Amplitude Of Event-related Potentials Components Research Articles

Measuring presence in video games: An investigation of the potential use of physiological measures as indicators of presence

Abstract Presence has become an increasingly central component of Games User Research (GUR) as developments in technology continuously make modern video games more conducive to the sensation of ‘being there’ in virtual environments. The quality of games is now commonly evaluated based on how reliably they elicit presence; however, no standardized objective measure of presence currently exists. This study investigated two physiological measures, Galvanic Skin Response (GSR) and task-irrelevant Event-Related Potentials (ERPs), as potential objective indicators of presence in games. A total of 34 participants were divided into low or high presence groups based on their self-reported presence evoked from experiencing a horror game while task-irrelevant tones were being played. It was hypothesized that presence is associated with attentional resources being fully absorbed by the game, which would lead to less or insufficient perceptual resources available for processing the concurrent game-irrelevant oddball-task. This effect was expected to manifest as a measurable decrease in early ERP component amplitudes. It was also hypothesized that presence would make players react to emotion-eliciting events as if they were real, which would result in more GSR peaks throughout the game while not impacting event response magnitude. ERP components (N1, MMN and SW), GSR peaks/min and response magnitude were compared between the presence groups revealing significant differences in GSR peaks/min and early ERP components of N1 and MMN, but not in GSR response magnitude. The findings support the hypotheses and show that GSR peaks/min, N1 and MMN correlate with presence and have potential as presence indicators.

Aberrant Cortical Event-Related Potentials During Associative Learning in Rat Models for Presymptomatic Stages of Alzheimer's Disease.

Trace eyeblink conditioning is a hippocampus-dependent associative learning paradigm which is impaired in patients with Alzheimer's disease (AD) and animal AD models. Learning in this paradigm accompanies changes in oscillatory activity in forebrain regions, some of which are loci of pathogenic changes in prodromal AD stages. These observations motivated us to examine how cortical event-related potentials (ERPs) during this paradigm are affected by two features of the asymptomatic, AD-related brain abnormality, entorhinal tau accumulation and mild cholinergic deficit. Adult rats received viral overexpression of P301L mutant human tau in the entorhinal cortex, low-dose scopolamine treatment, or both. Electroencephalograms were recorded with epidural electrodes on the surface of the frontal, parietal, and temporal cortices during differential and reversal trace eyeblink conditioning. All rats developed conditioned responses to one of two stimuli (auditory or visual) paired with mild eyelid shock (CS+), but not to the other stimulus presented alone(CS-). They were also able to adjust the response when the stimulus contingency was reversed. With learning, the amplitude of several ERP components in the frontal and temporal cortices came to differentiate the CS+ from CS-. Scopolamine affected the learning-related change in temporal P2 and other learning-unrelated components in three regions. Entorhinal tau overexpression primary affected the amplitude of temporal visual ERPs and learning-unrelated frontal and temporal auditory ERP components. The double manipulation only affected two components of temporal auditory ERPs. Thus, cortical ERPs during differential associative learning are sensitive to asymptomatic brain abnormality associated with AD.

Investigating Duration Effects of Emotional Speech Stimuli in a Tonal Language by Using Event-Related Potentials

Studying event-related potentials (ERPs) is considered as an effective method for investigating cerebral mechanisms of processing emotional speech. It has been shown that the amplitudes of ERP components in the cognitive processing of emotional speech are modulated by acoustic characteristics, such as valence and arousal. However, whether the duration of emotional speech stimuli impacts emotion-related cognitive processing remains unclear. To better understand the effect of emotional speech stimulus duration on emotion-related cognitive processing, we explored whether emotional speech ERPs were influenced by the duration of stimuli presented. Specifically, this paper focused on the ERP investigation of different durations (short: 0.50–1.00 s; medium: 1.50–2.00 s; and long: 2.50–3.00 s) of Chinese emotional speech stimuli. Chinese is a typical tonal language, and the stimuli were excerpted from radio plays in order to make emotions more obvious and easier to distinguish. We investigated the three different stages of the emotional speech processing: sensory processing, salience detection, and cognition. During the experiment, participants passively listened to emotional utterances matched for semantics and prosody with four emotions (sadness, anger, happiness, and surprise). Our results showed significant differences in the amplitudes of ERP components for different emotions during short-duration emotional speech stimuli. These findings suggest that shorter duration emotional speech stimuli may be more effective for separating the ERP components representing different emotions (N100, P200, and N300).

