Conflict processing networks: A directional analysis of stimulus-response compatibilities using MEG

The suppression of distracting information in order to focus on an actual cognitive goal is a key feature of executive functions. The use of brain imaging methods to investigate the underlying neurobiological brain activations that occur during conflict processing have demonstrated a strong involvement of the fronto-parietal attention network (FPAN). Surprisingly, the directional interconnections, their time courses and activations at different frequency bands remain to be elucidated, and thus, this constitutes the focus of this study. The shared information flow between brain areas of the FPAN is provided for frequency bands ranging from the theta to the lower gamma band (4–40 Hz). We employed an adaptation of the Simon task utilizing Magnetoencephalography (MEG). Granger causality was applied to investigate interconnections between the active brain regions, as well as their directionality. Following stimulus onset, the middle frontal precentral cortex and superior parietal cortex were significantly activated during conflict processing in a time window of between 300 to 600ms. Important differences in causality were found across frequency bands between processing of conflicting stimuli in the left as compared to the right visual hemifield. The exchange of information from and to the FPAN was most prominent in the beta band. Moreover, the anterior cingulate cortex and the anterior insula represented key areas for conflict monitoring, either by receiving input from other areas of the FPAN or by generating output themselves. This indicates that the salience network is at least partly involved in processing conflict information. The present study provides detailed insights into the underlying neural mechanisms of the FPAN, especially regarding its temporal characteristics and directional interconnections.

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The spotlight of attention turns from rhythmic exploration-exploitation to a stable exploitation state

10.1101/2021.11.18.469122 ◽

2021 ◽

Author(s):

Maria Melcon ◽

Sander van Bree ◽

Yolanda Sanchez-Carro ◽

Laura Barreiro-Fernandez ◽

Luca D. Kolibius ◽

...

Keyword(s):

Temporal Dynamics ◽

Time Window ◽

Early Time ◽

Brain Regions ◽

Stimulus Onset ◽

Visuospatial Attention ◽

Right Visual Field ◽

Time Frequency ◽

Human Participants ◽

Exploration Exploitation

While traditional studies claim that visuospatial attention stays fixed at one location at a time, recent research has rather shown that attention rhythmically fluctuates between different locations at rates of prominent brain rhythms. However, little is known about the temporal dynamics of this fluctuation and, particularly, whether it changes over time. Thus, we addressed this question by investigating how visuospatial attention behaves over space and time. We recorded electroencephalographic activity of twenty-seven human participants while they performed a visuospatial cueing task, where attention was covertly oriented to the left or right visual field. In order to decode the spatial locus of attention from neural activity, we trained and tested a classifier on every timepoint of the orienting period, from the attentional cue to stimulus onset. This resulted in one temporal generalization matrix per participant, which was time-frequency decomposed to identify the sampling rhythm. Finally, a searchlight analysis was conducted to reveal the brain regions responsible for attention allocation. Our results show a dynamic evolution of the attentional spotlight, distinguishing between two states. In an early time window, attention explored both cued and uncued hemifield rhythmically at ~10 Hz. In a later time window attention focused on the cued hemifield. Classification was driven by occipital sources, while frontal regions exclusively became involved just before the spotlight settled onto the cued location. Together, our results define attentional sampling as a quasi-rhythmic dynamic process characterized by an initial rhythmic exploration-exploitation state, which is followed by a stable exploitation state.

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Modulation of Functional Connectivity in Response to Mirror Visual Feedback in Stroke Survivors: An MEG Study

Brain Sciences ◽

10.3390/brainsci11101284 ◽

2021 ◽

Vol 11 (10) ◽

pp. 1284

Author(s):

Ruei-Yi Tai ◽

Jun-Ding Zhu ◽

Chih-Chi Chen ◽

Yu-Wei Hsieh ◽

Chia-Hsiung Cheng

Keyword(s):

Functional Connectivity ◽

Motor Cortex ◽

Visual Feedback ◽

Primary Motor Cortex ◽

Brain Regions ◽

Beta Band ◽

Stroke Patients ◽

Brain Areas ◽

Frequency Bands ◽

Mirror Visual Feedback

Background. Several brain regions are activated in response to mirror visual feedback (MVF). However, less is known about how these brain areas and their connectivity are modulated in stroke patients. This study aimed to explore the effects of MVF on brain functional connectivity in stroke patients. Materials and Methods. We enrolled 15 stroke patients who executed Bilateral-No mirror, Bilateral-Mirror, and Unilateral-Mirror conditions. The coherence values among five brain regions of interest in four different frequency bands were calculated from magnetoencephalographic signals. We examined the differences in functional connectivity of each two brain areas between the Bilateral-No mirror and Bilateral-Mirror conditions and between the Bilateral-Mirror and Unilateral-Mirror conditions. Results. The functional connectivity analyses revealed significantly stronger connectivity between the posterior cingulate cortex and primary motor cortex in the beta band (adjusted p = 0.04) and possibly stronger connectivity between the precuneus and primary visual cortex in the theta band (adjusted p = 0.08) in the Bilateral-Mirror condition than those in the Bilateral-No mirror condition. However, the comparisons between the Bilateral-Mirror and Unilateral-Mirror conditions revealed no significant differences in cortical coherence in all frequency bands. Conclusions. Providing MVF to stroke patients may modulate the lesioned primary motor cortex through visuospatial and attentional cortical networks.

