Neural mapping of guilt: a quantitative meta-analysis of functional imaging studies

The neural correlates of guilt highlight preclinical manifestations between bipolar and major depressive disorders

BACKGROUND

Over 25 % of bipolar disorder (BD) patients are misdiagnosed with major depressive disorder (MDD). An urgent need exists for a biomarker to differentiate BD from MDD. Various manifestations and intensities of maladaptive guilt processing might uniquely contribute to the pathogenesis of BD compared to MDD.

METHOD

This study adopted a first-person perspective guilt-provoking functional magnetic resonance imaging (fMRI) task, respectively induced by painful and ambiguous scenarios in 111 individuals: 35 with remitted MDD, 38 with remitted bipolar I disorder (BD-I), and 38 matched controls.

RESULTS

A significant interaction between group and sense of agency in predicting guilt ratings for ambiguous, rather than painful, scenarios. The association between sense of agency and guilt was significant in MDD but not in BD-I patients or controls. Activation in the dorsomedial prefrontal cortex (dmPFC), pregenual anterior cingulate cortex (pgACC), and right inferior parietal lobule (IPL) was higher in BD-I than MDD subjects in response to ambiguous scenarios, whereas these were comparable to painful ones. The correlation between guilt ratings and activation in the dorsal anterior cingulate cortex (dACC) to ambiguous scenarios was significant in MDD, but not in BD-I or controls. The results of the multivariate pattern classification analysis showed that in the ambiguous scenarios, the accuracy of using brain activation patterns in the dmPFC, pgACC, and IPL to distinguish between participants with MDD and BD-I was 70.0 %, 71.5 %, and 68.7 %, respectively. An additional test of the classification model, employing a combined mask of the three ROIs to distinguish between the two mood disorders in ambiguous scenarios, achieved an accuracy of 78.6 % and an AUC value of 0.84.

CONCLUSIONS

Subjective reports and neural correlates of guilt in ambiguous social situations, as well as a sense of agency, could provide to be a potential biomarker to help distinguish between BD-I and MDD even in the remitted stage.

Graph analysis of guilt processing network highlights links with subclinical anxiety and self-blame

Maladaptive forms of guilt, such as excessive self-blame, are common characteristics of anxiety and depressive disorders. The underlying network consists of multiple associative areas, including the superior anterior temporal lobe (sATL), underlying the conceptual representations of social meaning, and fronto-subcortical areas involved in the affective dimension of guilt. Nevertheless, despite understanding the circuitry's anatomy, network-level changes related to subclinical anxiety and self-blaming behaviour have not been depicted. To fill this gap, we used graph theory analyses on a resting-state functional and diffusion-weighted magnetic resonance imaging dataset of 78 healthy adults (20 females, 20-35 years old). Within the guilt network, we found increased functional contributions of the left sATL for individuals with higher self-blaming, while functional isolation of the left pars opercularis and insula was related to higher trait anxiety. Trait anxiety was also linked to the structural network's mean clustering coefficient, with the circuitry's architecture favouring increased local information processing in individuals with increased anxiety levels, however, only when a highly specific subset of connections was considered. Previous research suggests that aberrant interactions between conceptual (sATL) and affective (fronto-limbic) regions underlie maladaptive guilt, and the current results align and expand on this theory by detailing network changes associated with self-blame and trait anxiety.

Enhancing Conceptual Clarity regarding the Construct of Moral Injury

BACKGROUND

The construct of "moral injury" is used widely in the research literature and media to broadly describe the impact of events involving perceived violations of one's sense of right and wrong (herein referred to as "potentially morally injurious events" [PMIEs]).

SUMMARY

In this theoretical review, we provided a brief overview of the "moral injury" construct and its limitations including the lack of consensus-drawn boundaries and operational definitions to guide hypothesis-driven research. We discussed whether this construct can be reliably distinguished from established psychiatric diagnoses and psychological constructs and the inherent challenges in separating or classifying the impact of high-magnitude stressful life events that likely form the majority of PMIEs. Assessments that purportedly measure "moral injury" are reviewed and limitations are discussed such as shared measurement variance with established psychological instruments.

