ASSESSING THE IMPACT OF CONGRUENT AND INCONGRUENT STIMULUS IN STROOP TASK, USING EVENT-RELATED POTENTIALS (ERP) IN PATIENTS WITH DEPRESSION

2018 ◽  
Vol 30 (05) ◽  
pp. 1850034
Author(s):  
Yeganeh Shahsavar ◽  
Majid Ghoshuni

The main goal of this event-related potentials (ERPs) study was to assess the effects of stimulations in Stroop task in brain activities of patients with different degrees of depression. Eighteen patients (10 males, with the mean age [Formula: see text]) were asked to fill out Beck’s depression questionnaire. Electroencephalographic (EEG) signals of subjects were recorded in three channels (Pz, Cz, and Fz) during Stroop test. This test entailed 360 stimulations, which included 120 congruent, 120 incongruent, and 120 neutral stimulations. To analyze the data, 18 time features in each type of stimulus were extracted from the ERP components and the optimal features were selected. The correlation between the subjects’ scores in Beck’s depression questionnaires and the extracted time features in each recording channel was calculated in order to select the best features. Total area, and peak-to-peak time window in the Cz channel in both the congruent and incongruent stimulus showed significant correlation with Beck scores, with [Formula: see text], [Formula: see text] and [Formula: see text], [Formula: see text], respectively. Consequently, given the correlation between time features and the subjects’ Beck scores with different degrees of depression, it can be interpreted that in case of growth in degrees of depression, stimulations involving congruent images would produce more challenging interferences for the patients compared to incongruent stimulations which can be more effective in diagnosing the level of disorder.

2021 ◽  
Vol 11 (10) ◽  
pp. 1329
Author(s):  
Yong Liu ◽  
Jia Zhao ◽  
Xinqi Zhou ◽  
Xiaolin Liu ◽  
Hong Chen ◽  
...  

Mind-wandering (MW) is a common phenomenon, defined as task-unrelated thoughts. This study is based on event-related potentials (ERPs), using modified sustained attention to response task (modified SART, mSART) to discuss the neural patterns of different types of MW. In the current study, we defined the MW realized by participants as self-caught MW, and the MW measurement acquired by probes as probe-caught MW. The behavioral results showed that the reaction times (RTs) during self-caught MW were greater than those during non-self-caught MW. The ERP results showed that during self-caught MW, the mean amplitudes of N1 decreased significantly, indicating that the participants’ attention had deviated from the current task. The increase in the mean amplitudes of P2 during self-caught MW indicated lower vigilance. We also found that the mean amplitudes of N300 reduced during self-caught MW, which indicated that cognitive control or monitoring might be affected by self-caught MW. The average amplitudes of P300 were significantly lower during probe-caught MW than during on-task, indicating the impact on high-level cognitive processing. In addition, the amplitudes of N1, P2, and N300 in anterior regions were greater than those in posterior regions. P300 amplitudes during probe-caught MW in the right hemisphere were greater than those of the left hemisphere. In summary, our research results demonstrated that alertness and cognitive processing decreased during both self-caught MW and probe-caught MW. ERPs were statistically different under the conditions of self-caught MW and probe-caught MW. The current study provided new insights into the relationship between MW and neural markers. It was the first study exploring the ERP correlates between self-caught MW and probe-caught MW based on mSART.


Sensors ◽  
2020 ◽  
Vol 20 (21) ◽  
pp. 6285
Author(s):  
Raquib-ul Alam ◽  
Haifeng Zhao ◽  
Andrew Goodwin ◽  
Omid Kavehei ◽  
Alistair McEwan

There has been a growing interest in computational electroencephalogram (EEG) signal processing in a diverse set of domains, such as cortical excitability analysis, event-related synchronization, or desynchronization analysis. In recent years, several inconsistencies were found across different EEG studies, which authors often attributed to methodological differences. However, the assessment of such discrepancies is deeply underexplored. It is currently unknown if methodological differences can fully explain emerging differences and the nature of these differences. This study aims to contrast widely used methodological approaches in EEG processing and compare their effects on the outcome variables. To this end, two publicly available datasets were collected, each having unique traits so as to validate the results in two different EEG territories. The first dataset included signals with event-related potentials (visual stimulation) from 45 subjects. The second dataset included resting state EEG signals from 16 subjects. Five EEG processing steps, involved in the computation of power and phase quantities of EEG frequency bands, were explored in this study: artifact removal choices (with and without artifact removal), EEG signal transformation choices (raw EEG channels, Hjorth transformed channels, and averaged channels across primary motor cortex), filtering algorithms (Butterworth filter and Blackman–Harris window), EEG time window choices (−750 ms to 0 ms and −250 ms to 0 ms), and power spectral density (PSD) estimation algorithms (Welch’s method, Fast Fourier Transform, and Burg’s method). Powers and phases estimated by carrying out variations of these five methods were analyzed statistically for all subjects. The results indicated that the choices in EEG transformation and time-window can strongly affect the PSD quantities in a variety of ways. Additionally, EEG transformation and filter choices can influence phase quantities significantly. These results raise the need for a consistent and standard EEG processing pipeline for computational EEG studies. Consistency of signal processing methods cannot only help produce comparable results and reproducible research, but also pave the way for federated machine learning methods, e.g., where model parameters rather than data are shared.


