Event-related potentials (ERPs) to hemifield presentations of emotional stimuli: differences between depressed patients and healthy adults in P3 amplitude and asymmetry

A sleepless night disrupts the resolution of emotional conflicts: Behavioural and neural evidence

The present study aims to investigate the influence of 24-hr sleep deprivation on implicit emotion regulation using the emotional conflict task. Twenty-five healthy young adults completed a repeated-measures study protocol involving a night of at-home normal sleep control and a night of in-laboratory sleep deprivation. Prior to the experimental session, all participants wore an actigraph watch and completed the sleep diary. Following each condition, participants performed an emotional conflict task with electroencephalographic recordings. Emotional faces (fearful or happy) overlaid with words ("fear" or "happy") were used as stimuli creating congruent or incongruent trials, and participants were instructed to indicate whether the facial expression was happy or fearful. We measured the accuracy and reaction time on the emotional conflict task, as well as the mean amplitude of the P300 component of the event-related potential at CPz. At the behavioural level, sleep-deprived participants showed reduced alertness with overall longer reaction times and higher error rates. In addition, participants in the sleep deprivation condition made more errors when the current trial followed congruent trials compared with when it followed incongruent trials. At the neural level, P300 amplitude evoked under the sleep-deprived condition was significantly more positive compared with the normal sleep condition, and this effect interacted with previous-trial and current-trial congruency conditions, suggesting that participants used more attentional resources to resolve emotional conflicts when sleep deprived. Our study provided pioneering data demonstrating that sleep deprivation may impair the regulation of emotional processing in the absence of explicit instruction among emerging adults.

Predictive modeling of antidepressant efficacy based on cognitive neuropsychological theory

BACKGROUND

We aimed to develop a clinical predictive model based on the cognitive neuropsychological (CNP) theory and machine-learning to examine SSRI efficacy in the treatment of MDD.

METHODS

Baseline assessments including clinical symptoms (HAMD, HAMA, BDI, and TEPS scores), negative biases (NEO-PI-R-N and NCPBQ scores), sociodemographic characteristics (social support and SES), and a 5-min eye-opening resting-state EEG were completed by 69 participants with first-episode major depressive disorder (MDD) and 36 healthy controls. The clinical symptoms and negative bias were again assessed after an 8-week treatment of depression with selective serotonin reuptake inhibitors (SSRIs). A multi-modality machine-learning model was developed to predict the effectiveness of SSRI antidepressants.

RESULTS

At baseline, we observed significant differences between MDD patients and healthy controls in terms of social support, clinical symptoms, and negative bias characteristics (p < 0.001). A negative association was found (p < 0.05) between neuroticism and alpha asymmetry in both the central and central-parietal areas, as well as between negative cognitive processing bias and alpha asymmetry in the parietal region. Compared to responders, non-responders exhibited less negative cognitive processing bias and greater alpha asymmetry in both central and central-parietal regions. Importantly, we developed a multi-modality machine-learning model with 83 % specificity using the above salient features.

CONCLUSIONS

Research results support the CNP theory of depression treatment. To some extent, the multimodal clinical model constructed based on the CNP theory effectively predicted the efficacy of this treatment in this population.

LIMITATIONS

Small sample and only focus on the mechanisms of delayed-onset SSRI treatment.

Recognition of unilateral lower limb movement based on EEG signals with ERP-PCA analysis

It has been confirmed that motor imagery (MI) and motor execution (ME) share a subset of mechanisms underlying motor cognition. In contrast to the well-studied laterality of upper limb movement, the laterality hypothesis of lower limb movement also exists, but it needs to be characterized by further investigation. This study used electroencephalographic (EEG) recordings of 27 subjects to compare the effects of bilateral lower limb movement in the MI and ME paradigms. Event-related potential (ERP) recorded was decomposed into meaningful and useful representatives of the electrophysiological components, such as N100 and P300. Principal components analysis (PCA) was used to trace the characteristics of ERP components temporally and spatially, respectively. The hypothesis of this study is that the functional opposition of unilateral lower limbs of MI and ME should be reflected in the different alterations of the spatial distribution of lateralized activity. Meanwhile, the significant ERP-PCA components of the EEG signals as identifiable feature sets were applied with support vector machine to identify left and right lower limb movement tasks. The average classification accuracy over all subjects is up to 61.85% for MI and 62.94% for ME. The proportion of subjects with significant results are 51.85% for MI and 59.26% for ME, respectively. Therefore, a potential new classification model for lower limb movement can be applied on brain computer interface (BCI) systems in the future.

The Neural Correlates of the Recognition of Emotional Intensity Deficits in Major Depression: An ERP Study

PURPOSE

Deficits in facial emotional intensity recognition have been associated with social cognition in patients with major depression. The study examined multiple event-related potential (ERP) components in patients with major depression and investigated the relationships between ERPs, social cognition, and clinical features.

PARTICIPANTS AND METHODS

Thirty-one patients met DSM-IV diagnosis of depression and 31 healthy participants completed the emotion intensity recognition task (EIRT), while ERPs were recorded. Data on ERP components (P100, N170, P200, and P300) were analyzed.

RESULTS

The behavioral results showed that patients with major depression performed worse on EIRT, including all six categories of emotions (sadness, disgust, happiness, surprise, anger, and fear), compared to healthy participants. The ERP results showed that patients with major depression exhibited higher P100 amplitudes for sad and happy faces than healthy participants; P300 amplitudes induced by sad and surprise faces were also higher than in healthy participants, mainly in the central and temporal lobes. A positive correlation was found between sadness intensity scores and P100 amplitudes in patients with major depression.

CONCLUSION

Patients with major depression are biased in their identification of facial expressions indicating emotional intensity. Specifically, they have emotional biases in the early and late stages of cognitive processing, mainly in the form of sensitivity to sad stimuli. It may lead to a persistent rumination of sadness that is detrimental to the remission of depression. Additionally, patients with major depression devote different amounts of cognitive resources for different intensities of sad faces during the preconscious stage of cognitive processing. The more intense their perception of sadness, the more cognitive resources they devote. Therefore, the assessment of the intensity of facial expressions is an important research topic, with clinical implications on social cognitive function in patients with major depression.

Aberrant social feedback processing and its impact on memory, social evaluation, and decision-making among individuals with depressive symptoms

BACKGROUND

Depression is associated with aberrant social feedback processing. However, little is known about the impact of these deficits on individuals' memory, social evaluation, and social decision-making.

METHODS

We examined event-related potentials (ERPs) during the processing of social feedback with different emotional valences and intensities, among individuals with high and low depressive symptoms. After three days, participants performed a recall test, along with social evaluation and money allocation.