KEY MESSAGES

We identified conceptual strategies for investigating behavioral and neurobiological features of PMIEs that could be used to inform the field of traumatic stress. We concluded that the construct of "moral injury" may provide an interpretive framework for positing why someone may be beset by guilt, shame, and/or rage whereas existing psychiatric diagnoses such as post-traumatic stress disorder and depression provide comprehensive descriptions regarding what someone might experience following extremely stressful events. We proposed directions to better clarify the boundaries of "moral injury" versus established psychiatric categories that could be used to enhance the conceptualization and assessment of this construct.

Posttraumatic survivor guilt is associated with white matter microstructure alterations

BACKGROUND

Military veterans with posttraumatic stress disorder (PTSD) commonly experience posttraumatic guilt. Guilt over commission or omission evolves when responsibility is assumed for an unfortunate outcome (e.g., the death of a fellow combatant). Survivor guilt is a state of intense emotional distress experienced by the weight of knowing that one survived while others did not.

METHODS

This study of the Translational Research Center for TBI and Stress Disorders (TRACTS) analyzed structural and diffusion-weighted magnetic resonance imaging data from 132 male Iraq/Afghanistan veterans with PTSD. The Clinician-Administered PTSD Scale for DSM-IV (CAPS-IV) was employed to classify guilt. Thirty (22.7 %) veterans experienced guilt over acts of commission or omission, 34 (25.8 %) experienced survivor guilt, and 68 (51.5 %) had no posttraumatic guilt. White matter microstructure (fractional anisotropy, FA), cortical thickness, and cortical volume were compared between veterans with guilt over acts of commission or omission, veterans with survivor guilt, and veterans without guilt.

RESULTS

Veterans with survivor guilt had significantly lower white matter FA compared to veterans who did not experience guilt (p < .001), affecting several regions of major white matter fiber bundles. There were no significant differences in white matter FA, cortical thickness, or volumes between veterans with guilt over acts of commission or omission and veterans without guilt (p > .050).

LIMITATIONS

This cross-sectional study with exclusively male veterans precludes inferences of causality between the studied variables and generalizability to the larger veteran population that includes women.

CONCLUSION

Survivor guilt may be a particularly impactful form of posttraumatic guilt that requires specific treatment efforts targeting brain health.

P3a amplitude to trauma-related stimuli reduced after successful trauma-focused PTSD treatment

An elevated P3a amplitude to trauma-related stimuli is strongly associated with posttraumatic stress disorder (PTSD), yet little is known about whether this response to trauma-related stimuli is affected by treatment that decreases PTSD symptoms. As an analysis of secondary outcome measures from a randomized controlled trial, we investigated the latency and amplitude changes of the P3a in responses in a three-condition oddball visual task that included trauma-related (combat scenes) and trauma-unrelated (threatening animals) distractors. Fifty-five U.S. veterans diagnosed with combat-related PTSD were randomized to receive either active or sham repetitive transcranial magnetic stimulation (rTMS). All received cognitive processing therapy, CPT+A, which requires a written account of the index trauma. They were tested before and 6 months after protocol completion. P3a amplitude and response time decreases were driven largely by the changes in the responses to the trauma-related stimuli, and this decrease correlated to the decrease in PTSD symptoms. The amplitude changes were greater in those who received rTMS + CPT than in those who received sham rTMS + CPT, suggesting that rTMS plays beneficial role in reducing arousal and threat bias, which may allow for more effective engagement in trauma-focused PTSD treatment.

