Unpleasant Images Research Articles

Transcutaneous Auricular Vagus Nerve Stimulation Enhances Emotional Processing and Long-Term Recognition Memory: Electrophysiological Evidence Across Two Studies.

Recently, we found that continuous transcutaneous auricular vagus nerve stimulation (taVNS) facilitates the encoding and later recollection of emotionally relevant information, as indicated by differences in the late positive potential (LPP), memory performance, and late ERP Old/New effect. Here, we aimed to conceptually replicate and extend these findings by investigating the effects of different time-dependent taVNS stimulation protocols. In Study 1, an identical paradigm to our previous study was employed with interval stimulation (30-s on/off). Participants viewed unpleasant and neutral scenes on two consecutive days while receiving taVNS or sham stimulation and completed a recognition test 1 week later. Replicating previous results, unpleasant images encoded under taVNS, compared to sham stimulation, elicited larger amplitudes in an earlier window of the LPP during encoding, as well as more pronounced late Old/New differences. However, no effects of taVNS on memory performance were found. In Study 2, we followed up on these findings by synchronizing the stimulation cycle with image presentation to determine the taVNS effects for images encoded during the on and off cycles. We could replicate the enhancing effects of taVNS on brain potentials (early LPP and late Old/New differences) and found that taVNS improved recollection-based memory performance for both unpleasant and neutral images, independently of the stimulation cycle. Overall, our results suggest that taVNS increases electrophysiological correlates of emotional encoding and retrieval in a time-independent manner, substantiating the vagus nerve's role in emotional processing and memory formation, opening new venues for improving mnemonic processes in both clinical and non-clinical populations.

Does Trauma Change the Way Individuals with Post-Traumatic Stress Disorder (PTSD) Deal with Positive Stimuli?

Post-Traumatic Stress Disorder (PTSD) is a highly prevalent disorder and a highly debilitating condition. Although current theories focused on depressed mood and intrusion as critical dimensions, the mechanism through which depression increases the risk of PTSD remains unclear. Research usually concentrates on the hyperactive negative valence system (NVS) (e.g., increased fear and threat responses), but some evidence suggests a significant role for the hypoactive positive valence system (PVS) (e.g., less neural activation towards rewards). The main aim of the present research was to investigate whether probable PTSD leads to a different evaluation of the implicit processing in a refugee's sample. Ratings of arousal, dominance, and valence from 60 International Affective Picture System (IAPS) pictures (positive, neutral, and negative) were collected from 42 individuals with probable PTSD, and a group of 26 trauma-exposed individuals (Mage = 28.49 years, SD = ±7.78). ANOVA results revealed a main group effect (η2p = 0.379) on arousal, dominance, valence dimensions, and pictures' categories (η2p = 0.620), confirming evidence according to which PTSD origins a state of maladaptive hyperarousal and troubles the regulation of emotions, and not supporting the view that such difficulties arise only with negative stimuli. Participants with probable PTSD deemed negative stimuli as more threatening than they really are, reacting to unpleasant images with greater negative emotionality (i.e., enhanced arousal and lower valence ratings) compared with individuals without PTSD. Moreover, they rated positive stimuli as less pleasant. Furthermore, arousal ratings were negatively correlated with valence (r = -0.709, p < 0.01) indicating that pictures with high arousal (negative) were associated with lower valence. Our findings supported evidence according to which PTSD caused a constant state of hyperarousal and difficulties in regulating emotions facing environmental stimuli. Positive stimuli are considered less pleasant, and this inhibits from completely benefiting from them. Our study provides evidence for a differential and potentially complementary involvement of NVS and PVS in PTSD development. Intervention for PTSD may, thus, target both negative and positive valence processing.

Event-related potentials and presaccadic activity in response to affective stimuli in participants with obsessive-compulsive disorder

Event-related potentials and presaccadic activity in response to affective stimuli in participants with obsessive-compulsive disorder

The moderating role of the late positive potential in the link between attachment anxiety and emotion regulation difficulties.