Improved cognitive performance and event-related potential changes following working memory training in patients with multiple sclerosis.

BackgroundFew studies of cognitive rehabilitation in multiple sclerosis (MS) have targeted working memory specifically.ObjectiveWe examined the effects of n-back working memory training on cognitive performance and brain function in patients with MS.MethodsPatients with MS (n = 12) and healthy controls (HC; n = 12) underwent 20 sessions of n-back working memory training. Before and after training (pre- and posttest) cognitive event-related potential (ERP) measures were obtained during a 3-back task. In addition, a battery of cognitive tests was administered.ResultsFollowing n-back training, both MS patients and HCs showed significant improvement on tests of working memory, processing speed, complex attention, and reasoning ability. MS and HCs also exhibited an enhancement of N2 ERP component amplitude, and earlier N2 and P3 latencies, following n-back training.ConclusionsTargeted training of working memory with the n-back task may improve cognitive function in MS. Enhancement of N2 ERP component amplitude and shorter N2 and P3 latency following training in patients with MS is consistent with plasticity of neural processes that are involved in working memory.

Single Trial Estimation of Peak Latency and Amplitude of Multiple Correlated ERP Components

Event related potentials (ERPs) are conventionally extracted by averaging EEG signals over many trials but some characteristics of these signals are lost as a result. Recently single-trial ERP extraction has become one of the main research areas in neuroscience. Spatiotemporal filtering method which uses more than one channel is one of these extraction methods. A modified spatiotemporal filtering method is proposed here for single-trial estimation of correlated ERP component parameters (peak latency and peak amplitude). The error of this method in extracting the peak amplitude and peak latency of ERP components is less than 10% and changing the temporal correlation coefficient of the main ERP components, does not change the results notably. Our proposed method for peak amplitude and peak latency estimation is proved to be better than other reported methods (especially for peak amplitude estimation) and has less computational cost in comparison with other spatiotemporal methods. The ability of our method to generalize to any number of correlated ERP components is one of the key points in our work.

Response characteristics of the rat anterior cingulate cortex to ultrasonic communicative vocalizations.

Emotional communication involves transmitting information on affective states. Rat 50- and 22-kHz ultrasonic vocalizations (USVs) are emotional communication signals that reflect positive or negative states, respectively. In general, emotional communication signals that elicit changes in event-related potentials (ERPs), suggesting a specific mechanism for processing these signals. As this is observed in several communication systems including humans, we hypothesized that rat USVs can also trigger such changes. In this study, we measured rat local field potentials and used them to calculate ERPs from the anterior cingulate cortex (ACC), an area related to motor production of USVs. In Experiment 1, we measured ERPs to pure tones with peak frequencies around 50 or 22 kHz to examine whether the ACC is involved in auditory sensory processing related to pitch. The results showed that pure tones around 50 kHz elicited large amplitude ERPs, whereas those around 22 kHz resulted in smaller ERPs. In Experiment 2, we compared ERPs in response to rat USVs (emotional stimuli) with ERPs to pure tones modeled after USVs (neutral stimuli). The peak frequencies were the same between USVs and neutral sounds, but USVs showed more frequency modulation than neutral sounds. USVs elicited larger changes in the amplitude of ERP components than neutral stimuli did. These experiments suggest that the rat ACC is sensitive to frequencies around 50 and 22 kHz, and is especially tuned to frequency modulation around these frequencies. Taken together, the rat ACC may process the emotional content of communication signals on the basis of pitch and frequency modulation.