Mortality salience enhances neural activities related to guilt and shame when recalling the past

Mortality salience (MS) influences cognition and behavior. However, its effect on emotion (especially moral emotions) and the underlying neural correlates are unclear. We investigated how MS priming modulated guilt and shame in a later recall task using functional magnetic resonance imaging. The behavioral results indicated that MS increased self-reported guilt but not shame. The neural results showed that MS strengthened neural activities related to the psychological processes of guilt and shame. Specifically, for both guilt and shame, MS increased activation in a region associated with self-referential processing (ventral medial prefrontal cortex). For guilt but not shame, MS increased the activation of regions associated with cognitive control (orbitofrontal cortex) and emotion processing (amygdala). For shame but not guilt, MS decreased brain functional connectivity related to self-referential processing. A direct comparison showed that MS more strongly decreased a functional connectivity related to self-referential processing in the shame than in the guilt condition. Additionally, the activation of insula during MS priming was partly predictive of neural activities related to guilt and shame in the subsequent recall task. Our study sheds light on the psychological and neural mechanisms of MS effects on moral emotions and provides theoretical insights for enriching terror management theory.

Shared increased entropy of brain signals across patients with different mental illnesses: A coordinate-based activation likelihood estimation meta-analysis

Entropy is a measurement of brain signal complexity. Studies have found increased/decreased entropy of brain signals in psychiatric patients. There is no consistent conclusion regarding the relationship between the entropy of brain signals and mental illness. Therefore, this meta-analysis aimed to identify consistent abnormalities in the brain signal entropy in patients with different mental illnesses. We conducted a systematic search to collect resting-state functional magnetic resonance imaging (rs-fMRI) studies in patients with psychiatric disorders. This work identified 9 eligible rs-fMRI studies, which included a total of 14 experiments, 67 activation foci, and 1383 subjects. We tested the convergence across their findings by using the activation likelihood estimation method. P-value maps were corrected by using cluster-level family-wise error p < 0.05 and permuting 2000 times. Results showed that patients with different psychiatric disorders shared commonly increased entropy of brain signals in the left inferior and middle frontal gyri, and the right fusiform gyrus, cuneus, precuneus. No shared alterations were found in the subcortical regions and cerebellum in the patient group. Our findings suggested that the increased entropy of brain signals in the cortex, not subcortical regions and cerebellum, might have associations with the pathophysiology across mental illnesses. This meta-analysis study provided the first comprehensive understanding of the abnormality in brain signal complexity across patients with different psychiatric disorders.

Neuropsychological Comparison of Guilt and Grief: A Review of Guilt Aspects in Prolonged Grief Disorder

Taking an integrative approach toward developmental psychology and neurophysiology, this review selects findings from the psychological and medical literature on guilt and bereavement that are relevant to considering whether and how guilt contributes to the development of prolonged grief disorder (PGD) in bereaved persons. Mention of guilt is ubiquitous in literature on general grief and PGD, including 54 articles related to the neuropsychological development and manifestations of guilt and grief, as well as their neuroimaging correlates, that met scoping review criteria. However, mechanisms connecting guilt to development of PGD are scarce. Aspects of guilt are conceptually connected to many PGD criteria, opening avenues to explore treatment of PGD by targeting guilt. Positive and prosocial aspects of guilt are especially neglected in the treatment of psychiatric disorders, and consideration of these aspects may improve interventions for PGD such as complicated grief treatment.

Cortical thinning in preschoolers with maladaptive guilt

Maladaptive guilt is a central symptom of preschool-onset depression associated with severe psychopathology in adolescence and adulthood. Although studies have found that maladaptive guilt is associated with structural alterations in the anterior insula (AI) and dorsomedial prefrontal cortex (dmPFC) in middle childhood and adolescence, no study has examined structural neural correlates of maladaptive guilt in preschool, when this symptom first emerges. This study examined a pooled sample of 3-to 6-year-old children (N = 76; 40.8% female) from two studies, both which used the same type of magnetic resonance imaging scanner and conducted diagnostic interviews for depression that included clinician ratings of whether children met criteria for maladaptive guilt. Preschoolers with maladaptive guilt displayed significantly thinner dmPFC than children without this symptom. Neither children's depressive severity nor their vegetative or other emotional symptoms of depression were associated with dmPFC thickness, suggesting that dmPFC thinning is specific to maladaptive guilt. Neither AI gray matter volume or thickness nor dmPFC gray matter volume differed between children with and without maladaptive guilt. This study is the first to identify a structural biomarker for a specific depressive symptom in preschool. Findings may inform neurobiological models of the development of depression and aid in detection of this symptom.