RESULTS

Compared with the control group, participants with depressive symptoms showed larger occipital P1 and parietal P3 amplitudes to negative social feedback, as well as larger frontal feedback-related negativity toward highly positive social feedback; this indicates toward altered attentional allocation, encoding, and anticipation in social feedback processing. After three days of social feedback processing, individuals in the depressive symptom group recalled negative social feedback better and gave less positive evaluations and allocated less money to the senders of highly negative social feedback compared with control group participants. Notably, ERPs predicted subsequent memory, social evaluation, and decision-making, suggesting a significant impact of aberrant social feedback processing on social cognition and behaviors in depression.

LIMITATIONS

Individuals with depressive symptoms rather than patients with depressive disorders were recruited and therefore caution is needed in applying the findings to clinical populations.

CONCLUSIONS

Individuals with depressive symptoms exhibit negative bias in anticipation, attentional allocation, and encoding processes during social feedback processing, which further influences their memory, social evaluation, and social decision-making in the long run. These aberrant biases should be targeted to prevent the development of major depressive disorders.

Exploring brain activity for positive and negative emotions by means of EEG microstates

Microstate analysis applied to electroencephalographic signals (EEG) allows both temporal and spatial imaging exploration and represents the activity across the scalp. Despite its potential usefulness in understanding brain activity during a specific task, it has been mostly exploited at rest. We extracted EEG microstates during the presentation of emotional expressions, presented either unilaterally (a face in one visual hemifield) or bilaterally (two faces, one in each hemifield). Results revealed four specific microstate’s topographies: (i) M1 involves the temporal areas, mainly in the right hemisphere, with a higher occurrence for stimuli presented in the left than in the right visual field; (ii) M2 is localized in the left temporal cortex, with higher occurrence and coverage for unilateral than bilateral presentations; (iii) M3, with a bilateral temporo-parietal localization, shows higher coverage for bilateral than unilateral presentation; (iv) M4, mainly localized in the right fronto-parietal areas and possibly representing the hemispheric specialization for the peculiar stimulus category, shows higher occurrence and coverage for unilateral stimuli presented in the left than in the right visual field. These results suggest that microstate analysis is a valid tool to explore the cerebral response to emotions and can add new insights on the cerebral functioning, with respect to other EEG markers.

Behavioural and neurophysiological differences in working memory function of depressed patients and healthy controls

OBJECTIVE

Major depressive disorder (MDD) is associated with deficits in working memory. Several cognitive subprocesses interact to produce working memory, including attention, encoding, maintenance and manipulation. We sought to clarify the contribution of functional deficits in these subprocesses in MDD by varying cognitive load during a working memory task.

METHODS

41 depressed participants and 41 age and gender-matched healthy controls performed the n-back working memory task at three levels of difficulty (0-, 1-, and 2-back) in a pregistered study. We assessed response times, accuracy, and event-related electroencephalography (EEG), including P2 and P3 amplitudes, and frontal theta power (4-8 Hz).

RESULTS

MDD participants had prolonged response times and more positive frontal P3 amplitudes (i.e., Fz) relative to controls, mainly in the most difficult 2-back condition. Working memory accuracy, P2 amplitudes and frontal theta event-related synchronisation did not differ between groups at any level of task difficulty.

CONCLUSIONS

Depression is associated with generalized psychomotor slowing of working memory processes, and may involve compensatory hyperactivity in frontal and parietal regions.

SIGNIFICANCE

These findings provide insights into MDD working memory deficits, indicating that depressed individuals dedicate greater levels of cortical processing and cognitive resources to achieve comparable working memory performance to controls.

The Effect of Task-Irrelevant Emotional Valence on Limited Attentional Resources During Deception: An ERPs Study

Deception is a complex and cognitively draining dyadic process that simultaneously involves cognitive and emotional processes, both of which demand/capture attentional resources. However, few studies have investigated the allocation of attentional resources between cognitive and emotional processes during deception. The current study presented facial expressions of different valences to 36 participants. While an electroencephalogram was recording, they were asked to make either truthful or deceptive gender judgments according to preceding cues. The results showed that deceptive responses induced smaller P300 amplitudes than did truthful responses. Task-irrelevant negative emotional information (TiN) elicited larger P300 amplitudes than did task-irrelevant positive emotional information (TiP). Furthermore, the results showed that TiN elicited larger LPP amplitudes than did TiP in deceptive responses, but not in truthful ones. The results suggested that attentional resources were directed away to deception-related cognitive processes and TiN, but not TiP, was consistently able to compete for and obtain attentional resources during deception. The results indicated that TiN could disrupt with deception and may facilitate deception detection.

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.

Comorbid anxiety and depression: Opposing effects on the electrocortical processing of negative imagery in a focal fear sample

BACKGROUND

Anxiety and depression are highly comorbid and share clinical characteristics, such as high levels of negative emotion. Attention toward negative stimuli in anxiety and depression has been studied primarily using negative pictures. Yet, negative mental imagery-that is, mental representations of imagined negative events or stimuli-might more closely mirror patient experience.

METHODS

The current study presents the first examination of neural response to negative imagery in 57 adults (39 female) who all shared a common "focal fear" diagnosis (i.e., specific phobia or performance-only social anxiety disorder), but varied in levels of comorbid anxiety and depression. After listening to standardized descriptions of negative and neutral scenes, participants imagined these scenes as vividly as possible. Associations between categorical and continuous measures of depression, generalized anxiety disorder (GAD), and social anxiety disorder with electrocortical and subjective responses to negative imagery were assessed.

RESULTS

Individuals who were more depressed showed reduced electrocortical processing of negative imagery, whereas those with GAD showed increased electrocortical processing of negative imagery-but only when controlling for depression. Furthermore, participants with higher levels of depression rated negative imagery as less negative and those with greater social anxiety symptoms rated negative imagery more negatively.

CONCLUSIONS

Depression and GAD are characterized by opposing electrocortical response to negative imagery; moreover, depression may suppress GAD-related increases in the electrocortical processing of negative imagery. Results highlight distinctions between different dimensions of distress-based psychopathology, and reveal the unique and complex contribution of comorbid depression to affective response in anxiety.

"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.

Dissociating disorders of depression, anxiety, and their comorbidity with measures of emotional processing: A joint analysis of visual brain potentials and auditory perceptual asymmetries

In a multigenerational study of families at risk for depression, individuals with a lifetime history of depression had: 1) abnormal perceptual asymmetry (PA; smaller left ear/right hemisphere [RH] advantage) in a dichotic emotion recognition task, and 2) reduced RH late positive potential (P3_RH) during an emotional hemifield task. We used standardized difference scores for processing auditory (PA sad-neutral) and visual (P3_RH negative-neutral) stimuli for 112 participants (52 men) in a logistic regression to predict history of depression, anxiety or comorbidity of both. Whereas comorbidity was separately predicted by reduced PA (OR = 0.527, p = .042) or P3_RH (OR = 0.457, p = .013) alone, an interaction between PA and P3_RH (OR = 2.499, p = .011) predicted depressive disorder. Follow-up analyses revealed increased probability of depression at low (lack of emotional differentiation) and high (heightened reactivity to negative stimuli) levels of both predictors. Findings suggest that reduced or heightened right-lateralized emotional responsivity to negative stimuli may be uniquely associated with depression.

