Long-term affective and non-affective brain alterations across three generations following the genocide in Cambodia

The literature has largely indicated that trauma can lead to post-traumatic stress disorder (PTSD) and alterations in brain functioning. However, to what extent these alterations remain present decades after the traumatic event, and how the next generations may also suffer from them, remains unclear, especially in a non-Western culture. Uniquely, the present project focused on survivors of the Cambodian genocide and the subsequent two generations to determine whether brain alterations are observable approximately five decades after the traumatic event and in subsequent generations from the same society. Using portable electroencephalography (EEG), we used four experimental tasks-two targeting non-affective processing (i.e., sensory gating, oddball) and two targeting affective processing (i.e., emotion recognition, threat processing). Results indicated that although the rate of PTSD symptoms was similar across generations, the affective reaction to threat for the LPP and FMθ was primarily observed or intensified in the directly affected generation (i.e., G0), regardless of the presence of PTSD. We also observed that G0 exhibited reduced attenuation over standard tones in the oddball task for the N100 and a reduced sensory gating effect on the auditory P200. The present study underscores that affective and non-affective alterations might still be present decades after a trauma, but are not necessarily observable in subsequent generations. Our results also support a dissociation between reported PTSD symptoms and neural alterations.

Insufficiently active individuals' electrocortical and self-reported responses to images of exercise of different types and settings

Most people are insufficiently physically active, and their automatic affective valuations of exercise may be a culprit. Physical activity campaigns use exercise images to encourage physical activity, but whether some types of images elicit more positive automatic affective valuations is unclear. Our study investigated whether the type (sport vs. gym) and setting (indoors vs. outdoors) of exercise images influence insufficiently active individuals' automatic affective valuations of them. Specifically, we recorded electroencephalography from insufficiently active participants while they completed an oddball task wherein exercise images of different settings and types were embedded among positive, neutral, and negative non-exercise images. We extracted the P3b event-related potential component elicited by the exercise images to measure automatic affective valuations of the images. We also recorded participants' self-reported evaluations of the images to measure explicit affective responses. The results of a mixed-effects model indicated that P3b amplitude was larger for outdoors and gym exercise images than indoors and sport exercise images, respectively, but these effects did not depend on whether the images were embedded among positive, neutral, or negative non-exercise images. This suggests the setting and type of exercise images influenced the degree to which they were cognitively processed but not their automatic affective valuation. We also found exercise images were explicitly perceived as neutral-to-positive and their setting and type did not affect this explicit affective evaluation. In summary, for insufficiently active individuals, the setting and type of exercise images were found to influence their cognitive processing but not their automatic or explicit affective evaluation.

Impaired somatosensory habituation in older adults with chronic pain during an affective oddball task

BACKGROUND

Chronic pain is one of the most common health conditions among older adults, triggering various disruptions in information processing across attentional, emotional, and somatosensory domains. However, there is insufficient information about how these aspects interact and their potential contribution to the vulnerability of older adults to chronic pain. This study aimed to investigate potential alterations induced by chronic pain during aging in attentional aspects of tactile stimulation and to observe the influence of affective context.

METHOD

Twenty-six older adults with chronic pain (70.00 ± 5.07 years; 11 males), 28 pain-free older adults (69.57 ± 3.96 years; 13 males) and 27 healthy younger adults (21.48 ± 1.80 years; 14 males) participated in the study. We compared the somatosensory evoked potentials elicited by frequent and deviant stimulation (probability 14%) applied when participants were viewing blocks of pleasant, unpleasant, and neutral images from the International Affective Picture System.

RESULTS

During frequent stimulation, older adults with chronic pain showed higher P50 and N100 amplitudes compared to pain-free older adults and younger individuals. Furthermore, the older group with pain exhibited higher P300 amplitude during emotional contexts compared to neutral scenarios. During deviant stimulation, older adults with chronic pain exhibited higher P50 and N100 amplitudes compared to pain-free older adults but displayed typical age-related flattening during P300.

CONCLUSIONS

These findings indicate that chronic pain leads to a decline in the ability to habituate to non-painful irrelevant somatosensory stimuli, especially when it is presented in an emotional context.

SIGNIFICANCE STATEMENT

In the present study, we have observed how older individuals suffering from chronic pain exhibit a decline in the habituation capacity of irrelevant somatosensory information. Furthermore, we have observed how the affective context in which these individuals are situated leads to an exacerbation of this deficit. Enhancing our comprehension of how aging and chronic pain interact to impact somatosensory processing could facilitate the tailoring of novel intervention strategies.

