scholarly journals Event Related Potential Signal Capture Can Be Enhanced through Dynamic SNR-Weighted Channel Pooling

Sensors ◽  
2021 ◽  
Vol 21 (21) ◽  
pp. 7258
Author(s):  
Sujoy Ghosh Ghosh Hajra ◽  
Careesa C. Liu ◽  
Shaun D. Fickling ◽  
Gabriela M. Pawlowski ◽  
Xiaowei Song ◽  
...  
Keyword(s):  
Language Processing ◽  
Simulated Data ◽  
Event Related Potentials ◽  
Real Data ◽  
Event Related Potential ◽  
New Technique ◽  
Pool Data ◽  
Experimental Conditions ◽  
Brain Functions ◽  
Related Potentials

Background: Electroencephalography (EEG)-derived event-related potentials (ERPs) provide information about a variety of brain functions, but often suffer from low inherent signal-to-noise ratio (SNR). To overcome the low SNR, techniques that pool data from multiple sensors have been applied. However, such pooling implicitly assumes that the SNR among sensors is equal, which is not necessarily valid. This study presents a novel approach for signal pooling that accounts for differential SNR among sensors. Methods: The new technique involves pooling together signals from multiple EEG channels weighted by their respective SNRs relative to the overall SNR of all channels. We compared ERP responses derived using this new technique with those derived using both individual channels as well as traditional averaged-based channel pooling. The outcomes were evaluated in both simulated data and real data from healthy adult volunteers (n = 37). Responses corresponding to a range of ERP components indexing auditory sensation (N100), attention (P300) and language processing (N400) were evaluated. Results: Simulation results demonstrate that, compared to traditional pooling technique, the new SNR-weighted channel pooling technique improved ERP response effect size in cases of unequal noise among channels (p’s < 0.001). Similarly, results from real-world experimental data showed that the new technique resulted in significantly greater ERP effect sizes compared to either traditional pooling or individual channel approach for all three ERP components (p’s < 0.001). Furthermore, the new channel pooling approach also resulted in larger ERP signal amplitudes as well as greater differences among experimental conditions (p’s < 0.001). Conclusion: These results suggest that the new technique improves the capture of ERP responses relative to traditional techniques. As such, SNR-weighted channel pooling can further enable widespread applications of ERP techniques, especially those that require rapid assessments in noisy out-of-laboratory environments.

Event-related Potential Correlates of Negation in a Sentence–Picture Verification Paradigm

2008 ◽  
Vol 20 (8) ◽  
pp. 1355-1370 ◽  
Author(s):  
Jana Lüdtke ◽  
Claudia K. Friedrich ◽  
Mónica De Filippis ◽  
Barbara Kaup
Keyword(s):  
Language Processing ◽  
Priming Effect ◽  
Time Window ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Foreground Object ◽  
Negative Particle ◽  
Sentence Meaning ◽  
Related Potentials ◽  
Main Effects

In a sentence–picture verification paradigm, participants were presented in a rapid-serial-visual-presentation paradigm with affirmative or negative sentences (e.g., “In the front of the tower there is a/no ghost”) followed by a matching or mismatching picture. Response latencies and event-related potentials (ERPs) were measured during reading and verification. An enhanced negative shift in the ERPs for the subject noun (i.e., “ghost”) in negative, compared to affirmative sentences, was found during reading. We relate this ERP deflection to enhanced processing demands required by the negative particle no. Although this effect suggests a direct impact of negation on language processing, results for picture processing reveal that negation is not immediately integrated into sentence meaning. When the delay of picture presentation was short (250 msec), verification latencies and ERPs evoked by the picture showed a priming effect independent of whether the sentence contained a negation. Unprimed pictures (foreground object not mentioned in the sentence) led to longer latencies and higher N400 amplitudes than primed pictures (foreground object mentioned in the sentence). Main effects of negation showed up only in a late positive-going ERP effect. In contrast, when the delay was long (1500 msec), we observed main effects of truth value and negation in addition to the priming effect already in the N400 time window, that is, negation is fully integrated into sentence meaning only at a later point in the comprehension process. When negation has not yet been integrated, verification decisions appear to be modulated by additional time-consuming reanalysis processes.

