Temperament Based Personality Types in Community-Dwelling Older Adults: A Latent Profile Analysis

Three adaptive trait-based personality types have been replicated across ages, cultures, clinical problems and clustering methods: Resilient, Undercontrolled and Overcontrolled type (RUO). Recently there is growing interest in and importance of biopsychosocial transdiagnostic factors underlying personality types, such as temperamental reactivity and self-regulation. Latter can be understood in terms of Behavioural Inhibition (BIS), Behavioural Activation Systems (BAS) and Effortful Control (EC). The occurrence of temperament based RUO types has not yet been confirmed in older adults with or without a mental disorder. Therefore, based on a person-centered approach, the current study investigates whether RUO types can be corroborated in older adults based on the aforementioned temperamental factors. Latent profile analysis yielded two distinct personality profiles in community-dwelling over-60s, which we tentatively labeled a resilient (n = 167) and overcontrolled/inhibited type (n = 241). Compared to the resilient type, the overcontrolled/inhibited type scored lower on EC and higher on BIS. We could not corroborate an undercontrolled type (profiles scored equally on BAS). Group comparisons revealed that overcontrolled/inhibited older adults demonstrated significantly more clinical symptoms, higher emotional instability, lower scores on adaptive traits, less resilience and were significantly more likely to use passive and avoidant coping styles, compared to resilient older adults.

Stress priming transcranial direct current stimulation (tDCS) enhances updating of emotional content in working memory

Transcranial direct current stimulation (tDCS) targeting the prefrontal cortex has emerged as a valuable tool in psychiatric research. Understanding the impact of affective states, such as stress at the time of stimulation, on the efficacy of prefrontal tDCS is crucial for advancing tDCS interventions. Stress-primed tDCS, wherein stress is used as a priming agent, has the potential to modulate neural plasticity and enhance cognitive functions, particularly in emotional working memory. However, prior research using stress-primed tDCS focused solely on non-emotional working memory performance, yielding mixed results. In this sham-controlled study, we addressed this gap by investigating the effects of stress-primed bifrontal tDCS (active versus sham) on both non-emotional and emotional working memory performance. The study was conducted in 146 healthy individuals who were randomly assigned to four experimental groups. The Trier Social Stress Test (TSST) or a control variant of the test was used to induce a stress versus control state. The results showed that stress priming significantly enhanced the effects of tDCS on the updating of emotional content in working memory, as evidenced by improved accuracy. Notably, no significant effects of stress priming were found for non-emotional working memory performance. These findings highlight the importance of an individual's prior affective state in shaping their response to tDCS, especially in the context of emotional working memory.

Dose-dependent response of prefrontal transcranial direct current stimulation on the heart rate variability: An electric field modeling study

Transcranial direct current stimulation (tDCS) of the prefrontal cortex (PFC) modulates the autonomic nervous system by activating deeper brain areas via top-down pathway. However, effects on the nervous system are heterogeneous and may depend on the amount of current that penetrates. Therefore, we aimed to investigate the variable effects of tDCS on heart rate variability (HRV), a measure of the functional state of the autonomic nervous system. Using three prefrontal tDCS protocols (1.5, 3 mA and sham), we associated the simulated individual electric field (E-field) magnitude in brain regions of interest with the HRV effects. This was a randomized, double-blinded, sham-controlled and within-subject trial, in which healthy young-adult participants received tDCS sessions separated by 2 weeks. The brain regions of interest were the dorsolateral PFC (DLPFC), anterior cingulate cortex, insula and amygdala. Overall, 37 participants were investigated, corresponding to a total of 111 tDCS sessions. The findings suggested that HRV, measured by root mean squared of successive differences (RMSSD) and high-frequency HRV (HF-HRV), were significantly increased by the 3.0 mA tDCS when compared to sham and 1.5 mA. No difference was found between sham and 1.5 mA. E-field analysis showed that all brain regions of interest were associated with the HRV outcomes. However, this significance was associated with the protocol intensity, rather than inter-individual brain structural variability. To conclude, our results suggest a dose-dependent effect of tDCS for HRV. Therefore, further research is warranted to investigate the optimal current dose to modulate HRV.

