scholarly journals Spatial and temporal features of the lambda response in fixation-related potentials

2016 ◽  
Vol 16 (12) ◽  
pp. 108
Author(s):  
Anthony Ries ◽  
Jon Touryan ◽  
Patrick Connolly
Keyword(s):  
Temporal Features ◽  
Related Potentials ◽  
Lambda Response

scholarly journals Temporal and Spatial Features of Single-Trial EEG for Brain-Computer Interface

2007 ◽  
Vol 2007 ◽  
pp. 1-14 ◽  
Author(s):  
Qibin Zhao ◽  
Liqing Zhang
Keyword(s):  
Brain Computer Interface ◽  
Hand Movement ◽  
Event Related Potentials ◽  
Computer Interface ◽  
Single Trial ◽  
Spatial Filters ◽  
Classification Rate ◽  
Temporal Features ◽  
Related Potentials

Brain-computer interface (BCI) systems create a novel communication channel from the brain to an output device bypassing conventional motor output pathways of nerves and muscles. Modern BCI technology is essentially based on techniques for the classification of single-trial brain signals. With respect to the topographic patterns of brain rhythm modulations, the common spatial patterns (CSPs) algorithm has been proven to be very useful to produce subject-specific and discriminative spatial filters; but it didn't consider temporal structures of event-related potentials which may be very important for single-trial EEG classification. In this paper, we propose a new framework of feature extraction for classification of hand movement imagery EEG. Computer simulations on real experimental data indicate that independent residual analysis (IRA) method can provide efficient temporal features. Combining IRA features with the CSP method, we obtain the optimal spatial and temporal features with which we achieve the best classification rate. The high classification rate indicates that the proposed method is promising for an EEG-based brain-computer interface.

Event-related potentials reveal a memory trace for temporal features

Neuroreport ◽  
1993 ◽  
Vol 5 (3) ◽  
pp. 310-312 ◽  
Author(s):  
Risto Näätänen ◽  
Deming Jiang ◽  
Juha Lavikainen ◽  
Kalevi Reinikainen ◽  
Petri Paavilainen
Keyword(s):  
Memory Trace ◽  
Event Related Potentials ◽  
Temporal Features ◽  
Related Potentials

The Temporal Features of Self-referential Processing Evoked by Chinese Handwriting

2008 ◽  
Vol 20 (5) ◽  
pp. 816-827 ◽  
Author(s):  
Antao Chen ◽  
Xuchu Weng ◽  
Jiajin Yuan ◽  
Xu Lei ◽  
Jiang Qiu ◽  
...  
Keyword(s):  
Medial Temporal Lobe ◽  
Time Window ◽  
Time Windows ◽  
Event Related Potentials ◽  
Cingulate Cortex ◽  
Anterior Cingulate ◽  
Processing Unit ◽  
Temporal Features ◽  
Referential Processing ◽  
Related Potentials

To explore the temporal features and underlying brain structures of self-referential processing, participants were shown examples of Chinese handwriting, half of which were their own and the other half belonged to others, and asked to judge whether the handwriting was their own. In Experiment 1, the task was to categorize the handwriting by pressing the correct key as quickly as possible. In Experiment 2, after the participants recognized the stimuli, they were required to gaze at the handwriting for 3000 msec before making a response rather than responding immediately after stimulus onset. The results showed prominent differences in event-related potentials elicited by own and other handwriting conditions in the 200–500 msec and 1000–2000 msec time windows. Dipole analyses of the difference waves, own minus other, were conducted in both of these time windows. There were two dipoles in the 200–500 msec time window localized to the medial-temporal lobe and the anterior cingulate cortex (ACC), and MTL activation preceded ACC activation. Only one dipole at the posterior cingulate cortex was fitted to the 1000–2000 msec time window. These structures were activated sequentially in a temporal course, which provides evidence that the cortex middle structures potentially form a specific self-related processing unit, which is involved in processing various aspects of the self.

scholarly journals Detection of Error-Related Potentials in Stroke Patients from EEG Using an Artificial Neural Network

Sensors ◽  
2021 ◽  
Vol 21 (18) ◽  
pp. 6274
Author(s):  
Nayab Usama ◽  
Imran Khan Niazi ◽  
Kim Dremstrup ◽  
Mads Jochumsen
Keyword(s):  
Neural Network ◽  
Artificial Neural Network ◽  
Stroke Rehabilitation ◽  
Retest Reliability ◽  
Linear Discriminant ◽  
Temporal Features ◽  
Continuous Eeg ◽  
Related Potentials ◽  
Artificial Neural ◽  
Test Retest Reliability

