A systematic review of event-related potentials as outcome measures of attention bias modification

Visual search attentional bias modification reduced the attentional bias in socially anxious individuals

Recent years have raised questions about the effectiveness of attentional bias modification (ABM) in individuals with social anxiety. In the current study, we employed a novel training method-ABM-positive-search training-to modify attentional bias in socially anxious individuals. The attentional bias was measured using the dot-probe task, and brain electrical activity was recorded. The ABM-positive-search group was instructed to search for a happy face in a 3 × 3 visual array. The placebo control group was asked to find out whether the only male from the female or the only female from the male. In terms of behavioral indicators, the results showed a significant reduction in the variability of trial level-bias score (TL-BS) in the ABM-positive-search group post-training. However, there was no significant change observed in the placebo control group. The electrophysiological results were consistent with the behavioral findings. To be specific, both groups displayed the N2pc effect in response to threatening faces before the training. After training, the N2pc effect disappeared in the ABM-positive search group, while it remained in the placebo control group. In conclusion, ABM-positive-search training can effectively modify the attentional bias of socially anxious individuals, and cognitive control plays an important role in this process.

The effect of attentional bias modification on positive affect dynamics

Negative attentional bias and alterations in positive affect dynamics constitute emotional vulnerability to depression. Attentional bias modification (ABM) aims to reduce emotional vulnerability to depression by fostering attentional deployment towards positive stimuli. In this randomized controlled trial, we examined whether ABM leads to changes in positive affect dynamics in a sample with an emotional vulnerability to depression (N = 65). Affect dynamics were measured based on experience sampling data gathered 14 days before and after ABM. During ABM, participants paid attention to pairs of emotional faces and responded to dots that were appearing in their place. There was an 87% chance for the dots to appear in place of the relatively more positive face, with the purpose to implicitly foster attentional focus on positive stimuli. In the control condition, there was a 50% chance of the dots to appear in place of the positive stimuli. Results showed that the lag-1 autocorrelation of affect ("inertia") increased within the ABM group and decreased in the control group, but the findings were not robust and it was unclear whether ABM was the cause. There were no changes in the other affect dynamics indices. Improvements in depression during ABM were not associated with changes in affect dynamics, and affect dynamics post ABM did not predict depression symptoms six months later. In conclusion, the study showed no clear effect of ABM on affect dynamics.

Neural Correlates of the Attentional Bias Towards Subliminal Pornographic Cues in Individuals with Tendencies Toward Problematic Pornography Use: An ERP Study Using a Dot-Probe Task

Attentional bias toward addiction-related stimuli has been implicated in the development and maintenance of addiction disorders. Several previous studies have reported an attentional bias toward pornographic cues in individuals with problematic pornography use (PPU). Since attentional bias can occur without conscious awareness, the purpose of this study was to use electroencephalography to examine whether individuals with a high tendency for PPU exhibit attentional bias at the level of the preconscious processing. Event-related potentials (ERPs) were recorded while male participants with high (n = 24) and low (n = 23) levels of subclinical PPU performed a masked version of the dot-probe task measuring attentional bias toward subliminally presented pornographic stimuli. Behavioral data revealed that participants from both groups with high and low tendencies for PPU reacted faster to probes replacing pornographic images than to probes replacing neutral images. ERPs revealed that individuals with a high tendency for PPU exhibited larger probe-locked P1 amplitudes following masked pornographic images (valid condition) compared with masked neutral images (invalid condition). Additionally, PPU symptom severity correlated positively with the P1 amplitude difference between valid and invalid conditions. These results highlight the automaticity of attentional capture by pornographic stimuli and support the hypothesis of an addiction-related attentional bias during preconscious processes. The implication of these findings for understanding the clinical phenomenon of out-of-control addictive behavior are discussed.