Development of Performance and ERPs in a Flanker Task in Children and Adolescents with Tourette Syndrome-A Follow-Up Study.

Background: Tourette Syndrome (TS) is a neurodevelopmental disorder with childhood-onset, with a typical decline in tic severity, as well as an increasing ability to suppress tics in late childhood and adolescence. These processes develop in parallel with general improvement of self-regulatory abilities, and performance monitoring during this age-span. Hence, changes in performance monitoring over time might provide insight into the regulation of tics in children and adolescents with TS.Method: We measured reaction time, reaction time variability, accuracy, and event-related potentials (ERP) in 17 children with TS, including 10 children with comorbid Attention-Deficit/Hyperactivity Disorder (ADHD), 24 children with ADHD, and 29 typically developing children, using a modified Eriksen Flanker task in two testing sessions administered on average 4.5 years apart. We then compared task performance, as well as ERP components across groups, and over time using regression models.Results: Task performance improved in all groups with age, and behavioral differences between children with TS and controls diminished at second assessment, while differences between controls and children with ADHD largely persisted. In terms of ERP, the early P3 developed earlier in children with TS compared with controls at the first assessment, but trajectories converged with maturation. ERP component amplitudes correlated with worst-ever tic scores.Conclusions: Merging trajectories between children with TS and controls are consistent with the development of compensatory self-regulation mechanisms during early adolescence, probably facilitating tic suppression, in contrast to children with ADHD. Correlations between ERP amplitudes and tic scores also support this notion.

Event-related Potentials (ERP) in Cognitive Neuroscience Research and Applications

This review is aimed at exploring the usefulness of measuring event-related potential (ERP) in cognitive tests and discusses several applications of the ERP technique. Analysis of ERP components is one of the most informative dynamic methods of investigation and monitoring of information processing stages in the human brain. Amplitude and latency of ERP components at specified topographies reflect early sensory perception processes and higher level processing including attention, cortical inhibition, memory update, error monitoring, and other cognitive activities. ERPs provide a method of studying cognitive processes in typical subjects, as well as a sensitive instrument to assess differences in individuals with neuro- and psychopathologies. Despite significant advances in functional neuroimaging, the ERP measure still represents an important tool for brain research in psychiatry, as many psychiatric diseases correlate with certain altered patterns of ERPs. Such ERP alterations can serve as valid biological markers for functional diagnostic or for better understanding of the cognitive functions which are disturbed in psychiatric disorders. Application of ERPs in psychiatric treatment research is an approach aimed at validation of specific ERP measures as sensitive functional outcomes of experimental neuromodulation interventions such as rTMS and neurofeedback. Also discussed are additional aspects of ERP usefulness in psychiatry research and treatment.

Developmental trajectories of event related potentials related to working memory

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.

Sequential Processing and the Matching-Stimulus Interval Effect in ERP Components: An Exploration of the Mechanism Using Multiple Regression.

In oddball tasks, increasing the time between stimuli within a particular condition (target-to-target interval, TTI; nontarget-to-nontarget interval, NNI) systematically enhances N1, P2, and P300 event-related potential (ERP) component amplitudes. This study examined the mechanism underpinning these effects in ERP components recorded from 28 adults who completed a conventional three-tone oddball task. Bivariate correlations, partial correlations and multiple regression explored component changes due to preceding ERP component amplitudes and intervals found within the stimulus series, rather than constraining the task with experimentally constructed intervals, which has been adequately explored in prior studies. Multiple regression showed that for targets, N1 and TTI predicted N2, TTI predicted P3a and P3b, and Processing Negativity (PN), P3b, and TTI predicted reaction time. For rare nontargets, P1 predicted N1, NNI predicted N2, and N1 predicted Slow Wave (SW). Findings show that the mechanism is operating on separate stages of stimulus-processing, suggestive of either increased activation within a number of stimulus-specific pathways, or very long component generator recovery cycles. These results demonstrate the extent to which matching-stimulus intervals influence ERP component amplitudes and behavior in a three-tone oddball task, and should be taken into account when designing similar studies.

