N200 in the flanker task as a neurobehavioral tool for investigating executive control

Rare incompatible stimuli evoke visual mismatch negativity in a flanker task

In the flanker task, the behavioral performance for incompatible stimuli is worse in the mostly compatible (rare) condition than in the equiprobable condition. Furthermore, incompatible stimuli evoke visual mismatch negativity (VMMN) when comparing the rare and equiprobable conditions. Compatible and incompatible stimuli differ in terms of their shape and type. This study aimed to examine whether VMMN evoked by rare incompatible stimuli were associated with the shape or type of the stimulus. In a modified version of the flanker task, stimuli were manipulated by two shapes (typical or peculiar) and two types (compatible or incompatible): typical compatible stimuli (< <  <  <  < and >  >  >  > >), typical incompatible stimuli (> >  <  >  > and <  <  >  < <), peculiar compatible stimuli (+ <  <  <  + and +  >  >  > +), and peculiar incompatible stimuli (+ >  <  >  + and +  <  >  < +). In the rare condition, typical incompatible, peculiar compatible, and peculiar incompatible stimuli were presented with a probability of 10%, whereas all the stimuli were presented equally in the equiprobable condition. Right posterior negativity from 200 to 250 ms was significantly more negative in the rare condition than in the equiprobable condition for typical and peculiar incompatible stimuli; however, this difference was not observed for peculiar compatible stimuli. VMMN was significantly more negative for typical and peculiar incompatible stimuli than for peculiar compatible stimuli, and was not significantly different between typical and peculiar incompatible stimuli. These findings suggest that VMMN for incompatible stimuli is associated with the type rather than the shape of the stimulus.

Motor inhibition errors and interference suppression errors differ systematically on neural and behavioural features of response monitoring

Action inhibition and error commission are prominent in everyday life. Inhibition comprises at least two facets: motor inhibition and interference suppression. When motor inhibition fails, a strong response impulse cannot be inhibited. When interference suppression fails, we become distracted by irrelevant stimuli. We investigated the neural and behavioural similarities and differences between motor inhibition errors and interference suppression errors systematically from stimulus-onset to post-response adaptation. To enable a direct comparison between both error types, we developed a complex speeded choice task where we assessed the error types in two perceptually similar conditions. Comparing the error types along the processing stream showed that the P2, an early component in the event-related potential associated with sensory gating, is the first marker for differences between the two error types. Further error-specific variations were found for the parietal P3 (associated with context updating and attentional resource allocation), for the lateralized readiness potential (LRP, associated with primary motor cortex activity), and for the Pe (associated with error evidence accumulation). For motor inhibition errors, the P2, P3 and Pe tended to be enhanced compared to successful inhibition. The LRP for motor inhibition errors was marked by multiple small response impulses. For interference suppression errors, all components were more similar to those of successful inhibition. Together, these findings suggest that motor inhibition errors arise from a deficient early inhibitory process at the perceptual and motor level, and become more apparent than interference suppression errors, that arise from an impeded response selection process.

The effect of age on executive functions in adults is not sex specific

OBJECTIVE

Numerous studies have shown a decrease in executive functions (EF) associated with aging. However, few investigations examined whether this decrease is similar between sexes throughout adulthood. The present study investigated if age-related decline in EF differs between men and women from early to late adulthood.

METHODS

A total of 302 participants (181 women) aged between 18 and 78 years old completed four computer-based cognitive tasks at home: an arrow-based Flanker task, a letter-based Visual search task, the Trail Making Test, and the Corsi task. These tasks measured inhibition, attention, cognitive flexibility, and working memory, respectively. To investigate the potential effects of age, sex, and their interaction on specific EF and a global EF score, we divided the sample population into five age groups (i.e., 18-30, 31-44, 45-54, 55-64, 65-78) and conducted analyses of covariance (MANCOVA and ANCOVA) with education and pointing device as control variables.

RESULTS

Sex did not significantly affect EF performance across age groups. However, in every task, participants from the three youngest groups (< 55 y/o) outperformed the ones from the two oldest. Results from the global score also suggest that an EF decrease is distinctly noticeable from 55 years old onward.

CONCLUSION

Our results suggest that age-related decline in EF, including inhibition, attention, cognitive flexibility, and working memory, becomes apparent around the age of 55 and does not differ between sexes at any age. This study provides additional data regarding the effects of age and sex on EF across adulthood, filling a significant gap in the existing literature.

The Effect of Rhythmic Audio-Visual Stimulation on Inhibitory Control: An ERP Study

Inhibitory control, as an essential cognitive ability, affects the development of higher cognitive functions. Rhythmic perceptual stimulation has been used to improve cognitive abilities. It is unclear, however, whether it can be used to improve inhibitory control. This study used the Go/NoGo task and the Stroop task to assess various levels of inhibitory control using rhythmic audio-visual stimuli as the stimulus mode. Sixty subjects were randomly divided into three groups to receive 6 Hz, 10 Hz, and white noise stimulation for 30 min. Two tasks were completed by each subject both before and after the stimulus. Before and after the task, closed-eye resting EEG data were collected. The results showed no differences in behavioral and EEG measures of the Go/NoGo task among the three groups. While both 6 Hz and 10 Hz audio-visual stimulation reduced the conflict effect in the Stroop task, only 6 Hz audio-visual stimulation improved the amplitude of the N2 component and decreased the conflict score. Although rhythmic audio-visual stimulation did not enhance response inhibition, it improved conflict inhibition.

The neutral condition in conflict tasks: On the violation of the midpoint assumption in reaction time trends

Although the relation between congruent and incongruent conditions in conflict tasks has been the primary focus of cognitive control studies, the neutral condition is often set as a baseline directly between the two conditions. However, empirical evidence suggests that the average neutral reaction time (RT) is not placed evenly between the two opposing conditions. This article set out to establish two things: First, to reinforce the informative nature of the neutral condition and second, to highlight how it can be useful for modelling. We explored how RT in the neutral condition of conflict tasks (Stroop, Flanker, and Simon Tasks) deviated from the predictions of current diffusion models. Current diffusion models of conflict tasks predict a neutral RT that is the average of the congruent and incongruent RT, called the midpoint assumption. To investigate this, we first conducted a cursory limited search that recorded the average RT's of conflict tasks with neutral conditions. Upon finding evidence of a midpoint assumption violation which showed a larger disparity between average neutral and incongruent RT, we tested the previously mentioned conflict tasks with two different sets of stimuli to establish the robustness of the effect. The midpoint assumption violation is sometimes inconsistent with the prediction of diffusion models of conflict processing (e.g., the Diffusion Model of Conflict), suggesting possible elaborations of such models.

Incorporating Evidence-Based Gamification and Machine Learning to Assess Preschool Executive Function: A Feasibility Study

Computerized assessments and digital games have become more prevalent in childhood, necessitating a systematic investigation of the effects of gamified executive function assessments on performance and engagement. This study examined the feasibility of incorporating gamification and a machine learning algorithm that adapts task difficulty to individual children's performance into a traditional executive function task (i.e., Flanker Task) with children ages 3-5. The results demonstrated that performance on a gamified version of the Flanker Task was associated with performance on the traditional version of the task and standardized academic achievement outcomes. Furthermore, gamification grounded in learning science and developmental psychology theories applied to a traditional executive function measure increased children's task enjoyment while preserving psychometric properties of the Flanker Task. Overall, this feasibility study indicates that gamification and adaptive machine learning algorithms can be successfully incorporated into executive function assessments with young children to increase enjoyment and reduce data loss with developmentally appropriate and intentional practices.