Vagally-mediated HRV as a marker of trait rumination in healthy individuals? A large cross-sectional analysis

The tendency to ruminate (i.e., repetitive, self-referential, negative thoughts) is a maladaptive form of emotional regulation and represents a transdiagnostic vulnerability factor for stress-related psychopathology. Vagally-mediated heart rate variability (vmHRV) provides a non-invasive, surrogate measure of vagal modulation of the heart, and higher HRV is considered an indicator of susceptibility, or ability to respond to stress. Past research has suggested a link between trait rumination and vmHRV; however, inconsistent results exist in healthy individuals. In this study, we investigated the association between the tendency to ruminate, brooding, and reflection (using the Ruminative Response Scale) with vmHRV measured at baseline in a healthy population using a large cross-sectional dataset (N = 1189, 88% female; mean age = 21.55, ranging from 17 to 48 years old), which was obtained by combining samples of healthy individuals from different studies from our laboratory. The results showed no cross-sectional correlation between vmHRV and trait rumination (confirmed by Bayesian analysis), even after controlling for important confounders such as gender, age, and depressive symptoms. Also, a non-linear relationship was rejected. In summary, based on our results in a large sample of healthy individuals, vmHRV is not a marker of trait rumination (as measured by the Ruminative Response Scale).

Unraveling how the adolescent brain deals with criticism using dynamic causal modeling

Sensitivity to criticism, which can be defined as a negative evaluation that a person receives from someone else, is considered a risk factor for the development of psychiatric disorders in adolescents. They may be more vulnerable to social evaluation than adults and exhibit more inadequate emotion regulation strategies such as rumination. The neural network involved in dealing with criticism in adolescents may serve as a biomarker for vulnerability to depression. However, the directions of the functional interactions between the brain regions within this neural network in adolescents are still unclear. In this study, 64 healthy adolescents (aged 14 to 17 years) were asked to listen to a series of self-referential auditory segments, which included negative (critical), positive (praising), and neutral conditions, during fMRI scanning. Dynamic Causal Modeling (DCM) with Parametric Empirical Bayesian (PEB) analysis was performed to map the interactions within the neural network that was engaged during the processing of these segments. Three regions were identified to form the interaction network: the left pregenual anterior cingulate cortex (pgACC), the left dorsolateral prefrontal cortex (DLPFC), and the right precuneus (preCUN). We quantified the modulatory effects of exposure to criticism and praise on the effective connectivity between these brain regions. Being criticized was found to significantly inhibit the effective connectivity from the preCUN to the DLPFC. Adolescents who scored high on the Perceived Criticism Measure (PCM) showed less inhibition of the preCUN-to-DLPFC connectivity when being criticized, which may indicate that they required more engagement of the Central Executive Network (which includes the DLPFC) to sufficiently disengage from negative self-referential processing. Furthermore, the inhibitory connectivity from the DLPFC to the pgACC was strengthened by exposure to praise as well as criticism, suggesting a recruitment of cognitive control over emotional responses when dealing with positive and negative evaluative feedback. Our novel findings contribute to a more profound understanding of how criticism affects the adolescent brain and can help to identify potential biomarkers for vulnerability to develop mood disorders before or during adulthood.

Uncovering the underlying factors of ERP changes in the cyberball paradigm: A systematic review investigating the impact of ostracism and paradigm characteristics

The Cyberball is the most commonly employed paradigm for the investigation of the effects of social exclusion, also called ostracism. The analysis of event-related potentials (ERPs), short-term stimulus-induced fluctuations in the EEG signal, has been employed for the identification of time-sensitive neural responses to ostracism-related information. Changes in ERPs during the Cyberball are normally attributed to the effect of ostracism, but it has been argued that characteristics of the paradigm, not ostracism, are the driving force for these changes. To elucidate the origin of the ERP changes in the Cyberball, we systematically reviewed the Cyberball-ERP literature of healthy, adult populations, and evaluated whether the social context of ostracism or characteristics of the paradigm are better suited for the explanation of the found results. Our results show that for many components no clear origin can be identified, but that expectancy violations, not ostracism, best explains the results of the P3 complex. Future research should therefore also employ other paradigms for the research into the effects of ostracism on ERPs.