Passive perception of auditory stimuli in healthy and mild mentally retarded adolescents from Northern Russia

Event-related potentials (ERPs) during passive perception of auditory stimuli were studied using the oddball paradigm in healthy and mild mentally retarded adolescents. The study involved 25 subjects aged 11–15 (13.1 ± 1.4) years from Northern Russia, including Arctic regions. The peak latency of the difference wave for deviant and standard stimuli in frontal central derivation was 129 ± 21 ms in the healthy children, and the mean amplitude was–2.6 ± 1.3 μV. In the mentally retarded group, a negative peak of the difference wave was observed only in 9 out of 13 adolescents, its latency was more than in the healthy adolescents (156 ± 29 ms), and the mean amplitude was–2.1 ± 1.4 μV. Differences in perception of deviant and standard stimuli were observed in the healthy adolescents, in particular, along the central line. In the adolescents with mental disorders, there was no significant difference in the fronto-central and central derivations. A discriminant analysis of the amplitudes of ERP components observed in the fronto-central derivations in response to deviant stimuli and the difference in amplitude between ERPs evoked in the fronto-central derivation by standard and deviant stimuli differentiated the adolescents with and without mental disorders. Based on the findings, ERP components in the oddball paradigm were assumed to provide potential markers of disorders in mental development.

Quantifying Different Tactile Sensations Evoked by Cutaneous Electrical Stimulation Using Electroencephalography Features.

Psychophysical tests and standardized questionnaires are often used to analyze tactile sensation based on subjective judgment in conventional studies. In contrast with the subjective evaluation, a novel method based on electroencephalography (EEG) is proposed to explore the possibility of quantifying tactile sensation in an objective way. The proposed experiments adopt cutaneous electrical stimulation to generate two kinds of sensations (vibration and pressure) with three grades (low/medium/strong) on eight subjects. Event-related potentials (ERPs) and event-related synchronization/desynchronization (ERS/ERD) are extracted from EEG, which are used as evaluation indexes to distinguish between vibration and pressure, and also to discriminate sensation grades. Results show that five-phase P1–N1–P2–N2–P3 deflection is induced in EEG. Using amplitudes of latter ERP components (N2 and P3), vibration and pressure sensations can be discriminated on both individual and grand-averaged ERP (p < 0.05). The grand-average ERPs can distinguish the three sensations grades, but there is no significant difference on individuals. In addition, ERS/ERD features of mu rhythm (8–13 Hz) are adopted. Vibration and pressure sensations can be discriminated on grand-average ERS/ERD (p < 0.05), but only some individuals show significant difference. The grand-averaged results show that most sensation grades can be differentiated, and most pairwise comparisons show significant difference on individuals (p < 0.05). The work suggests that ERP- and ERS/ERD-based EEG features may have potential to quantify tactile sensations for medical diagnosis or engineering applications.

Detecting target/nontarget differences in ERP components from a visual oddball task with separate PCAs: Young vs. older adults