Total Sleep Deprivation Triggers a Compensatory Mechanism During Conflict Monitoring Process: Evidence From Event-Related Potentials

Sleep deprivation impairs cognitive function and is accompanied by a simultaneous compensatory effect, one of the brain's capacities to maintain function in emergency situations. However, the time course of the compensatory effect is unclear. In this study, 22 male participants completed a pronunciation working memory task that included congruent and incongruent stimuli trials with EEG recordings before and after total sleep deprivation (TSD). Behavioral performance analysis showed that after TSD, the participants' reaction time (RT) was shortened, but accuracy was reduced significantly. Analysis of event-related potential (ERP) results showed that the amplitude of N2 (an early visual ERP) was larger (i.e., more negative) after TSD than at baseline. A significant interaction between congruency and sleep condition was seen. Compared to that before TSD, the increase in amplitude of P3 (a stimulus-induced positive deflection component) under an incongruent stimulus was larger than that under a congruent stimulus after TSD. Moreover, a significant negative correlation was found between P3 amplitude and RT. Our results suggest that TSD impairs cognitive function. Meanwhile, the brain activates a compensatory mechanism after TSD, which is comprehensive during the conflict-detection and information-updating stages. This study provides a fresh viewpoint for understanding how TSD affects cognitive function.

Effects of Two Online Mindfulness-Based Interventions for Early Adolescents for Attentional, Emotional, and Behavioral Self-Regulation

(1) Background: Mindfulness-based interventions (MBIs) have shown interesting preliminary effects on self-regulation processes in early adolescence. However, programs have typically combined different types of interventions with no understanding of the specific effect of each intervention type on attentional, emotional, and behavioral regulation. The objective of this research was to evaluate the effect of two MBIs-one focused on classic attentional practices and another focused on the recognition and expression of emotions-on attentional, emotional, and behavioral self-regulation in early adolescents. (2) Method: An experimental paradigm was used. A sample of 74 children aged between 8 and 12 years old were randomly assigned to three experimental conditions: (1) an MBI with a focus on attentional practices, (2) an MBI with a focus on recognition and expression of emotions, and (3) a control group. The interventions lasted 8 weeks, with a weekly, 1 h online synchronous session plus home practices. Children were evaluated before starting the intervention and at the end of the 8-week period. The assessed outcomes were (1) mindfulness; (2) emotional regulation; (3) attentional regulation, and (4) behavioral regulation. (3) Results: Children who participated in both intervention programs increased their mindfulness and emotional and behavioral regulation scores. Only children who participated in the MBI with a focus on attention showed significant changes in their ability to self-regulate attention. (4) Conclusions: The use of online MBIs, with attention to external and internal stimuli practices, can be a good strategy to strengthen self-regulation skills for attention, emotions, and behavior in early adolescence.

EEG correlates of trait test anxiety in the flanker task for adolescents

Adolescents face constant exams and often experience severe test anxiety. Previous studies suggested that test anxiety impairs individuals' inhibitory control. Neurophysiological evidence suggests that anxiety interferes with the recruitment of the prefrontal region of the brain, which modulates top-down attentional control during the completion of inhibitory control tasks. However, there is little neurophysiological evidence regarding how test anxiety impairs inhibitory control in adolescents. This study used the flanker task to measure individuals' inhibitory control ability, and both event-related potential and electroencephalography indicators were used to measure neurophysiological processes. The results showed that increased trait test anxiety was significantly negatively correlated with theta power oscillation, while adolescents performed both incongruent and congruent trials. This finding suggests that trait test anxiety adolescents are less able to exert greater effort to complete the inhibitory control task and show impoverished top-down attentional control resources.

Influence of Transcutaneous Vagus Nerve Stimulation on Motor Planning: A Resting-State and Task-State EEG Study

Transcutaneous vagus nerve stimulation (tVNS) shows a potential regulatory role for motor planning. Still, existing research mainly focuses on behavioral studies, and the neural modulation mechanism needs to be clarified. Therefore, we designed a multi-condition (active or sham, pre or under, difficult or easy, left-hand or right-hand) motor planning experiment to explore the effect of online tVNS (i.e., tVNS and tasks synchronized). Twenty-eight subjects were recruited and randomly assigned to active and sham groups. Both groups performed the same tasks in the experiment and separately collected task-state EEG and 5-min eye-open resting-state EEG. The results showed that the changes in event-related potential (ERP) and movement-related cortical potential (MRCP) amplitudes were more significant for the left-hand difficult task (LD) under active-tVNS. According to the power spectrum results, active-tVNS significantly modulated the activities of the contralateral motor cortex at beta and gamma bands in the resting state. The functional connectivity based on partial directed coherence (PDC) showed significant changes in the parietal lobe after active-tVNS. These findings suggest that tVNS is a promising way to improve motor planning ability.

Associations between physical activity, sedentary time, and neurocognitive function during adolescence: Evidence from accelerometry and the flanker P300

Physical activity and sedentary behavior are two lifestyle factors related to overall health during adolescence. Public health efforts emphasize the importance of increasing physical activity to improve physical and mental health outcomes, including neurocognitive functioning. However, the unique effects of sedentary behavior on neurocognitive functioning remain unclear. This study aimed to investigate associations between daily moderate-to-vigorous physical activity (MVPA), sedentary time, and neurocognitive functioning during adolescence. Fifty-seven participants (37% female) between the ages of 13 and 17 years wore an accelerometer on their non-dominant wrist for approximately 1 week to quantify daily MVPA and sedentary time prior to completing a flanker task to elicit P300 amplitude at a laboratory visit. Results indicated that daily MVPA and sedentary time exhibited unique, significant associations with P300 amplitude in opposing directions: increased daily MVPA was correlated with larger P300 amplitudes, while increased daily sedentary time was linked to reduced P300 amplitudes. Notably, these associations remained significant even after adjusting for age, sex, and BMI-for-age percentile. These findings underscore the independent influence of daily MVPA and sedentary time on neurocognitive functioning during adolescence. Future research should explore whether modifying MVPA levels can improve neurocognitive outcomes-including the P300-during adolescence, and determine whether reducing sedentary time results in similar or differential effects.

Effect of motion state variability on error-related potentials during continuous feedback paradigms and their consequences for classification

BACKGROUND

An erroneous motion would elicit the error-related potential (ErrP) when humans monitor the behavior of the external devices. This EEG modality has been largely applied to brain-computer interface in an active or passive manner with discrete visual feedback. However, the effect of variable motion state on ErrP morphology and classification performance raises concerns when the interaction is conducted with continuous visual feedback.

NEW METHOD

In the present study, we designed a cursor control experiment. Participants monitored a continuously moving cursor to reach the target on one side of the screen. Motion state varied multiple times with two factors: (1) motion direction and (2) motion speed. The effects of these two factors on the morphological characteristics and classification performance of ErrP were analyzed. Furthermore, an offline simulation was performed to evaluate the effectiveness of the proposed extended ErrP-decoder in resolving the interference by motion direction changes.

RESULTS

The statistical analyses revealed that motion direction and motion speed significantly influenced the amplitude of feedback-ERN and frontal-Pe components, while only motion direction significantly affected the classification performance.

COMPARISON WITH EXISTING METHODS

Significant deviation was found in ErrP detection utilizing classical correct-versus-erroneous event training. However, this bias can be alleviated by 16% by the extended ErrP-decoder.

CONCLUSION

The morphology and classification performance of ErrP signal can be affected by motion state variability during continuous feedback paradigms. The results enhance the comprehension of ErrP morphological components and shed light on the detection of BCI's error behavior in practical continuous control.

Neurophysiological error processing and addiction self-awareness correlates of reduced insight in cannabis use disorder

BACKGROUND AND AIMS

Cannabis use disorder (CUD) prevalence has increased, while perceived risks of cannabis use and CUD treatment need have decreased. Chronic cannabis use may also impair the neural and behavioral mechanisms of insight, further hampering treatment-seeking. This study aimed to measure whether CUD is characterized by reduced self-monitoring in drug-related contexts (objectively-assessed insight), subserved by functional neural abnormalities in error-processing and manifested clinically as decreased awareness of the need to change.

DESIGN

Case-control laboratory study was used.