Changes in the neural correlates of self-blame following mindfulness-based cognitive therapy in remitted depressed participants

Mindfulness-Based-Cognitive-Therapy (MBCT) reduces vulnerability for relapse into depression by helping individuals to counter tendencies to engage in maladaptive repetitive patterns of thinking and respond more compassionately to negative self-judgment. However, little is known about the neural correlates underlying these effects. To elucidate these correlates, we investigated fMRI brain activation during a task eliciting feelings of blaming oneself or others. Sixteen participants in remission from major depressive disorder (MDD) completed fMRI assessments before and after MBCT, alongside self-reported levels of self-compassion, mindfulness, and depression symptoms. Analyses of self-blame versus other-blame contrasts showed a reduction in activation in the bilateral dorsal anterior cingulate/medial superior frontal gyrus after MBCT compared to baseline. Further, exploratory analyses showed that increases in self-kindness after MBCT correlated with reduced activation in the posterior cingulate cortex (PCC)/precuneus in self-blame versus rest contrasts. These findings suggest that MBCT is associated with a reduction in activations in cortical midline regions to self-blame which may be mediated by increasing self-kindness. However, this is a small, uncontrolled study with 16 participants and therefore our results will need confirmation in a controlled study.

Neural signatures of promotion versus prevention goal priming: fMRI evidence for distinct cognitive-motivational systems

Regulatory focus theory (RFT) postulates two cognitive-motivational systems for personal goal pursuit: the promotion system, which is associated with ideal goals (an individual's hopes, dreams, and aspirations), and the prevention system, which is associated with ought goals (an individual's duties, responsibilities, and obligations). The two systems have been studied extensively in behavioral research with reference to differences between promotion and prevention goal pursuit as well as the consequences of perceived attainment versus nonattainment within each system. However, no study has examined the neural correlates of each combination of goal domain and goal attainment status. We used a rapid masked idiographic goal priming paradigm and functional magnetic resonance imaging to present individually selected promotion and prevention goals, which participants had reported previously that they were close to attaining ("match") or far from attaining ("mismatch"). Across the four priming conditions, significant activations were observed in bilateral insula (Brodmann area (BA) 13) and visual association cortex (BA 18/19). Promotion priming discriminantly engaged left prefrontal cortex (BA 9), whereas prevention priming discriminantly engaged right prefrontal cortex (BA 8/9). Activation in response to promotion goal priming was also correlated with an individual difference measure of perceived success in promotion goal attainment. Our findings extend the construct validity of RFT by showing that the two systems postulated by RFT, under conditions of both attainment and nonattainment, have shared and distinct neural correlates that interface logically with established network models of self-regulatory cognition.

Children's theory of mind as a mechanism linking parents' mind-mindedness in infancy with children's conscience

Growing research on parental mind-mindedness has revealed significant positive associations between parents' appropriate mind-minded (MM) comments to their infants and children's future theory of mind (ToM). In turn, ToM has been broadly linked with a range of social-moral competencies. However, few (if any) studies have examined long-term paths from mothers' and fathers' mind-mindedness in infancy to conscience at early school age, with ToM serving as a mediator of those links. We tested such a model in a prospective longitudinal study of 102 community infants, mothers, and fathers. Parents' MM comments to their infants were coded in naturalistic interactions in snack and play contexts at 7 months. Children's ToM was assessed in false-belief tasks at 4.5 and 5.5 years, and two aspects of their conscience were assessed at 6.5 years: discomfort following transgressions and prosocial judgments in hypothetical moral dilemmas. We tested our model in a comprehensive path analysis that accounted for developmental continuity of both aspects of conscience. Children's ToM was positively associated with both measures of future conscience. The long-term paths from parental mind-mindedness in infancy to conscience were found for mother-child relationships only. For mothers and children, we supported the paths from maternal appropriate MM comments during a snack context in infancy to both aspects of children's conscience mediated by children's ToM. The findings extend earlier evidence suggesting the potentially important role of the parent-child interactive context for long-term effects of early parental mind-mindedness and highlight differences in the roles MM comments may play in mother-child and father-child relationships.