Understanding how adults experience and regulate their emotions is strongly linked to attachment orientations. Numerous studies indicate emotional regulation difficulties in both attachment avoidance and anxiety. Additionally, emotional Event-Related Potentials (ERPs), such as the Late Positive Potential (LPP), reveal the process of emotional information at the cerebral level, and thus, LPP is commonly used in studies examining emotion regulation processes. For instance, when individuals are asked to use cognitive strategies to increase, maintain, or decrease their emotional responses to stimuli, changes in LPP amplitude can reflect the effectiveness of these regulation strategies. However, little is known about the potential moderating effect of the LPP during the implementation of emotional regulation strategies in the relationship between attachment dimensions and emotional dysregulation. To address this oversight, the purpose of the present study was to examine the association between both dimensions of attachment, anxiety and avoidance, and emotional dysregulation, as well as the moderating role of the LPP during the induced implementation of cognitive reappraisal. Brain activity was recorded using EEG from n = 63 adults while they performed a task in which they were instructed to either reappraise or suppress emotions elicited by unpleasant images. To assess the associations between LPP, emotional dysregulation, and attachment orientations, the Difficulties in Emotion Regulation Scale Spanish version (DERS-E) and the Experiences in Close Relationships questionnaire (ECR-12) were used. Interestingly, we found that greater LPP amplitudes during reappraisal implementation intensified the association between attachment anxiety and emotional regulation difficulties. Conversely, this relationship was non-significant under lower levels of LPP amplitude-Providing supporting evidence for the moderating role of LPP. Our results highlight how attachment anxiety can influence the ability to regulate emotions. This study provides new insights into how variations in LPP contribute to the effectiveness of emotion regulation strategies.

Negative auditory hallucinations are associated with increased activation of the defensive motivational system in schizophrenia

Negative auditory hallucinations are associated with increased activation of the defensive motivational system in schizophrenia

Revealing the distinct impacts of effectiveness recognition and memory retention on the transfer of creative cognitive reappraisal

ABSTRACT Previous research has shown that creative cognitive reappraisal is highly effective in regulating negative emotions. We conducted three experiments to explore its transferability. In Experiment 1, we observed that free recall performance was better for creative reappraisal compared to non-creative reappraisal. Memory retention of reappraisals was associated with creativity ratings, but not with perceived effectiveness ratings. In Experiment 2, participants generated reappraisals for newly introduced unpleasant images before (pre-session) and after (post-session) exposure to creative reappraisal, non-creative reappraisal, and descriptive control interpretation. Results showed increased reflective effectiveness of self-generated reappraisals in the post-session. The level of creativity of the self-generated reappraisals was associated with differences in perceived effectiveness between creative and non-creative exposed reappraisals. In Experiment 3, we investigated how two processing approaches (effectiveness-oriented vs. memory-oriented) influenced the transferability of creative reappraisal. We observed creativity levels of self-generated reappraisals increased in both conditions. The reflective effectiveness of the self-generated reappraisals tended to increase only in the effectiveness-oriented processing condition. Our findings demonstrate that recognising the effectiveness of creative reappraisal plays a crucial role in its transfer across different situations.

Assessing motivational biases in brain and behavior: Event-related potential and response time concomitants of the approach-avoidance task.

The approach-avoidance task (AAT) is designed to measure implicit motivated action biases instantiated by emotional stimuli and alterations in such biases that drive psychiatric disorder. While some research has measured AAT event-related potential (ERP) correlates to establish bias sensitivity even at a neural level, a lack of work with unpleasant, pleasant, and neutral stimuli together and a common focus on psychiatric disorder-matched (rather than generally emotional) content limits conclusions that can be drawn. Thus, current work extends the AAT literature by testing ERP modulations across normatively unpleasant, pleasant, and neutral conditions; and supporting the task's use as an individual difference assessment, it also provides data on AAT reliability and initially explores anxiety-related effects when stimuli are not disorder-matched. In 38 participants including 19 anxiety treatment-seeking individuals, 32 sensor electroencephalography revealed robust N100, N200, and late positive potential (LPP) ERP components and bias-consistent modulations for unpleasant images (reduced N200s on unpleasant push relative to pull trials; enhanced LPP for unpleasant compared to neutral trials). Meanwhile, modulations were less consistent with emotion-driven bias for other conditions-that is, LPPs were enhanced but N200 was not modulated for pleasant images, and for neutral images, N200 was unexpectedly enhanced on push compared to pull trials. Following these analyses, reliability tests revealed excellent raw ERP reliabilities but lower reliabilities for modulation scores, and comparing treatment- to non-treatment-seeking groups showed no preliminary indication of ERP modulation changes when stimuli are not personally relevant. How these findings together inform understanding of AAT as a measure of bias is discussed.