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.

Perceived social support moderates neural reactivity to emotionally valenced stimuli during pregnancy

Reactivity to emotional information, measurable at the level of neural activity using event-related potentials, is linked to symptoms of affective disorders. Behavioral evidence suggests that contextual factors, such as social support, can alter emotional reactivity such that affective responding is normalized when social support is high. This possibility remains largely untested at the neural level, specifically through approaches that can offer insight into the mechanistic processes contributing to individual differences in emotional reactivity. Yet, such knowledge could be useful for prevention and intervention efforts, particularly with groups at risk for increased emotional reactivity, such as pregnant mothers for whom emotional distress predicts both maternal and child outcomes. Expectant mothers took part in a longitudinal study that tested whether the late positive potential (LPP), a neural index of reactivity to emotional information, was moderated by maternal perceptions of social support. In the third trimester of pregnancy, lower perceived social support was associated with an absence of a traditional LPP effect, which differentiates valenced from neutral stimuli. Findings suggest that perceptions of social support may normalize emotional processing at the neural level and highlight the potential importance of social support modulation of emotional reactivity during times of known biological change.

Significance?& Significance! Empirical, methodological, and theoretical connections between the late positive potential and P300 as neural responses to stimulus significance: An integrative review

Event-related potential studies of emotional processing have focused on the late positive potential (LPP), a sustained positive deflection in the ERP that is increased for emotionally arousing stimuli. A prominent theory suggests that modulation of the LPP is a response to stimulus significance, defined in terms of the activation of appetitive and aversive motivational systems. The current review incorporates experimental studies showing that manipulations that alter the significance of stimuli alter LPP amplitude. Complementing these within-person studies, also included is individual differences research on depression wherein the LPP has been used to study reduced neural sensitivity to emotional stimuli. Finally, the current review builds an existing framework that the LPP observed in studies in emotional processing and the P300 observed in classic oddball studies may reflect a common response to stimulus significance. This integrative account has implications for the functional interpretation of these ERPs, their neurobiological mechanisms, and clinical applications.

The neuroscience of sadness: A multidisciplinary synthesis and collaborative review

Sadness is typically characterized by raised inner eyebrows, lowered corners of the mouth, reduced walking speed, and slumped posture. Ancient subcortical circuitry provides a neuroanatomical foundation, extending from dorsal periaqueductal grey to subgenual anterior cingulate, the latter of which is now a treatment target in disorders of sadness. Electrophysiological studies further emphasize a role for reduced left relative to right frontal asymmetry in sadness, underpinning interest in the transcranial stimulation of left dorsolateral prefrontal cortex as an antidepressant target. Neuroimaging studies - including meta-analyses - indicate that sadness is associated with reduced cortical activation, which may contribute to reduced parasympathetic inhibitory control over medullary cardioacceleratory circuits. Reduced cardiac control may - in part - contribute to epidemiological reports of reduced life expectancy in affective disorders, effects equivalent to heavy smoking. We suggest that the field may be moving toward a theoretical consensus, in which different models relating to basic emotion theory and psychological constructionism may be considered as complementary, working at different levels of the phylogenetic hierarchy.

Attenuated LPP to Emotional Face Stimuli Associated with Parent- and Self-Reported Depression in Children and Adolescents

Individuals diagnosed with a depressive disorder have been found to show reduced reactions to emotional information consistent with the hypothesis of an emotional context insensitivity. However, there are contradictory findings of enhanced reactivity and mood-congruent processing. Electroencephalography (EEG) recordings of the late positive potential (LPP) can display such blunted or enhanced activity. Due to these contradictory findings, there is a need to clarify the role of the LPP in the emergence and presence of depressive disorders especially in children. We used an emotional Go/NoGo task to investigate modulations of the LPP to emotional (fearful, happy, sad) and calm faces in a sample of children and adolescents (age 11;00-14;11) diagnosed with a depressive disorder according to diagnostic parent interviews (K-SADS-PL) (n = 26) compared to a group of age-matched healthy controls (n = 26). LPP positivity was attenuated in children and adolescents with a depressive disorder as well as with higher self-reported depressive symptoms, suggesting reduced reactivity to emotional and calm faces. This is the first study to find generally blunted LPP responses in a clinical sample of depressed youth across reporters. Such dysfunctional modulation of neural activity may represent a potential biomarker for depressive disorders. The results call for further prospective studies investigating the course of the LPP before and after the onset of a depressive disorder in youth.

Maternal Neural Reactivity During Pregnancy Predicts Infant Temperament

Maternal biological systems impact infant temperament as early as the prenatal period, though the mechanisms of this association are unknown. Using a prospective, longitudinal design, we found that maternal (N = 89) amplitudes of the late positive potential (LPP) in response to negative stimuli during the second, but not the third, trimester of pregnancy predicted observed and physiological indices of temperamental reactivity in infants at age 4 months. Maternal LPP was positively associated with observed infant fear and negatively associated with frontal EEG asymmetry and cortisol reactivity in infants at age 4 months. Results identify a putative mechanism, early in pregnancy, for the intergenerational transmission of emotional reactivity from mother to infant.

Preschool-Onset Major Depressive Disorder is Characterized by Electrocortical Deficits in Processing Pleasant Emotional Pictures

Reductions in positive affect are a salient feature of preschool-onset major depressive disorder. Yet, little is known about the psychophysiological correlates of this blunted positive affect and whether reduced physiological responding to pleasant stimuli may differentiate depressed and healthy young children. 120 four-to-seven year old children with current depression and 63 psychiatrically healthy 4-to-7 year old children completed a simple picture-viewing task of pleasant and neutral pictures while event-related potentials (ERPs) were recorded. The early-childhood version of the Kiddie Schedule for Affective Disorders and Depression was used to establish psychiatric diagnoses. A one-way ANCOVA was used to test for group differences in response to pleasant and neutral pictures. Young children with depression showed a reduced response to pleasant vs. neutral pictures (LPP), after controlling for children's age (F(1,180) = 4.15, p = 0.04, η2 = 0.02). The LPP for the children with preschool-onset depression (M = 0.99, SE = 0.65) was significantly smaller than the LPP in the healthy group of young children (M = 3.27, SE = 0.90). This difference did not vary as a function of depression or anhedonia severity within the group with depression or the healthy children. Similar to older children and adolescents with depression, young children with depression display reductions in responsivity to pleasant stimuli as indexed by the LPP. These findings extend prior findings indicating a blunted response to pleasant stimuli in preschool- onset depression. Given the greater neuroplasticity of emotional response and regulation, these findings suggest clinical attention to emotional response to pleasure is an important target in preschool-onset depression. Clinical trial registration information: A Randomized Control Trial of PCIT-ED for Preschool Depression; http://clinicaltrials.gov/;NCT02076425.