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Modifications in the Topological Structure of EEG Functional Connectivity Networks during Listening Tonal and Atonal Concert Music in Musicians and Non-Musicians

Brain Sciences ◽

10.3390/brainsci11020159 ◽

2021 ◽

Vol 11 (2) ◽

pp. 159

Author(s):

Almudena González ◽

Manuel Santapau ◽

Antoni Gamundí ◽

Ernesto Pereda ◽

Julián J. González

Keyword(s):

Topological Structure ◽

Phase Synchronization ◽

Random Network ◽

Small World ◽

Surrogate Data ◽

Musical Structure ◽

Beta Band ◽

Tonal Music ◽

Frequency Bands ◽

Concert Music

The present work aims to demonstrate the hypothesis that atonal music modifies the topological structure of electroencephalographic (EEG) connectivity networks in relation to tonal music. To this, EEG monopolar records were taken in musicians and non-musicians while listening to tonal, atonal, and pink noise sound excerpts. EEG functional connectivities (FC) among channels assessed by a phase synchronization index previously thresholded using surrogate data test were computed. Sound effects, on the topological structure of graph-based networks assembled with the EEG-FCs at different frequency-bands, were analyzed throughout graph metric and network-based statistic (NBS). Local and global efficiency normalized (vs. random-network) measurements (NLE|NGE) assessing network information exchanges were able to discriminate both music styles irrespective of groups and frequency-bands. During tonal audition, NLE and NGE values in the beta-band network get close to that of a small-world network, while during atonal and even more during noise its structure moved away from small-world. These effects were attributed to the different timbre characteristics (sounds spectral centroid and entropy) and different musical structure. Results from networks topographic maps for strength and NLE of the nodes, and for FC subnets obtained from the NBS, allowed discriminating the musical styles and verifying the different strength, NLE, and FC of musicians compared to non-musicians.

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The processing of visual food cues during bitter aftertaste perception in females with high vs. low disgust propensity: an fMRI study

Brain Imaging and Behavior ◽

10.1007/s11682-021-00455-2 ◽

2021 ◽

Author(s):

Anne Schienle ◽

Albert Wabnegger

Keyword(s):

Personality Trait ◽

Visual Cues ◽

Critical Role ◽

Relevant Information ◽

Anterior Cingulate ◽

Conflict Monitoring ◽

Food Cues ◽

Sweet Food ◽

Visual Food Cues ◽

Disgust Propensity

AbstractAn extremely bitter taste can signal food spoilage, and therefore typically elicits disgust. The present cross-modal functional magnetic resonance imaging experiment investigated whether the personality trait ‘disgust propensity’ (DP; temporally stable tendency to experience disgust across different situations) has an influence on the processing of visual food cues during bitter aftertaste perception. Thirty females with high DP and 30 females with low DP viewed images depicting sweet food (e.g., cakes, ice cream) and vegetables, once in combination with an extremely bitter aftertaste (concentrated wormwood tea), and once with a neutral taste (water). Females highly prone to disgust (compared to low disgust-prone females) showed increased activity in the anterior cingulate cortex (ACC) and increased mPFC-insula connectivity when presented with the mismatch of a bitter aftertaste and visual cues of sweet food. The ACC is involved in conflict monitoring and is strongly interconnected with insular areas. This connection plays a critical role in awareness of changes in homeostatic states. Our findings indicate that the personality trait DP is associated with cross-modal integration processes of disgust-relevant information. Females high in DP were more alert to food-related sensory mismatch (pleasant visual features, aversive taste) than females low in DP.

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Peripheral arterial stiffness during electrocutaneous stimulation is positively correlated with pain-related brain activity and subjective pain intensity: an fMRI study

Scientific Reports ◽

10.1038/s41598-021-83833-6 ◽

2021 ◽

Vol 11 (1) ◽

Author(s):

Toshio Tsuji ◽

Fumiya Arikuni ◽

Takafumi Sasaoka ◽

Shin Suyama ◽

Takashi Akiyoshi ◽

...