The Legacy of War: How Trauma Affects Empathy in Future Generations

Empathy towards out-groups is essential for maintaining peaceful and favourable relationships with other nations. The experience of war can damage the empathy between two nations. New developments in trauma studies reveal that the impacts of war can be inherited. This study investigated whether war experiences impact future generations' ability to empathize with out-groups with negative experiences. In this fMRI study, 30 healthy participants (15 individuals with a family history of trauma from the Iran and Iraq wars and 15 controls) viewed video clips of Iraqi, Afghan, and Iranian patients displaying facial expressions of pain. Next, they were asked to rate the level of distress shown. Participants from families not affected by war exhibit more empathy-related brain activity when watching videos of Iraqi patients. The affected regions are the corpus callosum, limbic and hippocampal areas, and, partially, the prefrontal lobe. Participants from the main group showed increased activity in the occipital lobe when watching Iraqi pain and insula regions when viewing video clips of the suffering of Irani patients, indicating a stronger response to unpleasant images and a preference for their group. The research found that war trauma negatively affects the next generation's empathetic feelings toward hostile ethnic groups.

Effects of Mindfulness Training on Emotional Reactivity

Abstract Background: Mindfulness, rooted in ancient practices, is being studied for its impact on emotion regulation and mental well-being. Objective: The study aimed to investigate whether there would be a significant change in reactivity to emotional stimuli following mindfulness-based training. This was assessed through two measures: a) self-perception of valence and arousal in evaluating images, and b) postural sway while visualizing these images. Methods: Fifty graduate students, divided into a training and a control group, participated in the study. They went through two data collection events, with the same collection procedure, and mindfulness-based training was offered to the training group between the collection events. These individuals were presented with pleasant, unpleasant, and neutral images and data was collected regarding the postural sway and individual evaluation of these images for valence (pleasant - unpleasant) and arousal (high - low). Data were compared using the repeated measures ANOVA statistical test. Results: The results pointed to a change in the postural pattern of the training group for the neutral images, indicating a more flexible posture, with greater exploration of the space in the standing position, and changes in the perception of arousal for unpleasant images, with a significant reduction in the mobilization of individuals who underwent the training. Conclusion: These are important results for the advancement of research, since the physiological measures are not subject to conscious manipulation by the participant. Keywords: Mindfulness, Emotional reactivity, Postural sway.

Unconscious Activation of Negative Emotional Memories Increases Pain Unpleasantness.

The influence of unconscious emotional processes on pain remains poorly understood. The present study tested whether cues to forgotten unpleasant images might amplify pain (i.e., in the absence of conscious recall). Seventy-two healthy female adults (19 to 34 years) performed an adapted Think/No-think paradigm (T/NT) using 72 combinations of neutral face images (cues) paired with 36 neutral and 36 unpleasant images. After completion of the T/NT task, cues associated with forgotten neutral or unpleasant images were identified. Cues to either neutral or unpleasant images from the NT condition were then presented in randomized order while participants received intermediate-level thermal pain stimulation on the left hand. Ratings of both pain intensity and unpleasantness were acquired after each trial. Mean pain unpleasantness ratings were greater during presentation of cues to forgotten negative versus neutral images (5.52 [SD = 2.06] versus 5.23 [SD = 2.10]; p = .02). This pattern was also present when comparing cues to remembered negative versus neutral images (5.62 [SD = 1.94] versus 5.04 [SD = 1.90]; p < .001). Mean pain intensity ratings were higher for cues to negative versus neutral images when remembered (5.48 [SD = 1.79] versus 5.00 [SD = 1.69]; p < .001), but not when forgotten (5.27 [SD = 1.96] versus 5.16 [SD = 1.93]; p = .30). Using an adapted T/NT-Pain paradigm, this study demonstrated that cues to nonrecallable (but potentially unconsciously activated) negative emotional memories amplify pain unpleasantness, similar to known effects of conscious negative emotions.

