Time course of affective processing bias in major depression: An ERP study

Event-related dynamic phase-amplitude coupling analysis reveals facial emotional processing deficits in patients with major depressive disorder: a cross-sectional study

BACKGROUND

Phase-amplitude coupling (PAC) measures the interaction between neural oscillations in different frequency bands and reflects brain functional network coordination in psychiatric patients. The event-related dynamic changes in PAC characteristics and their association with the neural physiological mechanisms under emotional stimulation in major depressive disorder (MDD) remain poorly understood.

METHODS

We proposed a cross-sectional study that investigated three PAC methods using simulated data and selected the Gaussian-Copula Event-Related PAC (GC-ERPAC) method for dynamic analysis of 128-channel electroencephalogram data from 53 participants, including 24 patients with MDD and 29 healthy controls (HCs). Participants were exposed to three emotional stimuli (fearful, happy, and sad). The correlation between PAC strengths and clinical scales was then analyzed in each condition.

RESULTS

The MDD group exhibited abnormal PAC patterns. With happy stimuli, the strengths of delta-gamma coupling (DGC), theta-gamma coupling (TGC), and alpha-gamma coupling (AGC) in the frontal-parietal regions of the MDD group were lower compared to HCs. With fearful stimuli, the strength of AGC in the occipital region was higher in the MDD group. The correlation between TGC and AGC was weaker for couplings among different frequencies in the MDD group. Additionally, AGC was negatively correlated with the clinical scale in MDD but positively correlated with HCs.

CLINICAL TRIAL NUMBER

Not applicable.

CONCLUSIONS

This study confirmed that GC-ERPAC was an effective method for revealing emotion recognition features in MDD. We provided novel evidence of abnormal spatiotemporal PAC patterns linked to emotional processing deficits. Reduced DGC and TGC, along with increased AGC, suggest potential biomarkers in MDD.

Effects of menstrual cycle phases on approach-avoidance behaviors in women: a behavioral and event-related potentials study

Menstrual cycle influences approach-avoidance behavior in females as a result of fluctuations in sex hormone levels, but the underlying neuropsychological processes are unknown. Therefore, we collected the approach-avoidance behavior and electroencephalogram (EEG) data of 27 naturally cycling women during early follicular, late follicular, and mid-luteal phases, focusing on the effects of estradiol and progesterone levels on women's approach-avoidance behavior. Results found that women in the late follicular phase approached positive stimuli more quickly, and N2 amplitudes were the smallest for impulsive benefit-approach reaction. Women in the mid-luteal phase avoided negative stimuli more quickly, and P1/N2 amplitudes were the smallest for impulsive harm-avoidance reaction. Correlation results showed that estradiol levels positively predicted benefit-approach behavior, and progesterone levels positively predicted harm-avoidance behavior. Behavioral and event-related potential (ERP) results suggest that women in different menstrual cycles have different sensitivities to approach-avoidance behaviors of different emotional stimuli, characterized by less consumption of cognitive resources in the early stages of emotional motivation processing, which is in part mediated by estradiol and progesterone. These findings provide a deeper understanding of the relationship between ovarian hormones and approach-avoidance behavior in women.

The neural correlates of emotion processing and reappraisal as reflected in EEG

Successful reappraisal modulates the impact of emotion-inducing stimuli through reinterpretation of their meaning and decreases subjective emotional experience. Here the question is addressed how the altered emotional experience is related to altered electro-cortical responses, and about the neural mechanisms underlying regulation itself. To this end, we recorded EEG during a cued emotion-regulation paradigm including negative and neutral pictures. Firstly, based on hypothesis-driven analysis of the Late Positive Potential (LPP), we found that the early fronto-centro-parietal LPP (400-1000 ms) increased when passively viewing negative versus neutral pictures. Reappraisal did not decrease this LPP. Instead, only during reappraisal, the emotion effect on the parietal LPP was sustained until the picture offset. Secondly, we applied a localizer approach to uncover reappraisal effects with other spatiotemporal characteristics than the traditional LPP but did not observe such effects. Despite indications of theta oscillations being associated with cognitive and/or affective control, no significant effects were found on theta activity for emotion processing or reappraisal. Our findings suggest that emotion regulation may affect the LPP in several ways, depending on the task design and including affective as well as more cognitive influences. A potential role for theta in emotion regulation remains to be elucidated.