Family Risk for Depression and Prioritization of Religion or Spirituality: Early Neurophysiological Modulations of Motivated Attention

The personal importance of religion or spirituality (R/S) has been associated with a lower risk for major depression (MDD), suicidal behavior, reduced cortical thinning and increased posterior EEG alpha, which has also been linked to antidepressant treatment response in MDD. Building on prior event-related potential (ERP) findings using an emotional hemifield paradigm, this study examined whether abnormal early (preconscious) responsivity to negative arousing stimuli, which is indicative of right parietotemporal dysfunction in both MDD patients and individuals at clinical high risk for MDD, is likewise moderated by R/S. We reanalyzed 72-channel ERP data from 127 individuals at high or low family risk for MDD (Kayser et al., 2017, NeuroImage Clin. 14, 692-707) after R/S stratification (low R/S importance, low/high risk, n = 38/61; high R/S importance, n = 15/13). ERPs were transformed to reference-free current source density (CSD) and quantified by temporal principal components analysis (tPCA). This report focused on N2 sink (peak latency 212 ms), the earliest prominent CSD-tPCA component previously found to be sensitive to emotional content. While overall N2 sink reflected activation of occipitotemporal cortex (prestriate/cuneus), as estimated via a distributed inverse solution, affective significance was marked by a relative (i.e., superimposed) positivity. Statistical analyses employed both non-parametric permutation tests and repeated measures ANOVA for mixed factorial designs with unstructured covariance matrix, including sex, age, and clinical covariates. Participants with low R/S importance, independent of risk status, showed greater ERP responsivity to negative than neutral stimuli, particularly over the right hemisphere. In contrast, early emotional ERP responsivity and asymmetry was substantially reduced for high risk individuals with high R/S importance, however, enhanced for low risk individuals with high R/S importance. Hemifield modulations of these effects (i.e., emotional ERP enhancements with left visual field/right hemisphere stimulus presentations) further corroborated these observations. Results suggest down-regulation of a right-lateralized network for salience detection at an early processing stage in high risk and high R/S importance individuals, presumably to prevent overactivation of ventral brain regions further downstream. These findings may point to a neurophysiological mechanism underlying resilience of families at risk for depression with high R/S prioritization.

The emotion regulation effect of cognitive control is related to depressive state through the mediation of rumination: An ERP study

Deficits in cognitive control have been found in depression, but how they contribute to depressive symptoms remains unknown. The present study investigated whether the regulatory efficacy of cognitive control on negative emotion varies with depression level and whether the regulatory efficacy affects depressive symptoms via the mediation of rumination. Fifty participants screened by the Zung Self-Rating Depressive Scale (SDS) with high and low depression levels were selected. They were instructed to controlled-process different semantic representations of aversive pictures, and the amplitude of the late positive potential (LPP) evoked by the pictures was used as the measure of electrocortical response. We found that controlled-processing neutral representations of aversive pictures significantly decreased the amplitude of LPP relative to that under controlled-processing unpleasant ones in an early window in the low depression group and that this regulatory effect was impaired in the high depression group. Furthermore, a mediation analyses indicated that the regulatory efficacy of controlled-processing different semantic representations was associated with SDS score via the mediation of rumination. These findings shed light on the mechanisms underlying the association between the function of cognitive control in emotion generation and depressive symptoms and indicated a pathway from the regulatory efficacy of cognitive control to depression via rumination.

Does concealing familiarity evoke other processes than concealing untrustworthiness? - Different forms of concealed information modulate P3 effects

It was investigated whether concealing learned stimulus attributes (i.e., trustworthiness vs. untrustworthiness) has similar effects on the P3 amplitude than concealing stimulus familiarity. According to salience hypothesis, known, deceptive stimuli (probe) are (perceived) more relevant than truthful, unknown stimuli (irrelevant) evoking a more positive probe P3 amplitude. When all stimuli are known, concealing information is more cognitively demanding than non-concealing information evoking a less positive P3 amplitude according to the mental effort account. Ninety-seven participants concealed knowledge of previously learned faces in the familiarity condition (probe vs. irrelevant stimuli). In the trustworthiness condition, participants concealed untrustworthiness to previously learned faces and responded truthfully to previously learned trustworthy and untrustworthy faces (known, concealed vs. known, truthful stimuli). The parietal mean P3 amplitude was more positive for probe stimuli than for irrelevant stimuli in the familiarity condition providing evidence for the salience hypothesis. In the trustworthiness condition, concealing untrustworthiness showed the smallest parietal mean P3 amplitude suggesting evidence for the mental effort hypothesis. Individual differences of perpetrator's sensitivity to injustice modulated the P3 amplitude in the trustworthiness condition.

The P300 component decreases in a bimodal oddball task in individuals with depression: An event-related potentials study

OBJECTIVE

In this study, we investigated auditory-visual stimulation-induced P300 and examined whether P300 was differentially modulated between individuals with clinical depression and healthy controls. We hypothesized that the P300 component would significantly differ between individuals with depression and healthy individuals Specifically, we predicted that the P300 component induced by the bimodal oddball task would be significantly different from that induced by the unimodal task.

METHODS

Forty-five individuals with depression and forty-five healthy controls participated in this study. All participants were instructed to complete three oddball tasks-auditory (A), visual (V), and bimodal (AV)-while their electroencephalographic signals were recorded.

RESULTS

Individuals with depression had a lower P300 amplitude and a longer latency than controls in the bimodal task. P300 amplitudes in the bimodal task were significantly higher than in the auditory or visual tasks in both groups. In the depression group, the P300 amplitude was negatively correlated with Hamilton Depression Rating Scale (HAM-D) scores in the bimodal task.

CONCLUSIONS

Our results, which agree with those reported previously, suggest that there is a heightened P300 amplitude sensitivity in the bimodal task in individuals with depression. Our data also suggest that P300 amplitudes in the bimodal task may reflect the severity of depression.

SIGNIFICANCE

The reduced task-related ERP response in individuals with depression suggests significant impairments in these individuals in stimulus integration and response functions.