Age-Related Effects on Facial Emotion Recognition in Schoolchildren: An ERP Study

The ability to recognize emotions in others is crucial for social interaction and develops during childhood. We studied the effects of age on emotional facial recognition in schoolchildren using ERP components. Children aged 6, 8, and 10 completed identity, sex, and emotion recognition (happiness, anger, sadness) tasks. The oldest group had the highest accuracy and fastest reaction times. Only the LPP component showed age-related differences, with lower amplitudes in older children. LPP showed higher amplitude during emotion recognition, which may be associated with motivational evaluation. ERP accounted for the temporal dynamics of facial processing, which involve cognitive and emotional processes.

How to elicit a negative bias? Manipulating contrast and saturation with the facial emotion salience task

Introduction

Emotion recognition impairments and a tendency to misclassify neutral faces as negative are common in schizophrenia. A possible explanation for these deficits is aberrant salience attribution. To explore the possibility of salience driven emotion recognition deficits, we implemented a novel facial emotion salience task (FEST).

Methods

Sixty-six healthy participants with variations in psychometric schizotypy completed the FEST. In the FEST, we manipulated physical salience (FEST-1: contrast, FEST-2: saturation) of emotionally salient (positive, i.e., happy and negative, i.e., fearful) and non-salient (neutral) facial expressions.

Results

When salience was high (increased contrast), participants recognized negative facial expressions faster, whereas neutral faces were recognized more slowly and were more frequently misclassified as negative. When salience was low (decreased saturation), positive expressions were recognized more slowly. These measures were not associated with schizotypy in our sample.

Discussion

Our findings show that the match between physical and emotional salience influences emotion recognition and suggest that the FEST is suitable to simulate aberrant salience processing during emotion recognition in healthy participants.

Is misokinesia sensitivity explained by visual attentional orienting? ERP evidence from an emotional oddball task suggests no

Misokinesia is a prevalent condition characterized by strong, negative emotional reactions to the sight of repetitive fidgeting movements in others. Here we present the results of a study designed to explore the relationship between misokinesia sensitivity (MKS) and attentional sensitivity to affectively-valenced visual stimuli. In particular, we asked participants with either high or low levels of MKS to perform an emotional oddball task that included responding to faces that had either angry or happy expressions, while we recorded event-related potentials. We found that there were no significant differences between the two MKS groups in attentional sensitivity to these faces, as indexed by the amplitude of the P300 ERP component they elicited. Importantly, we could not ascribe this null ERP finding to either low statistical power or the idiosyncrasies of our ERP analysis parameters. As such, our findings add to growing evidence that MKS may not be the simple result of heightened attentional orienting responses to visual events, but rather, it may be associated with other aspects of cognitive-affective processing.

Depression Severity, Slow- versus Fast-Wave Neural Activity, and Symptoms of Melancholia

Melancholia is a major and severe subtype of depression, with only limited data regarding its association with neurological phenomena. To extend the current understanding of how particular aspects of melancholia are correlated with brain activity, electroencephalographic data were collected from 100 adults (44 males and 56 females, all aged 18 y or more) and investigated for the association between symptoms of melancholia and the ratios of alpha/beta activity and theta/beta activity at parietal-occipital EEG sites PO1 and PO2. The results indicate differences in these associations according to the depressive status of participants and the particular symptom of melancholia. Depressed participants exhibited meaningfully direct correlations between alpha/beta and theta/beta activity and the feeling that "Others would be better off if I was dead" at PO1, whereas non-depressed participants had significant inverse correlations between theta/beta activity and "Feeling useless and not needed" and "I find it hard to make decisions" at PO1. The results are discussed in terms of the relative levels of fast-wave (beta) versus slow-wave (alpha, theta) activity exhibited by depressed and non-depressed participants in the parietal-occipital region and the cognitive activities that are relevant to that region.

The 3,4-methylenedioxymethamphetamine enhances early visual processing for salient socio-emotional stimuli

The 3,4-methylenedioxymethamphetamine (MDMA) has long been used non-medically, and it is currently under investigation for its potential therapeutic benefits. Both uses may be related to its ability to enhance empathy, sociability, emotional processing and its anxiolytic effects. However, the neural mechanisms underlying these effects, and their specificity to MDMA compared to other stimulants, are not yet fully understood. Here, using electroencephalography (EEG), we investigated the effects of MDMA and a prototypic stimulant, methamphetamine (MA), on early visual processing of socio-emotional stimuli in an oddball emotional faces paradigm. Specifically, we examined whether MDMA or MA enhance the processing of facial expressions, compared to placebo, during the early stages of visual perception. MDMA enhanced an event-related component that is sensitive to detecting faces (N170), specifically for happy and angry expressions compared to neutral faces. MA did not affect this measure, and neither drug altered other components of the response to emotional faces. These findings provide novel insights into the neural mechanisms underlying the effects of MDMA on socio-emotional processing and may have implications for the therapeutic use of MDMA in the treatment of social anxiety and other psychiatric disorders.