Neural mechanisms underlying attentional bias modification in fibromyalgia patients: a double-blind ERP study

There is a growing interest in the potential benefits of attentional bias modification (ABM) training in chronic pain patients. However, studies examining the effectiveness of ABM programs in fibromyalgia patients have demonstrated inconclusive effects on both behavioral indices and clinical symptoms. Additionally, underlying neural dynamics of ABM effects could yield new insights but remain yet unexplored. Current study, therefore, aims to investigate the effects of ABM training on known neural electrophysiological indicators of attentional bias to pain (P2, N2a). Thirty-two fibromyalgia patients were enrolled and randomly assigned to an ABM training (N = 16) or control (N = 16) condition (2 weeks duration). Within the ABM training condition participants performed five sessions consisting of a modified version of the dot-probe task in which patients were trained to avoid facial pain expressions, whereas in the control group participants performed five sessions consisting of a standard version of the dot-probe task. Potential ABM training effects were evaluated by comparing a single pre- and post-treatment session, in which event-related potentials (ERPs) were recorded in response to both facial expressions and target stimuli. Furthermore, patients filled out a series of self-report questionnaires assessing anxiety, depression, pain-related worrying, fear of pain, fatigue and pain status. After training, results indicated an overall reduction of the amplitude of the P2 component followed by an enhancement of N2a amplitude for the ABM condition compared to control condition. In addition, scores on anxiety and depression decreased in patients assigned to the training condition. However, we found no effects derived from the training on pain-related and fatigue status. Present study offers new insights related to the possible neural mechanisms underlying the effect of ABM training in fibromyalgia. Clinical trial (TRN: NCT05905159) retrospectively registered (30/05/2023).

The effect of an odd-one-out visual search task on attentional bias, body size adaptation, and body dissatisfaction

Body image disturbance is a both a risk factor for, and a symptom of, many eating disorders and refers to the misperception of and dissatisfaction with one's own body. Women with high body dissatisfaction have been shown to direct more attention to low body mass index (BMI) bodies, which results in the overestimation of body size via body size adaptation. Therefore, attention may have a causal role in body image disturbance. We conducted a novel training visual search task with 142 young adult women who we trained to attend to either high or low BMI bodies. We assessed the effects of this training on attention to bodies of different sizes, body size adaptation, and body dissatisfaction. Women trained to attend to low BMI bodies decreased their perceptions of a 'normal' body size via adaptation from pre- to post-training (p < 0.001); however, women trained to attend to high BMI bodies showed no change in their perception of a 'normal' body size. We found no lasting effects of the training on attention to body size or body dissatisfaction; however, our visual search task showed poor internal consistency as a measure of attention. These findings indicate that attention to low BMI bodies may exacerbate body image disturbance in women. However, more reliable measures of attentional are required to confirm this finding.

Combining electrodermal activity analysis and dynamic causal modeling to investigate the visual-odor multimodal integration during face perception

Objective. This study presents a novel methodological approach for incorporating information related to the peripheral sympathetic response into the investigation of neural dynamics. Particularly, we explore how hedonic contextual olfactory stimuli influence the processing of neutral faces in terms of sympathetic response, event-related potentials and effective connectivity analysis. The objective is to investigate how the emotional valence of odors influences the cortical connectivity underlying face processing and the role of face-induced sympathetic arousal in this visual-olfactory multimodal integration.Approach. To this aim, we combine electrodermal activity (EDA) analysis and dynamic causal modeling to examine changes in cortico-cortical interactions.Results. The results reveal that stimuli arising sympathetic EDA responses are associated with a more negative N170 amplitude, which may be a marker of heightened arousal in response to faces. Hedonic odors, on the other hand, lead to a more negative N1 component and a reduced the vertex positive potential when they are unpleasant or pleasant. Concerning connectivity, unpleasant odors strengthen the forward connection from the inferior temporal gyrus (ITG) to the middle temporal gyrus, which is involved in processing changeable facial features. Conversely, the occurrence of sympathetic responses after a stimulus is correlated with an inhibition of this same connection and an enhancement of the backward connection from ITG to the fusiform face gyrus.Significance. These findings suggest that unpleasant odors may enhance the interpretation of emotional expressions and mental states, while faces capable of eliciting sympathetic arousal prioritize identity processing.