scholarly journals The Impact of Proficiency on Syntactic Second-language Processing of German and Italian: Evidence from Event-related Potentials

2006 ◽  
Vol 18 (12) ◽  
pp. 2030-2048 ◽  
Author(s):  
Sonja Rossi ◽  
Manfred F. Gugler ◽  
Angela D. Friederici ◽  
Anja Hahne
Keyword(s):  
Second Language ◽  
Language Processing ◽  
Native Speakers ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Word Category ◽  
L2 Learners ◽  
Related Potentials ◽  
Anterior Negativity ◽  
The Impact

The present study investigated the role of proficiency in late second-language (L2) processing using comparable stimuli in German and Italian. Both sets of stimuli consisted of simple active sentences including a word category violation, a morphosyntactic agreement violation, or a combination of the two. Four experiments were conducted to study high- and low-proficiency L2 learners of German as well as high- and low-proficiency L2 learners of Italian. High-proficiency L2 learners in both languages showed the same event-related potential (ERP) components as native speakers for all syntactic violations. For the word category violation, they displayed an early anterior negativity (ELAN), an additional negativity reflecting reference-related processes, and a late P600 evidencing processes of reanalysis. For the processing of the morphosyntactic error, an anterior negativity (LAN) and a P600 were observed, whereas for the combined violation, the same ERP components were found as in the pure category violation. In high-proficiency L2 learners, the timing of the processing steps was equivalent to that of native speakers, although some amplitude differences were present. Low-proficiency L2 learners, however, showed qualitative differences in the agreement violation characterized by the absence of the LAN and quantitative differences reflected in a delayed P600 in every violation condition. These findings emphasize that with a high proficiency, late L2 learners can indeed show native-like neural responses with the timing approximating that of native speakers. This challenges the idea that there are fundamental differences in language processing in the brain between natives and late L2 learners.

scholarly journals Exploring the Organization of Semantic Memory through Unsupervised Analysis of Event-related Potentials

2018 ◽  
Vol 30 (3) ◽  
pp. 381-392 ◽  
Author(s):  
Marijn van Vliet ◽  
Marc M. Van Hulle ◽  
Riitta Salmelin
Keyword(s):  
Semantic Memory ◽  
Clustering Algorithm ◽  
Mental Lexicon ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Experimental Conditions ◽  
Strict Adherence ◽  
Neurophysiological Data ◽  
Related Potentials ◽  
N400 Component

Modern multivariate methods have enabled the application of unsupervised techniques to analyze neurophysiological data without strict adherence to predefined experimental conditions. We demonstrate a multivariate method that leverages priming effects on the evoked potential to perform hierarchical clustering on a set of word stimuli. The current study focuses on the semantic relationships that play a key role in the organization of our mental lexicon of words and concepts. The N400 component of the event-related potential is considered a reliable neurophysiological response that is indicative of whether accessing one concept facilitates subsequent access to another (i.e., one “primes” the other). To further our understanding of the organization of the human mental lexicon, we propose to utilize the N400 component to drive a clustering algorithm that can uncover, given a set of words, which particular subsets of words show mutual priming. Such a scheme requires a reliable measurement of the amplitude of the N400 component without averaging across many trials, which was here achieved using a recently developed multivariate analysis method based on beamforming. We validated our method by demonstrating that it can reliably detect, without any prior information about the nature of the stimuli, a well-known feature of the organization of our semantic memory: the distinction between animate and inanimate concepts. These results motivate further application of our method to data-driven exploration of disputed or unknown relationships between stimuli.

scholarly journals Retrieval (N400) and integration (P600) in expectation-based comprehension