SETTING

University setting was in Alabama, USA.

PARTICIPANTS

There were 42 CUD participants and 47 age-, sex-, and nicotine use-matched controls.

MEASUREMENTS

Participants completed a probabilistic choice task, adapted for the first time for CUD, in which they selected pleasant, unpleasant, neutral, and cannabis-related images according to their preference. Reduced versus accurate insight was operationalized as the correspondence between self-reported and actual most chosen image type. Neurophysiological error-processing during an inhibitory control task was recorded using electroencephalography. Participants with CUD completed measures of cannabis problem recognition and motivation to change.

FINDINGS

Compared with controls, the CUD group made significantly more cannabis selections on the choice task (mean difference [MD] = 8.11, 95% confidence interval [CI] [4.88 11.35], p < 0.001) and had significantly reduced insight into cannabis choice (odds ratio [OR] = 9.69, 95% CI [1.06 88.65], p = 0.04). CUD participants with reduced insight on the choice task had significantly decreased neurophysiological reactivity to errors on the inhibitory control task (error-related negativity) compared with CUD participants with accurate insight (MD = 2.64 μV, 95% CI [0.74 μV 4.54 μV], p = 0.008) and controls (MD = 4.05 μV, 95% CI [1.29 μV 6.80 μV], p = 0.005). Compared with CUD participants with accurate insight on the choice task, CUD participants with reduced insight reported significantly less agreement that they had a cannabis problem (MD = -5.06, 95% CI [-8.49-1.62], p = 0.003).

CONCLUSIONS

People with CUD who show reduced insight on a drug-related choice task may also have decreased early neural error-processing and less cannabis problem recognition.

Unraveling the influence of trial-based motivational changes on performance monitoring stages in a flanker task

Performance monitoring (PM) is a vital component of adaptive behavior and known to be influenced by motivation. We examined effects of potential gain (PG) and loss avoidance (LA) on neural correlates of PM at different processing stages, using a task with trial-based changes in these motivational contexts. Findings suggest more attention is allocated to the PG context, with higher amplitudes for respective correlates of stimulus and feedback processing. The PG context favored rapid responses, while the LA context emphasized accurate responses. Lower response thresholds in the PG context after correct responses derived from a drift-diffusion model also indicate a more approach-oriented response style in the PG context. This cognitive shift is mirrored in neural correlates: negative feedback in the PG context elicited a higher feedback-related negativity (FRN) and higher theta power, whereas positive feedback in the LA context elicited higher P3a and P3b amplitudes, as well as higher theta power. There was no effect of motivational context on response-locked brain activity. Given the similar frequency of negative feedback in both contexts, the elevated FRN and theta power in PG trials cannot be attributed to variations in reward prediction error. The observed variations in the FRN indicate that the effect of outcome valence is modulated by motivational salience.

Effects of the number of competing responses on neural signatures of pre- and post-response conflict

The optimization of human performance requires the continuous monitoring of behavioral conflicts. According to conflict monitoring theory, the dorsal anterior cingulate cortex registers response conflict which is reflected by two electrophysiological signatures, the N2 and the Ne/ERN. The theory assumes that, if a stimulus activates an incorrect response that competes with the correct response, pre-response conflict on correct trials (reflected by the N2) is enhanced but post-response conflict on error trials (reflected by the Ne/ERN) is reduced. Here, we asked whether response conflict depends on the number of competing incorrect responses activated by a stimulus, that is, whether the N2 is further enhanced and the Ne/ERN is further reduced if two incorrect responses are activated as compared to one. To this end, we used a modified flanker paradigm, in which the two flankers were associated either with the same incorrect response or with different incorrect responses. Our results indicate an increased N2 on correct trials and a reduced Ne/ERN on error trials in the latter as compared to the former condition. These results confirm central predictions of conflict monitoring theory and demonstrate that response conflict is directly related to the number of competing incorrect responses.

Lateralization difference in functional activity during Stroop tasks: a functional near-infrared spectroscopy and EEG simultaneous study

Introduction

Conflict monitoring and processing is an important part of the human cognitive system, it plays a key role in many studies of cognitive disorders.

Methods

Based on a Chinese word-color match Stroop task, which included incongruent and neutral stimuli, the Electroencephalogram (EEG) and functional Near-infrared Spectroscopy (fNIRS) signals were recorded simultaneously. The Pearson correlation coefficient matrix was calculated to analyze brain connectivity based on EEG signals. Granger Causality (GC) method was employed to analyze the effective connectivity of bilateral frontal lobes. Wavelet Transform Coherence (WTC) was used to analyze the functional connectivity of the bilateral hemisphere and ipsilateral hemisphere.

Results

Results indicated that brain connectivity analysis on EEG signals did not show any significant lateralization, while fNIRS analysis results showed the frontal lobes especially the left frontal lobe play the leading role in dealing with conflict tasks. The human brain shows leftward lateralization while processing the more complicated incongruent stimuli. This is demonstrated by the higher functional connectivity in the left frontal lobe and the information flow from the left frontal lobe to the right frontal lobe.

Discussion

Our findings in brain connectivity during cognitive conflict processing demonstrated that the dual modality method combining EEG and fNIRS is a valuable tool to excavate more information through cognitive and physiological studies.

Cognitive control in adults with high-functioning autism spectrum disorder: a study with event-related potentials

Introduction

Little is known about cognitive control in adults with high-functioning forms of autism spectrum disorder because previous research focused on children and adolescents. Cognitive control is crucial to monitor and readjust behavior after errors to select contextually appropriate reactions. The congruency effect and conflict adaptation are measures of cognitive control. Post-error slowing, error-related negativity and error positivity provide insight into behavioral and electrophysiological correlates of error processing. In children and adolescent with autism spectrum disorder deficits in cognitive control and error processing have been shown by changes in post-error slowing, error-related negativity and error positivity in the flanker task.

Methods

We performed a modified Eriksen flanker task in 17 adults with high-functioning autism spectrum disorder and 17 healthy controls. As behavioral measures of cognitive control and error processing, we included reaction times and error rates to calculate congruency effects, conflict adaptation, and post-error slowing. Event-related potentials namely error-related negativity and error positivity were measured to assess error-related brain activity.

Results

Both groups of participants showed the expected congruency effects demonstrated by faster and more accurate responses in congruent compared to incongruent trials. Healthy controls exhibited conflict adaptation as they obtained performance benefits after incongruent trials whereas patients with autism spectrum disorder did not. The expected slowing in reaction times after errors was observed in both groups of participants. Individuals with autism spectrum disorder demonstrated enhanced electrophysiological error-processing compared to healthy controls indicated by increased error-related negativity and error positivity difference amplitudes.

Discussion

Our findings show that adults with high-functioning autism spectrum disorder do not show the expected upregulation of cognitive control in response to conflicts. This finding implies that previous experiences may have a reduced influence on current behavior in these patients which possibly contributes to less flexible behavior. Nevertheless, we observed intact behavioral reactions after errors indicating that adults with high-functioning autism spectrum disorder can flexibly adjust behavior in response to changed environmental demands when necessary. The enhancement of electrophysiological error-processing indicates that adults with high-functioning autism spectrum disorder demonstrate an extraordinary reactivity toward errors reflecting increased performance monitoring in this subpopulation of autism spectrum disorder patients.

Negative inhibition is poor in sub-threshold depression individuals: Evidence from ERP and a Go/No-go task

In this study, Go/No-go task combined with ERP technology were used to explore the characteristics of negative emotion inhibition in SD and healthy individuals and whether there are differences between negative emotion inhibition and neutral emotion inhibition in SD. The results showed that SD showed the same poor negative inhibition as depressive patients in behavior, but there was no significant difference between SD and CG in ERPs. Overall, compared with neutral emotional information, negative emotional information would reduce attention control in conflict processing, lead to faster conflict processing, attract attention, occupy more cognitive resources, and be more difficult to inhibit. It is concluded that the negative attention bias of SD individuals is only reflected in the bottom-up stimulation processing, but has not developed into the top-down cognitive control, which also suggests that the corresponding intervention measures at the early stage of depression may have better effects.