Influence of Betrayal on Emotional Modulation of Executive Control: Evidence From ERPs

Previous studies have found that betrayal increases negative attentional bias and hinders executive control. However, it remains unclear how betrayal influences emotional modulation of executive control. What's more, according to the dual mechanisms of control model, executive control can be divided into reactive and proactive control. It also requires clarification whether both aspects of executive control are affected equally by betrayal in emotional contexts. Thus, the present study aims to provide insight into how betrayal influences the emotional modulation of executive control. Betrayal was induced using a repeated trust game in two experiments. Eighty-two participants (40 for Experiment 1 and 42 for Experiment 2) completed emotional executive control tasks while event-related potentials were recorded. In Experiment 1, an emotional Go/No-go task was used to explore the impact of betrayal on the emotional modulation of executive control. The results indicated that betrayal resulted in inefficient top-down attention processing towards negative stimuli and impaired executive control over these stimuli. This was evidenced by higher N2a and N2b amplitudes in the angry Go condition, and smaller angry No-go P3 amplitudes in individuals who experienced betrayal compared to the control group. In Experiment 2, a modified emotional Stroop task was employed to measure proactive and reactive control in emotional contexts. The results indicated that betrayal impaired only reactive control towards negative stimuli and did not affect proactive control. This was evidenced by the betrayed group exhibiting smaller SP amplitudes under the happy incongruent condition in the most congruent context, with no significant difference observed in the most incongruent context. In summary, betrayal decreases the efficiency of top-down attentional processing directed towards negative stimuli and hampers executive control over negative stimuli. Moreover, this impairment appears to be confined to reactive control strategy.

P1 evoked by facial expression images is enhanced in Parkinson's disease patients with depressive symptoms

Introduction

Depressive symptoms are most common non-motor symptoms in Parkinson's disease (PD), which is often overlooked due to absence of rapid and objective diagnostic biomarkers. Electroencephalography (EEG)-based event-related potentials (ERPs) is commonly used to assess emotional processes. The aim of this study was to investigate changes in ERPs in PD patients exhibiting depressive symptoms and to provide a reliable biomarker for assisting in the diagnosis of PD with depressive symptoms.

Methods

We conducted a case-control study involving 30 PD patients with (dPD group) or without depressive symptoms (nPD group) and 13 age matched healthy controls (HC). We recorded EEG of the patients during the emotional picture stimulation task and analyzed the difference in the early ERPs potentials (P1, N170, early posterior negativity) and their correlation with the severity of symptoms in PD patients.

Results

Our results found that P1 amplitude in the occipital region of the dPD group in response to emotional faces was significantly higher than that of nPD and HC group, and it was positively correlated with severity of depressive symptoms in PD patients.

Conclusion

Our study shows that facial expression-induced enhancement of P1 amplitude can be utilized as a rapid and objective indicator to screen for depressive symptoms in PD.

Modulation of brain function and antidepressant effects by transcranial alternating current stimulation in patients with major depressive disorder: Evidence from ERP

Transcranial alternating current stimulation (tACS) is an emerging non-invasive neuromodulation treatment for major depressive disorder (MDD), but its mechanism remains unclear. Therefore, we evaluated the effects of tACS on event-related potentials (ERP) based on a randomized controlled study. All patients were divided into two groups to receive either 20 sessions 77.5Hz-tACS or 20 sessions of sham stimulation during 4 weeks. The Hamilton Depression Rating Scale for Depression -17 item (HAMD-17) and ERP during face-word Stroop task were recorded before and after the treatment (the fourth weekend). Our findings indicate a significant alleviation of depressive symptoms after tACS. For the behavioral performance, sham group showed a significant decrease in reaction time to the sad incongruent condition and an increase in accuracy to the happy condition. The active group showed an increase in accuracy to the incongruent condition. ERP analysis revealed that tACS significantly shortened the latency of P2 to incongruent condition, decreased the amplitude and prolonged the latency of N2 to negative condition. These ERP alterations suggest a potential rectification of negative bias and enhancement of cognitive functioning in patients with MDD, offering insights into the antidepressant mechanisms of tACS.

Hemispheric engagement during the processing of affective adjectives-an ERP divided visual field study

The study looked into the hemispheres' involvement in emotional word encoding. It combined brain activity measures (ERPs) with behavioural data during the affective categorization task in the divided visual field presentation paradigm. Forty healthy right-handed student volunteers took part in the study, in which they viewed and evaluated 33 positive and 33 negative emotional adjectives presented to either the left or right visual field. We observed a marginally significant effect on the earlier time window (220-250 ms, the P2 component) with higher mean amplitudes evoked to the words presented to the right hemisphere, and then a strong effect on the 340-400 ms (the P3) with a reversed pattern (higher amplitudes for words presented to the left hemisphere). The latter effect was also visible in the error rates and RTs, with better overall performance for adjectives presented to the left hemisphere. There was also an effect on behavioural data of positive words only (higher error rates, shorter RTs). Thus, the study showed a particular "progression" pattern of hemispheric engagement: dependence of the initial stages of affective lexico-semantic processing on the right hemisphere, replaced by the left-hemispheric dominance for content evaluation and response programming stages.