A Neurobiological-Behavioral Approach to Predicting and Influencing Private Events

The primary goals of behavior analysis are the prediction and influence of behavior. These goals are largely achieved through the identification of functional relations between behaviors and the stimulating environment. Behavior-behavior relations are insufficient to meet these goals. Although this environment-behavior approach has been highly successful when applied to public behaviors, extensions to private events have been limited. This article discusses technical and conceptual challenges to the study of private events. We introduce a neurobiological-behavioral approach which seeks to understand private behavior as environmentally controlled in part by private neurobiological stimuli. These stimuli may enter into functional relations with both public and private behaviors. The analysis builds upon several current approaches to private events, delineates private behaviors and private stimulation, and emphasizes the reciprocal interaction between the two. By doing so, this approach can improve treatment and assessment of behavior and advance understanding of concepts such as motivating operations. We then describe the array of stimulus functions that neurobiological stimuli may acquire, including eliciting, discriminative, motivating, reinforcing, and punishing effects, and describe how the overall approach expands the concept of contextual influence. Finally, we describe how advances in behavioral neuroscience that enable the measurement and analysis of private behaviors and stimuli are allowing these once private events to affect the public world. Applications in the area of human-computer interfaces are discussed.

The influence of single-session reward-based attentional bias modification on attentional biases towards threat as measured by the N2pc component

Attentional biases toward threatening faces have repeatedly been studied in the context of social anxiety, with etiological theories suggesting exacerbated biases as a possible cause for the latter. To counteract these postulated effects, research has focused on the concept of attentional bias manipulation (ABM), in which spatial contingencies between succeeding stimuli are traditionally employed in training paradigms designed to deliberately shift automatic attention processes away from threat-related stimuli. The ABM research field has been faced with various methodological challenges, such as inconsistent results, low reliabilities of dependent variables and a high susceptibility to moderating factors. We aimed to combine several recent approaches to address these issues. Drawing upon theories of value-driven attention, we explored reward-based contingencies in a Dot Probe task to improve the training's efficacy, combined with neurophysiological measures for greater reliability compared to reaction times, while evaluating the moderating effect of explicitness in the instruction. In a healthy sample (N = 60) and within a single session, we found a general attentional bias toward angry faces present across all conditions as indicated by the N2pc, which was, however, marked by large intrinsic lateralization effects, with submeasures exhibiting opposing polarities. This prompted us to explore an alternative, intrahemispheric calculation method. The new N2pc variant showed the attentional bias to have disappeared at the end of the training session within the explicit instruction group. Reliabilities of the main dependent variables were varied from excellent to questionable, which, together with the exploratory nature of the analysis, leaves this result as preliminary.

Identifying emotional components of event-related potentials in the brain functioning of individuals with contamination obsessions and comparison with healthy control group

The present study aimed to examine the emotional components of event-related potentials (ERPs) in individuals with contamination OCD and compare them with a healthy control group. A convenience sample of 45 participants was included, consisting of 30 individuals diagnosed with contamination-type OCD and 15 individuals in a healthy control group. Both groups participated in an ERP study where they encountered a computer-based task presenting both contamination and neutral pictures, while their brain activity was recorded. The data were analyzed using repeated measures analysis of variance (RANOVA) with SPSS-24 and Matlab software. Findings suggest that in P3 amplitude, only individuals with OCD exhibited a larger positive amplitude (p < 0.05) in response to contaminated pictures compared to neutral pictures and in N2 amplitude, only individuals with OCD exhibited a larger negative amplitude (p < 0.05) in response to contaminated pictures compared to neutral pictures in the central vertex (Fz). These findings hold promising implications for the development of more targeted and effective treatments for contamination OCD, emphasizing the importance of emotion-oriented approaches to address the unique neural patterns observed in the frontal vertex.