A Diffusion Model Analysis of Object-Based Selective Attention in the Eriksen Flanker Task

Selective attention might be space-, feature-, and/or object-based. Clear support for the involvement of an object-based mechanism is rather scarce, possibly because the predictions of models from these different classes often overlap. Yet, only object-based models can account for a larger congruency effect (CE) in the Eriksen flanker task when flankers are more (vs. less) strongly grouped to the target, but spacing and other response-irrelevant features of target and flankers are held constant. Exactly this was observed by Kramer and Jacobson (1991). So far, this theoretically relevant finding has not been replicated closely. We replicated the finding in two web-based experiments. Specifically, CEs were larger when flanker lines were connected to the central target line (vs. to outer neutral lines). We also successfully fitted the Diffusion Model for Conflict tasks (DMC) to the experimental data. Critically, diffusion modeling (DMC) and distributional analyses (delta functions) revealed that object membership primarily affected target processing strength rather than strength or timing of flanker processing. This challenges the prominent attentional spreading (sensory enhancement) account of object-based selective attention and motivates an alternative target attenuation account.

Childhood trauma predicts blunted error monitoring in adulthood: An event-related potential study

Abuse and neglect have detrimental consequences on emotional and cognitive functioning during childhood and adolescence, including error monitoring, which is a critical aspect of cognition that has been implicated in certain internalizing and externalizing psychopathologies. It is unclear, however, whether (a) childhood trauma has effects on error monitoring and, furthermore whether, (b) error monitoring mediates the relation between childhood trauma and psychopathology in adulthood. To this end, in a large sample of young adults (ages 18-30) who were oversampled for psychopathology (N = 390), the present study assessed relations between childhood trauma and error-related negativity (ERN), which is a widely used neurophysiological indicator of error monitoring. Cumulative childhood trauma predicted ERN blunting, as did two specific types of traumas: sexual abuse and emotional neglect. Furthermore, the ERN partially mediated the effects of cumulative childhood trauma and emotional neglect on externalizing-related symptoms. Future studies should further examine the relations between childhood trauma and error monitoring in adulthood, which can help to inform intervention approaches.

Functional neural architecture of cognitive control mediates the relationship between individual differences in bilingual experience and behaviour

Bilinguals have often, but not always, been found to outperform monolinguals on domain-general attentional control. Inconsistent findings have been argued to stem, at least partly, from treating bilingualism as a uniform category and from not considering how neural adaptations to bilingual experiences modulate behavioural outcomes. The present study investigated how patterns of language experience, including language switching behaviour, duration and intensity/diversity of bilingual language use, influence the brain processes underlying cognitive control, and how these in turn translate to cognitive control performance. We examined reaction times and spectral dynamics of the electroencephalograms (EEG) of two-hundred-and-thirty-nine participants (about 70% bilinguals) with diverse language experiences during two cognitive control paradigms testing interference suppression (flanker and Simon task). Using structural equation modelling, we found that different bilingual experience factors were related with neurocognitive measures, which in turn were related with behavioural interference effects, for the flanker but not the Simon task. More specifically, increased frequency of language switching and intensity / diversity of bilingual language usage was negatively related to induced top-down control measures (especially midline-frontal theta), which in turn was beneficial for interference control. In contrast, duration of bilingual engagement correlated negatively with evoked bottom-up control measures (especially P3) and was therefore detrimental to interference control. We demonstrate here for the first time how the different factors of bilingual experience lead to different neural adaptations which impact behavioural outcomes. SIGNIFICANCE STATEMENT: Like other intensive experiences, bilingualism leads to brain adaptations. It results in structural changes in language areas, and, due to demands on language control, in brain areas associated with domain-general cognitive control. Related to this, bilinguals often outperform monolinguals on cognitive control tasks. But what is often ignored is that bilingualism is a multi-dimensional phenomenon, with variations such as diversity of language usage and duration of language use. The present large-scale study of neural functioning in bilingualism revealed for the first time how individual differences in bilingual experience lead to adaptations to brain functioning which in turn affect cognitive control behaviour. It exemplifies how the complexity of individual experiences plays a fundamental role in brain function.

Effects of the social context on the neurophysiological correlates of observed error monitoring

Monitoring the motor performance of others, including the correctness of their actions, is crucial for the human behavior. However, while performance (and error) monitoring of the own actions has been studied extensively at the neurophysiological level, the corresponding studies on monitoring of others' errors are scarce, especially for ecological actions. Moreover, the role of the context of the observed action has not been sufficiently explored. To fill this gap, the present study investigated electroencephalographic (EEG) indices of error monitoring during observation of images of interrupted reach-to-grasp actions in social (an object held in another person's hand) and non-social (an object placed on a table) contexts. Analysis in time- and time-frequency domain showed that, at the level of conscious error awareness, there were no effects of the social context (observed error positivity was present for erroneous actions in both contexts). However, the effects of the context were present at the level of hand image processing: observing erroneous actions in the non-social context was related to larger occipito-temporal N1 and theta activity, while in the social context this pattern was reversed, i.e., larger N1 and theta activity were present for the correct actions. These results suggest that, in case of easily predictable ecological actions, action correctness is processed as early as at the level of hand image perception, since the hand posture conveys information about the action (e.g., motor intention). The social context of actions might make the correct actions more salient, possibly through the saliency of the correctly achieved common goal.

Comparison of language awareness in Kurdish-Persian bilingual children and Persian monolingual children

The present study examines language awareness between bilinguals and monolingual children. Language awareness is a person's explicit understanding of language and its role in thinking, learning, and social life, which is associated with executive functioning. Delis-Kaplan Executive Function System (D-KEFS) test was designed to evaluate executive functioning. The test includes two parts: verbal and non-verbal. In this study, the verbal part including Twenty Questions, Word context, and proverb of D-KEFS was used. Kurdish-Persian bilinguals and Persian monolinguals attended this study. The results showed that in the Twenty Questions, word context, and proverb, there was a significant difference between bilinguals and monolinguals. Bilinguals outperformed monolinguals in both twenty-question and word context tests, while they performed lower on the proverb test. It can be concluded that bilingualism affects language awareness and also influences different aspects of executive functioning in different manners.

Conflict Adaptation Effect on Numerical Inductive Reasoning: An ERP Study

Conflict adaptation is of particular importance to human information processing, as it assists in efficient responding when confronted with inconsistent information. Past investigators have focused on the role and mechanisms of conflict adaptation effects in cognitive control tasks, but there have been few studies of conflict adaptation effects in numerical inductive reasoning. In this study we adopted identical, perceptual mismatch and rule violation conditions to investigate conflict adaptation in numerical inductive reasoning. Behaviorally, we found shorter response times on trials following our experimental condition, as compared to pre-trials. In our event-related potential (ERP) electroencephalogram (EEG) results, N2 reflected the improvement in processing efficiency of rule violations in numerical inductive reasoning. Thus, these data suggest the presence of a conflict adaptation effect in high-level processing.

Effects of a three-week executive control training on adaptation to task difficulty and emotional interference

Intact executive functions are characterized by flexible adaptation to task requirements, while these effects are reduced in internalizing disorders. Furthermore, as executive functions play an important role in emotion regulation, deficits in executive functions may contribute to symptom generation in psychological disorders through increased emotional interference. Thus, the present study investigated transfer effects of a three-week executive control training on adaptation to task difficulty and emotional interference in healthy participants (n = 24) to further explore the training's suitability for clinical application. To assess the adaptation to task difficulty, the proportion congruency effect on behavioral data (response times, error rates) and ERP measures (N2, CRN) was assessed in a flanker task with varying frequency of incompatible trials (25%, 75%). To quantify emotional interference, flanker stimuli were superimposed on neutral or negative pictures. Replicating previous results, the training increased interference control as indexed by decreased response times and errors rates, increased N2 amplitude and decreased CRN amplitude in incompatible trials after training. Proportion congruency effects were weaker than expected and not affected by the training intervention. The training lead to a shift in the time-point of emotional interference: before training negative pictures lead to a reduction in CRN amplitude, while after training this reduction was observed for the N2. This pattern illustrates that the training leads to a change in task processing mode from predominant response-related cognitive control to predominant stimulus-related cognitive control (N2), indicating a proactive processing mode.