Depressive states in healthy subjects lead to biased processing in frontal-parietal ERPs during emotional stimuli

Subthreshold depressive (sD) states and major depression are considered to occur on a continuum, and there are only quantitative and not qualitative differences between depressive states in healthy individuals and patients with depression. sD is showing a progressively increasing prevalence and has a lifelong impact, and the social and clinical impacts of sD are no less than those of major depressive disorder (MDD). Because depression leads to biased cognition, patients with depression and healthy individuals show different visual processing properties. However, it remains unclear whether there are significant differences in visual information recognition among healthy individuals with various depressive states. In this study, we investigated the event-related potentials (ERPs) and event-related spectrum perturbation (ERSP) of healthy individuals with various depressive states during the perception of emotional visual stimulation. We show that different neural activities can be detected even among healthy individuals. We divided healthy participants into high, middle, and low depressive state groups and found that participants in a high depressive state had a lower P300 amplitude and significant differences in fast and slow neural responses in the frontal and parietal lobes. We anticipate our study to provide useful parameters for assessing the evaluation of depressive states in healthy individuals.

Impact of depressed state on attention and language processing during news broadcasts: EEG analysis and machine learning approach

While information enriches daily life, it can also sometimes have a negative impact, depending on an individual's mental state. We recorded electroencephalogram (EEG) signals from depressed and non-depressed individuals classified based on the Beck Depression Inventory-II score while they listened to news to clarify differences in their attention to affective information and the impact of attentional bias on language processing. Results showed that depressed individuals are characterized by delayed attention to positive news and require a more increased load on language processing. The feasibility of detecting a depressed state using these EEG characteristics was evaluated by classifying individuals as depressed and non-depressed individuals. The area under the curve in the models trained by the EEG features used was 0.73. This result shows that individuals' mental states may be assessed based on EEG measured during daily activities like listening to news.

The role of the dorsolateral and ventromedial prefrontal cortex in emotion regulation in females with major depressive disorder (MDD): A tDCS study

BACKGROUND

Individuals with major depressive disorder (MDD) have deficits in emotion regulation, which plays a putative role in psychopathology. The ventromedial prefrontal cortex (vmPFC) and dorsolateral prefrontal cortex (dlPFC) are assumed to be involved in respective processes. In the present study, we aimed to explore the effect of stimulation over the dlPFC and vmPFC on emotion regulation in female with MDD.

MATERIAL AND METHODS

Twenty women with MDD performed the Emotional Stroop, Emotional Go/No-Go, and Emotional 1-Back tasks during transcranial direct current stimulation (tDCS) in three separate sessions with the following electrode montages: anodal dlPFC (F3)/cathodal vmPFC (Fp2), anodal vmPFC (Fp2)/cathodal dlPFC (F3), and sham stimulation.

RESULTS

Independent of the valence of the respective stimuli, accuracy and speed of interference control, accuracy of pre-potent inhibition, and accuracy, but not speed, of working memory performance improved during anodal left dlPFC/cathodal right vmPFC stimulation. Independent of stimulation conditions, interference control was reduced for sad faces, as compared to happy and neutral faces, and working memory performance was faster for happy than for neutral and sad faces. For the impact of stimulation on specific emotional qualities, anodal left dlPFC/cathodal right vmPFC, compared to sham stimulation, led to improved interference control of sad and neutral faces in the emotional Stroop task, as shown by faster reaction times. Furthermore, in that task accuracy with respect to neutral and happy face conditions was higher during both real stimulation conditions, as compared to sham stimulation.

CONCLUSION

The dlPFC is involved in emotion regulation in MDD. Emotional valence is moreover relevant for the effect of stimulation over this area on interference control in MDD.

An Eye Tracking and Event-Related Potentials Study With Visual Stimuli for Adolescents Emotional Issues

BACKGROUND

Psychological issues are common among adolescents, which have a significant impact on their growth and development. However, the underlying neural mechanisms of viewing visual stimuli in adolescents are poorly understood.

MATERIALS AND METHODS

This study applied the Chinese version of the DSM-V self-assessment scales to evaluate 73 adolescents' psychological characteristics for depressive and manic emotional issues. Combined with eye-tracking and event-related potential (ERP), we explored the characteristics of their visual attention and neural processing mechanisms while freely viewing positive, dysphoric, threatening and neutral visual stimuli.

RESULTS

Compared to controls, adolescents with depressive emotional tendencies showed more concentrated looking behavior with fixation distribution index than the controls, while adolescents with manic emotional tendencies showed no such trait. ERP data revealed individuals with depressive tendencies showed lower arousal levels toward emotional stimuli in the early stage of cognitive processing (N1 amplitude decreased) and with prolonged reaction time (N1 latency increased) than the control group. We found no significant difference between the manic group and the control group. Furthermore, the depression severity scores of the individuals with depressive tendencies were negatively correlated with the total fixation time toward positive stimuli, were negatively correlated with the fixation distribution index toward threatening stimuli, and were positively correlated with the mean N1 amplitudes while viewing dysphoric stimuli. Also, for the individuals with depressive tendencies, there was a positive correlation between the mean N1 amplitudes and the fixation time on the area of interest (AOI) while viewing dysphoric stimuli. For the individuals with manic tendencies, the manic severity scores of the individuals with manic tendencies were positively correlated with the total fixation time toward the positive stimuli. However, no significant correlations were found between the manic severity scores and N1 amplitudes, and between N1 amplitudes and eye-tracking output variables.