Neurocognitive Mechanisms Underlying Attention Bias Towards Pain: Evidence From a Drift-Diffusion Model and Event-Related Potentials

Although combining computational modeling with event-related potentials (ERPs) can precisely characterize neurocognitive processes involved in attention bias, it has yet to be applied in the context of pain. Here, a hierarchical drift-diffusion model (DDM) along with ERPs was used to characterize the neurocognitive mechanisms underlying attention bias towards pain. A spatial cueing paradigm was adopted, in which the locations of targets were either validly or invalidly predicted by spatial cues related to pain or nonpain signals. DDM-derived nondecision time was shorter for targets validly cued by pain signals than by nonpain signals, thus indicating speeded attention engagement towards pain; drift rate was slower for targets invalidly cued by pain signals than by nonpain signals, reflecting slower attention disengagement from pain. The facilitated engagement towards pain was partially mediated by the enhanced lateralization of cue-evoked N1 amplitudes, which relate to the bottom-up, stimulus-driven processes of detecting threatening signals. On the other hand, the retarded disengagement from pain was partially mediated by the enhanced target-evoked anterior N2 amplitudes, which relate to the top-down, goal-driven processes of conflict monitoring and behavior regulating. These results demonstrated that engagement and disengagement components of pain-related attention bias are governed by distinct neurocognitive mechanisms. However, it remains possible that the findings are not pain-specific, but rather, are related to threat or aversiveness in general. This deserves to be further examined by adding a control stimulus modality. PERSPECTIVE: This study characterized the neurocognitive processes involved in attention bias towards pain through combining a hierarchical DDM and ERPs. Our results revealed distinctive neurocognitive mechanisms underlying engagement and disengagement components of attention bias. Future studies are warranted to examine whether our findings are pain-specific or not.

Brain iron content and cognitive function in patients with β-thalassemia

Patients with β-thalassemia (β-TM) may have brain iron overload from long-term blood transfusions, ineffective erythropoiesis, and increased intestinal iron absorption, leading to cognitive impairment. Brain magnetic resonance imaging (MRI) methods such as the transverse relaxation rate, susceptibility-weighted imaging, and quantitative susceptibility mapping can provide quantitative, in vivo measurements of brain iron. This review assessed these MRI methods for brain iron quantification and the measurements for cognitive function in patients with β-TM. We aimed to identify the neural correlates of cognitive impairment, which should help to evaluate therapies for improving cognition and quality of life in patients with β-TM.

Effects of attention bias modification for anxiety: Neurophysiological indices and moderation by symptom severity

OBJECTIVE

Attention bias modification (ABM) aims to decrease anxiety symptom severity through the reduction of threat-related attention bias (AB). Individual differences in treatment response and poor measurement reliability of AB have called its clinical promise into question. The current study examined whether individual differences in anxiety severity at baseline moderated treatment response, and employed both behavioral and neurophysiological metrics of AB.

METHODS

Participants (N = 99) were randomly assigned to four weeks of ABM or placebo control training (PT). Self-reported anxiety symptom severity, and AB metrics and ERPs generated during the dot probe task were collected at baseline (Time 1), one-week post-intervention (Time 5), and at a three-month follow-up (Time 6).

RESULTS

ABM, relative to PT, reduced ERPs indexing attention discrimination (N170) and increased ERPs indexing salience tracking (P3). Increases in P3 were associated with ABM-related reductions in anxiety. Anxiety severity was reduced following ABM, but only among those with higher baseline anxiety symptom severity.

CONCLUSIONS

ABM effectively reduced symptom severity among those with higher levels of anxiety, and modulated neurophysiological indices of AB.

SIGNIFICANCE

Results provide evidence for attention-relevant ERPs as outcomes of ABM treatment responsivity and suggest that ABM may be most beneficial for those with more severe anxiety symptoms.

Event-related potential patterns of selective attention modulated by perceptual load

INTRODUCTION

A high perceptual load can effectively prevent attention from being drawn to irrelevant stimuli; however, the neural pattern underlying this process remains unclear.

METHODS

This study adopted a perceptual load paradigm to examine the temporal processes of attentional modulation by incorporating conditions of perceptual load, distractor-target compatibility, and eccentricity.

RESULTS

The behavioral results showed that a high perceptual load significantly reduced attentional distraction caused by peripheral distractors. The event-related potential results further revealed that shorter P2 latencies were observed for peripheral distractors than for central distractors under a high perceptual load and that a suppressed compatibility effect with increasing load was reflected by the P3 component.