Emotion-Related Consciousness Detection in Patients With Disorders of Consciousness Through an EEG-Based BCI System

For patients with disorders of consciousness (DOC), such as vegetative state (VS) and minimally conscious state (MCS), detecting and assessing the residual cognitive functions of the brain remain challenging. Emotion-related cognitive functions are difficult to detect in patients with DOC using motor response-based clinical assessment scales such as the Coma Recovery Scale-Revised (CRS-R) because DOC patients have motor impairments and are unable to provide sufficient motor responses for emotion-related communication. In this study, we proposed an EEG-based brain-computer interface (BCI) system for emotion recognition in patients with DOC. Eight patients with DOC (5 VS and 3 MCS) and eight healthy controls participated in the BCI-based experiment. During the experiment, two movie clips flashed (appearing and disappearing) eight times with a random interstimulus interval between flashes to evoke P300 potentials. The subjects were instructed to focus on the crying or laughing movie clip and to count the flashes of the corresponding movie clip cued by instruction. The BCI system performed online P300 detection to determine which movie clip the patients responsed to and presented the result as feedback. Three of the eight patients and all eight healthy controls achieved online accuracies based on P300 detection that were significantly greater than chance level. P300 potentials were observed in the EEG signals from the three patients. These results indicated the three patients had abilities of emotion recognition and command following. Through spectral analysis, common spatial pattern (CSP) and differential entropy (DE) features in the delta, theta, alpha, beta, and gamma frequency bands were employed to classify the EEG signals during the crying and laughing movie clips. Two patients and all eight healthy controls achieved offline accuracies significantly greater than chance levels in the spectral analysis. Furthermore, stable topographic distribution patterns of CSP and DE features were observed in both the healthy subjects and these two patients. Our results suggest that cognitive experiments may be conducted using BCI systems in patients with DOC despite the inability of such patients to provide sufficient behavioral responses.

Using Event-Related Potentials and Startle to Evaluate Time Course in Anxiety and Depression

The National Institute of Mental Health's Research Domain Criteria initiative is a research framework designed toward understanding psychopathology as abnormalities of dimensional neurobehavioral constructs rather than in terms of DSM-defined categories. Research Domain Criteria constructs within the negative valence domain are particularly relevant for understanding anxiety and depressive disorders, which are pervasive, debilitating, and characterized by negative processing bias. One important direction for Research Domain Criteria research is investigating processes and parameters related to the time course (or chronometry) of negative valenced constructs. Two reliable methods for assessing chronometry are event-related potentials (ERPs) and startle blink. In this qualitative review, we examine ERP and startle studies of individuals with anxiety or depression or individuals vulnerable to affective disorders. The aim of the review is to highlight how these methods can inform the role of chronometry in the spectrum of anxiety and depression. ERP studies examining different chronometry facets of negative valenced responses have shown that transdiagnostic groups of individuals with internalizing psychopathologies exhibit abnormalities at early stages of processing. Startle reactivity studies have robustly differentiated fear-based disorders (e.g., panic disorder, social phobia) from other anxiety disorders (e.g., generalized anxiety disorder) and have also shown that different internalizing phenotypes exhibit different patterns of habituation. Findings lend support to the value of ERP and startle measures in identifying groups that cut across conventional classification systems. We also highlight methodological issues that can aid in the validity and reproducibility of ERP and startle findings and, ultimately, in the goal of developing more precise models of anxiety and depression.

The influence of frontal alpha-asymmetry on the processing of approach- and withdrawal-related stimuli-A multichannel psychophysiology study

The approach-withdrawal model of hemispheric activation suggests that left frontal cortical areas mediate approach, while right frontal cortical areas mediate withdrawal motivation. Within this framework, the present study investigates the association of frontal cortical asymmetry with attentional and emotional responses toward approach- and withdrawal-related emotional stimuli. Resting frontal asymmetry was measured from 43 students before they passively viewed negative, neutral, and positive emotional pictures. The startle reflex, skin conductance response, and subjective ratings of valence and arousal were assessed to quantify emotional responding, while attention was assessed with ERPs. We also assessed frontal asymmetry in response to the pictures. Results indicated that relatively stronger right frontal cortical activation was associated with increased N1 amplitudes and more negative subjective emotional evaluation of all stimuli. Furthermore, enhanced right frontal asymmetry (state and trait) was associated with diminished emotional modulation of the late positive potential. In contrast, no association of frontal asymmetry with defensive reflex physiology or activation of sympathetic nervous system activity was found. The current data suggest dissociable influence of resting frontal brain asymmetry on attentional and physiological processing of withdrawal- and approach-related stimuli. That is, asymmetrical frontal cortical brain activation might not modulate approach-/withdrawal-related motor responses and sympathetic arousal directly, but instead enhances allocation of attentional resources to subjectively significant stimuli. The results are discussed in terms of their potential importance for emotion perception in anxiety disorders and their contribution to the understanding of frontal asymmetry.

Right brain, left brain in depressive disorders: Clinical and theoretical implications of behavioral, electrophysiological and neuroimaging findings

The right and left side of the brain are asymmetric in anatomy and function. We review electrophysiological (EEG and event-related potential), behavioral (dichotic and visual perceptual asymmetry), and neuroimaging (PET, MRI, NIRS) evidence of right-left asymmetry in depressive disorders. Recent electrophysiological and fMRI studies of emotional processing have provided new evidence of altered laterality in depressive disorders. EEG alpha asymmetry and neuroimaging findings at rest and during cognitive or emotional tasks are consistent with reduced left prefrontal activity in depressed patients, which may impair downregulation of amygdala response to negative emotional information. Dichotic listening and visual hemifield findings for non-verbal or emotional processing have revealed abnormal perceptual asymmetry in depressive disorders, and electrophysiological findings have shown reduced right-lateralized responsivity to emotional stimuli in occipitotemporal or parietotemporal cortex. We discuss models of neural networks underlying these alterations. Of clinical relevance, individual differences among depressed patients on measures of right-left brain function are related to diagnostic subtype of depression, comorbidity with anxiety disorders, and clinical response to antidepressants or cognitive behavioral therapy.

Motivated attention and family risk for depression: Neuronal generator patterns at scalp elicited by lateralized aversive pictures reveal blunted emotional responsivity

Behavioral and electrophysiologic evidence suggests that major depression (MDD) involves right parietotemporal dysfunction, a region activated by arousing affective stimuli. Building on prior event-related potential (ERP) findings (Kayser et al. 2016 NeuroImage 142:337–350), this study examined whether these abnormalities also characterize individuals at clinical high risk for MDD. We systematically explored the impact of family risk status and personal history of depression and anxiety on three distinct stages of emotional processing comprising the late positive potential (LPP). ERPs (72 channels) were recorded from 74 high and 53 low risk individuals (age 13–59 years, 58 male) during a visual half-field paradigm using highly-controlled pictures of cosmetic surgery patients showing disordered (negative) or healed (neutral) facial areas before or after treatment. Reference-free current source density (CSD) transformations of ERP waveforms were quantified by temporal principal components analysis (tPCA). Component scores of prominent CSD-tPCA factors sensitive to emotional content were analyzed via permutation tests and repeated measures ANOVA for mixed factorial designs with unstructured covariance matrix, including gender, age and clinical covariates. Factor-based distributed inverse solutions provided descriptive estimates of emotional brain activations at group level corresponding to hierarchical activations along ventral visual processing stream. Risk status affected emotional responsivity (increased positivity to negative-than-neutral stimuli) overlapping early N2 sink (peak latency 212 ms), P3 source (385 ms), and a late centroparietal source (630 ms). High risk individuals had reduced right-greater-than-left emotional lateralization involving occipitotemporal cortex (N2 sink) and bilaterally reduced emotional effects involving posterior cingulate (P3 source) and inferior temporal cortex (630 ms) when compared to those at low risk. While the early emotional effects were enhanced for left hemifield (right hemisphere) presentations, hemifield modulations did not differ between risk groups, suggesting top-down rather than bottom-up effects of risk. Groups did not differ in their stimulus valence or arousal ratings. Similar effects were seen for individuals with a lifetime history of depression or anxiety disorder in comparison to those without. However, there was no evidence that risk status and history of MDD or anxiety disorder interacted in their impact on emotional responsivity, suggesting largely independent attenuation of attentional resource allocation to enhance perceptual processing of motivationally salient stimuli. These findings further suggest that a deficit in motivated attention preceding conscious awareness may be a marker of risk for depression.