CONCLUSION

This study proposes the application of eye-tracking and ERP to provide better biological evidence to alter the neural processing of emotional stimuli for adolescents with emotional issues.

Impairments of Implicit Emotional Neurocognitive Processing in College Students With Subthreshold Depression: An ERP Study

PURPOSE

Previous studies have proved that the people with subthreshold depression (SD) had negative cognitive bias in conscious level. However, it still remains a point of controversy whether they have impairment in unconscious level. The present study aimed to explore whether the implicit emotional processing differed between people with SD and healthy controls (HCs) and the details by analyzing the event-related potentials.

METHODS

We recruited 35 SD participants and 35 age- and sex-matched HCs to collect event-related potential data. A visual oddball task was used to investigate implicit emotional processing with three types of emotional pictures (positive, negative, and neutral as stimuli). The N2 and P3 components were used to compare the neurocognitive differences of implicit emotional processing between two groups.

RESULTS

Compared with the HC group, the SD participants showed no significant differences in the amplitudes or latencies of the N2 component for any kind of emotional stimuli but smaller P3 amplitudes for all kinds of emotional stimuli. The P3 latencies for positive stimuli were slower than the negative ones in the SD group but not in the HC group. The SD group showed slower P3 latencies than the HC group only for positive stimuli. There was a positive correlation between Center for Epidemiological Survey, Depression Scale score and average N2 and P3 amplitudes.

CONCLUSIONS

The SD people demonstrate implicit cognitive processing impairments, and the impairments of emotional cognitive processing in SD may exist mainly in evaluative stage and primarily for positive stimuli.

"She finds you abhorrent" - The impact of emotional context information on the cortical processing of neutral faces in depression

Depression is associated with abnormalities in patterns of information processing, particularly in the context of processing of interpersonal information. The present study was designed to investigate the differences in depressive individuals in cortical processing of facial stimuli when neutral faces were presented in a context that involved information about emotional valence as well as self-reference. In 21 depressive patients and 20 healthy controls, event-related potentials (ERPs) were recorded during the presentation of neutral facial expressions, which were accompanied by affective context information that was either self- or other-related. Across conditions, depressive patients showed larger mean P100 amplitudes than healthy controls. Furthermore, mean late positive potential (LPP) amplitudes of depressive patients were larger in response to faces in self-related than in other-related context. In addition, irrespective of self-reference, mean LPP responses of depressive patients to faces presented after socially threatening sentences were larger compared with faces presented after neutral sentences. Results regarding self-reference supported results of previous studies indicating larger mean amplitudes in self-related conditions. Findings suggest a general heightened initial responsiveness to emotional cues and a sustained emotion processing of socially threatening information in depressive patients.

Crossmodal Audiovisual Emotional Integration in Depression: An Event-Related Potential Study

Depression is related to the defect of emotion processing, and people's emotional processing is crossmodal. This article aims to investigate whether there is a difference in audiovisual emotional integration between the depression group and the normal group using a high-resolution event-related potential (ERP) technique. We designed a visual and/or auditory detection task. The behavioral results showed that the responses to bimodal audiovisual stimuli were faster than those to unimodal auditory or visual stimuli, indicating that crossmodal integration of emotional information occurred in both the depression and normal groups. The ERP results showed that the N2 amplitude induced by sadness was significantly higher than that induced by happiness. The participants in the depression group showed larger amplitudes of N1 and P2, and the average amplitude of LPP evoked in the frontocentral lobe in the depression group was significantly lower than that in the normal group. The results indicated that there are different audiovisual emotional processing mechanisms between depressed and non-depressed college students.

Major Depression and Brain Asymmetry in a Decision-Making Task with Negative and Positive Feedback

Depressed patients are characterized by hypoactivity of the left and hyperactivity of the right frontal areas during the resting state. Depression is also associated with impaired decision-making, which reflects multiple cognitive, affective, and attentional processes, some of which may be lateralized. The aim of this study was to investigate brain asymmetry during a decision-making task performed in negative and positive feedback conditions in patients with Major Depressive Disorder (MDD) in comparison to healthy control participants. The electroencephalogram (EEG) was recorded from 60 MDD patients and 60 healthy participants while performing a multi-stage decision-making task. Frontal, central, and parietal alpha asymmetry were analyzed with EEGlab/ERPlab software. Evoked potential responses (ERPs) showed general lateralization suggestive of an initial right dominance developing into a more complex pattern of asymmetry across different scalp areas as information was processed. The MDD group showed impaired mood prior to performance, and decreased confidence during performance in comparison to the control group. The resting state frontal alpha asymmetry showed lateralization in the healthy group only. Task-induced alpha power and ERP P100 and P300 amplitudes were more informative biomarkers of depression during decision making. Asymmetry coefficients based on task alpha power and ERP amplitudes showed consistency in the dynamical changes during the decision-making stages. Depression was characterized by a lack of left dominance during the resting state and left hypoactivity during the task baseline and subsequent decision-making process. Findings add to understanding of the functional significance of lateralized brain processes in depression.