Parental criticism affects adolescents' mood and ruminative state: Self-perception appears to influence their mood response

Feeling and/or being criticized is a known risk factor for various psychiatric disorders in adolescents. However, the link between the experience of social stressors and the development of psychopathological symptoms is not yet fully understood. Identifying which adolescent subgroups are more vulnerable to parental criticism could be of great clinical relevance. In this study, 90 nondepressed 14- to 17-year-old adolescents were exposed to a sequence of auditory segments with a positive, neutral, and finally negative valence, mirroring parental criticism. Their mood and ruminative states were assessed before and after exposure to criticism. We observed an overall increase in mood disturbance and ruminative thoughts. Self-perception appeared to influence these mood changes, whereas no significant influence by perceived criticism, self-worth, or the general tendency to ruminate was found. Emotional awareness seemed to account for some of the variance in positive mood state changes. These findings point to the importance of adolescent self-perception (and emotional awareness) in dealing with parental criticism.

Acute stress impacts reaction times in older but not in young adults in a flanker task

Acute psychosocial stress effects on inhibition have been investigated in young adults, but little is known about these effects in older adults. The present study investigated effects of the Trier Social Stress Test on cognitive inhibition (i.e., ability to ignore distracting information) using a cross-over (stress vs. control) design in healthy young (N = 50; 18-30 years; Mage = 23.06) versus older adults (N = 50; 65-84 years; Mage = 71.12). Cognitive inhibition was measured by a letter flanker task and psychophysiological measures (cortisol, heart rate, subjective stress) validated the stress induction. The results showed that while stress impaired overall accuracy across age groups and sessions, stress (vs. control) made older adults' faster in session 1 and slower in session 2. Given that session 2 effects were likely confounded by practice effects, these results suggest that acute psychosocial stress improved older adults' RTs on a novel flanker task but impaired RTs on a practiced flanker task. That is, the interaction between stress and learning effects might negatively affect response execution when testing older adults on flanker tasks. If confirmed by future research, these results might have important implications especially in settings where repeated cognitive testing is performed under acute stress.

Prefrontal transcranial direct current stimulation over the right prefrontal cortex reduces proactive and reactive control performance towards emotional material in healthy individuals

The prefrontal cortex plays a crucial role in cognitive processes, both during anticipatory and reactive modes of cognitive control. Transcranial Direct Current Stimulation (tDCS) can modulate these cognitive resources. However, there is a lack of research exploring the impact of tDCS on emotional material processing in the prefrontal cortex, particularly in regard to proactive and reactive modes of cognitive control. In this study, 35 healthy volunteers underwent both real and sham tDCS applied to the right prefrontal cortex in a counterbalanced order, and then completed the Cued Emotion Control Task (CECT). Pupil dilation, a measure of cognitive resource allocation, and behavioral outcomes, such as reaction time and accuracy, were collected. The results indicate that, as compared to sham stimulation, active right-sided tDCS reduced performance and resource allocation in both proactive and reactive modes of cognitive control. These findings highlight the importance of further research on the effects of tDCS applied to the right prefrontal cortex on cognitive engagement, particularly for clinical trials utilizing the present electrode montage in combination with cognitive interventions.

The contextual goal dependent attentional flexibility (CoGoDAF) framework: A new approach to attention bias in depression

Successful adaptation to the environment requires attentional prioritization of emotional information relevant to the current situational demands. Accordingly, the presence of an attention bias (AB) for both positive and negative information may allow preferential processing of stimuli in line with the current situational goals. However, AB for negative information sometimes becomes maladaptive, being antithetical to the current adaptive needs and goals of an individual, such as in the case of affective disorders such as depression. Although difficulties in flexible shifting between emotional stimuli in depression have increasingly become a topic of discussion in the field, an integrative approach towards biased versus flexible emotional attentional processes remains absent. In the present paper, we advance a novel and integrative view of conceptualizing potentially aberrant affective attention patterns in depression as a function of the current contextual features. We propose that flexible emotional attention takes place as a result of attention prioritization towards goal-relevant emotional stimuli depending upon the current context of the individual. Specifically, the roles of context, distal and proximal goals, and approach and avoidance motivation processes are considered in a unified manner. The empirical, clinical, and interventional implications of this integrative framework provide a roadmap for future psychological and neurobiological experimental and translational research.