PLoS ONE ◽  
2021 ◽  
Vol 16 (9) ◽  
pp. e0257430
Author(s):  
Christoph Aurnhammer ◽  
Francesca Delogu ◽  
Miriam Schulz ◽  
Harm Brouwer ◽  
Matthew W. Crocker
Keyword(s):  
Language Processing ◽  
Language Comprehension ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Lexical Retrieval ◽  
Related Potentials ◽  
Lexical Association ◽  
Reading Experiment ◽  
Continuous Relation ◽  
Open Question

Expectation-based theories of language processing, such as Surprisal theory, are supported by evidence of anticipation effects in both behavioural and neurophysiological measures. Online measures of language processing, however, are known to be influenced by factors such as lexical association that are distinct from—but often confounded with—expectancy. An open question therefore is whether a specific locus of expectancy related effects can be established in neural and behavioral processing correlates. We address this question in an event-related potential experiment and a self-paced reading experiment that independently cross expectancy and lexical association in a context manipulation design. We find that event-related potentials reveal that the N400 is sensitive to both expectancy and lexical association, while the P600 is modulated only by expectancy. Reading times, in turn, reveal effects of both association and expectancy in the first spillover region, followed by effects of expectancy alone in the second spillover region. These findings are consistent with the Retrieval-Integration account of language comprehension, according to which lexical retrieval (N400) is facilitated for words that are both expected and associated, whereas integration difficulty (P600) will be greater for unexpected words alone. Further, an exploratory analysis suggests that the P600 is not merely sensitive to expectancy violations, but rather, that there is a continuous relation. Taken together, these results suggest that the P600, like reading times, may reflect a meaning-centric notion of Surprisal in language comprehension.

scholarly journals How Native Background Affects Human Performance in Real-World Visual Object Detection: An Event-Related Potential Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Yue Wang ◽  
Jianpu Yan ◽  
Zhongliang Yin ◽  
Shenghan Ren ◽  
Minghao Dong ◽  
...  
Keyword(s):  
Object Detection ◽  
Real World ◽  
Visual Processing ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Visual Object ◽  
Detection Accuracy ◽  
Natural Scenes ◽  
Experimental Conditions ◽  
Related Potentials

Visual processing refers to the process of perceiving, analyzing, synthesizing, manipulating, transforming, and thinking of visual objects. It is modulated by both stimulus-driven and goal-directed factors and manifested in neural activities that extend from visual cortex to high-level cognitive areas. Extensive body of studies have investigated the neural mechanisms of visual object processing using synthetic or curated visual stimuli. However, synthetic or curated images generally do not accurately reflect the semantic links between objects and their backgrounds, and previous studies have not provided answers to the question of how the native background affects visual target detection. The current study bridged this gap by constructing a stimulus set of natural scenes with two levels of complexity and modulating participants' attention to actively or passively attend to the background contents. Behaviorally, the decision time was elongated when the background was complex or when the participants' attention was distracted from the detection task, and the object detection accuracy was decreased when the background was complex. The results of event-related potentials (ERP) analysis explicated the effects of scene complexity and attentional state on the brain responses in occipital and centro-parietal areas, which were suggested to be associated with varied attentional cueing and sensory evidence accumulation effects in different experimental conditions. Our results implied that efficient visual processing of real-world objects may involve a competition process between context and distractors that co-exist in the native background, and extensive attentional cues and fine-grained but semantically irrelevant scene information were perhaps detrimental to real-world object detection.

scholarly journals Pre-attentive processing of Alzheimer's disease: an event-related potential study

2019 ◽  
Author(s):  
Eunchan Na ◽  
Kanghee Lee ◽  
Eun Ji Kim ◽  
Jong Bin Bae ◽  
Seung Wan Suh ◽  
...  
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Visual Processing ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
Oddball Paradigm ◽  
Brain Functions ◽  
Oddball Task ◽  
Related Potentials ◽  
Visual Oddball