Event Abstract Back to Event Detecting target/nontarget differences in ERP components from a visual oddball task with separate PCAs: Young vs. older adults Genevieve Z. Steiner1, 2*, Robert J. Barry2 and Jack S. Fogarty2 1 Western Sydney University, The National Institute of Complementary Medicine (NICM), Australia 2 University of Wollongong, Brain & Behaviour Research Institute and School of Psychology, Australia Aims: Barry et al. (2016) demonstrated that condition-related differences between Go and NoGo event-related potential (ERP) components are best identified using separate principal components analyses (PCAs). This optimised PCA methodology was established using ERPs from an auditory equiprobable task completed by young adults. The present study aimed to test the sensitivity of this approach in differentiating target/nontarget condition effects between young and older adults in a visual oddball task. Methods: Equal numbers of young (N = 19, Mage = 21.2, SD = 3.7 years) and older adults (N = 19, Mage = 68.1, SD = 4.6 years) completed a visual oddball task and had their electroencephalographic (EEG) activity recorded. ERP component amplitudes were quantified with separate unrestricted PCAs for each age group and stimulus condition using Varimax rotation. Results: Error rates (omission/commission) and reaction times did not differ between groups. The four separate PCAs detected a range of ERP components. For rare targets, both groups showed a centro-parietal N1 (young = 108 ms, older = 100 ms), central P2 (young = 148 ms, older = 140 ms), centro-parietal P3 (young and older = 372 ms), and a frontally-negative/parietally-positive Slow Wave (SW; young and older = 452 ms). Target N2 was more clearly identifiable in young (N2 = 204 ms) compared to older adults. For frequent nontargets, both groups had identifiable N1s (young = 76 ms, older = 68 ms), temporo-occipital Processing Negativity (PN; young = 116 ms, older = 148 ms), and diffuse nontarget P3 (young = 308 ms, older = 356 ms). Conclusions: Despite statistically indistinguishable task performance and broadly similar component latencies, older adults had more topographically-diffuse components cf. young adults. Results from separate PCAs suggest that task performance can be maintained in healthy ageing via the recruitment of a wider range of associative neuronal networks. Acknowledgements We thank The Illawarra Retirement Trust (IRT) and the management of IRT Links Seaside for their kind assistance in providing facilities and encouraging resident participation in this project. We also thank Frances De Blasio for collecting the data. References Barry, R.J., De Blasio, F.M., Fogarty, J.S., Karamacoska, D., 2016. ERP Go/NoGo condition effects are better detected with separate PCAs. International Journal of Psychophysiology, 106, 50-64. Keywords: event-related potentials (ERP), target, Nontarget, oddball task, older adults, Healthy Ageing, Ageing, Principal Components Analysis (PCA) Conference: ASP2016 - The 26th Annual Meeting of the Australasian Society for Psychophysiology, Adelaide Australia, Adelaide,SA, Australia, 12 Dec - 14 Dec, 2016. Presentation Type: Oral Presentation Topic: Abstract (general) Citation: Steiner GZ, Barry RJ and Fogarty JS (2016). Detecting target/nontarget differences in ERP components from a visual oddball task with separate PCAs: Young vs. older adults. Conference Abstract: ASP2016 - The 26th Annual Meeting of the Australasian Society for Psychophysiology, Adelaide Australia. doi: 10.3389/conf.fnhum.2016.221.00006 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 20 Nov 2016; Published Online: 05 Dec 2016. * Correspondence: Dr. Genevieve Z Steiner, Western Sydney University, The National Institute of Complementary Medicine (NICM), Penrith, New South Wales, 2751, Australia, G.Steiner@westernsydney.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Genevieve Z Steiner Robert J Barry Jack S Fogarty Google Genevieve Z Steiner Robert J Barry Jack S Fogarty Google Scholar Genevieve Z Steiner Robert J Barry Jack S Fogarty PubMed Genevieve Z Steiner Robert J Barry Jack S Fogarty Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Single-Trial ERP Component Analysis Using a Spatiotemporal LCMV Beamformer.

For statistical analysis of event-related potentials (ERPs), there are convincing arguments against averaging across stimuli or subjects. Multivariate filters can be used to isolate an ERP component of interest without the averaging procedure. However, we would like to have certainty that the output of the filter accurately represents the component. We extended the linearly constrained minimum variance (LCMV) beamformer, which is traditionally used as a spatial filter for source localization, to be a flexible spatiotemporal filter for estimating the amplitude of ERP components in sensor space. In a comparison study on both simulated and real data, we demonstrated the strengths and weaknesses of the beamformer as well as a range of supervised learning approaches. In the context of measuring the amplitude of a specific ERP component on a single-trial basis, we found that the spatiotemporal LCMV beamformer is a filter that accurately captures the component of interest, even in the presence of both structured noise (e.g., other overlapping ERP components) and unstructured noise (e.g., ongoing brain activity and sensor noise). The spatiotemporal LCMV beamformer method provides an accurate and intuitive way to conduct analysis of a known ERP component, without averaging across trials or subjects. Eliminating averaging allows us to test more detailed hypotheses and apply more powerful statistical models. For example, it allows the usage of multilevel regression models that can incorporate between subject/stimulus variation as random effects, test multiple effects simultaneously, and control confounding effects by partial regression.