CONCLUSION

These findings suggested that (1) P2 and P3 components effectively captured different sides of attentional processing modulated by load (i.e., the filter processing of the object and the overall attentional resource allocation) and (2) response patterns of selective attention modulated by perceptual load were influenced by eccentricity. Our electrophysiological evidence confirmed the behavioral findings, indicating the neural mechanisms of attentional modulation.

General deficits of attentional inhibition in high trait anxiety: ERP evidence

Behavioral evidence shows that individuals with high trait anxiety tend to be distracted by irrelevant stimulation not only for threat-related stimuli but also for non-emotional neutral stimuli. These findings suggest that there may be a general deficit of attentional control in trait anxiety. However, the neural mechanism underlying the anxiety-related deficit in attentional control, especially inhibition function, is still unclear. Here, we examined the attentional processing of the non-emotional neutral distractor on 66 young adults with different levels of trait anxiety, using the ERP indices of attentional selection (N2pc) and top-down inhibition (Pd) in a search task with geometric stimuli. We found that the distractor-evoked N2pc amplitude did not vary with anxiety levels, but increased anxiety was associated with smaller Pds (i.e. worse inhibition). Besides, delayed attentional selection of targets was associated with higher anxiety levels. These correlations of trait anxiety remained significant even after controlling for state anxiety, and state anxiety did not affect the attentional processing of distractors and targets, suggesting that trait anxiety, not current anxiety, affects attentional function. Our findings clarify the mechanism underlying the general attentional deficits in trait anxiety, e.g. reduced distractor inhibition and delayed target selection.

Effects of the concentration level, eye fatigue and coffee consumption on the performance of a BCI system based on visual ERP-P300

BACKGROUND

A widely used paradigm for Brain-Computer Interfaces (BCI) is based on detecting P300 Event-Related Potentials (ERPs) in response to stimulation and concentration tasks. An open challenge corresponds to maximizing the performance of a BCI by considering artifacts arising from the user's cognitive and physical conditions during task execution.

NEW METHOD

In this study, an analysis of the performance of a visual BCI-P300 system was performed under the metrics of Sensitivity (Sen), Specificity (Spe), Accuracy (Acc), and Area-Under the ROC Curve (AUC), considering the main reported factors affecting the neurophysiological behavior of the P300 signal: Concentration Level, Eye Fatigue, and Coffee Consumption.

COMPARISON WITH EXISTING METHODS

We compared the performance of three P300 signal detection methods (MA-LDA, CCA-RLR, and MA+CCA-RLR) using a public database (GigaScience) in different groups. Data were segmented according to three factors of interest: high and low levels of concentration, high and low eye fatigue, and coffee consumption at different times.

RESULTS

The results showed a significant improvement between 3% and 6% for the metrics evaluated for identifying the P300 signal in relation to concentration levels and coffee consumption.

CONCLUSION

P300 signal can be influenced by physical and mental factors during the execution of ERPs evocation tasks, which could be controlled to maximize the interface's capacity to detect the individual's intention.

Preference for ugly faces? -A cognitive study of attentional and memorial biases toward facial information among young females with facial dissatisfaction

Dissatisfaction with facial appearance is one of the strongest contributors to body image disturbance among young Chinese females and leads to a series of psychological and behavioral disorders. By conducting behavioral and ERP experiments, this study illustrates how young females in China with facial dissatisfaction process different levels of facial attractiveness. Experiments 1 and 2 are behavioral experiments in which the dot-probe paradigm was used to explore the participant's attentional bias to facial attractiveness. The results showed that regardless of whether the face image was presented above or below the threshold, young females with facial dissatisfaction exhibited attentional orientation toward lowly attractive faces and attentional avoidance to both lowly and highly attractive faces, while the control group showed difficulty in attentional disengagement from highly attractive faces. In experiment 3, the learning-recognition task was used to examine mnemonic bias toward facial attractiveness among females with facial dissatisfaction, and EEG data were also recorded during the encoding and retrieval phases. The study found that young females with facial dissatisfaction exhibited a mnemonic preference for lowly attractive images at both the encoding and retrieving stages, with higher P1, N170, P2, and N300 induced by lowly attractive faces, while the control group preferred highly attractive faces. In conclusion, young females with facial dissatisfaction tend to exhibit attentional orientation and mnemonic bias toward lowly attractive faces.