Emergence of Emotion Selectivity in Deep Neural Networks Trained to Recognize Visual Objects.

Recent neuroimaging studies have shown that the visual cortex plays an important role in representing the affective significance of visual input. The origin of these affect-specific visual representations is debated: they are intrinsic to the visual system versus they arise through reentry from frontal emotion processing structures such as the amygdala. We examined this problem by combining convolutional neural network (CNN) models of the human ventral visual cortex pre-trained on ImageNet with two datasets of affective images. Our results show that in all layers of the CNN models, there were artificial neurons that responded consistently and selectively to neutral, pleasant, or unpleasant images and lesioning these neurons by setting their output to zero or enhancing these neurons by increasing their gain led to decreased or increased emotion recognition performance respectively. These results support the idea that the visual system may have the intrinsic ability to represent the affective significance of visual input and suggest that CNNs offer a fruitful platform for testing neuroscientific theories.

Electrocortical Correlates of Emotion Processing and Resilience in Individuals with Adverse Childhood Experiences

Childhood trauma is associated with poor health outcomes in adulthood, largely due to the impact of chronic stress on the body. Fortunately, there are certain protective characteristics, such as constraint (i.e., impulse control, inhibition, and avoidance of unconventional behavior and risk) and cognitive reappraisal (i.e., reframing circumstances in a more positive light). In the present study, we investigated the interaction between childhood trauma, resilience, and neural correlates of emotion processing. Participants responded to survey questions regarding childhood trauma and resilient characteristics. They were later invited to passively view neutral, unpleasant, and pleasant images while their brain activity was recorded via electroencephalography (EEG). We analyzed two event-related potential (ERP) components of interest: the Early Posterior Negativity (EPN) and Late Positive Potential (LPP). We found that childhood trauma was associated with decreased constraint and reduced sensitivity to unpleasant images (i.e., decreased LPP amplitude differences between neutral and unpleasant images as compared to controls). Further, constraint predicted increased sensitivity to pleasant images. In a hierarchical linear regression analysis, we found that constraint moderated the relation between childhood trauma and emotion processing, such that it predicted increased sensitivity to unpleasant images for adults with childhood trauma in particular. Childhood trauma and cognitive reappraisal independently predicted decreased sensitivity to unpleasant images, (i.e., decreased LPP amplitude differences between neutral and unpleasant images). Our findings suggest that childhood trauma and resilient characteristics independently and interactively influence emotion processing.

The impact of culture on Emotion Suppression: Insights from an Electrophysiological Study of Emotion Regulation in Japan

The impact of culture on Emotion Suppression: Insights from an Electrophysiological Study of Emotion Regulation in Japan

The impact of attention bias modification training on behavioral and physiological responses

The impact of attention bias modification training on behavioral and physiological responses

Emotional processing deficits in individuals with problematic pornography use: Unpleasant bias and pleasant blunting.