Relationships between event-related potentials and behavioral and scholastic measures of reading ability: A large-scale, cross-sectional study.

In the cognitive, computational, neuropsychological, and educational literatures, it is established that children approach text in unique ways, and that even adult readers can differ in the strategies they bring to reading. In the developmental event-related potential (ERP) literature, however, children with differing degrees of reading ability are, the majority of the time, placed in monolithic groups such as 'normal' and 'dyslexic' (e.g. Araújo etal., 2012) and analyzed only at the group level. This is likely done due to methodological concerns - such as low sample size or a lack of statistical power - that can make it difficult to perform analysis at the individual level. Here, we collected ERPs and behavior from > 100 children in grades pre-K-7, as they read unconnected text silently to themselves. This large sample, combined with the statistical power of the Linear Mixed Effects Regression (LMER) technique, enables us to address individual differences in ERP component effects due to reading ability at an unprecedented level of detail. Results indicate that it is possible to predict reading-related report card scores from ERP component amplitudes - especially that of the N250, a component pertaining to sublexical processing (including phonological decoding). Results also reveal relationships between behavioral measures of reading ability and ERP component effects that have previously been elusive, such as the relationship between vocabulary and N400 mean amplitude (cf. Henderson etal., 2011). We conclude that it is possible to meaningfully examine reading-related ERP effects at the single subject level in developing readers, and that this type of analysis can provide novel insights into both behavior and scholastic achievement.

Age-related processing strategies and go-nogo effects in task-switching: an ERP study.

We studied cognitive and age-related changes in three task-switching (TS) paradigms: (1) informatively cued TS with go stimuli, (2) informatively cued TS with go and nogo stimuli, (3) non-informatively cued TS with go and nogo stimuli. This design allowed a direct comparison, how informative and non-informative cues influenced preparatory processes, and how nogo stimuli changed the context of the paradigm and cognitive processing in different aging groups. Beside the behavioral measures [reaction time (RT), error rate], event-related potentials (ERPs) were registered to the cue and target stimuli in young (N = 39, mean age = 21.6 ± 1.6 years) and older (N = 40, mean age = 65.7 ± 3.2 years) adults. The results provide evidence for declining performance in the older group: they had slower RT, less hits, more erroneous responses, higher mixing costs and decreased amplitude of ERP components than the participants of the younger group. In the task without the nogo stimuli young adults kept the previous task-set active that could be seen in shorter RT and larger amplitude of cue-locked late positivity (P3b) in task repeat (TR) trials compared to task switch trials. If both go and nogo stimuli were presented, similar RTs and P3b amplitudes appeared in the TR and TS trials. In the complex task situations older adults did not evolve an appropriate task representation and task preparation, as indicated by the lack of cue-locked P3b, CNV, and target-locked P3b. We conclude that young participants developed explicit representation of task structures, but the presence of nogo stimuli had marked effects on such representation. On the other hand, older people used only implicit control strategy to solve the task, hence the basic difference between the age groups was their strategy of task execution.

A P300 brain-computer interface based on a modification of the mismatch negativity paradigm.