Attentional bias in MDD: ERP components analysis and classification using a dot-probe task

BACKGROUND AND OBJECTIVE

Strands of evidence have supported existence of negative attentional bias in patients with depression. This study aimed to assess the behavioral and electrophysiological signatures of attentional bias in major depressive disorder (MDD) and explore whether ERP components contain valuable information for discriminating between MDD patients and healthy controls (HCs).

METHODS

Electroencephalography data were collected from 17 patients with MDD and 17 HCs in a dot-probe task, with emotional-neutral pairs as experimental materials. Fourteen features related to ERP waveform shape were generated. Then, Correlated Feature Selection (CFS), ReliefF and GainRatio (GR) were applied for feature selection. For discriminating between MDDs and HCs, k-nearest neighbor (KNN), C4.5, Sequential Minimal Optimization (SMO) and Logistic Regression (LR) were used.

RESULTS

Behaviorally, MDD patients showed significantly shorter reaction time (RT) to valid than invalid sad trials, with significantly higher bias score for sad-neutral pairs. Analysis of split-half reliability in RT indices indicated a strong reliability in RT, while coefficients of RT bias scores neared zero. These behavioral effects were supported by ERP results. MDD patients had higher P300 amplitude with the probe replacing a sad face than a neutral face, indicating difficult attention disengagement from negative emotional faces. Meanwhile, data mining analysis based on ERP components suggested that CFS was the best feature selection algorithm. Especially for the P300 induced by valid sad trials, the classification accuracy of CFS combination with any classifier was above 85%, and the KNN (k = 3) classifier achieved the highest accuracy (94%).

CONCLUSIONS

MDD patients show difficulty in attention disengagement from negative stimuli, reflected by P300. The CFS over other methods leads to a good overall performance in most cases, especially when KNN classifier is used for P300 component classification, illustrating that ERP component may be applied as a tool for auxiliary diagnosis of depression.

Recent Advances in Non-invasive Brain Stimulation for Major Depressive Disorder

Non-invasive brain stimulation (NBS) is a promising treatment for major depressive disorder (MDD), which is an affective processing disorder involving abnormal emotional processing. Many studies have shown that repetitive transcranial magnetic stimulation (rTMS) and transcranial direct current stimulation (tDCS) over the prefrontal cortex can play a regulatory role in affective processing. Although the clinical efficacy of NBS in MDD has been demonstrated clinically, the precise mechanism of action remains unclear. Therefore, this review article summarizes the current status of NBS methods, including rTMS and tDCS, in the treatment of MDD. The article explores possible correlations between depressive symptoms and affective processing, highlighting the relevant affective processing mechanisms. Our review provides a reference for the safety and efficacy of NBS methods in the clinical treatment of MDD.

Emotion Regulating Attentional Control Abnormalities In Major Depressive Disorder: An Event-Related Potential Study

Major depressive disorders (MDD) exhibit cognitive dysfunction with respect to attention. The deficiencies in cognitive control of emotional information are associated with MDD as compared to healthy controls (HC). However, the brain mechanism underlying emotion that influences the attentional control in MDD necessitates further research. The present study explores the emotion-regulated cognitive competence in MDD at a dynamic attentional stage. Event-Related Potentials (ERPs) were recorded from 35 clinical MDD outpatients and matched HCs by applying a modified affective priming dot-probe paradigm, which consisted of various emotional facial expression pairs. From a dynamic perspective, ERPs combined with sLORETA results showed significant differences among the groups. In compared to HC, 100 ms MDD group exhibited a greater interior-prefrontal N100, sensitive to negative-neutral faces. 200 ms MDD showed an activated parietal-occipital P200 linked to sad face, suggesting that the attentional control ability concentrated on sad mood-congruent cognition. 300 ms, a distinct P300 was observed at dorsolateral parietal cortex, representing a sustained attentional control. Our findings suggested that a negatively sad emotion influenced cognitive attentional control in MDD in the early and late attentional stages of cognition. P200 and P300 might be predictors of potential neurocognitive mechanism underlying the dysregulated attentional control of MDD.

An event-related potential study on the time course of mental rotation in upper-limb amputees

OBJECTIVE

Mental rotation of body parts involves sequential cognitive processes, including visual processing, categorization and the mental rotation process itself. However, how these processes are affected by the amputation of a limb is still unclear.