Abstract Background: While identifying Alzheimer’s Disease (AD) in its early stages is crucial, traditional neuropsychological tests tend to lack sensitivity and specificity for its diagnosis. Based on the early visual attention deficits of adults with AD, which are apparent before cognitive deficits emerge, this study aimed to investigate visual attentional characteristics of adults with AD, from pre-attentive to attentive processing, using a visual oddball task and event-related potentials (ERPs).Methods: Cognitively normal elderly controls (NC, n=27) and patients with probable AD (AD, n=10) were recruited. Participants performed a three-stimulus visual oddball task and were asked to press a designated button in response to the target stimuli. The amplitudes of 4 ERPs were analyzed. Visual mismatch-negativity (vMMN) was analyzed around the parieto-occipital and temporo-occipital regions. P3a was analyzed around the fronto-central regions, whereas P3b was analyzed around the centro-parietal regions.Results: Late vMMN amplitudes of the AD group were significantly smaller than those of the NC group, while early vMMN amplitudes were comparable. Compared to the NC group, P3a amplitudes of the AD group were significantly smaller for the infrequent deviant stimuli but the amplitudes for the standard stimuli were comparable. Lastly, the AD group had significantly smaller P3b amplitudes than the NC group.Conclusion: Our findings imply that AD patients exhibit pre-attentive visual processing deficits, known to affect later higher-order brain functions. In a clinical setting, the visual oddball paradigm could be used to provide helpful diagnostic information since pre-attentive ERPs can be induced by passive exposure to infrequent stimuli.

Neural dynamics of trainee teachers' emotional conflict processing: An event-related potential study

2019 ◽  
Vol 47 (7) ◽  
pp. 1-9
Author(s):  
Li Jin ◽  
Xu Li ◽  
Jiamei Lu ◽  
Nianqu Chen ◽  
Lin Cheng ◽  
...  
Keyword(s):  
School Context ◽  
Event Related Potentials ◽  
Event Related Potential ◽  
The Body ◽  
Educational Context ◽  
Congruent Condition ◽  
Slow Potential ◽  
Emotional Conflict ◽  
Trainee Teachers ◽  
Related Potentials

We investigated emotional conflict in an educational context with an emotional body–word Stroop paradigm, examining whether the N450 (a late fronto-central phasic negative event-related potential signature) and slow potential (SP) effects could be evoked in trainee teachers. The N450 effect is characterized by topography and negative polarity of an incongruent minus congruent difference potential, and the SP effect has positive polarity (incongruent minus congruent difference potential). Positive and negative body language examples were obtained from pupils in an actual school context, and emotional words were selected. Compound stimuli were presented, each comprising a congruent or incongruent word displayed across a body image. Event-related potentials were recorded while participants judged body expression valence. Reaction times were longer and accuracies were lower for the incongruent compared to the congruent condition. The N450 component amplitude in the incongruent condition was more negative than in the congruent condition. Results showed a behavioral interference effect and an N450 effect for trainee teachers in this context, thus indicating that the body–word task was efficient in assessing emotional conflict in an educational context, and trainee teachers' perception of body expressions of students could be influenced by emotional signals. The findings further the understanding of emotional conflict in an educational context.

scholarly journals Eliciting and Recording Event Related Potentials (ERPs) in Behaviourally Unresponsive Populations: A Retrospective Commentary on Critical Factors

2021 ◽  
Vol 11 (7) ◽  
pp. 835
Author(s):  
Alexander Rokos ◽  
Richard Mah ◽  
Rober Boshra ◽  
Amabilis Harrison ◽  
Tsee Leng Choy ◽  
...  
Keyword(s):  
Event Related Potentials ◽  
Stimulus Presentation ◽  
Event Related Potential ◽  
Critical Factors ◽  
Healthy Elderly ◽  
States Of Consciousness ◽  
Long Latency ◽  
Eeg Data ◽  
Related Potentials ◽  
The Relationship