2019 ◽  
Author(s):  
Jeremi K. Ochab ◽  
Jerzy Szwed ◽  
Katarzyna Oleś ◽  
Anna Bereś ◽  
Dante R. Chialvo ◽  
...  

ABSTRACTThe duration of sleep, wakefulness and dynamic changes in human performance are determined by neural and genetic mechanisms. Sleep deprivation and chronic restriction of sleep cause perturbations of circadian rhythmicity and degradation of waking alertness as reflected in attention, cognitive efficiency and memory. In this work we report on multiple neurobehavioral correlates of sleep loss in healthy adults in an unprecedented study comprising 21 consecutive days divided into periods of 4 days of regular life (a baseline), 10 days of chronic partial sleep restriction and 7 days of recovery. Throughout the whole experiment we continuously measured the spontaneous locomotor activity by means of actigraphy with 1-minute resolution in two acquisition modes (frequency and intensity of movement). Moreover, on daily basis the subjects were undergoing EEG measurements (64-electrodes with 500 Hz sampling frequency): resting state with eyes open and closed (RS; 8 minutes long each) followed by Stroop task (ST; 22 minutes). Altogether we analyzed actigraphy (distributions of rest and activity durations), behavioral measures (accuracy and reaction times from Stroop task) and EEG (amplitudes, latencies and scalp maps of event-related potentials from Stroop task and power spectra from resting states). The actigraphy measures clearly indicate rapid changes after sleep restriction onset, confirming our former investigations — the novel insight is a slow and incomplete relaxation to the original locomotor behavior. The pattern of partial recovery appears also in accuracy (in ST) and power of delta rhythm (in RS). The impact of sleep loss is also evident in reaction times (in ST), yet followed by complete recovery, and finally in ERP amplitudes and latencies, which however did not return to the baseline at all. The results indicate that short periods (a few days) of recovery sleep subsequent to prolonged periods of sleep restriction are overall insufficient to recover fully.


F1000Research ◽  
2015 ◽  
Vol 3 ◽  
pp. 316
Author(s):  
Sheila Bouten ◽  
Hugo Pantecouteau ◽  
J. Bruno Debruille

Qualia, the individual instances of subjective conscious experience, are private events. However, in everyday life, we assume qualia of others and their perceptual worlds, to be similar to ours. One way this similarity is possible is if qualia of others somehow contribute to the production of qualia by our own brain and vice versa. To test this hypothesis, we focused on the mean voltages of event-related potentials (ERPs) in the time-window of the P600 component, whose amplitude correlates positively with conscious awareness. These ERPs were elicited by stimuli of the international affective picture system in 16 pairs of friends, siblings or couples going side by side through hyperscanning without having to interact. Each of the 32 members of these 16 pairs faced one half of the screen and could not see what the other member was presented with on the other half. One stimulus occurred on each half simultaneously. The sameness of these stimulus pairs was manipulated as well as the participants’ belief in that sameness by telling subjects’ pairs that they were going to be presented with the same stimuli in two blocks and with different ones in the two others. In the P600 time window, belief, and thus social cognition, was found to have an effect on ERPs only at left anterior electrode sites. In contrast, ERPs were more positive at all electrode subsets for stimulus pairs that were   inconsistent with the belief than for those that were consistent. In the N400 time window, at frontal electrode sites, ERPs were again more positive for inconsistent than for consistent stimuli. As participants had no way to see the stimulus their partner was presented with, and thus no way to detect inconsistence, we proposed that these data could support the existence of spontaneous brain-to-brain communications. Such communications might provide a research avenue when trying to explain the similarity of qualia across individuals, which is assumed in virtually all instants of every day life.


2013 ◽  
Vol 27 (4) ◽  
pp. 149-164 ◽  
Author(s):  
Montserrat Zurrón ◽  
Marta Ramos-Goicoa ◽  
Fernando Díaz

With the aim of establishing the temporal locus of the semantic conflict in color-word Stroop and emotional Stroop phenomena, we analyzed the Event-Related Potentials (ERPs) elicited by nonwords, incongruent and congruent color words, colored words with positive and negative emotional valence, and colored words with neutral valence. The incongruent, positive, negative, and neutral stimuli produced interference in the behavioral response to the color of the stimuli. The P150/N170 amplitude was sensitive to the semantic equivalence of both dimensions of the congruent color words. The P3b amplitude was smaller in response to incongruent color words and to positive, negative, and neutral colored words than in response to the congruent color words and colored nonwords. There were no differences in the ERPs induced in response to colored words with positive, negative, and neutral valence. Therefore, the P3b amplitude was sensitive to interference from the semantic content of the incongruent, positive, negative, and neutral words in the color-response task, independently of the emotional content of the colored words. In addition, the P3b amplitude was smaller in response to colored words with positive, negative, and neutral valence than in response to the incongruent color words. Overall, these data indicate that the temporal locus of the semantic conflict generated by the incongruent color words (in the color-word Stroop task) and by colored words with positive, negative, and neutral valence (in the emotional Stroop task) appears to occur in the range 300–450 ms post-stimulus.