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Emotional hemifield ERP task with 127 individuals at high and low family risk for MDD

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CSD-PCA methods summarized affective modulation of late positive potential (LPP).

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High risk and prior diagnosis of MDD or anxiety disorder independently reduced LPP.

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Suggested hypoarousal (top-down) of right temporoparietal and other emotional regions

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Left hemifield (bottom-up) modulations of early emotional asymmetries were preserved.

Commonalities and differences in the neural substrates of threat predictability in panic disorder and specific phobia

Different degrees of threat predictability are thought to induce either phasic fear or sustained anxiety. Maladaptive, sustained anxious apprehension is thought to result in overgeneralization of anxiety and thereby to contribute to the development of anxiety disorders. Therefore, differences in threat predictability have been associated with pathological states of anxiety with specific phobia (SP) representing phasic fear as heightened response to predictable threat, while panic disorder (PD) is characterized by sustained anxiety (unpredictable threat) and, as a consequence, overgeneralization of fear. The present study aimed to delineate commonalities and differences in the neural substrates of the impact of threat predictability on affective processing in these two anxiety disorders. Twenty PD patients, 20 SP patients and 20 non-anxious control subjects were investigated with an adapted NPU-design (no, predictable, unpredictable threat) using whole-head magnetoencephalography (MEG). Group independent neural activity in the right dlPFC increased with decreasing threat predictability. PD patients showed a sustained hyperactivation of the vmPFC under threat and safety conditions. The magnitude of hyperactivation was inversely correlated with PDs subjective arousal and anxiety sensitivity. Both PD and SP patients revealed decreased parietal processing of affective stimuli. Findings indicate overgeneralization between threat and safety conditions and increased need for emotion regulation via the vmPFC in PD, but not SP patients. Both anxiety disorders showed decreased activation in parietal networks possibly indicating attentional avoidance of affective stimuli. Present results complement findings from fear conditioning studies and underline overgeneralization of fear, particularly in PD.

Enhanced Neural Reactivity to Threatening Faces in Anxious Youth: Evidence from Event-Related Potentials

Anxiety disorders are characterized by enhanced reactivity to threat, and event-related potentials (ERPs) are useful neural measures of the dynamics of threat processing. In particular, the late positive potential (LPP) is an ERP component that reflects sustained attention towards motivationally salient information. Previous studies in adults suggest that the LPP is enhanced to threatening stimuli in anxiety but blunted in depression; however, very little work has evaluated the LPP to threat in anxious youth. We measured the LPP during an emotional face-matching task in youth (age 7-19) with current anxiety disorders (n = 53) and healthy controls with no history of psychopathology (n = 37). We evaluated group differences, as well as the effect of depressive symptoms on the LPP. Youth with anxiety disorders exhibited enhanced LPPs to angry and fearful faces 1000-2000 ms after stimulus onset. Higher depressive symptoms were associated with reduced LPPs to angry faces across both groups. Enhanced LPPs to threatening faces were most apparent for social anxiety disorder, as opposed to generalized anxiety disorder or separation anxiety disorder. Results suggest the LPP may be a useful neural measure of threat reactivity in youth with anxiety disorders and highlight the importance of accounting for symptoms of both depression and anxiety when examining emotional processing.

Neural Reactivity to Emotional Stimuli Prospectively Predicts the Impact of a Natural Disaster on Psychiatric Symptoms in Children

BACKGROUND

Natural disasters expose entire communities to stress and trauma, leading to increased risk for psychiatric symptoms. Yet, the majority of exposed individuals are resilient, highlighting the importance of identifying underlying factors that contribute to outcomes.

METHODS

The current study was part of a larger prospective study of children in Long Island, New York (n = 260). At age 9, children viewed unpleasant and pleasant images while the late positive potential (LPP), an event-related potential component that reflects sustained attention toward salient information, was measured. Following the event-related potential assessment, Hurricane Sandy, the second costliest hurricane in United States history, hit the region. Eight weeks after the hurricane, mothers reported on exposure to hurricane-related stress and children's internalizing and externalizing symptoms. Symptoms were reassessed 8 months after the hurricane.

RESULTS

The LPP predicted both internalizing and externalizing symptoms after accounting for prehurricane symptomatology and interacted with stress to predict externalizing symptoms. Among children exposed to higher levels of hurricane-related stress, enhanced neural reactivity to unpleasant images predicted greater externalizing symptoms 8 weeks after the disaster, while greater neural reactivity to pleasant images predicted lower externalizing symptoms. Moreover, interactions between the LPP and stress continued to predict externalizing symptoms 8 months after the hurricane.

CONCLUSIONS

Results indicate that heightened neural reactivity and attention toward unpleasant information, as measured by the LPP, predispose children to psychiatric symptoms when exposed to higher levels of stress related to natural disasters, while greater reactivity to and processing of pleasant information may be a protective factor.