A consistent limitation when designing event-related potential paradigms and interpreting results is a lack of consideration of the multivariate factors that affect their elicitation and detection in behaviorally unresponsive individuals. This paper provides a retrospective commentary on three factors that influence the presence and morphology of long-latency event-related potentials—the P3b and N400. We analyze event-related potentials derived from electroencephalographic (EEG) data collected from small groups of healthy youth and healthy elderly to illustrate the effect of paradigm strength and subject age; we analyze ERPs collected from an individual with severe traumatic brain injury to illustrate the effect of stimulus presentation speed. Based on these critical factors, we support that: (1) the strongest paradigms should be used to elicit event-related potentials in unresponsive populations; (2) interpretation of event-related potential results should account for participant age; and (3) speed of stimulus presentation should be slower in unresponsive individuals. The application of these practices when eliciting and recording event-related potentials in unresponsive individuals will help to minimize result interpretation ambiguity, increase confidence in conclusions, and advance the understanding of the relationship between long-latency event-related potentials and states of consciousness.

scholarly journals Proficiency Differences in Syntactic Processing of Monolingual Native Speakers Indexed by Event-related Potentials

2010 ◽  
Vol 22 (12) ◽  
pp. 2728-2744 ◽  
Author(s):  
Eric Pakulak ◽  
Helen J. Neville
Keyword(s):  
Language Proficiency ◽  
Language Processing ◽  
English Language ◽  
Native Speakers ◽  
Memory Span ◽  
Wide Spectrum ◽  
Event Related Potentials ◽  
Related Potentials ◽  
Native Speakers Of English ◽  
Proficiency Scores

Although anecdotally there appear to be differences in the way native speakers use and comprehend their native language, most empirical investigations of language processing study university students and none have studied differences in language proficiency, which may be independent of resource limitations such as working memory span. We examined differences in language proficiency in adult monolingual native speakers of English using an ERP paradigm. ERPs were recorded to insertion phrase structure violations in naturally spoken English sentences. Participants recruited from a wide spectrum of society were given standardized measures of English language proficiency, and two complementary ERP analyses were performed. In between-groups analyses, participants were divided on the basis of standardized proficiency scores into lower proficiency and higher proficiency groups. Compared with lower proficiency participants, higher proficiency participants showed an early anterior negativity that was more focal, both spatially and temporally, and a larger and more widely distributed positivity (P600) to violations. In correlational analyses, we used a wide spectrum of proficiency scores to examine the degree to which individual proficiency scores correlated with individual neural responses to syntactic violations in regions and time windows identified in the between-groups analyses. This approach also used partial correlation analyses to control for possible confounding variables. These analyses provided evidence for the effects of proficiency that converged with the between-groups analyses. These results suggest that adult monolingual native speakers of English who vary in language proficiency differ in the recruitment of syntactic processes that are hypothesized to be at least in part automatic as well as of those thought to be more controlled. These results also suggest that to fully characterize neural organization for language in native speakers it is necessary to include participants of varying proficiency.

scholarly journals Automaticity of Early Sexual Attention: An Event-Related Potential Study

Sexual Abuse ◽  
2021 ◽  
pp. 107906322110242
Author(s):  
Anastasios Ziogas ◽  
Benedikt Habermeyer ◽  
Wolfram Kawohl ◽  
Elmar Habermeyer ◽  
Andreas Mokros
Keyword(s):  
Sexual Orientation ◽  
Sexual Interest ◽  
Event Related Potentials ◽  
Forensic Assessment ◽  
Event Related Potential ◽  
Behavioral Measures ◽  
Sexual Preferences ◽  
Motor Responses ◽  
Related Potentials ◽  
Promising Line

A promising line of research on forensic assessment of paraphilic sexual interest focuses on behavioral measures of visual attention using sexual stimuli as distractors. The present study combined event-related potentials (ERPs) with behavioral measures to investigate whether detection of a hidden sexual preference can be improved with ERPs. Normal variants of sexual orientation were used for a proof-of-concept investigation. Accordingly, 40 heterosexual and 40 gay men participated in the study. Within each group, half of the participants were instructed to hide their sexual orientation. The results showed that a match between sexual orientation and stimulus delays responses and influences ERP before motor responses. Late ERP components showed higher potential in differentiating hidden sexual preferences than motor responses, thereby showing how ERPs can be used in combination with reaction time measures to potentially facilitate the detection of hidden sexual preferences.

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