The P300-based brain-computer interface (BCI) is an extension of the oddball paradigm, and can facilitate communication for people with severe neuromuscular disorders. It has been shown that, in addition to the P300, other event-related potential (ERP) components have been shown to contribute to successful operation of the P300 BCI. Incorporating these components into the classification algorithm can improve the classification accuracy and information transfer rate (ITR). In this paper, a single character presentation paradigm was compared to a presentation paradigm that is based on the visual mismatch negativity. The mismatch negativity paradigm showed significantly higher classification accuracy and ITRs than a single character presentation paradigm. In addition, the mismatch paradigm elicited larger N200 and N400 components than the single character paradigm. The components elicited by the presentation method were consistent with what would be expected from a mismatch paradigm and a typical P300 was also observed. The results show that increasing the signal-to-noise ratio by increasing the amplitude of ERP components can significantly improve BCI speed and accuracy. The mismatch presentation paradigm may be considered a viable option to the traditional P300 BCI paradigm.

Low Frequency EEG and Performance Accuracy in Cued Contexts

Event Abstract Back to Event Low Frequency EEG and Performance Accuracy in Cued Contexts Diana Karamacoska1* and Robert J. Barry1 1 University of Wollongong, School of Psychology, Australia Event-related potentials (ERPs) and reaction times (RTs) to stimuli are greatly enhanced when cued. Reductions in electroencephalographic (EEG) activity in the cue-stimulus interval have been reported, but few studies have examined these in relation to stimulus-response processes. Delta, theta, alpha, and beta levels occurring immediately prior to cued stimuli were assessed here to determine their effects on post-stimulus ERPs and RTs. Continuous EEGs were recorded (N = 60) during a cued Continuous Performance Test where numbers were visually presented and a button press was required to the Go (9) when preceded by the cue (1). Cued numbers between 0 and 8 were considered as NoGos and were not to be responded to. ERPs for the cued Go/NoGos that were correctly responded to were separated using Principal Components Analyses (PCA). The maximal sites of activity were identified for the four EEG band levels in the 500 ms preceeding Go and NoGo stimuli and for ERP component amplitudes; these were then correlated. RTs were also correlated with EEG levels. EEG activity was found to be dominant across the midline, and the following PCA components were analysed: Go N2c and P3b, and NoGo N2b, P3a, and Slow Wave. A weak negative correlation with prestimulus beta levels was observed for the Go P3b, with no effects for RTs. Greater prestimulus delta and beta levels were associated with enhanced NoGo N2b amplitudes, and more theta activity was weakly linked to larger P3a positivity. These results suggest that EEG at maximal sites as a determining state measure may be suboptimal in cued contexts, and alternate measures, such as the EEG change from cue to the stimulus, should be considered. However, the contributions of delta and theta activity to cognitively controlled aspects of NoGo stimulus processing extend prior findings assessing post-stimulus band activity, and overall performance accuracy. Keywords: Prestimulus EEG, Event-related potentials, Cueing, cognitive control, Principal Components Analysis (PCA) Conference: ASP2015 - 25th Annual Conference of the Australasian Society for Psychophysiology, Sydney, Australia, 2 Dec - 4 Dec, 2015. Presentation Type: Poster Presentation Topic: Psychophysiology Citation: Karamacoska D and Barry RJ (2015). Low Frequency EEG and Performance Accuracy in Cued Contexts. Conference Abstract: ASP2015 - 25th Annual Conference of the Australasian Society for Psychophysiology. doi: 10.3389/conf.fnhum.2015.219.00029 Copyright: The abstracts in this collection have not been subject to any Frontiers peer review or checks, and are not endorsed by Frontiers. They are made available through the Frontiers publishing platform as a service to conference organizers and presenters. The copyright in the individual abstracts is owned by the author of each abstract or his/her employer unless otherwise stated. Each abstract, as well as the collection of abstracts, are published under a Creative Commons CC-BY 4.0 (attribution) licence (https://creativecommons.org/licenses/by/4.0/) and may thus be reproduced, translated, adapted and be the subject of derivative works provided the authors and Frontiers are attributed. For Frontiers’ terms and conditions please see https://www.frontiersin.org/legal/terms-and-conditions. Received: 20 Oct 2015; Published Online: 30 Nov 2015. * Correspondence: Miss. Diana Karamacoska, University of Wollongong, School of Psychology, Wollongong, NSW, 2500, Australia, d.karamacoska@westernsydney.edu.au Login Required This action requires you to be registered with Frontiers and logged in. To register or login click here. Abstract Info Abstract The Authors in Frontiers Diana Karamacoska Robert J Barry Google Diana Karamacoska Robert J Barry Google Scholar Diana Karamacoska Robert J Barry PubMed Diana Karamacoska Robert J Barry Related Article in Frontiers Google Scholar PubMed Abstract Close Back to top Javascript is disabled. Please enable Javascript in your browser settings in order to see all the content on this page.