The influence of selective attention to specific emotions on the processing of faces as revealed by event-related brain potentials

Event-related potential studies using affective words have indicated that selective attention to valence can increase affective discrimination at early perceptual stages. This effect most likely relies on neural associations between perceptual features of a stimulus and its affective value. Similar to words, emotional expressions in human faces are linked to specific visual elements. Therefore, selectively attending to a given emotion should allow for the preactivation of neural networks coding for the emotion and associated first-order visual elements, leading to enhanced early processing of faces expressing the attended emotion. To investigate this, we employed an expression detection task (N = 65). Fearful, happy, and neutral faces were randomly presented in three blocks while participants were instructed to respond only to one predefined target level of expression in each block. Reaction times were the fastest for happy target faces, which was accompanied by an increased occipital P1 for happy compared with fearful faces. The N170 yielded an arousal effect (emotional > neutral) while both components were not modulated by target status. In contrast, the early posterior negativity (EPN) arousal effect tended to be larger for target compared with nontarget faces. The late positive potential (LPP) revealed large effects of status and expression as well as an interaction driven by an increased LPP specifically for nontarget fearful faces. These findings tentatively indicate that selective attention to facial affect may enhance early emotional processing (EPN) even though further research is needed. Moreover, late controlled processing of facial emotions appears to involve a negativity bias.

Social acquisition context matters: Increased neural responses for native but not nonnative taboo words

This study examined whether the context of acquisition of a word influences its visual recognition and subsequent processing. We utilized taboo words, whose meanings are typically acquired socially, to ensure that differences in processing were based on learned social taboo, rather than proficiency. American English-speaking participants made word/non-word decisions on American taboo (native dialect), British taboo (non-native dialect), positive, neutral, and pseudo- words while EEG was recorded. Taboo words were verified as taboo by both American and British English speakers in an independent norming survey. American taboo words showed a more positive amplitude of the Late Positive Complex (LPC), a neural correlate of emotionality and social processing, compared with British taboo words and all other word categories. Moreover, in an item-wise analysis, LPC amplitudes of American taboo words were positively correlated with their taboo ratings. British taboo words did not show this effect. This indicates that American participants, who had very limited social contact with British English, did not have the same perception of social threat from British taboo words as they had from American taboo words. These results point to the importance of social context of acquisition in establishing social-affective meaning in language.

Proof-of-concept evidence for trimodal simultaneous investigation of human brain function

The link between spatial (where) and temporal (when) aspects of the neural correlates of most psychological phenomena is not clear. Elucidation of this relation, which is crucial to fully understand human brain function, requires integration across multiple brain imaging modalities and cognitive tasks that reliably modulate the engagement of the brain systems of interest. By overcoming the methodological challenges posed by simultaneous recordings, the present report provides proof‐of‐concept evidence for a novel approach using three complementary imaging modalities: functional magnetic resonance imaging (fMRI), event‐related potentials (ERPs), and event‐related optical signals (EROS). Using the emotional oddball task, a paradigm that taps into both cognitive and affective aspects of processing, we show the feasibility of capturing converging and complementary measures of brain function that are not currently attainable using traditional unimodal or other multimodal approaches. This opens up unprecedented possibilities to clarify spatiotemporal integration of brain function.

Non-stationary Group-Level Connectivity Analysis for Enhanced Interpretability of Oddball Tasks

Neural responses of oddball tasks can be used as a physiological biomarker to evaluate the brain potential of information processing under the assumption that the differential contribution of deviant stimuli can be assessed accurately. Nevertheless, the non-stationarity of neural activity causes the brain networks to fluctuate hugely in time, deteriorating the estimation of pairwise synergies. To deal with the time variability of neural responses, we have developed a piecewise multi-subject analysis that is applied over a set of time intervals within the stationary assumption holds. To segment the whole stimulus-locked epoch into multiple temporal windows, we experimented with two approaches for piecewise segmentation of EEG recordings: a fixed time-window, at which the estimates of FC measures fulfill a given confidence level, and variable time-window, which is segmented at the change points of the time-varying classifier performance. Employing the weighted Phase Lock Index as a functional connectivity metric, we have presented the validation in a real-world EEG data, proving the effectiveness of variable time segmentation for connectivity extraction when combined with a supervised thresholding approach. Consequently, we performed a piecewise group-level analysis of electroencephalographic data that deals with non-stationary functional connectivity measures, evaluating more carefully the contribution of a link node-set in discriminating between the labeled oddball responses.