Control of Attention in Rhesus Monkeys Measured Using a Flanker Task

At least three processes determine whether information we encounter is attended to or ignored. First, attentional capture occurs when attention is drawn automatically by "bottom up" processes, to distinctive, salient, rewarding, or unexpected stimuli when they enter our sensory field. Second, "top down" attentional control can direct cognitive processing towards goal-relevant targets. Third, selection history, operates through repeated exposure to a stimulus, particularly when associated with reward. Attentional control is measured using tasks that require subjects to selectively attend to goal-relevant stimuli in the face of distractions. In the Eriksen flanker task, human participants report which direction a centrally placed arrow is facing, while ignoring "flanking" arrows that may point in the opposite direction. Attentional control is evident to the extent that performance reflects only the direction of the central arrow. We describe four experiments in which we systematically assessed attentional control in rhesus monkeys using a flanker task. In Experiment 1, monkeys responded according to the identity of a central target, and accuracy and latency varied systematically with manipulations of flanking stimuli, validating our adaptation of the Eriksen flanker task. We then tested for converging evidence of attentional control across three experiments in which flanker performance was modulated by the distance separating targets from flankers (Experiment 2), luminance differences (Experiment 3), and differences in associative value (Experiment 4). The approach described is a new and reliable measure of attentional control in rhesus monkeys that can be applied to a wide range of situations with freely behaving animals.

Error-related activity of the sensorimotor network contributes to the prediction of response to cognitive-behavioral therapy in obsessive-compulsive disorder

BACKGROUND

Although cognitive behavioral therapy is a highly effective treatment for obsessive-compulsive disorder (OCD), yielding large symptom reductions on the group level, individual treatment response varies considerably. Identification of treatment response predictors may provide important information for maximizing individual treatment response and thus achieving efficient treatment resource allocation. Here, we investigated the predictive value of previously identified biomarkers of OCD, namely the error-related activity of the supplementary motor area (SMA) and the sensorimotor network (SMN, postcentral gyrus/precuneus).

METHODS

Seventy-two participants with a primary diagnosis of OCD underwent functional magnetic resonance imaging (fMRI) scanning while performing a flanker task prior to receiving routine-care CBT.

RESULTS

Error-related BOLD response of the SMN significantly contributed to the prediction of treatment response beyond the variance accounted for by clinical and sociodemographic variables. Stronger error-related SMN activity at baseline was associated with a higher likelihood of treatment response.

CONCLUSIONS

The present results illustrate that the inclusion of error-related SMN activity can significantly increase treatment response prediction quality in OCD. Stronger error-related activity of the SMN may reflect the ability to activate symptom-relevant processing networks and may thus facilitate response to exposure-based CBT interventions.

Time of Day Effects on Inhibitory Functioning: Cognitive and Neural Evidence of Sundowning in Amnestic Mild Cognitive Impairment

Background: Amnestic mild cognitive impairment (aMCI), a prodromal phase of Alzheimer’s disease (AD), is characterized by episodic memory dysfunction, but inhibitory deficits have also been commonly reported. Time of day (TOD) effects have been confirmed in 1) healthy aging on cognitive processes such as inhibitory control, and 2) on behavior in AD (termed the sundowning effect), but no such research has addressed aMCI. Objective: The present study examined the impact of TOD on the behavioral and electrophysiological correlates of inhibition in 54 individuals with aMCI and 52 healthy controls (HCs), all of morning chronotype. Methods: Participants were randomly assigned to complete two inhibition tasks (Go-NoGo and Flanker) during their optimal (morning) or non-optimal (evening) TOD, while electroencephalography was recorded. Results: Both tasks elicited changes in N2 and P3 event-related potential (ERP) components, which commonly index inhibitory functioning. Analyses showed that the Go-NoGo difference in P3 amplitude was reduced in individuals with aMCI relative to HCs. Compared to HCs, the Flanker difference in P3 amplitude was also reduced and coincided with more errors in the aMCI group. Notably, these behavioral and ERP differences were exaggerated in the non-optimal TOD relative to the optimal TOD. Conclusion: Findings confirm the presence of inhibition deficits in aMCI and provide novel evidence of sundowning effects on inhibitory control in aMCI. Results reinforce the need to consider the influences of TOD in clinical assessments involving individuals with aMCI.

Concurrent working memory task increases or decreases the flanker-related N2 amplitude

Concurrent working memory (WM) task reduces available attentional control resources to perform the flanker task. However, controversy exists as to whether concurrent WM task increases or decreases flanker-related N2 amplitude. In a flanker task experiment, individuals were confronted with a low, middle, or high WM load task, while electroencephalography (EEG) data were recorded. The ERP results showed a larger flanker-related N2 amplitude while completing a middle or high WM load task compared to a low one. However, completing an additional high WM load task could not increase flanker-related N2 amplitude versus completing an additional middle WM load task. In sum, these results suggest that WM load can impair top-down cognitive control processes, thereby hampering flanker task performance. Importantly, the present study supports the account of flanker-related N2 processes linked to top-down attentional control resource allocation, but challenges the account of flanker-related N2 reflecting response conflict processes.

Belief or disbelief in feedback influences the detection efficiency of the feedback concealed information test

The feedback concealed information test (fCIT) is a new variant of the CIT that added feedback about participants’ concealing performances in the classical CIT. The advantage of the fCIT is that the resulting feedback related event-related potentials (ERPs) can be used to detect concealed information. However, the detection efficiency of feedback-based ERPs varies across studies. The present experiment examined whether the extent participants believed the feedback influenced their detection efficiency. Specifically, participants did a mock crime and were then tested in a fCIT. Following the fCIT, participants were asked to report how much they believed the feedback was accurate. Results showed that there were no significant correlations between the amplitude of the feedback related negativity (FRN), feedback P300, and participants’ self-report at the group level. However, individual analyses showed that the detection efficiency of both the FRN and feedback P300 were influenced by participants’ belief about the presented feedback. The detection efficiency of the FRN and the feedback P300 was higher among participants who believed the feedback. These findings suggest that the fCIT is dependent to some extent on the participants’ level of belief in the feedback.

The role of attentional control over interference in minor hallucinations in Parkinson's disease

BACKGROUND

Minor hallucinations in Parkinson's disease are associated with connectivity changes in attentional networks and increased risk of structured hallucinations. However, the clinical translation of these abnormalities in attention processes is not well-defined, and commonly used neuropsychological tests are not able to detect significant deficits in Parkinson's disease patients with isolated minor hallucinations.

OBJECTIVES

To analyze the behavioral and electrophysiological correlates of minor hallucinations in Parkinson's disease during an attentional task assessing response inhibition and interference control.

METHODS

Fifty-five non-demented Parkinson's disease patients with (PD-mH; n = 27) and without minor hallucinations (PD-NH; n = 28) were included in the analysis. An Ericksen flanker task was performed to compare the effect of presenting congruent and incongruent stimuli on accuracy, reaction times and stimulus-locked event-related potentials morphology.

RESULTS

Although both groups showed equivalent performance in a standard neuropsychological assessment, in the flanker task accuracy rates were lower in the PD-mH group in incongruent trials (p = 0.005). In the event-related potentials, PD-mH patients showed increased amplitude of the N2 at Fz [t(53); p < 0.05] and decreased amplitude of the P300 at Pz [t(53); p < 0.05] for the incongruent trials.

