss in a-MCI may have important implications for predicting those most likely to harbor AD-related pathology and for disease monitoring. Dual process models of memory argue that recognition memory is subserved by the dissociable processes of recollection and familiarity. Work studying recognition memory in a-MCI from this perspective has been controversial, particularly with regard to the integrity of familiarity. Event-related potentials (ERPs offer an alternative means for assessing these functions without the associated assumptions of behavioral estimation methods. ERPs were recorded while a-MCI patients and cognitively normal (CN age-matched adults performed a recognition memory task. When retrieval success was measured (hits versus correct rejections in which performance was matched by group, a-MCI patients displayed similar neural correlates to that of the CN group, including modulation of the FN400 and the late parietal complex (LPC which are thought to index familiarity and recollection, respectively. Alternatively, when the integrity of these components were measured based on retrieval attempts (studied versus unstudied items, a-MCI patients displayed a reduced FN400 and LPC. Furthermore, modulation of the FN400 correlated with a behavioral estimate of familiarity and the LPC with a behavioral estimates of recollection obtained in a separate experiment in the same individuals, consistent with the proposed mappings of these indices. These results support a global decline of recognition memory in a-MCI, which suggests that the memory loss of prodromal AD may be qualitatively distinct from normal aging.
Schefter, Maria; Werheid, Katja; Almkvist, Ove; Lönnqvist-Akenine, Ulrika; Kathmann, Norbert; Winblad, Bengt
This study examined the temporal course of emotional face recognition in amnestic mild cognitive impairment (aMCI). Patients and healthy controls (HC) performed a face recognition task, giving old/new responses to previously studied and novel faces displaying a negative or neutral expression. In aMCI patients, recognition accuracy was preserved for negative faces. Event-related potentials (ERPs) revealed disease-related changes in early perceptual components but not in ERP indices of explicit recognition. Specifically, aMCI patients showed impaired recognition effects for negative faces on the amplitudes of N170 and P2, suggesting deficient memory-related processing of negative faces at the stage of structural encoding and during an early recognition stage at which faces are individuated, respectively. Moreover, while a right-lateralized emotion effect specifically observed for correctly recognized faces on the amplitude of N170 was absent in aMCI, a similar emotion effect for successfully recognized faces on P2 was preserved in the patients, albeit with a different distribution. This suggests that in aMCI facilitated processing of successfully recognized emotional faces starts later in the processing sequence. Nonetheless, an early frontal old/new effect confined to negative faces and a parietal old/new effect unaffected by facial emotion were observed in both groups. This indicates that familiarity and conceptual priming processes may specifically contribute to recognition of negative faces in older adults and that aMCI patients can recruit the same retrieval mechanisms as controls, despite disease-related changes on early perceptual ERP components.
Full Text Available The relationship between human fluid intelligence and social-emotional abilities has been a topic of considerable interest. The current study investigated whether adolescents with different intellectual levels had different automatic neural processing of facial expressions. Two groups of adolescent males were enrolled: a high IQ group and an average IQ group. Age and parental socioeconomic status were matched between the two groups. Participants counted the numbers of the central cross changes while paired facial expressions were presented bilaterally in an oddball paradigm. There were two experimental conditions: a happy condition, in which neutral expressions were standard stimuli (p = 0.8 and happy expressions were deviant stimuli (p = 0.2, and a fearful condition, in which neutral expressions were standard stimuli (p = 0.8 and fearful expressions were deviant stimuli (p = 0.2. Participants were required to concentrate on the primary task of counting the central cross changes and to ignore the expressions to ensure that facial expression processing was automatic. Event-related potentials (ERPs were obtained during the tasks. The visual mismatch negativity (vMMN components were analyzed to index the automatic neural processing of facial expressions. For the early vMMN (50-130 ms, the high IQ group showed more negative vMMN amplitudes than the average IQ group in the happy condition. For the late vMMN (320-450 ms, the high IQ group had greater vMMN responses than the average IQ group over frontal and occipito-temporal areas in the fearful condition, and the average IQ group evoked larger vMMN amplitudes than the high IQ group over occipito-temporal areas in the happy condition. The present study elucidated the close relationships between fluid intelligence and pre-attentive change detection on social-emotional information.
McDonald, John J; Green, Jessica J
Attention-directing cues presented at fixation evoke several lateralized event-related potential (ERP) components prior to the onset of visual targets. These components have been associated with the control of visuo-spatial attention, but the neuro-cognitive operations and neural generators of the components are still largely unknown. Here, we isolated cue-elicited ERP activity in different ways to home in on different neuro-cognitive operations and to gain a better understanding about the possible neuroanatomical sources of the cue-elicited ERP activities. To isolate lateralized cue-ERP activity, we compared shift-left and shift-right cue ERPs to shift-up cue ERPs. To measure all of the ERP activity related to attentional control, including spatially nonspecific activity that is removed in the process of isolating lateralized cue-ERP components, we compared shift-cue ERPs to neutral-cue (i.e., no-shift) ERPs. Isolated lateralized-ERP activity was seen in the contralateral-occipital lobe in the early phase of the cue-target interval and in the ipsilateral-occipital lobe in the late phase. The later, ipsilateral activity indicates that the late directing attention positivity (LDAP) reflected processing of the to-be-ignored location. The neutral-cue isolation revealed a shift-related positivity over posterior scalp regions and a shift-related negativity over more anterior scalp regions. The spatio-temporal sequence of shift-related activity observed on the scalp, together with estimates of distributed source activity underlying the shift-related ERP components, indicated that frontal and parietal regions of cortex participated in the control of attention and led to pre-target biasing in visual cortical areas.