METHODS

Twenty-five right upper-limb amputees and the same number of matched healthy controls participated in a hand mental rotation task. Thirty-two-channel electroencephalography (EEG) was recorded and the event-related potentials (ERPs) were analyzed.

RESULTS

In the early visual processing phase, amputees and controls showed a similar P100. During the categorization phase, the amputees exhibited a decreased N200 compared with controls, and the decline was positively correlated with the time since amputation. In the mental rotation phase, controls had a larger ERP for the right upright hand than for the left upright hand, while amputees had a larger ERP for the left (intact) upright hand than for the right (affected) upright hand.

CONCLUSIONS

Early visual processing was not affected by limb amputation. However, the perceptual salience of hand pictures decreased and the intact hand gained more significance in the amputees.

SIGNIFICANCE

Event-related potentials had the capability of showing the differences in categorization and mental rotation phases between amputees and controls.

Just Swap Out of Negative Vibes? Rumination and Inhibition Deficits in Major Depressive Disorder: Data from Event-Related Potentials Studies

Major depression is a serious disorder of impaired emotion regulation. Emotion hyperactivity leads to excessive negative ruminations that daily hijack the patient’s mental life, impacting their mood. Evidence from past researches suggest that depressive patients present several cognitive impairments in attention and working memory, leading to a more acute selective attention for negative stimuli and a greater accessibility of negative memories. Recently, is has been proposed that impaired inhibitory functioning with regard to emotional information processing might be one of the mechanisms of ruminations linking memory, attention and depression. It seems that inhibition deficit is present at both the input level (i.e., the ability to reduce the interference from emotional distracters) and the higher level (i.e., the ability to direct the attention away from emotional material that has already been processed) of emotional information processing. Event-related potentials (ERP) have widely been used to study inhibition in adults suffering from various psychopathological states. In particular, depressive disorder has been linked to ERPs modulations, at early as well as at latter stages of the information-processing stream, when processing affective material. For instance, deficits in inhibiting negative information have been indexed by changes in the parameters (amplitudes and latencies) of early P2, P1 and N1 components while other ERP studies have shown an ability to differentiate depressed patients from normal controls based upon response inhibition difficulties in go-nogo tasks, indexed by later NoGo P3 differences. In this review, we will focus on results of ERP studies investigating inhibition and its interaction with emotional related cue processing in depressive populations. Implications for future research and theoretical perspectives will be discussed within the framework of current models of depressive disorder, based upon the hypothesis that negative ruminations are at the center of depression processes.

Attention Bias Modification training in individuals with depressive symptoms: A randomized controlled trial

BACKGROUND AND OBJECTIVES

Negative attentional biases are often considered to have a causal role in the onset and maintenance of depressive symptoms. This suggests that reduction of such biases may be a plausible strategy in the treatment of depressive symptoms. The present clinical randomized controlled trial examined long-term effects of a computerized attention bias modification (ABM) procedure on individuals with elevated depressive symptoms.

METHODS

In a double-blind study design, 77 individuals with ongoing mild to severe symptoms of depression were randomly assigned to one of three conditions: 1) ABM training (n = 27); 2) placebo (n = 27); 3) assessment-only (n = 23). In both the ABM and placebo conditions, participants completed 8 sessions of 216-trials (1728 in total) during a 2-week period. Assessments were conducted at pre-training and post-training (0, 2, 4, 8-week, 3, 7-month follow-ups). Change in depressive symptoms and restoration of asymptomatic level were the primary outcome measures.

RESULTS

In the ABM, but not the other two conditions, significant reductions in depressive symptoms were found at post-training and maintained during the 3-month follow-up. Importantly, more participants remained asymptomatic in the ABM condition, as compared to the other two conditions, from post-training to 7-month follow-up. ABM also significantly reduced secondary outcome measures including rumination and trait anxiety, and notably, the ABM effect on reducing depressive symptoms was mediated by rumination.

LIMITATION

Generalization of the findings may be limited because the present sample included only college students.

CONCLUSIONS

The ABM effect on reducing depressive symptoms was maintained for at least 3-month duration in individuals with elevated depressive symptoms, and these results suggest that ABM may be a useful tool for the prevention of depressive symptoms. CLINICALTRIALS.GOV: NCT01628016.

Early processing of emotional faces in a Go/NoGo task: lack of N170 right-hemispheric specialisation in children with major depression

Emotionally biased information processing towards sad and away from happy information characterises individuals with major depression. To learn more about the nature of these dysfunctional modulations, developmental and neural aspects of emotional face processing have to be considered. By combining measures of performance (attention control, inhibition) in an emotional Go/NoGo task with an event-related potential (ERP) of early face processing (N170), we obtained a multifaceted picture of emotional face processing in a sample of children and adolescents (11-14 years) with major depression (MDD, n = 26) and healthy controls (CTRL, n = 26). Subjects had to respond to emotional faces (fearful, happy or sad) and withhold their response to calm faces or vice versa. Children of the MDD group displayed shorter N170 latencies than children of the CTRL group. Typical right lateralisation of the N170 was observed for all faces in the CTRL but not for happy and calm faces in the MDD group. However, the MDD group did not differ in their behavioural reaction to emotional faces, and effects of interference by emotional information on the reaction to calm faces in this group were notably mild. Although we could not find a typical pattern of emotional bias, the results suggest that alterations in face processing of children with major depression can be seen at early stages of face perception indexed by the N170. The findings call for longitudinal examinations considering effects of development in children with major depression as well as associations to later stages of processing.