Mean diffusivity related to rule-breaking guilt: the Macbeth effect in the sensorimotor regions

Guilt, a self-conscious emotion, includes self-focused role taking and also correlates with other-oriented role-taking. Excess guilt proneness might be relevant to obsessive compulsive disorders. The white matter (WM) neural correlates of the degree of guilt have not yet been determined. We hypothesized that the WM structures involved in feelings of guilt are associated with social and moral cognition (inferior parietal lobule [IPL], prefrontal cortex [PFC], and cingulate), and aimed to visualize this using diffusion MRI. We investigated the association between regional WM structures (WM volume, and fractional anisotropy, and mean diffusivity [MD]), and feelings of guilt in 1196 healthy, young students using MRI and the Guilty Feeling Scale, which comprises interpersonal situation (IPS; guilt from hurting friends) and rule-breaking situation (RBS; deontological guilt) scores. The primary novel finding presented here is that MD in the right somatosensory and motor cortices from arm to hand were positively correlated with RBS scores. Further, consistent with our hypothesis, RBS scores were positively correlated with MD in the same regions. These results would be predicted by the Macbeth effect, an obsession with dirt leading to hand-washing rituals resulting from guilt, made famous by the Shakespearian character Lady Macbeth. “What, will these hands ne’er be clean?” William Shakespeare (Shakespeare, 1606) Macbeth.

Punishing the Self: Post-Traumatic Guilt Mediates the Link Between Trauma and Deficient Pain Modulation

Trauma survivors may suffer from post-traumatic stress disorder (PTSD), elevated post-traumatic guilt (PG), and alterations in the pain system. However, the association between PG and alterations in pain perception and modulation among trauma survivors has not been established, nor has the possible underlying role of PG. This longitudinal study investigated: 1) the unique contribution of PG in predicting pain perception and modulation, while controlling for PTSD symptoms; and 2) the mediating role of PG in explaining pain perception and modulation among torture survivors, above and beyond PTSD symptoms. Participants were 59 torture survivors and 44 age-matched controls. PG and PTSD symptoms were assessed in 2003 (T1). Heat-pain threshold, heat-pain tolerance, temporal summation of pain (TSP), and conditioned pain modulation (CPM) were measured 5 years later (T2). Torture survivors had elevated PG and PTSD symptoms, enhanced TSP, and reduced CPM, compared to controls. While PTSD predicted reduced pain tolerance and CPM, PG predicted increased pain tolerance. Moreover, PG mediated the associations between torture and (increased) pain threshold, pain tolerance, and TSP. It appears that PTSD and PG induce opposite effects on the pain modulation capacity of torture survivors, a dichotomy that may explain paradoxical pain responses among trauma survivors, as discussed. PERSPECTIVE: This longitudinal study sheds light on the possible mechanisms underlying variations in pain perception and modulation among trauma survivors. PTSD and PG each mediated opposing pain modulation profiles, suggesting that individual responses to trauma, rather than the trauma itself, influence pain responses.

Brain structures and functional connectivity associated with individual differences in trait proactive aggression

Although considerable efforts have been made to understand the neural underpinnings of (state) reactive aggression, which is triggered by provocation or perceived threat, little is known about the neural correlates of proactive aggression, which is driven by instrumental motivations to obtain personal gains through aggressive means and which varies dramatically across individuals in terms of tendency of appealing to such means. Here, by combining structural (grey matter density, GMD) and functional (resting-state functional connection, RSFC) fMRI, we investigated brain structures and functional networks related to trait proactive aggression. We found that individual differences in trait proactive aggression were positively associated with GMD in bilateral dorsolateral prefrontal cortex (DLPFC) and negatively correlated with GMD in posterior cingulate cortex (PCC); they were also negatively correlated with the strength of functional connectivity between left PCC and other brain regions, including right DLPFC, right IPL, right MPFC/ACC, and bilateral precuneus. These findings shed light on the differential brain bases of proactive and reactive aggressions and suggested the neural underpinnings of proactive aggression.