Interplay between uncertainty intolerance, emotion regulation, cognitive flexibility, and psychopathology during the COVID-19 pandemic: a multi-wave study

The COVID-19 pandemic has created a significant mental health burden on the global population. Studies during the pandemic have shown that risk factors such as intolerance of uncertainty and maladaptive emotion regulation are associated with increased psychopathology. Meanwhile, protective factors such as cognitive control and cognitive flexibility have been shown to protect mental health during the pandemic. However, the potential pathways through which these risk and protective factors function to impact mental health during the pandemic remain unclear. In the present multi-wave study, 304 individuals (18 years or older, 191 Males), residing in the USA during data collection, completed weekly online assessments of validated questionnaires across a period of five weeks (27th March 2020-1st May 2020). Mediation analyses revealed that longitudinal changes in emotion regulation difficulties mediated the effect of increases in intolerance of uncertainty on increases in stress, depression, and anxiety during the COVID-19 pandemic. Further, individual differences in cognitive control and flexibility moderated the relationship between intolerance of uncertainty and emotion regulation difficulties. While intolerance of uncertainty and emotion regulation difficulties emerged as risk factors for mental health, cognitive control and flexibility seems to protect against the negative effects of the pandemic and promote stress resilience. Interventions aimed at enhancing cognitive control and flexibility might promote the protection of mental health in similar global crises in the future.

Effects of acute psychosocial stress on source level EEG power and functional connectivity measures

The usage of EEG to uncover the influence of psychosocial stressors (PSSs) on neural activity has gained significant attention throughout recent years, but the results are often troubled by confounding stressor types. To investigate the effect of PSSs alone on neural activity, we employed a paradigm where participants are exposed to negative peer comparison as PSS, while other possible stressors are kept constant, and compared this with a condition where participants received neutral feedback. We analyzed commonly used sensor level EEG indices (frontal theta, alpha, and beta power) and further investigated whether source level power and functional connectivity (i.e., the temporal dependence between spatially seperated brain regions) measures, which have to our knowledge not yet been used, are more sensitive to PSSs than sensor level-derived EEG measures. Our results show that on sensor level, no significant frontal power changes are present (all p's > 0.16), indicating that sensor level frontal power measures are not sensitive enough to be affected by only PSSs. On source level, we find increased alpha power (indicative of decreased cortical activity) in the left- and right precuneus and right posterior cingulate cortex (all p's < 0.03) and increased functional connectivity between the left- and right precuneus (p < 0.001), indicating that acute, trial based PSSs lead to decreased precuneus/PCC activity, and possibly indicates a temporary disruption in the self-referential neural processes of an individual.

Online Contingent Attention Training (OCAT): transfer effects to cognitive biases, rumination, and anxiety symptoms from two proof-of-principle studies

The aim of the present research was to develop and test the efficacy of a novel online contingent attention training (i.e., OCAT) to modify attention and interpretation biases, improve emotion regulation, and reduce emotional symptom levels in the face of major stressors. Two proof-of-principle studies were carried out. In study 1, 64 undergraduates who were about to start a major stressful period (i.e., final exams) were randomized to undergo 10 days of active OCAT or a sham-control training. Emotion regulation (habitual use of rumination and reappraisal) and symptom levels (depression and anxiety) were assessed before and after the intervention. In study 2, the same 2 × 2 mixed design was used with 58 individuals from the general population undergoing a major stressful situation (the lockdown period at the beginning of the COVID-19 pandemic in 2020). In both studies, the OCAT group showed significant improvements on attention towards negative information and interpretation biases in comparison to the sham-control group. Additionally, changes in cognitive biases transferred to reductions of participants' use of rumination and anxiety symptom levels. These results show preliminary evidence regarding the efficacy of the OCAT to target attention and interpretation biases as well as to improve emotion regulation processes and to buffer against the effects of major stressors.