Caffeine Effects on ERP Components and Performance in an Equiprobable Auditory Go/NoGo Task.

Background: Research has reliably demonstrated that caffeine produces a general increase in physiological arousal in humans, but we previously failed to obtain the expected arousal-based changes in manually quantified event-related potential (ERP) components in response to the stimuli in a simple Go/NoGo task. Methods: A single oral dose of caffeine (250 mg) was used in a randomized double-blind placebo-controlled repeated-measures cross-over study. Adult participants (N=24) abstained from caffeine for 4 hours before each of two sessions, approximately 1 week apart. An equiprobable auditory Go/NoGo task was used, with a random mix of 75 tones at 1,000 Hz and 75 at 1,500 Hz. All tones were 50 ms duration (rise/fall time 5 ms) at 60 dB SPL, with a fixed stimulus-onset asynchrony of 1100 ms. Principal component analysis (a form of factor analysis) was used to quantify orthogonal ERP components. Results: ERP components reflected the different sequential processing of each stimulus type in this paradigm, replicating previous results. Caffeine was associated with a reduction in reaction time and fewer omission errors. The major ERP effects of caffeine were apparent as a slightly enhanced Processing Negativity and larger P3b amplitudes to Go stimuli. There were few effects on components to NoGo stimuli. Conclusions: The results confirm our previous findings that caffeine improves aspects of the differential processing related to response production and task performance, but may be interpreted as supporting the simple amplification of ERP component amplitudes predicted by the general arousal induced by caffeine.

NR2B Antagonist CP-101,606 Abolishes Pitch-Mediated Deviance Detection in Awake Rats.

Schizophrenia patients exhibit a decreased ability to detect change in their auditory environment as measured by auditory event-related potentials (ERP) such as mismatch negativity. This deficit has been linked to abnormal NMDA neurotransmission since, among other observations, non-selective channel blockers of NMDA reliably diminish automatic deviance detection in human subjects as well as in animal models. Recent molecular and functional evidence links NR2B receptor subtype to aberrant NMDA transmission in schizophrenia. However, it is unknown if NR2B receptors participate in pre-attentive deviance detection. We recorded ERP from the vertex of freely behaving rats in response to frequency mismatch protocols. We saw a robust increase in N1 response to deviants compared to standard as well as control stimuli indicating true deviance detection. Moreover, the increased negativity was highly sensitive to deviant probability. Next, we tested the effect of a non-selective NMDA channel blocker (ketamine, 30 mg/kg) and a highly selective NR2B antagonist, CP-101,606 (10 or 30 mg/kg) on deviance detection. Ketamine attenuated deviance mainly by increasing the amplitude of the standard ERP. Amplitude and/or latency of several ERP components were also markedly affected. In contrast, CP-101,606 robustly and dose-dependently inhibited the deviant’s N1 amplitude, and as a consequence, completely abolished deviance detection. No other ERPs or components were affected. Thus, we report first evidence that NR2B receptors robustly participate in processes of automatic deviance detection in a rodent model. Lastly, our model demonstrates a path forward to test specific pharmacological hypotheses using translational endpoints relevant to aberrant sensory processing in schizophrenia.