Neuronal generator patterns at scalp elicited by lateralized aversive pictures reveal consecutive stages of motivated attention

Event-related potential (ERP) studies have provided evidence for an allocation of attentional resources to enhance perceptual processing of motivationally salient stimuli. Emotional modulation affects several consecutive components associated with stages of affective-cognitive processing, beginning as early as 100-200ms after stimulus onset. In agreement with the notion that the right parietotemporal region is critically involved during the perception of arousing affective stimuli, some ERP studies have reported asymmetric emotional ERP effects. However, it is difficult to separate emotional from non-emotional effects because differences in stimulus content unrelated to affective salience or task demands may also be associated with lateralized function or promote cognitive processing. Other concerns pertain to the operational definition and statistical independence of ERP component measures, their dependence on an EEG reference, and spatial smearing due to volume conduction, all of which impede the identification of distinct scalp activation patterns associated with affective processing. Building on prior research using a visual half-field paradigm with highly controlled emotional stimuli (pictures of cosmetic surgery patients showing disordered [negative] or healed [neutral] facial areas before or after treatment), 72-channel ERPs recorded from 152 individuals (ages 13-68years; 81 female) were transformed into reference-free current source density (CSD) waveforms and submitted to temporal principal components analysis (PCA) to identify their underlying neuronal generator patterns. Using both nonparametric randomization tests and repeated measures ANOVA, robust effects of emotional content were found over parietooccipital regions for CSD factors corresponding to N2 sink (212ms peak latency), P3 source (385ms) and a late centroparietal source (630ms), all indicative of greater positivity for negative than neutral stimuli. For the N2 sink, emotional effects were right-lateralized and modulated by hemifield, with larger amplitude and asymmetry for left hemifield (right hemisphere) presentations. For all three factors, more positive amplitudes at parietooccipital sites were associated with increased ratings of negative valence and greater arousal. Distributed inverse solutions of the CSD-PCA-based emotional effects implicated a sequence of maximal activations in right occipitotemporal cortex, bilateral posterior cingulate cortex, and bilateral inferior temporal cortex. These findings are consistent with hierarchical activations of the ventral visual pathway reflecting subsequent processing stages in response to motivationally salient stimuli.

Impact of electroconvulsive therapy on magnetoencephalographic correlates of dysfunctional emotional processing in major depression

In major depressive disorder (MDD), electrophysiological and imaging studies provide evidence for a reduced neural activity in parietal and dorsolateral prefrontal regions. In the present study, neural correlates and temporal dynamics of visual affective perception have been investigated in patients with unipolar depression in a pre/post treatment design using magnetoencephalography (MEG). Nineteen in-patients and 19 balanced healthy controls passed MEG measurement while passively viewing pleasant, unpleasant and neutral pictures. After a 4-week treatment with electroconvulsive therapy or 4-week waiting period without intervention respectively, 16 of these patients and their 16 corresponding controls participated in a second MEG measurement. Before treatment neural source estimations of magnetic fields evoked by the emotional scenes revealed a general bilateral parietal hypoactivation in depressed patients compared to controls predominately at early and mid-latency time intervals. Successful ECT treatment, as reflected by a decline in clinical scores (Hamilton Depression Scale; HAMD) led to a normalization of this distinct parietal hypoactivation. Effective treatment was also accompanied by relatively increased neural activation at right temporo-parietal regions. The present study indicates dysfunctional parietal information processing and attention processes towards emotional stimuli in MDD patients which can be returned to normal by ECT treatment. Since convergent neural hypoactivations and treatment effects have recently been shown in MDD patients before and after pharmacological therapy, this electrophysiological correlate might serve as a biomarker for objective treatment evaluation and thereby potentially advance treatment options and support the prediction of individual treatment responses.

Prepare for scare-Impact of threat predictability on affective visual processing in spider phobia

The visual processing of emotional faces is influenced by individual's level of stress and anxiety. Valence unspecific affective processing is expected to be influenced by predictability of threat. Using a design of phasic fear (predictable threat), sustained anxiety (unpredictable threat) and safety (no threat), we investigated the magnetoencephalographic correlates and temporal dynamics of emotional face processing in a sample of phobic patients. Compared to non-anxious controls, phobic individuals revealed decreased parietal emotional attention processes during affective processing at mid-latency and late processing stages. While control subjects showed increasing parietal processing of the facial stimuli in line with decreasing threat predictability, phobic subjects revealed the opposite pattern. Decreasing threat predictability also led to increasing neural activity in the orbitofrontal and dorsolateral prefrontal cortex at mid-latency stages. Additionally, unpredictability of threat lead to higher subjective discomfort compared to predictability of threat and no threat safety condition. Our findings indicate that visual processing of emotional information is influenced by both stress induction and pathologic anxiety.

Brain laterality, depression and anxiety disorders: New findings for emotional and verbal dichotic listening in individuals at risk for depression

Studies using dichotic listening tests and electroencephalographic (EEG) measures of hemispheric asymmetry have reported evidence of abnormal brain laterality in patients having depressive disorders. We present new findings from a multigenerational study of risk for depression, in which perceptual asymmetry was measured in dichotic listening tests of emotional and verbal processing. Biological offspring and grandchildren of probands with a major depressive disorder (MDD) who were at high risk and those of nondepressed controls who were at low risk were tested on dichotic emotional recognition and consonant-vowel syllable tests. In the emotion test, individuals with a lifetime diagnosis of MDD had a smaller right hemisphere advantage than those without a MDD, but there was no difference between high- and low-risk groups or between those with or without an anxiety disorder. In the syllable test, a smaller left hemisphere advantage was found in individuals with an anxiety disorder compared to those without an anxiety disorder, but there was no difference between high- and low-risk groups or between those with or without a MDD. This double dissociation indicates that lifetime diagnosis of MDD and anxiety disorders have a differential impact on lateralized hemispheric processing of emotional and verbal information.

Diagnostic and symptom-based predictors of emotional processing in generalized anxiety disorder and major depressive disorder: An event-related potential study

The delineation of specific versus overlapping mechanisms in GAD and MDD could shed light on the integrity of these diagnostic categories. For example, negative emotion generation is one mechanism that may be especially relevant to both disorders. Emotional processing abnormalities were examined among 97 outpatients with generalized anxiety disorder (GAD) or major depressive disorder (MDD) and 25 healthy adults, using the late positive potential (LPP), an event-related potential that is larger for emotional versus neutral stimuli. GAD and MDD were also assessed dimensionally across all participants. Both MDD diagnosis and dimensional depression scores were associated with reduced ΔLPP. When controlling for MDD diagnosis/dimension, both the diagnosis and dimension of GAD were associated with increased ΔLPP. Both MDD and GAD dimensions, but not diagnoses, were associated with increased ΔRT to targets that followed emotional pictures. Therefore, MDD and GAD have distinguishable and opposing features evident in neural measures of emotion processing.

Magnetoencephalographic Correlates of Emotional Processing in Major Depression Before and After Pharmacological Treatment

BACKGROUND

In major depressive disorder (MDD), electrophysiological and imaging studies suggest reduced neural activity in the parietal and dorsolateral prefrontal cortex regions. In the present study, neural correlates of emotional processing in MDD were analyzed for the first time in a pre-/post-treatment design by means of magnetoencephalography (MEG), allowing for detecting temporal dynamics of brain activation.

METHODS

Twenty-five medication-free Caucasian in-patients with MDD and 25 matched controls underwent a baseline MEG session with passive viewing of pleasant, unpleasant, and neutral pictures. Fifteen patients were followed-up with a second MEG session after 4 weeks of antidepressant monopharmacotherapy with mirtazapine. The corresponding controls received no intervention between the measurements. The clinical course of depression was assessed using the Hamilton Depression scale.