Keyword(s):

Arterial Stiffness ◽

Pain Intensity ◽

Brain Activity ◽

Brain Regions ◽

Anterior Cingulate ◽

Electrocutaneous Stimulation ◽

Pain Matrix ◽

Fmri Study ◽

Subjective Pain ◽

Peripheral Arterial

AbstractBrain activity associated with pain perception has been revealed by numerous PET and fMRI studies over the past few decades. These findings helped to establish the concept of the pain matrix, which is the distributed brain networks that demonstrate pain-specific cortical activities. We previously found that peripheral arterial stiffness $${\beta }_{\text{art}}$$ β art responds to pain intensity, which is estimated from electrocardiography, continuous sphygmomanometer, and photo-plethysmography. However, it remains unclear whether and to what extent $${\beta }_{\text{art}}$$ β art aligns with pain matrix brain activity. In this fMRI study, 22 participants received different intensities of pain stimuli. We identified brain regions in which the blood oxygen level-dependent signal covaried with $${\beta }_{\text{art}}$$ β art using parametric modulation analysis. Among the identified brain regions, the lateral and medial prefrontal cortex and ventral and dorsal anterior cingulate cortex were consistent with the pain matrix. We found moderate correlations between the average activities in these regions and $${\beta }_{\text{art}}$$ β art (r = 0.47, p < 0.001). $${\beta }_{\text{art}}$$ β art was also significantly correlated with self-reported pain intensity (r = 0.44, p < 0.001) and applied pain intensity (r = 0.43, p < 0.001). Our results indicate that $${\beta }_{\text{art}}$$ β art is positively correlated with pain-related brain activity and subjective pain intensity. This study may thus represent a basis for adopting peripheral arterial stiffness as an objective pain evaluation metric.

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Cannabinoids, reward processing, and psychosis

Psychopharmacology ◽

10.1007/s00213-021-05801-2 ◽

2021 ◽

Author(s):

Brandon Gunasekera ◽

Kelly Diederen ◽

Sagnik Bhattacharyya

Keyword(s):

Psychotic Disorders ◽

Neural Substrates ◽

Brain Regions ◽

Reward Processing ◽

Anterior Cingulate ◽

Psychotic Symptoms ◽

Dopamine Synthesis ◽

Future Research ◽

Drug Challenge ◽

Psychotomimetic Effects

Abstract Background Evidence suggests that an overlap exists between the neurobiology of psychotic disorders and the effects of cannabinoids on neurocognitive and neurochemical substrates involved in reward processing. Aims We investigate whether the psychotomimetic effects of delta-9-tetrahydrocannabinol (THC) and the antipsychotic potential of cannabidiol (CBD) are underpinned by their effects on the reward system and dopamine. Methods This narrative review focuses on the overlap between altered dopamine signalling and reward processing induced by cannabinoids, pre-clinically and in humans. A systematic search was conducted of acute cannabinoid drug-challenge studies using neuroimaging in healthy subjects and those with psychosis Results There is evidence of increased striatal presynaptic dopamine synthesis and release in psychosis, as well as abnormal engagement of the striatum during reward processing. Although, acute THC challenges have elicited a modest effect on striatal dopamine, cannabis users generally indicate impaired presynaptic dopaminergic function. Functional MRI studies have identified that a single dose of THC may modulate regions involved in reward and salience processing such as the striatum, midbrain, insular, and anterior cingulate, with some effects correlating with the severity of THC-induced psychotic symptoms. CBD may modulate brain regions involved in reward/salience processing in an opposite direction to that of THC. Conclusions There is evidence to suggest modulation of reward processing and its neural substrates by THC and CBD. Whether such effects underlie the psychotomimetic/antipsychotic effects of these cannabinoids remains unclear. Future research should address these unanswered questions to understand the relationship between endocannabinoid dysfunction, reward processing abnormalities, and psychosis.

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Sensor-Level Wavelet Analysis Reveals EEG Biomarkers of Perceptual Decision-Making

Sensors ◽

10.3390/s21072461 ◽

2021 ◽

Vol 21 (7) ◽

pp. 2461

Author(s):

Alexander Kuc ◽

Vadim V. Grubov ◽

Vladimir A. Maksimenko ◽

Natalia Shusharina ◽

Alexander N. Pisarchik ◽

...

Keyword(s):

Decision Making ◽

Sensory Information ◽

Stimulus Onset ◽

Perceptual Process ◽

Perceptual Decision Making ◽

Beta Band ◽

Perceptual Decision ◽

Time Frequency ◽

Band Power ◽

Sensory Features

Perceptual decision-making requires transforming sensory information into decisions. An ambiguity of sensory input affects perceptual decisions inducing specific time-frequency patterns on EEG (electroencephalogram) signals. This paper uses a wavelet-based method to analyze how ambiguity affects EEG features during a perceptual decision-making task. We observe that parietal and temporal beta-band wavelet power monotonically increases throughout the perceptual process. Ambiguity induces high frontal beta-band power at 0.3–0.6 s post-stimulus onset. It may reflect the increasing reliance on the top-down mechanisms to facilitate accumulating decision-relevant sensory features. Finally, this study analyzes the perceptual process using mixed within-trial and within-subject design. First, we found significant percept-related changes in each subject and then test their significance at the group level. Thus, observed beta-band biomarkers are pronounced in single EEG trials and may serve as control commands for brain-computer interface (BCI).