Error-related potentials (ErrPs) have been proposed as a means for improving brain–computer interface (BCI) performance by either correcting an incorrect action performed by the BCI or label data for continuous adaptation of the BCI to improve the performance. The latter approach could be relevant within stroke rehabilitation where BCI calibration time could be minimized by using a generalized classifier that is continuously being individualized throughout the rehabilitation session. This may be achieved if data are correctly labelled. Therefore, the aims of this study were: (1) classify single-trial ErrPs produced by individuals with stroke, (2) investigate test–retest reliability, and (3) compare different classifier calibration schemes with different classification methods (artificial neural network, ANN, and linear discriminant analysis, LDA) with waveform features as input for meaningful physiological interpretability. Twenty-five individuals with stroke operated a sham BCI on two separate days where they attempted to perform a movement after which they received feedback (error/correct) while continuous EEG was recorded. The EEG was divided into epochs: ErrPs and NonErrPs. The epochs were classified with a multi-layer perceptron ANN based on temporal features or the entire epoch. Additionally, the features were classified with shrinkage LDA. The features were waveforms of the ErrPs and NonErrPs from the sensorimotor cortex to improve the explainability and interpretation of the output of the classifiers. Three calibration schemes were tested: within-day, between-day, and across-participant. Using within-day calibration, 90% of the data were correctly classified with the entire epoch as input to the ANN; it decreased to 86% and 69% when using temporal features as input to ANN and LDA, respectively. There was poor test–retest reliability between the two days, and the other calibration schemes led to accuracies in the range of 63–72% with LDA performing the best. There was no association between the individuals’ impairment level and classification accuracies. The results show that ErrPs can be classified in individuals with stroke, but that user- and session-specific calibration is needed for optimal ErrP decoding with this approach. The use of ErrP/NonErrP waveform features makes it possible to have a physiological meaningful interpretation of the output of the classifiers. The results may have implications for labelling data continuously in BCIs for stroke rehabilitation and thus potentially improve the BCI performance.

Sensory and Cognitive Components of Auditory Processing in Individuals With Tinnitus

2019 ◽  
Vol 28 (4) ◽  
pp. 834-842
Author(s):  
Harini Vasudevan ◽  
Hari Prakash Palaniswamy ◽  
Ramaswamy Balakrishnan
Keyword(s):  
Selective Attention ◽  
Auditory Processing ◽  
Function Analysis ◽  
Event Related Potential ◽  
Oscillatory Activity ◽  
Default Mode ◽  
Auditory Selective Attention ◽  
Cognitive Components ◽  
Mode Function ◽  
Related Potentials

Purpose The main purpose of the study is to explore the auditory selective attention abilities (using event-related potentials) and the neuronal oscillatory activity in the default mode network sites (using electroencephalogram [EEG]) in individuals with tinnitus. Method Auditory selective attention was measured using P300, and the resting state EEG was assessed using the default mode function analysis. Ten individuals with continuous and bothersome tinnitus along with 10 age- and gender-matched control participants underwent event-related potential testing and 5 min of EEG recording (at wakeful rest). Results Individuals with tinnitus were observed to have larger N1 and P3 amplitudes along with prolonged P3 latency. The default mode function analysis revealed no significant oscillatory differences between the groups. Conclusion The current study shows changes in both the early sensory and late cognitive components of auditory processing. The change in the P3 component is suggestive of selective auditory attention deficit, and the sensory component (N1) suggests an altered bottom-up processing in individuals with tinnitus.

Temporal Characteristics of Speech in Simultaneous Communication

1995 ◽  
Vol 38 (5) ◽  
pp. 1014-1024 ◽  
Author(s):  
Robert L. Whitehead ◽  
Nicholas Schiavetti ◽  
Brenda H. Whitehead ◽  
Dale Evan Metz
Keyword(s):  
Pause Duration ◽  
Vowel Duration ◽  
Vowel Perception ◽  
Temporal Characteristics ◽  
Spoken English ◽  
Temporal Features ◽  
Before And After ◽  
Word Duration ◽  
Rate Of Speech ◽  
Speech Condition

The purpose of this investigation was twofold: (a) to determine if there are changes in specific temporal characteristics of speech that occur during simultaneous communication, and (b) to determine if known temporal rules of spoken English are disrupted during simultaneous communication. Ten speakers uttered sentences consisting of a carrier phrase and experimental CVC words under conditions of: (a) speech, (b) speech combined with signed English, and (c) speech combined with signed English for every word except the CVC word that was fingerspelled. The temporal features investigated included: (a) sentence duration, (b) experimental CVC word duration, (c) vowel duration in experimental CVC words, (d) pause duration before and after experimental CVC words, and (e) consonantal effects on vowel duration. Results indicated that for all durational measures, the speech/sign/fingerspelling condition was longest, followed by the speech/sign condition, with the speech condition being shortest. It was also found that for all three speaking conditions, vowels were longer in duration when preceding voiced consonants than vowels preceding their voiceless cognates, and that a low vowel was longer in duration than a high vowel. These findings indicate that speakers consistently reduced their rate of speech when using simultaneous communication, but did not violate these specific temporal rules of English important for consonant and vowel perception.

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