Cognitive training in mental disorders: update and future directions

OBJECTIVE

This article reviews the conceptual basis, definitions, and evolution of cognitive training approaches for the treatment of mental disorders.

METHOD

The authors review the current state of the knowledge on cognitive training in psychiatric illnesses, and its neural and behavioral targets, and summarize the factors that appear to relate to a successful response, including learner characteristics that influence clinical outcome. They also discuss methodological issues relevant to the development and testing of cognitive training approaches, with the goal of creating maximally efficient and effective approaches to training. Finally, they identify gaps in existing knowledge and outline key research directions for the future.

RESULTS

While much of the early research has been conducted in schizophrenia, cognitive training has more recently been applied to a widening range of neuropsychiatric illnesses, including attention deficit hyperactivity disorder, mood disorders, and substance use disorders. Cognitive training harnesses the inherent neuroplastic capacities of the brain, targeting neural system function across psychiatric disorders, thus improving the cognitive processes that play a role in emotion regulation, clinical symptoms, and adaptive community functioning.

CONCLUSIONS

Cognitive training offers considerable promise, especially given the limited efficacy of pharmacological interventions in ameliorating cognitive deficits. However, more research is needed to understand the mechanisms underlying cognitive training, predictors of response, generalization and real-world applicability, and approaches to dissemination in practice settings.

ERP differences between processing of physical characteristics and personality attributes

Background

Limited data from behavioral and brain-imaging studies indicate that personality traits and physical characteristics are processed differently by the brain. Additionally, electrophysiological results of studies comparing the processing of positive and negative words have produced mixed results. It is therefore not clear how physical and personality attributes with emotional valence (i.e., positive and negative valence) are processed. Thus, this study aimed to examine the neural activity associated with words describing personality traits and physical characteristics with positive or negative emotional valence using Event Related Potentials (ERPs).

Methods

A sample of 15 healthy adults (7 men, 8 women) participated in a computerized word categorization task. Participants were asked to categorize visual word stimuli as physical characteristics or personality traits, while ERPs were recorded synchronously.

Results

Behavioral reaction times to negative physical stimuli were shorter compared to negative personality words, however reaction times did not significantly differ for positive stimuli. Electrophysiological results showed that personality stimuli elicited larger P2 and LPC (Late Positive Component) amplitudes compared to physical stimuli, regardless of negative or positive valence. Moreover, negative as compared with positive stimuli elicited larger P2 and LPC amplitudes.

Conclusion

Personality and physical stimuli were processed differently regardless of positive or negative valence. These findings suggest that personality traits and physical characteristics are differentially classified and are associated with different motivational significance.

Facial emotion triggered cerebral potentials in treatment-resistant depression and borderline personality disorder patients of both genders

BACKGROUND

Processing facial expressions of emotion is deteriorated in depression, which might be more pronounced in treatment-resistant depression (TRD), especially when the latter is comorbid with borderline personality disorder (BPD). Neurophysiologically, both early perceptual and late cognitive cerebral processes of facial emotions can be illustrated by event-related potentials (ERPs).

METHODS

We therefore tried the ERPs to facial expressions of Neutral, Anger, Happiness, and Sadness in 25 patients with TRD, 15 with BPD, 22 with their comorbidity (TRD+BPD), as well as in 37 healthy volunteers. The depression levels of participants were measured with the Plutchik-van Praag Depressive Inventory (PVP).

RESULTS

There was no group difference regarding either N1 (N170), P2, N2, P3a or P3b latency or amplitude to the four facial emotions. Reaction times (RTs) to Anger (p<.01), Happiness (p<.01), and Sadness (p<.001) in TRD, and those to Anger (p<.01) and Happiness (p<.01) in TRD+BPD patients were longer than those in the healthy volunteers. RTs to the four facial expressions were positively correlated (p<.01) with their depressive moods in all participants. In addition, PVP was positively correlated with the P2 latency to Anger in TRD+BPD patients (Fz, p<.01; Cz, p<.01; Pz, p<.01).

CONCLUSIONS

BPD contributed little to TRD or TRD+BPD regarding cerebral processing of facial emotions, however, other cognitive and behavioral data suggest a generalized impairment when responding to facial emotions in TRD and TRD+BPD patients, and a deteriorated perceptual processing of Anger in TRD+BPD patients.