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P.185 Nx4 influences stress-induced activity of the anterior cingulate cortex and associated brain regions

European Neuropsychopharmacology ◽

10.1016/j.euroneuro.2019.09.229 ◽

2019 ◽

Vol 29 ◽

pp. S141-S142

Author(s):

L. Herrmann ◽

V. Kasties ◽

Y. Fan ◽

L. Danyeli ◽

T. Tar ◽

...

Keyword(s):

Anterior Cingulate Cortex ◽

Cingulate Cortex ◽

Brain Regions ◽

Anterior Cingulate

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Acetaminophen Reduces Social Pain

Psychological Science ◽

10.1177/0956797610374741 ◽

2010 ◽

Vol 21 (7) ◽

pp. 931-937 ◽

Cited By ~ 250

Author(s):

C. Nathan DeWall ◽

Geoff MacDonald ◽

Gregory D. Webster ◽

Carrie L. Masten ◽

Roy F. Baumeister ◽

...

Keyword(s):

Brain Activity ◽

Brain Regions ◽

Daily Basis ◽

Social Rejection ◽

Neural Mechanisms ◽

Anterior Cingulate ◽

Neural Responses ◽

Physical Pain ◽

Social Pain ◽

Dorsal Anterior Cingulate Cortex

Pain, whether caused by physical injury or social rejection, is an inevitable part of life. These two types of pain—physical and social—may rely on some of the same behavioral and neural mechanisms that register pain-related affect. To the extent that these pain processes overlap, acetaminophen, a physical pain suppressant that acts through central (rather than peripheral) neural mechanisms, may also reduce behavioral and neural responses to social rejection. In two experiments, participants took acetaminophen or placebo daily for 3 weeks. Doses of acetaminophen reduced reports of social pain on a daily basis (Experiment 1). We used functional magnetic resonance imaging to measure participants’ brain activity (Experiment 2), and found that acetaminophen reduced neural responses to social rejection in brain regions previously associated with distress caused by social pain and the affective component of physical pain (dorsal anterior cingulate cortex, anterior insula). Thus, acetaminophen reduces behavioral and neural responses associated with the pain of social rejection, demonstrating substantial overlap between social and physical pain.

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When Heuristics Clash with Parsing Routines: ERP Evidence for Conflict Monitoring in Sentence Perception

Journal of Cognitive Neuroscience ◽

10.1162/jocn.2006.18.7.1181 ◽

2006 ◽

Vol 18 (7) ◽

pp. 1181-1197 ◽

Cited By ~ 129

Author(s):

Marieke van Herten ◽

Dorothee J. Chwilla ◽

Herman H. J. Kolk

Keyword(s):

Event Related Potential ◽

Anterior Cingulate ◽

Syntactic Analysis ◽

Conflict Monitoring ◽

N400 Effect ◽

Word Meanings ◽

Late Positivity ◽

Error Related Negativity ◽

Monitoring Process ◽

Outcome Monitoring

Monitoring refers to a process of quality control designed to optimize behavioral outcome. Monitoring for action errors manifests itself in an error-related negativity in event-related potential (ERP) studies and in an increase in activity of the anterior cingulate in functional magnetic resonance imaging studies. Here we report evidence for a monitoring process in perception, in particular, language perception, manifesting itself in a late positivity in the ERP. This late positivity, the P600, appears to be triggered by a conflict between two interpretations, one delivered by the standard syntactic algorithm and one by a plausibility heuristic which combines individual word meanings in the most plausible way. To resolve this conflict, we propose that the brain reanalyzes the memory trace of the perceptual input to check for the possibility of a processing error. Thus, as in Experiment 1, when the reader is presented with semantically anomalous sentences such as, “The fox that shot the poacher…,” full syntactic analysis indicates a semantic anomaly, whereas the word-based heuristic leads to a plausible interpretation, that of a poacher shooting a fox. That readers actually pursue such a word-based analysis is indicated by the fact that the usual ERP index of semantic anomaly, the so-called N400 effect, was absent in this case. A P600 effect appeared instead. In Experiment 2, we found that even when the word-based heuristic indicated that only part of the sentence was plausible (e.g., “…that the elephants pruned the trees”), a P600 effect was observed and the N400 effect of semantic anomaly was absent. It thus seems that the plausibility of part of the sentence (e.g., that of pruning trees) was sufficient to create a conflict with the implausible meaning of the sentence as a whole, giving rise to a monitoring response.

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