CONCLUSIONS

Parkinson's disease patients with isolated minor hallucinations were more susceptible to interference mediated by irrelevant stimuli and had less cognitive control for suppressing these interferences. The failure of these systems could precipitate the intrusion and overrepresentation of peripheral irrelevant stimuli perceived as minor hallucinations. The Ericksen flanker task could be used as a sensitive clinical marker of the attentional defects leading to hallucinations in Parkinson's disease.

EEG correlates of neutral working memory training induce attentional control improvements in test anxiety

Attentional control theory states that high test anxious (HTA) individuals suffer from impaired attentional control. However, through working memory training it may be possible to improve such individuals' attentional control ability. This study investigated whether 20 days of working memory training (with emotionally neutral stimuli) does result in improved HTA individuals' attentional control ability. Pre- and post-outcomes of attentional control were measured using Flanker and Go/Nogo experimental tasks in a test-related stress situation, and EEG data were also collected. Results only showed a significant decrease in Nogo alpha power in HTA individuals after neutral working memory training (i.e., post-outcome versus pre-outcome). However, we failed to provide evidence for beneficial transfer effects of neutral working memory training on enhanced task performance in both the Flanker and the Go/Nogo tasks. So, the present study demonstrates that neutral working memory training is clearly associated with important neurophysiological correlates while performing the Go/Nogo task, but the transfer effect is rather limited.

Electrophysiological correlates of action monitoring in brain-damaged patients: A systematic review

Action monitoring is crucial to the successful execution of an action and understanding the actions of others. It is often impaired due to brain lesions, in particular after stroke. This systematic review aims to map the literature on the neurophysiological correlates of action monitoring in patients with brain lesions. Eighteen studies were identified and divided into two groups: studies on monitoring of one's own actions and studies on monitoring of the actions of others. The first group included EEG studies on monitoring of self-performed erroneous and correct actions. Impaired error detection (decreased error-related negativity) was observed in patients with lesions in the performance-monitoring network, as compared to healthy controls. Less consistent results were shown for error positivity and behavioral error monitoring performance. The second group of studies on monitoring of others' actions reported decreased mu frequency suppression, impaired readiness potential in the affected hemisphere and decreased EEG indices of error observation (observed error positivity and theta power) in stroke patients. As a whole, these results indicate distinct patterns of impaired neurophysiological activity related to monitoring one's own versus others' actions in patients with brain lesions. EEG recordings of this dissociation in the same patients might be a useful index of motor recovery, and therefore, potentially also beneficial in rehabilitation protocols.

Auricular Transcutaneous Vagus Nerve Stimulation Diminishes Alpha-Band-Related Inhibitory Gating Processes During Conflict Monitoring in Frontal Cortices

BACKGROUND

Pursuing goals is compromised when being confronted with interfering information. In such situations, conflict monitoring is important. Theoretical considerations on the neurobiology of response selection and control suggest that auricular transcutaneous vagus nerve stimulation (atVNS) should modulate conflict monitoring. However, the neurophysiological-functional neuroanatomical underpinnings are still not understood.

METHODS

AtVNS was applied in a randomized crossover study design (n = 45). During atVNS or sham stimulation, conflict monitoring was assessed using a Flanker task. EEG data were recorded and analyzed with focus on theta and alpha band activity. Beamforming was applied to examine functional neuroanatomical correlates of atVNS-induced EEG modulations. Moreover, temporal EEG signal decomposition was applied to examine different coding levels in alpha and theta band activity.

RESULTS

AtVNS compromised conflict monitoring processes when it was applied at the second appointment in the crossover study design. On a neurophysiological level, atVNS exerted specific effects because only alpha-band activity was modulated. Alpha-band activity was lower in middle and superior prefrontal regions during atVNS stimulation and thus lower when there was also a decline in task performance. The same direction of alpha-band modulations was evident in fractions of the alpha-band activity coding stimulus-related processes, stimulus-response translation processes, and motor response-related processes.

CONCLUSIONS

The combination of prior task experience and atVNS compromises conflict monitoring processes. This is likely due to reduction of the alpha-band-associated inhibitory gating process on interfering information in frontal cortices. Future research should pay considerable attention to boundary conditions affecting the direction of atVNS effects.

The Neural Responses of Visual Complexity in the Oddball Paradigm: An ERP Study

This research measured human neural responses to images of different visual complexity levels using the oddball paradigm to explore the neurocognitive responses of complexity perception in visual processing. In the task, 24 participants (12 females) were required to react to images with high complexity for all stimuli. We hypothesized that high-complexity stimuli would induce early visual and attentional processing effects and may elicit the visual mismatch negativity responses and the emergence of error-related negativity. Our results showed that the amplitude of P1 and N1 were unaffected by complexity in the early visual processing. Under the target stimuli, both N2 and P3b components were reported, suggesting that the N2 component was sensitive to the complexity deviation, and the attentional processing related to complexity may be derived from the occipital zone according to the feature of the P3b component. In addition, compared with the low-complexity stimulus, the high-complexity stimulus aroused a larger amplitude of the visual mismatch negativity. The detected error negativity (Ne) component reflected the error detection of the participants’ mismatch between visual complexity and psychological expectations.

The Effects of Aging and Time of Day on Inhibitory Control: An Event-Related Potential Study

Time of day (TOD) influences on executive functions have been widely reported, with greater efficiency demonstrated at optimal relative to non-optimal TOD according to one's chronotype (i.e., synchrony effect). Older adults (OAs) show declines in inhibitory control and are more sensitive to the effects of circadian variation on executive functioning. To date, no studies have investigated the effects of TOD and aging on executive functioning using electrophysiological measures. The present study investigated the effects of aging and TOD on the neural correlates of inhibitory processing (N2 and P3) using event-related potentials (ERPs). Go-NoGo and Flanker tasks were administered to 52 OAs of morning chronotype and 51 younger adults (YAs) of afternoon-to-evening chronotype who were randomly assigned to morning or afternoon test sessions, with the optimal TOD for OAs in the morning and for YAs in the afternoon/evening. While behavioral results demonstrated no TOD effects, ERPs indicated synchrony effects. Both YAs and OAs showed greater modulation of Go-NoGo N2 and greater P3 amplitude during the non-optimal than optimal TOD, consistent with the synchrony effect. For the Flanker task, age differences in P3 amplitude were only apparent during the non-optimal TOD. These results suggest that processes associated with inhibitory control are differentially affected by TOD and aging, with age-related reductions in inhibitory efficiency during off-peak test times on measures of interference control. These findings highlight the sensitivity of ERPs to detect TOD effects in the absence of behavioral differences, confirm more pronounced TOD effects in OAs relative to YAs on ERP measures of interference control, and reinforce the need to assess and control for circadian typology in research studies.

Electrophysiological Evidence of Impaired Cognitive Reappraisal in Amnestic Mild Cognitive Impairment: An Event-related Potential Study

BACKGROUND

Emotion dysregulation symptoms are associated with higher conversion rates from MCI to dementia. Thus, understanding the neural mechanism underlying emotion regulation in people with MCI could provide useful information in early detection and intervention of MCI. This study investigated cognitive reappraisal, an emotion regulation strategy, in people with MCI using event-related potentials analysis.

METHODS

Late positive potential (LPP) was measured in 46 amnestic MCI subjects and 47 healthy elderly controls (HECs) as they viewed neutral and unpleasant images. All participants viewed a brief description of the upcoming image; neutral images were neutrally described (the Neut condition), and negative images were preceded with either more neutral/positive (the Rea condition) or more negative (the Neg condition) interpretations.