Cognitive training for impaired neural systems in neuropsychiatric illness

Neuropsychiatric illnesses are associated with dysfunction in distributed prefrontal neural systems that underlie perception, cognition, social interactions, emotion regulation, and motivation. The high degree of learning-dependent plasticity in these networks-combined with the availability of advanced computerized technology-suggests that we should be able to engineer very specific training programs that drive meaningful and enduring improvements in impaired neural systems relevant to neuropsychiatric illness. However, cognitive training approaches for mental and addictive disorders must take into account possible inherent limitations in the underlying brain 'learning machinery' due to pathophysiology, must grapple with the presence of complex overlearned maladaptive patterns of neural functioning, and must find a way to ally with developmental and psychosocial factors that influence response to illness and to treatment. In this review, we briefly examine the current state of knowledge from studies of cognitive remediation in psychiatry and we highlight open questions. We then present a systems neuroscience rationale for successful cognitive training for neuropsychiatric illnesses, one that emphasizes the distributed nature of neural assemblies that support cognitive and affective processing, as well as their plasticity. It is based on the notion that, during successful learning, the brain represents the relevant perceptual and cognitive/affective inputs and action outputs with disproportionately larger and more coordinated populations of neurons that are distributed (and that are interacting) across multiple levels of processing and throughout multiple brain regions. This approach allows us to address limitations found in earlier research and to introduce important principles for the design and evaluation of the next generation of cognitive training for impaired neural systems. We summarize work to date using such neuroscience-informed methods and indicate some of the exciting future directions of this field.

Neuromagnetic indication of dysfunctional emotion regulation in affective disorders

Dysfunctional emotion regulation is often reported in affective disorders, but it is unclear whether this dysfunction concerns initial processing of emotional input or regulation of resulting emotion. The present study addressed these aspects in 27 depressive and 15 borderline personality disorder patients and 28 healthy controls who were instructed to either passively view unpleasant and neutral pictures or downregulate emotional responses by reappraisal, while neuromagnetic brain activity was measured. All three groups showed more early response to unpleasant than to neutral pictures, whereas patients failed to show subsequent activity suppression under instructions to down-regulate. This deficient emotion regulation was evident primarily in those subjects reporting high childhood adversity. Results support intact emotional input processing but impaired emotion regulation in affective disorders and indicate a moderating influence of early life stress.

Early attentional modulation by alcohol-related cues in young binge drinkers: an event-related potentials study

OBJECTIVE

Episodic excessive alcohol consumption (i.e., binge drinking) is now considered to be a major concern in our society. Previous studies have shown that alcohol cues can capture attentional resources in chronic alcoholic populations and that the phenomenon is associated with the development and maintenance of alcoholism. Using event-related potentials (ERPs), we investigated the responses of binge drinkers to alcohol-related pictures.

METHODS

Two groups of college students (n=18 in each group) were recruited for the study. One group was composed of binge drinkers and the other of controls. Each student completed a simple visual oddball paradigm in which alcohol-related and non-alcohol-related pictures (positive, neutral or negative) were presented. ERPs were recorded to explore the electrophysiological activity associated with the processing of each cue during the different cognitive steps.

RESULTS

Although there were no behavioural differences between the two groups after detection of alcohol- and non-alcohol-related cues, the ERP data indicated that processing of alcohol-related stimuli was modulated by binge drinking: in the binge drinkers, the P100 amplitudes elicited by the alcohol-related pictures were significantly larger than those elicited by the non-alcohol pictures.

CONCLUSIONS

The present study provides evidence for an early processing enhancement, indexed by increased P100 amplitude, in binge drinkers when confronted with alcohol cues.

SIGNIFICANCE

These findings suggest that higher reactivity to alcohol cues is not a phenomenon limited to adult alcoholics, but that young binge drinkers exhibit signs of prioritizing processing related to alcohol. Prevention intervention for alcohol misuse in young people should consider approaches that address this automatic cue reactivity.

Neural responses to negative feedback are related to negative emotionality in healthy adults

Prior neuroimaging and electrophysiological evidence suggests that potentiated responses in the anterior cingulate cortex (ACC), particularly the rostral ACC, may contribute to abnormal responses to negative feedback in individuals with elevated negative affect and depressive symptoms. The feedback-related negativity (FRN) represents an electrophysiological index of ACC-related activation in response to performance feedback. The purpose of the present study was to examine the FRN and underlying ACC activation using low resolution electromagnetic tomography source estimation techniques in relation to negative emotionality (a composite index including negative affect and subclinical depressive symptoms). To this end, 29 healthy adults performed a monetary incentive delay task while 128-channel event-related potentials were recorded. We found that enhanced FRNs and increased rostral ACC activation in response to negative--but not positive--feedback was related to greater negative emotionality. These results indicate that individual differences in negative emotionality--a putative risk factor for emotional disorders--modulate ACC-related processes critically implicated in assessing the motivational impact and/or salience of environmental feedback.