Emotional oddball: A review on memory effects

How do emotional stimuli influence perception, attention, and ultimately memory? This debate at the cross-section of emotion and cognition research has a long tradition. The emotional oddball paradigm (EOP) has frequently been applied to investigate the detection and processing of (emotional) change detection (Schlüter & Bermeitinger, 2017). However, the EOP has also been used to reveal the effects of emotional deviants on memory for serially presented stimuli. In this integrative article, we review the results of 29 experiments published between the years 2000 and 2017. Based on these data, we provide an overview of how the EOP is applied in the context of memory research. We also review and integrate the empirical evidence for memory effects in the EOP (with a special focus on retrograde and anterograde emotion-induced effects) and present theories of emotional memory as well as their fit with the results obtained by the EOP. Directions for future research are presented that would help to address important issues of the current debate around emotion-induced memory effects.

Integration of spatio-temporal dynamics in emotion-cognition interactions: A simultaneous fMRI-ERP investigation using the emotional oddball task

Although a large corpus of evidence has identified brain regions and networks involved in emotion-cognition interactions, it remains unclear how spatial and temporal dynamics of the mechanisms by which emotion interfaces with cognition are integrated. Capitalizing on multi-modal brain imaging approaches, we used simultaneous functional magnetic resonance imaging (fMRI) and event-related potential (ERP) recordings, to investigate the link between spatial and temporal aspects of processing in an emotional oddball task, and in relation to personality measures reflecting basic affective responses and emotion control. First, fMRI captured expected dorso-ventral dissociations, with greater response to targets in regions of dorsal brain networks (e.g., dorsolateral prefrontal cortex) and to emotional distracters in regions of ventral networks (e.g., ventrolateral prefrontal cortex, vlPFC). Also, ERP responses to targets were associated with a prominent P300, and responses to distracters with the late positive potential (LPP). Second, providing evidence for spatio-temporal integration of brain signals, ERP-informed fMRI analyses showed a link between LPP amplitude at parietal electrodes and the fMRI signal in the vlPFC, to emotional distraction. Third, regarding the link to personality measures, increased emotional arousability and attentional impulsiveness was associated with greater LPP differences between negative distracters and targets and enhanced response to negative distracters in the amygdala, respectively. Furthermore, we identified opposing relations between responses to emotional distraction and individual scores for cognitive reappraisal and self-control impulsiveness in posterior vlPFC. This suggests a greater engagement of this region in participants with reduced tendencies to employ reappraisal as a coping strategy and those with reduced ability to control impulsive responses during emotional distraction. Together, supporting the feasibility of integrating multi-dimensional approaches to clarify neural mechanisms of emotion-cognition interactions, these results point to convergence and complementarity between measures that differentially capture spatio-temporal dynamics of brain activity, and their associations with measures of individual differences in affective responses and control.

An intra-individual approach for detecting evaluation with event-related potentials

The P3-based concealed information test (CIT) is an accurate indirect measure of non-evaluative memories (e.g., knowledge of an incriminating item). Less clear and established, however, is the accuracy of indirect measures that rely on the P3-like late positive potentials (LPPs) in discriminating evaluative (e.g., pleasant or unpleasant) memories. Using an LPP-based evaluative oddball paradigm in which participants were truthful on half of the trials about their evaluation toward pictures and concealed their evaluation on the other half of trials toward pictures, we applied an intra-individual Bayesian scheme to classify whether participants' evaluations were congruent or incongruent with a preceding context. LPPs were predictably larger to evaluatively incongruent than congruent pictures, and this LPP effect was reduced during misreporting presumably because of enhanced cognitive load. Notably, across two experiments the sensitivity (80%) was respectable during truth telling, but poor during concealment (sensitivity = 35%). Taken together, these data suggest that indirect measures such as the LPP-based evaluative oddball may be useful for detecting individual evaluation, but more work is warranted that explores conditions under which concealment of evaluation may be more accurately assessed.

Distraction and facilitation: The impact of emotional sounds in an emoji oddball task

Emotional stimuli are argued to capture attention and consume attentional resources differently depending on their emotional content. The present study investigates the impact of the automatic detection of unexpected and to-be-ignored emotional stimuli on human behavioral responses, and aims to unravel the differences in distraction between two negative emotional stimuli: sadness and anger. Forty participants (M_age = 25.5 years) performed a visual categorization task where angry and sad emoji faces were presented after either a standard neutral tone (in 80% of trials) or a deviant emotional sound (tone changing in pitch; sad or angry sound in 10% of trials each) that was to be ignored. Deviant trials were either congruent (e.g., sad sound-sad face) or incongruent (e.g., angry sound-sad face). Although the stimuli presented to the participants were brief and to-be-ignored, results indicate that participants were significantly more distracted by sad compared to angry stimuli (seen as prolonged response times). Findings are discussed with reference to the nature of the two negative emotions.