Huang, Wenwen; Liu, Sinan; Luo, Bin; Meng, Huanhuan; Ji, Mengmeng; Li, Maojuan; Chen, Xiping; Tao, Luyang
Numerous studies have explored the physical attribute features or face perceptions in conflict processing, while complicate gradient conflicts were rarely discussed. The aim of the study was to discuss the relationship between the event-related potential (ERP) component features and different visual acuity levels by using the modified S1-S2 task under non-attention status. Three visual acuity levels were applied, each with four orientations of "E" optotype stimuli randomly presented in the center of the visual field while participants were required to concentrate on listening to stories. The results showed that the amplitudes of P1 and P3 as well as difference P3 were larger in supra-threshold condition. In threshold condition, larger amplitudes for both N2 and difference N2 exhibited in frontal and central areas. In sub-threshold condition, there was no endogenous component elicited by mismatch stimuli except smaller anterior N1. Meanwhile, the specific distributions of N1 and N2 were presented and compared with previous face processing. The findings showed that visual conflict processing took place not only at an early stage but also at the late period, which might be as the consequences of interaction between conflict strength and involuntary attention. We concluded that automatic conflict detecting of visual icons by the serial ERP components could distinguish different visual acuity levels. The involvement of endogenous components could reveal the specific mechanism of more precise and fine conflict identification of complex physical attributes under non-attention status, furthermore could be used as valid markers to estimate the magnitude of visual acuity objectively. Copyright © 2018 IBRO. Published by Elsevier Ltd. All rights reserved.
Ma, Qingguo; Jin, Jia; Yuan, Ruixian; Zhang, Wuke
Fans of celebrities commonly exist in modern society. Researchers from social science have been concerned with this problem for years. Furthermore, such researchers have attempted to measure people's involvement with celebrities in various ways. However, no study measured the degree of addiction to a specific celebrity at the neurological level. Therefore, the current study employed visually evoked event related potentials (ERPs) to examine people's attitude toward celebrities by comparing different brain activities of fans and non-fans when they were shown a set of photos. These photos include a specific celebrity, a familiar person, a stranger and a butterfly. Furthermore, to examine the validity of the detected neural index, we also investigated the correlation between brain activity and the score of the Celebrity Attitude Scale (CAS), which was a questionnaire used to explore people's attitude toward celebrities at behavioral level. Two groups of subjects were asked to complete an implicit task, i.e., to press a button when a picture of a butterfly appeared. Results revealed that fans showed significant positive N2 and P300 deflection when viewing the photos of their favorite celebrity, whereas in the non-fan group, the subjects only showed larger P300 amplitude as a response to the celebrity's photos. Furthermore, a positive correlation between P300 amplitude elicited by the stimuli of a celebrity face and CAS scores was also observed. These findings indicated fan attitude to a specific celebrity can also be observed at the neurological level and suggested the potential utility of using ERP component as an index of fandom involvement.
Full Text Available Transient event-related potentials (ERPs and steady-state responses (SSRs have been popularly employed to investigate the function of the human brain, but their relationship still remains a matter of debate. Some researchers believed that SSRs could be explained by the linear summation of successive transient ERPs (superposition hypothesis, while others believed that SSRs were the result of the entrainment of a neural rhythm driven by the periodic repetition of a sensory stimulus (oscillatory entrainment hypothesis. In the present study, taking auditory modality as an example, we aimed to clarify the distinct features of SSRs, evoked by the 40-Hz and 60-Hz periodic auditory stimulation, as compared to transient ERPs, evoked by a single click. We observed that (1 SSRs were mainly generated by phase synchronization, while late latency responses (LLRs in transient ERPs were mainly generated by power enhancement; (2 scalp topographies of LLRs in transient ERPs were markedly different from those of SSRs; (3 the powers of both 40-Hz and 60-Hz SSRs were significantly correlated, while they were not significantly correlated with the N1 power in transient ERPs; (4 whereas SSRs were dominantly modulated by stimulus intensity, middle latency responses (MLRs were not significantly modulated by both stimulus intensity and subjective loudness judgment, and LLRs were significantly modulated by subjective loudness judgment even within the same stimulus intensity. All these findings indicated that high-frequency SSRs were different from both MLRs and LLRs in transient ERPs, thus supporting the possibility of oscillatory entrainment hypothesis to the generation of SSRs. Therefore, SSRs could be used to explore distinct neural responses as compared to transient ERPs, and help us reveal novel and reliable neural mechanisms of the human brain.
René eSan Martín
Full Text Available In order to control behavior in an adaptive manner the brain has to learn how some situations and actions predict positive or negative outcomes. During the last decade cognitive neuroscientists have shown that the brain is able to evaluate and learn from outcomes within a few hundred milliseconds of their occurrence. This research has been primarily focused on the feedback-related negativity (FRN and the P3, two event-related potential (ERP components that are elicited by outcomes. The FRN is a frontally distributed negative-polarity ERP component that typically reaches its maximal amplitude 250 ms after outcome presentation and tends to be larger for negative than for positive outcomes. The FRN has been associated with activity in the anterior cingulate cortex. The P3 (~300-600 ms is a parietally distributed positive-polarity ERP component that tends to be larger for large magnitude than for small magnitude outcomes. The neural sources of the P3 are probably distributed over different regions of the cortex. This paper examines the theories that have been proposed to explain the functional role of these two ERP components during outcome processing. Special attention is paid to extant literature addressing how these ERP components are modulated by outcome valence (negative vs. positive, outcome magnitude (large vs. small, outcome probability (unlikely vs. likely and behavioral adjustment. The literature offers few generalizable conclusions, but is beset with a number of inconsistencies across studies. This paper discusses the potential reasons for these inconsistencies and points out some challenges that will shape the field over the next decade.