A growing body of evidence indicates a connection between emotional processes and the emergence and progression of addiction. However, scant research has examined the involvement of emotional processing within the framework of problematic pornography use (PPU). This study aimed to examine the electrophysiological and subjective differences in emotional processing between male individuals with PPU and healthy controls (HCs) following exposure to everyday affective images. Event-related potentials (ERPs) were recorded from 42 PPU participants (mean age = 20.14 years, SD = 1.35) and 45 HCs (mean age = 20.04 years, SD = 1.45) during an oddball task, in which unpleasant, pleasant, and neutral images were presented as deviant stimuli, while a neutral kettle image served as the standard stimulus. The Self-Assessment Manikin (SAM) was employed to assess participants' subjective experience on the dimensions of valence and arousal. Regarding subjective measures of emotion, individuals with PPU reported lower valence ratings for unpleasant images compared to HCs. In terms of electrophysiological measures of emotion, PPU participants reported larger P2 amplitudes for unpleasant pictures compared to both pleasant and neutral pictures. Moreover, HCs showed enhanced P3 amplitudes in response to pleasant images compared to neutral images, whereas this effect was not observed in PPU participants. These findings indicate that individuals with PPU may display deficits in emotional processing characterized by enhanced responsiveness to negative stimuli and attenuated responsiveness to positive stimuli. The heightened sensitivity to negative stimuli may contribute to the inclination of individuals with PPU to engage in pornography as a coping mechanism for stress regulation. Conversely, their diminished sensitivity to positive stimuli presents a challenge in seeking alternative natural rewards to counter potentially addictive behaviors.

Clinical high risk for psychosis syndrome is associated with reduced neural responding to unpleasant images.

Deficits in emotion processing are core features of psychotic disorders. Electrophysiology research in schizophrenia suggests deficits in sustained engagement with emotional content (indexed by the late positive potential [LPP]) may contribute to emotion processing impairments. Despite similar behavioral emotion processing dysfunction in those at clinical high risk (CHR) for psychosis, limited research has examined neural mechanisms of impaired emotion processing in the high-risk period, where research can inform risk models. To examine mechanisms of emotion processing deficits in those at CHR for psychosis, the present study used a passive viewing task to elicit the LPP in response to emotionally engaging and neutral stimuli in 28 CHR and 32 control participants (60% female). Relative to controls, CHR participants showed reduced LPP amplitude when viewing unpleasant images (d = 0.75, p = .005) but similar LPP amplitude in response to both neutral (d = 0.35, p = .19) and pleasant images (d = 0.31, p = .24). This pattern suggests that individuals at CHR for psychosis exhibit a deficit in sustained engagement with unpleasant stimuli. Clinical and trait questionnaires were administered to examine potential exploratory explanations for group differences in LPP amplitude. Consistent with evidence suggesting LPP amplitude reflects engagement of approach/avoidance motivational systems, greater LPP amplitude was associated with greater trait-level behavioral avoidance in control participants (r = .42, p = .032) but not CHR participants (r = -.21, p = .40). Together, the present research is consistent with LPP studies in psychosis and implicates reduced sustained engagement with emotional content in the high-risk period. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Impact of negative links on the structural balance of brain functional network during emotion processing

Activation of specific brain areas and synchrony between them has a major role in process of emotions. Nevertheless, impact of anti-synchrony (negative links) in this process still requires to be understood. In this study, we hypothesized that quantity and topology of negative links could influence a network stability by changing of quality of its triadic associations. Therefore, a group of healthy participants were exposed to pleasant and unpleasant images while their brain responses were recorded. Subsequently, functional connectivity networks were estimated and quantity of negative links, balanced and imbalanced triads, tendency to make negative hubs, and balance energy levels of two conditions were compared. The findings indicated that perception of pleasant stimuli was associated with higher amount of negative links with a lower tendency to make a hub in theta band; while the opposite scenario was observed in beta band. It was accompanied with smaller number of imbalanced triads and more stable network in theta band, and smaller number of balanced triads and less stable network in beta band. The findings highlighted that inter regional communications require less changes to receive new information from unpleasant stimuli, although by decrement in beta band stability prepares the network for the upcoming events.

Altered emotional response pattern related to complex trauma in patients with borderline personality disorder.