RESULTS

Prior to treatment, an overall neocortical hypoactivation during emotional processing, particularly at the parietal regions and areas at the right temporoparietal junction, as well as abnormal valence-specific reactions at the right parietal and bilateral dorsolateral prefrontal cortex (dlPFC) regions were observed in patients compared to controls. These effects occurred <150 ms, suggesting dysfunctional processing of emotional stimuli at a preconscious level. Successful antidepressant treatment resulted in a normalization of the hypoactivation at the right parietal and right temporoparietal regions. Accordingly, both dlPFC regions revealed an increase of activity after therapy.

CONCLUSIONS

The present study provides neurophysiological evidence for dysfunctional emotional processing in a fronto-parieto-temporal network, possibly contributing to the pathogenesis of MDD. These activation patterns might have the potential to serve as biomarkers of treatment success.

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.

Event-related potentials in response to emotional words in patients with major depressive disorder and healthy controls

BACKGROUND

Dysfunctional cognitive processing and abnormal brain activation in response to emotional stimuli have long been recognized as core features of the major depressive disorder (MDD). The aim of this study was to examine how Chinese patients with MDD process Chinese emotional words presented to either the left (LH) or right hemisphere (RH).

METHODS

Reaction time (RT) and the late positive component of the event-related potential were measured while subjects judged the valence (positive or negative) of emotional words written in Chinese.

RESULTS

Compared to healthy controls, patients with MDD exhibited slower RTs in response to negative words. In all subjects, the RTs in response to negative words were significantly faster than RTs in response to positive words presented to the LH, as well as significantly faster than responses to negative words presented to the RH. Compared to healthy controls, MDD patients exhibited reduced activation of the central and left regions of the brain in response to both negative and positive words. In healthy controls, the posterior brain areas were more active than the anterior brain areas when responding to negative words.

CONCLUSION

All individuals showed faster RTs in response to negative words compared to positive words. In addition, MDD patients showed lateralization of brain activity in response to emotional words, whereas healthy individuals did not show this lateralization. Posterior brain areas appear to play an especially important role in discriminating and experiencing negative emotional words. This study provides further evidence in support of the negative bias hypothesis and the emotional processing theory.

Emotional arousal modulation of right temporoparietal cortex in depression depends on parental depression status in women: first evidence

BACKGROUND

Structural and Electroencephalography (EEG) abnormalities in right temporoparietal cortex have been associated with family history of depression (FH). Here we investigate if functional abnormalities in this area, indexed by attenuated responses to emotionally arousing stimuli, are also family-history-dependent.

METHODS

Neuromagnetic activity for emotional and neutral complex scenes was recorded by Magnetoencephalography (MEG) in 20 depressed patients without, 8 depressed patients with FH, and 15 healthy controls. Emotion-sensitive neuronal steady state responses were cortical source localized and tested for group-by-emotion interactions.

RESULTS

The group-by-emotion interaction (F(4, 80)=4.4, p=0.004) was explained by a significant modulation of right temporoparietal cortex activity by emotional arousal in controls and patients without FH. This effect was reduced in FH positive patients. The difference between patient groups remained when clinical variables such as symptom severity were accounted for.

LIMITATIONS

All patients were medicated, but differences between patient groups remained after accounting for medication dosage. Further, the sample size was limited, but data-driven resampling statistics showed the robustness of our effects. Finally, the sample consists of female patients only and we cannot generalize our results to male samples.

CONCLUSIONS

Patients with FH show impaired recruitment of attention-relevant cortical circuitry by emotional stimuli. The neuroanatomical locus of this effect accords with previous reports on structural abnormalities and electrophysiological deficits at rest in individuals with FH. Our results speak to the relevance of right temporoparietal dysfunction in emotional information processing as a potential endophenotype for depression with FH.

Threat/reward-sensitivity and hypomanic-personality modulate cognitive-control and attentional neural processes to emotional stimuli

Temperamental-traits (e.g. threat/reward-sensitivity) are found to modulate cognitive-control and attentional-processes. Yet, it is unclear exactly how these traits interact with emotional-stimuli in the modulation of cognitive-control, as reflected by the N2 event-related potential (ERP), and attentional-processes, as reflected by the P2 and P3 ERPs. Here in an ERP emotional-Go/NoGo task, 36 participants were instructed to inhibit their response to Fearful- and Happy-faces. Individual-differences in threat-sensitivity, reward-sensitivity and hypomanic-personality were assessed through self-report. Hypomanic-personality was assessed, given its relationship with reward-sensitivity and relevance to mood-disorder symptoms. Concerning cognitive-control, individuals with elevated threat-sensitivity displayed more-negative N2s to Happy-NoGo (relative to Fearful-NoGo) faces, whereas both individuals with elevated reward-sensitivity and hypomanic-personality displayed more-negative N2s to Fearful-NoGo (relative to Happy-NoGo) faces. Accordingly, when cognitive-control is required (during Go/NoGo), a mismatch between one's temperament and the valence of the NoGo-stimulus elevates detection of the need for cognitive-control. Conversely, the modulation of attentional-processing was specific to threat-sensitivity, as there was no relationship between either reward-sensitivity or hypomanic-personality and attentional-processing. Elevated threat-sensitivity was associated with enhanced early (P2s) and later (P3s) attentional-processing to Fearful-NoGo (relative to Happy-NoGo) faces. These latter findings support the negative attentional-bias model relating elevated threat-sensitivity with attentional-biases toward negative-stimuli and away from positive-stimuli.

Familial risk for distress and fear disorders and emotional reactivity in adolescence: an event-related potential investigation

BACKGROUND

The late positive potential (LPP) is an event-related potential component that is sensitive to the motivational salience of stimuli. Children with a parental history of depression, an indicator of risk, have been found to exhibit an attenuated LPP to emotional stimuli. Research on depressive and anxiety disorders has organized these conditions into two empirical classes: distress and fear disorders. The present study examined whether parental history of distress and fear disorders was associated with the LPP to emotional stimuli in a large sample of adolescent girls.

METHOD

The sample of 550 girls (ages 13.5-15.5 years) with no lifetime history of depression completed an emotional picture-viewing task and the LPP was measured in response to neutral, pleasant and unpleasant pictures. Parental lifetime history of psychopathology was determined via a semi-structured diagnostic interview with a biological parent, and confirmatory factor analysis was used to model distress and fear dimensions.

RESULTS

Parental distress risk was associated with an attenuated LPP to all stimuli. In contrast, parental fear risk was associated with an enhanced LPP to unpleasant pictures but was unrelated to the LPP to neutral and pleasant pictures. Furthermore, these results were independent of the adolescent girls' current depression and anxiety symptoms and pubertal status.

CONCLUSIONS

The present study demonstrates that familial risk for distress and fear disorders may have unique profiles in terms of electrocortical measures of emotional information processing. This study is also one of the first to investigate emotional/motivational processes underlying the distress and fear disorder dimensions.