Exaggerated envy and guilt measured by economic games in Japanese women with anorexia nervosa

Background

Anorexia nervosa (AN) patients are assumed to express high levels of guilt and envy. Ultimatum game (UG) is a standard behavioral task that focuses on interpersonal behavior when splitting a sum of money between two players. UG studies consistently demonstrate that people tend to decrease their inequity in outcomes, one explanation being that economically irrational decision-making may partly arise from the emotions guilt and envy. We assumed that AN patients would perform excessively fair in UG, reflecting high guilt and envy.

Methods

We utilized UG to investigate the characteristics of guilt and envy among 24 Japanese AN patients and 22 age-matched healthy controls (HC). The relation between the outcome of UG and decision strategy confirmed by post-experimental questionnaires was analyzed.

Results

As proposer, AN offered a larger amount to the responder compared with HC (p = 0.002) while, on the other hand, as responder, AN demanded much higher allocation to accept the offer compared with HC (p = 0.026). Regarding the strategy as responder, AN put more emphasis on fairness and less emphasis on monetary reward compared with HC (p = 0.046, p = 0.042, respectively).

Conclusions

The results indicate that Japanese AN patients demonstrate strong preference for fairness, with high guilt and high envy. High sensitivity to guilt and envy of AN patients can affect not only their own behavior concerning eating attitude and body shape, but also decision-making in interpersonal situations. Behavioral experimental settings among social situations will enable us to evaluate and help actual decision-making in the real life of patients.

Guilt leads to enhanced facing-the-viewer bias

As an important moral emotion, guilt plays a critical role in social interaction. It has been found that people tended to exhibit prosocial behavior under circumstances of guilt. However, all extant studies have predominantly focused on the influence of guilt on macro-level behavior. So far, no study has investigated whether guilt affects people’s micro-level perception. The current study closes this gap by examining whether guilt affects one’s inclination to perceive approaching motion. We achieved this aim by probing a facing-the-viewer bias (FTV bias). Specifically, when an ambiguous walking biological motion display is presented to participants via the point-light display technique, participants tend to perceive a walking agent approaching them. We hypothesized that guilt modulated FTV bias. To test this hypothesis, we adopted a two-person situation induction task to induce guilt, whereby participants were induced to feel that because of their poor task performance, their partner did not receive a satisfactory payment. We found that when participants were told that the perceived biological motion was motion-captured from their partner, the FTV bias was significantly increased for guilty participants relative to neutral participants. However, when participants were informed that the perceived biological motion was from a third neutral agent, the FTV bias was not modulated by guilt. These results suggest that guilt influences one’s inclination to perceive approaching motion, but this effect is constrained to the person towards whom guilt is directed.

Depression in chronic ketamine users: Sex differences and neural bases

Chronic ketamine use leads to cognitive and affective deficits including depression. Here, we examined sex differences and neural bases of depression in chronic ketamine users. Compared to non-drug using healthy controls (HC), ketamine-using females but not males showed increased depression score as assessed by the Center of Epidemiological Studies Depression Scale (CES-D). We evaluated resting state functional connectivity (rsFC) of the subgenual anterior cingulate cortex (sgACC), a prefrontal structure consistently implicated in the pathogenesis of depression. Compared to HC, ketamine users (KU) did not demonstrate significant changes in sgACC connectivities at a corrected threshold. However, in KU, a linear regression against CES-D score showed less sgACC connectivity to the orbitofrontal cortex (OFC) with increasing depression severity. Examined separately, male and female KU showed higher sgACC connectivity to bilateral superior temporal gyrus and dorsomedial prefrontal cortex (dmPFC), respectively, in correlation with depression. The linear correlation of sgACC-OFC and sgACC-dmPFC connectivity with depression was significantly different in slope between KU and HC. These findings highlighted changes in rsFC of the sgACC as associated with depression and sex differences in these changes in chronic ketamine users.