This work aims to demonstrate, through the International Affective Picture System (IAPS) responses, an altered emotional pattern in borderline personality disorder (BPD) patients and to find a specific emotional response pattern by understanding their relationship with traumatic experiences and attachment bonds towards their primary caregivers. A total of 50 BPD patients and 39 control patients were evaluated using the IAPS, and its assessment was carried out through the Self-Assessment Manikin (SAM). Paternal and maternal attachment bonds as well as traumatic experiences in BPD patients were evaluated. Statistical associations were analysed in the different variables. Significant differences between BPD and control patients were found in all emotional response components for pleasant, unpleasant and neutral images (p < .01), with one exception, the arousal in pleasant images. Patients' experience of traumatic experiences was positively related to scores on the happiness component of pleasant imagery (p = .057) and on the arousal component of unpleasant imagery (p = .058). Poorer maternal bonding in BPD patients was significantly related to lower scores on happiness (p < .01) and dominance (p < .05) components of pleasant imagery and all emotional response components for unpleasant imagery (p < .01). The results of the study confirm an impaired emotional response pattern in patients with borderline personality disorder (BPD), showing an emotional response to pleasant images similar to that of depression, while the pattern found to unpleasant images could be related to the complex trauma observed in these patients, which includes PTSD experiences such as sexual abuse and attachment trauma experiences.

Effect of Taste-Induced Mood on ERP and Emotional Assessment of Images.

Tastes affect the body and our emotions. We used tasteless, sweet, and bitter stimuli to induce participants' moods, and we examined the effect of mood on an emotional evaluation of pleasant, neutral, and unpleasant images using event-related potentials, N2, N400, and late positive potential (LPP), which reflect emotional evaluation in the brain. The results indicated that mood valence was most positive for sweetness and most negative for bitterness. Moreover, there was no significant mood effect on subjective valence ratings of emotional images. Furthermore, the N2 amplitude, which is related to the early semantic processing of preceding stimuli, was unaffected by the taste induced mood. In contrast, we found that the N400 amplitude, which is related to the mismatch of emotional valence between stimuli, increased significantly for unpleasant images when participants were in a positive rather than negative mood state. Also, the LPP amplitude, which is related to the emotional valence of images, showed only the main effect of the images' emotional valence. The N2's results suggest that the early semantic processing of taste stimuli might have had a negligible impact on emotional evaluation because taste stimuli minimize semantic processing that accompanies mood induction. In contrast, the N400 reflected the effects of the induced mood, and the LPP reflected the impact of the valence of emotional images. The use of taste stimuli to induce mood revealed different brain processing of taste-induced mood effects on emotional evaluation, including N2's involvement in semantic processing, N400's involvement in matching emotions between mood and stimuli, and LPP's involvement in subjective evaluations of stimuli.

Emotional processing and positive affect after acute exercise in healthy older adults.

The well-elucidated improvement of mood immediately after exercise in older adults presumably involves adaptations in emotion-processing brain networks. However, little is known about effects of acute exercise on appetitive and aversive emotion-related network recruitment in older adults. The purpose of this study was to determine the effect of acute exercise, compared to a seated rest control condition, on pleasant and unpleasant emotion-related regional activation in healthy older adults. Functional MRI data were acquired from 32 active older adults during blocked presentations of pleasant, neutral and unpleasant images from the International Affective Pictures System. fMRI data were collected after participants completed 30 min of moderate to vigorous intensity cycling or seated rest, performed in a counterbalanced order across separate days in a within-subject design. The findings suggest three ways that emotional processing in the brain may be different immediately after exercise (relative to immediately after rest): First, reduced demands on emotional regulation during pleasant emotional processing as indicated by lower precuneus activation for pleasant stimuli; second, reduced processing of negative emotional stimuli in visual association areas as indicated by lower activation for unpleasant stimuli in the bilateral fusiform and ITG; third, an increased recruitment in activation associated with regulating/inhibiting unpleasant emotional processing in the bilateral medial superior frontal gyrus (dorsomedial prefrontal cortex), angular gyri, supramarginal gyri, left cerebellar crus I/II and a portion of right dorsolateral prefrontal cortex. Overall, these findings support that acute exercise in active older adults alters activation in key emotional processing and regulating brain regions.