RESULTS

MCI subjects reduced their emotional intensity to a smaller extent than HEC subjects. For MCI subjects, the decreased level of emotional intensity was positively correlated with function in the verbal and executive domains. The reduced intensity (Rea - Neg) was also inversely correlated with the LPP difference (Rea - Neg) 3,600-5,000 ms after stimulus onset. Compared with HEC subjects, MCI subjects showed hypoactivation in the cuneus in the N2 time range (240-310 ms) and in the inferior parietal lobule and supramarginal gyrus in the 3,600-5,000 ms range.

CONCLUSION

These results suggest that MCI subjects failed to maintain the reappraisal of negative stimuli in the late time window, which contributed to a smaller success with reappraisal.

Unpleasant Odors Affect Alerting Attention in Young Men: An Event-Related Potential Study Using the Attention Network Test

Attention to unpleasant odors is crucial for human safety because they may signal danger; however, whether odor concentration also plays a role remains debated. Here, we explored the effects of two concentrations of pleasant and unpleasant odors on the attention network, comprising the alerting, orienting, and executive control networks. Behavioral responses were examined using the Attention Network Test, while electrophysiological responses were examined by assessing N1 and N2 amplitudes in 30 young men. We found that irrespective of odor concentration, an unpleasant odor induced larger cue-related N1 and N2 amplitudes in the alerting and executive control networks at occipital and frontal electrode sites and that was only paralleled by a reduced behavioral response time of cue-related trails in the alerting network. Thus, our results do not provide supporting evidence for a concentration-dependent effect, but they do suggest that more attentional resources are allocated to alerting-relevant stimuli to improve behavioral response times to a potential threat in young men.

Anger, race, and the neurocognition of threat: attention, inhibition, and error processing during a weapon identification task

This study measured event-related brain potentials (ERPs) to test competing hypotheses regarding the effects of anger and race on early visual processing (N1, P2, and N2) and error recognition (ERN and Pe) during a sequentially primed weapon identification task. The first hypothesis was that anger would impair weapon identification in a biased manner by increasing attention and vigilance to, and decreasing recognition and inhibition of weapon identification errors following, task-irrelevant Black (compared to White) faces. Our competing hypothesis was that anger would facilitate weapon identification by directing attention toward task-relevant stimuli (i.e., objects) and away from task-irrelevant stimuli (i.e., race), and increasing recognition and inhibition of biased errors. Results partially supported the second hypothesis, in that anger increased early attention to faces but minimized attentional processing of race, and did not affect error recognition. Specifically, angry (vs. neutral) participants showed increased N1 to both Black and White faces, ablated P2 race effects, and topographically restricted N2 race effects. Additionally, ERN amplitude was unaffected by emotion, race, or object type. However, Pe amplitude was affected by object type (but not emotion or race), such that Pe amplitude was larger after the misidentification of harmless objects as weapons. Finally, anger slowed overall task performance, especially the correct identification of harmless objects, but did not impact task accuracy. Task performance speed and accuracy were unaffected by the race of the face prime. Implications are discussed.

Tasting rewards. Effects of orosensory sweet signals on human error processing

Human research has shown interactions between rewards and cognitive control. In animal models of affective neuroscience, reward administration typically involves administering orosensory sugar signals (OSS) during caloric-deprived states. We adopted this procedure to investigate neurophysiological mechanisms of reward-cognitive control interactions in humans. We predicted that OSS would affect neurophysiological and behavioral indices of error processing oppositely, depending on the relative weight of the OSS-induced 'wanting' and 'liking' components of reward. We, therefore, conducted a double-blind, non-nutritive sweetener-controlled study with a within-subject design. Fasted (16 hr) participants (N = 61) performed a modified Flanker task to assess neurophysiological (error-related negativity [N_e/ERN]) and behavioral (post-error adaptations) measures of error processing. Non-contingent to task performance, we repeatedly administered either a sugar (glucose) or non-nutritive sweetener (aspartame) solution, which had to be expulsed after short oral stimulation to prevent post-oral effects. Consistent with our hypothesis on how 'liking' would affect N_e/ERN amplitude, we found the latter to be decreased for sugar compared to aspartame. Unexpectedly, we found post-error accuracy, instead of post-error slowing, to be reduced by sugar relative to aspartame. Our findings suggest that OSS may interact with error processing through the 'liking' component of rewards. Adopting our reward-induction procedure (i.e. administering OSS in a state of high reward sensitivity [i.e. fasting], non-contingent to task performance) might help future research investigating the neural underpinnings of reward-cognitive control interactions in humans.

A Pilot Event-Related Potentials Study on Mechanisms Underlying a tDCS-Enhanced Food-Specific Response Inhibition Task for Patients With Binge Eating Disorder

Behavioural studies demonstrate alterations in cognitive functioning, particularly impaired response inhibition and increased attentional bias towards food in binge eating disorder (BED). This pilot study aimed to investigate the neurophysiological processing of a food-specific inhibition training combined with anodal transcranial direct current stimulation (tDCS) of the right dorsolateral prefrontal cortex (DLPFC) in 16 patients with BED (mean age = 38.6, mean BMI = 33.7 kg/m²). Patients performed a food-specific antisaccade task at baseline (T0) and in a cross-over design with verum vs. sham stimulation at T1 and T2. We investigated (i) event-related potentials (ERPs; N2, ERN and P3 amplitudes) while executing the task at baseline, (ii) whether baseline ERPs would predict task performance at T1 and T2 and (iii) associations between ERPs, eating disorder pathology and impulsivity at baseline. The mean amplitude of N2 was less pronounced in erroneous saccades (ES) than correct saccades (CS), whereas ERN and P3 mean amplitudes were more pronounced in ES. Moreover, the P3 mean amplitude of ES predicted the percentage of ES at both follow up-measurements irrespective of the applied stimulation (sham vs. verum). N2 in trials with correct saccades were negatively correlated with nonplanning trait impulsivity, while P3 in erroneous antisaccade trials was negatively correlated with food-related impulsivity. Overall, the findings of reduced ERN, enhanced P3 and N2 amplitude might be interpreted as difficulties in response inhibition towards food in individuals with BED. In particular, P3 predicts task outcome at follow-up and might represent a potential marker for inhibitory control processes.

Cognitive control is quickly adapted to actual task requirements despite misleading context cues-Evidence from the N2, CRN, and ERN

Cognitive control is flexibly adapted to task requirements in healthy individuals. Medio-frontal negativities in the event-related potential of the electroencephalogram can serve as indicators of cognitive control. With increasing conflict frequency, stimulus-locked control, as indexed by the N2, is increased and response-locked control, as indexed by the correct-related negativity, is reduced. On the behavioral level, this shift is associated with improved conflict resolution as evident in reduced response times and error rates in incompatible trials and a reduced response time congruency effect. Cognitive control adaptation might be implemented through experience-based task sets specifying advantageous processing strategies. Here, we investigated whether the cognitive control task set will be sustained when coupled with a contextual cue, even when the initial task requirements are no longer present. A flanker task with two conflict frequency conditions (25% incompatible and 75% incompatible trials) was presented. In the training phase, the conflict frequency conditions were paired with a distinct context cue (i.e., background color). In the test phase, the previously associated cues were again presented, but conflict frequency was identical in both conditions (50% incompatible trials). Although typical cognitive control adaptation was observed in the training phase on the behavioral and event-related potentials level, this pattern was not sustained in the test phase. Thus, the present study provides further evidence that cognitive control is flexibly adapted to task requirements even in the presence of misleading cues.