2014 ◽  
Vol 33 (10) ◽  
pp. 723-727
Author(s):  
M. Westermann ◽  
I. W. Husstedt ◽  
A. Okegwo ◽  
S. Evers

SummaryEvent-related potentials (ERP) are regarded as age dependent. However, it is not known whether this is an intrinsic property of ERP or an extrinsic factor. We designed a setting in which ERP were evoked using a modified oddball paradigm with highly differentiable and detectable target and non-target stimuli. A total of 98 probands were enrolled in this study. We evaluated the latency and amplitude of the P3 component of visually evoked ERP. The mean P3 latency was 294 ± 28 ms and was not related to age (r = –0.089; p = 0.382; Spearman-rank-correlation). The P3 amplitude was related to age in the total sample (r = –0.323; p = 0.001; Spearmanrank-correlation) but not in the probands under the age of 60 years. There were no significant differences regarding sex. Our findings suggest that ERP are not age dependent if highly differentiable and detectable stimuli are used. This should be considered when normal values of ERP are created for clinical use.


2016 ◽  
Vol 48 (2) ◽  
pp. 103-110 ◽  
Author(s):  
Song Xue ◽  
Shanshan Wang ◽  
Xia Kong ◽  
Jiang Qiu

Emotional conflict has received increased attention as a research topic. The objective of this study is to confirm that the processing of emotional conflict is impaired in treatment-resistant depression (TRD). We compared the event-related potentials of 17 patients with TRD and 17 healthy controls during the face-word Stroop task, which is an effective way of assessing the effects of emotional conflict directly. Compared with healthy controls, the accuracy scores of the TRD patients were lower in both “congruent stimuli” and “incongruent stimuli” conditions, and their response times were longer. The TRD patients also had larger N2 amplitudes over the frontal region, regardless of stimulus condition, which might reflect that TRD patients pay more attention to emotional information. A larger P3 amplitude over the frontal region for “incongruent stimuli minus congruent stimuli” was also found among patients with TRD, which indicates interference effects in the Stroop task. The results of this study provide novel behavioral and neurophysiological evidence of anomalies in cognitive inhibition among patients with TRD using the word-face task. These findings not only improve our understanding of deficient inhibition in TRD, but also pave the way for a cognitive neuropsychiatric model of depression.


2019 ◽  
Vol 11 (1) ◽  
pp. 80-115
Author(s):  
Eva Koderman

Abstract Anxiety is characterized by a sustained state of heightened vigilance due to uncertain danger, producing increased attention to a perceived threat in one's environment. To further examine this exploited the temporal resolution afforded by event-related potentials to investigate the impact of predictability of threat on early perceptual activity. We recruited 28 participants and utilized a within-subject design to examine hypervigilance in anticipation of shock, unpleasant picture and unpleasant sound during a task with unpredictable, predictable and no threat. We investigated if habituation to stimuli was present by asking the participants to rate unpleasantness and intensity of the stimuli before and after the experiment. We observed hypervigilance in the unpredictable threat of shock. Habituation was observed for the visual stimuli. The present study suggests that unpredictability enhances attentional engagement with neutral somatosensory stimuli when the threat is of the same modality, meaning we observed the presence of hypervigilance which is a characteristic of anxiety.


2019 ◽  
Author(s):  
Solange Denervaud ◽  
Jean-François Knebel ◽  
Emeline Mullier ◽  
Patric Hagmann ◽  
Micah M. Murray

Within an inherently dynamic environment, unexpected outcomes are part of daily life. Performance monitoring allows us to detect these events and adjust behavior accordingly. The necessity of such an optimal functioning has made error-monitoring a prominent topic of research over the last decades. Event-related potentials (ERPs) have differentiated between two brain components involved in error-monitoring: the error-related negativity (ERN) and error-related positivity (Pe) that are thought to reflect detection vs. emotional/motivational processing of errors, respectively. Both ERN and Pe depend on the protracted maturation of the frontal cortices and anterior cingulate through adolescence. To our knowledge, the impact of schooling pedagogy on error-monitoring and its brain mechanisms remains unknown and was the focus of the present study. Swiss schoolchildren completed a continuous recognition task while 64-channel EEG was recorded and later analyzed within an electrical neuroimaging framework. They were enrolled either in a Montessori curriculum (N=13), consisting of self-directed learning through trial-and-error activities with sensory materials, or a traditional curriculum (N=14), focused on externally driven activities mainly based on reward feedback. The two groups were controlled for age, gender, socio-economic status, parental educational style, and scores of fluid intelligence. The ERN was significantly enhanced in Montessori schoolchildren (driven by a larger response to errors), with source estimation differences localized to the cuneus and precuneus. In contrast, the Pe was enhanced in traditional schoolchildren (driven by a larger response to correct trials), with source estimation differences localized to the ventral anterior cingulate. Receiver operating characteristic (ROC) analysis demonstrated that the ERN and Pe could reliably classify if a child was following a Montessori or traditional curriculum. Brain activity subserving error-monitoring is modulated differently according to school pedagogy.


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