Auditory and cross-modal attentional bias toward positive natural sounds: Behavioral and ERP evidence

Recently, researchers have expanded the investigation into attentional biases toward positive stimuli; however, few studies have examined attentional biases toward positive auditory information. In three experiments, the present study employed an emotional spatial cueing task using emotional sounds as cues and auditory stimuli (Experiment 1) or visual stimuli (Experiment 2 and Experiment 3) as targets to explore whether auditory or visual spatial attention could be modulated by positive auditory cues. Experiment 3 also examined the temporal dynamics of cross-modal auditory bias toward positive natural sounds using event-related potentials (ERPs). The behavioral results of the three experiments consistently demonstrated that response times to targets were faster after positive auditory cues than they were after neutral auditory cues in the valid condition, indicating that healthy participants showed a selective auditory attentional bias (Experiment 1) and cross-modal attentional bias (Experiment 2 and Experiment 3) toward positive natural sounds. The results of Experiment 3 showed that N1 amplitudes were more negative after positive sounds than they were after neutral sounds, which further provided electrophysiological evidence that positive auditory information enhances attention at early stages in healthy adults. The results of the experiments performed in the present study suggest that humans exhibit an attentional bias toward positive natural sounds.

The effect of attention on body size adaptation and body dissatisfaction

Attentional bias to low-fat bodies is thought to be associated with body dissatisfaction-a symptom and risk factor of eating disorders. However, the causal nature of this relationship is unclear. In three preregistered experiments, we trained 370 women to attend towards either high- or low-fat body stimuli using an attention training dot probe task. For each experiment, we analysed the effect of the attention training on (i) attention to subsequently presented high- versus low-fat body stimuli, (ii) visual adaptation to body size, and (iii) body dissatisfaction. The attention training had no effect on attention towards high- or low-fat bodies in an online setting (Experiment 1), but did increase attention to high-fat bodies in a laboratory setting (Experiment 2). Neither perceptions of a 'normal' body size nor levels of body dissatisfaction changed as a result of the attention training in either setting. The results in the online setting did not change when we reduced the stimulus onset-asynchrony of the dot probe task from 500 to 100 ms (Experiment 3). Our results provide no evidence that the dot probe training task used here has robust effects on attention to body size, body image disturbance or body dissatisfaction.

Mental Fatigue-Associated Decrease in Table Tennis Performance: Is There an Electrophysiological Signature?

Mental fatigue (MF) is a psychobiological state negatively impacting both cognitive and physical performance. Although recent research implies that some table tennis (TT) performance outcomes are impaired by MF, open skill sports such as TT require a more detailed overview of MF-related performance decrements. Moreover, research into MF and sport-specific psychomotor performance lacks the inclusion of brain-related measurements to identify MF mechanisms. Eleven experienced TT players participated in this randomized counterbalanced crossover trial. Participants were either required to perform an individualized Stroop task (MF condition) or watch a documentary (control condition). The primary outcomes were reaction time on a sport-specific visuomotor task and EEG activity throughout the trial. The subjective feeling of MF was significantly different between both conditions and confirmed that the MF condition induced the mentally fatigue state of participants (p < 0.001), though no behavioral indicators (i.e., decrease in performance on Stroop and flanker task) of MF. MF worsened reaction time on the visuomotor task, while other secondary measurements remained largely ambiguous. Spectral power (i.e., decreases in upper α band and θ band) was influenced by MF, while ERPs measured during the visuomotor task remained unaltered. The present study confirms that MF negatively impacts table tennis performance, specifically inhibitory stimuli during the visuomotor task. These findings also further augment our understanding of the effects of MF on human performance.