Irrelevant Robot Signals in a Categorization Task Induce Cognitive Conflict in Performance, Eye Trajectories, the N2 ERP-EEG Component, and Frontal Theta Oscillations

Understanding others' nonverbal behavior is essential for social interaction, as it allows, among others, to infer mental states. Although gaze communication, a well-established nonverbal social behavior, has shown its importance in inferring others' mental states, not much is known about the effects of irrelevant gaze signals on cognitive conflict markers during collaborative settings. Here, participants completed a categorization task where they categorized objects based on their color while observing images of a robot. On each trial, participants observed the robot iCub grasping an object from a table and offering it to them to simulate a handover. Once the robot "moved" the object forward, participants were asked to categorize the object according to its color. Before participants were allowed to respond, the robot made a lateral head/gaze shift. The gaze shifts were either congruent or incongruent with the object's color. We expected that incongruent head cues would induce more errors (Study 1), would be associated with more curvature in eye-tracking trajectories (Study 2), and induce larger amplitude in electrophysiological markers of cognitive conflict (Study 3). Results of the three studies show more oculomotor interference as measured in error rates (Study 1), larger curvatures eye-tracking trajectories (Study 2), and higher amplitudes of the N2 ERP of the EEG signals as well as higher event-related spectral perturbation amplitudes (Study 3) for incongruent trials compared with congruent trials. Our findings reveal that behavioral, ocular, and electrophysiological markers can index the influence of irrelevant signals during goal-oriented tasks.

Effects of a Green Oat Herb Extract on Cognitive Performance and Neurophysiological Activity: A Randomized Double-Blind Placebo-Controlled Study

Green oat extracts have been used for centuries in traditional medicine in view of their supposed beneficial effects on cognition and mood. Recently, a specific green oat formulation (Neuravena^®) showed to have significant bioactive compounds potentially associated with the enhancement of processing speed, working memory and attention. The main aim of the current study was to compare the potential effect of acute administration of 800 mg of Neuravena^® with placebo on a set of neurophysiological correlates of processing speed, attention, performance-monitoring and inhibitory control. Twenty healthy participants were randomized to receive either Neuravena^® or placebo. Electroencephalographic (EEG) signal acquisition was obtained while participants carried out the modified Eriksen flanker and oddball tasks. Both groups were compared on measures of behavioral task performance, and a set of event-related potentials (ERPs) components related to performance monitoring (the error-related negativity; ERN and the N2), target detection, and attention (P3a/P3b). Following active-intervention N2, ERN, and P3a/P3b were significantly reduced and performance was faster, with no loss of accuracy. Conversely, no neurophysiological differences were found in the placebo group before and after treatment and performance worsened significantly in terms of reaction time and accuracy. Acute administration of 800 mg of Neuravena^® appears to enhance the optimization of neural resources and positively influences cognitive performance in tasks associated with executive functions, processing speed and attention. Moreover, Neuravena^® prevents the deleterious effects of tiredness during task performance.

Identification of Food/Nonfood Visual Stimuli from Event-Related Brain Potentials

Although food consumption is one of the most basic human behaviors, the factors underlying nutritional preferences are not yet clear. The use of classification algorithms can clarify the understanding of these factors. This study was aimed at measuring electrophysiological responses to food/nonfood stimuli and applying classification techniques to discriminate the responses using a single-sweep dataset. Twenty-one right-handed male athletes with body mass index (BMI) levels between 18.5% and 25% (mean age: 21.05 ± 2.5) participated in this study voluntarily. The participants were asked to focus on the food and nonfood images that were randomly presented on the monitor without performing any motor task, and EEG data have been collected using a 16-channel amplifier with a sampling rate of 1024 Hz. The SensoMotoric Instruments (SMI) iView XTM RED eye tracking technology was used simultaneously with the EEG to measure the participants' attention to the presented stimuli. Three datasets were generated using the amplitude, time-frequency decomposition, and time-frequency connectivity metrics of P300 and LPP components to separate food and nonfood stimuli. We have implemented k-nearest neighbor (kNN), support vector machine (SVM), Linear Discriminant Analysis (LDA), Logistic Regression (LR), Bayesian classifier, decision tree (DT), and Multilayer Perceptron (MLP) classifiers on these datasets. Finally, the response to food-related stimuli in the hunger state is discriminated from nonfood with an accuracy value close to 78% for each dataset. The results obtained in this study motivate us to employ classifier algorithms using the features obtained from single-trial measurements in amplitude and time-frequency space instead of applying more complex ones like connectivity metrics.

Investigating Cortical Buffering Effects of Acute Moderate Intensity Exercise: A cTBS Study Targeting the Left Dorsolateral Prefrontal Cortex

Background: The beneficial effects of both single-session bouts of aerobic exercise and therapeutic exercise interventions on the cortical regions associated with top-down attentional control [i.e., prefrontal cortex (PFC)] have been well documented. However, it remains unclear whether aerobic exercise can be used to buffer against suppressive influences on the dorsolateral PFC (dlPFC). Objective: The current study sought to determine whether a single session of moderate intensity aerobic exercise can offset the expected suppressive effects of continuous theta burst stimulation (cTBS) targeting the dorsolateral prefrontal cortex (dlPFC). Methods: Twenty-two right-handed participants (aged 19-30) completed a 20-minute movement-only control session [10% heart rate reserve (HRR)] and moderate intensity (50% HRR) exercise in a counterbalanced order. Following each exercise session, participants received active cTBS to the left dlPFC. Changes in executive functions were quantified using a Flanker paradigm employed at baseline, post-exercise and post-cTBS time points. Additionally, EEG was used to measure changes in event-related potential components related to inhibitory control (i.e., N2) and attentional control (i.e., P3) during the flanker task. Results: Behavioral results from the flanker task revealed a significant improvement in task performance following an acute bout of moderate intensity exercise. Furthermore, the effect of cTBS in both the movement-only control and moderate intensity conditions were non-significant. Similarly, EEG data from P3b and N2 ERP components revealed no changes to amplitude across time and condition. P3b latency data revealed a significant effect of time in both the moderate intensity and movement-only conditions, such that P3b latencies were significantly shorter across time points. Latency data within the N2 ERP component revealed no significant interactions or main effects. Conclusion: The findings of the current study provide tentative support for the hypothesis that both moderate and light intensity exercise promote cortical buffering against the suppressive effects of cTBS targeting the dlPFC. However, in the absence of a no-movement control, a lack of expected suppressive effects of cTBS cannot be ruled out.

Event-related brain potentials reveal strategy selection in younger and older adults

It is well-established that younger adults prioritize information accrued during different stages of stimulus evaluation ("early" versus "late") to optimize performance. The extent to which older adults flexibly adjust their processing strategies, however, is largely unexplored. Twenty-four younger and twenty-four older participants completed a cued flanker task in which one of three cues, indicating the probability that a congruent array would appear (75 %, 50 %, or 25 %), was presented on each trial. Behavioral and ERP (CNV, LRP, N2, and P3b) analyses allowed us to infer cue-driven changes in strategy selection. Results indicate that when both younger and older adults expected an incongruent array, they prioritized late, target information, resulting in a decreased susceptibility to the performance-impairing effect of distractors, extending the conclusions of Gratton et al. (1992) to older adults and supporting the claim that strategic control remains largely intact during healthy aging.

Perceptual and cognitive processes in augmented reality - comparison between binocular and monocular presentations

In the present study, we investigated the difference between monocular augmented reality (AR) and binocular AR in terms of perception and cognition by using a task that combines the flanker task with the oddball task. A right- or left-facing arrowhead was presented as a central stimulus at the central vision, and participants were instructed to press a key only when the direction in which the arrowhead faced was a target. In a small number of trials, arrowheads that were facing in the same or opposite direction (flanker stimuli) were presented beside the central stimulus binocularly or monocularly as an AR image. In the binocular condition, the flanker stimuli were presented to both eyes, and, in the monocular condition, only to the dominant eye. The results revealed that participants could respond faster in the binocular condition than in the monocular one; however, only when the flanker stimuli were in the opposite direction was the response faster in the monocular condition. Moreover, the results of event-related brain potentials (ERPs) showed that all stimuli were processed in both the monocular and the binocular conditions in the perceptual stage; however, the influence of the flanker stimuli was attenuated in the monocular condition in the cognitive stage. The influence of flanker stimuli might be more unstable in the monocular condition than in the binocular condition, but more precise examination should be conducted in a future study.