Combining transcranial direct current stimulation with group cognitive behavioral therapy developed to treat rumination: a clinical pilot study

Background

As part of repetitive negative thinking (RNT), rumination is a maladaptive cognitive response style to stress or negative mood which can increase the risk of depression and may prohibit complete recovery. Cognitive behavioral therapy (CBT) and transcranial direct current stimulation (tDCS) both proved to be effective in decreasing rumination. However, the combined effects of tDCS and CBT interventions on rumination have not yet been explored. The first aim of this pilot study is to investigate whether the combination of tDCS and CBT has an accumulating positive effect on modulating state rumination. The second aim is to assess the feasibility and safety profile of the proposed combined approach.

Method

Seventeen adults aged 32-60 years, suffering from RNT, were referred by their primary care professional to participate in an 8-week group intervention for RNT ("Drop It") comprising 8 sessions of CBT. Before each CBT session, patients underwent one double-blinded prefrontal active (2 mA for 20 min) or sham tDCS (anode over F3, cathode over the right supraorbital region) combined with an internal cognitive attention task focused on individual RNT, i.e., online tDCS priming. During each session, the Brief State Rumination Inventory was used to assess state rumination.

Results

A mixed effects model analysis revealed no significant differences between the stimulation conditions, weekly sessions, or their interaction in terms of state rumination scores.

Conclusion

Overall, the combination of online tDCS priming followed by group CBT was found to be safe and feasible. On the other hand, no significant additional effects of this combined approach on state rumination were established. Although our pilot study may have been too small to find significant clinical effects, future larger RCT studies on combined tDCS-CBT treatment protocols may reevaluate the selection of internal cognitive attention tasks and more objective neurophysiological measurements, consider the optimal timing of the combination (concurrently or sequentially), or may add additional tDCS sessions when following CBT.

Regaining control of your emotions? Investigating the mechanisms underlying effects of cognitive control training for remitted depressed patients

Studies suggest that cognitive control training shows potential as a preventive intervention for depression. At the same time, little is known regarding the mechanisms underlying effects of cognitive control training. Informed by theoretical frameworks of cognitive risk for recurrent depression (De Raedt & Koster, 2010; Siegle et al., 2007), the current study sought to model direct effects of cognitive control training on the complex interplay between affect, emotion regulation, residual symptomatology, and resilience in a sample of remitted depressed patients (n = 92). Combining a 4-week experience sampling procedure with an experimental manipulation of cognitive control, we observed beneficial effects of cognitive control training on deployment of rumination. In addition, we obtained evidence for the causal involvement of cognitive control in efficacy of emotion regulation. In contrast to our expectations, cognitive control training did not exert immediate effects on residual symptomatology or resilience when compared with an active control condition, nor did cognitive control training impact the complex interplay between these variables. Overall, immediate effects of cognitive control training on functioning in daily life were limited. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Always look on the bright side of life: Individual differences in visual attentional breadth for understanding temperament and emotion regulation in adolescents

Introduction

Cognitive-affective models of depression show that negative and positive emotionality differentially confer risk for depression through maladaptive and adaptive emotion regulation (ER) strategies respectively. Yet, no research has examined the mechanisms through which these temperament traits shape individual differences in ER. The current study explored the mediating role of attentional breadth for emotional information in the distinct pathways from temperament to ER strategies in adolescents.

Methods

The hypotheses were tested in a selected sample of 71 adolescents (M = 14.15, SD = 1.90; 62% girls) using a previously validated measure of visuospatial attentional breadth.

Results

First, positive emotionality was positively associated with attentional breadth for positive stimuli and temperamental vulnerable adolescents showed deficits in the processing of positive stimuli when presented far from the center of the visual field. Second, attentional breadth towards neutral stimuli was positively related to adaptive ER strategies. Third, no evidence was found for the proposed mediation models. However, post-hoc analyses provided preliminary evidence for a reversed mediation model in which adaptive ER strategies mediate the relationship between temperament and attentional breadth towards neutral stimuli.

Discussion

The results underscore the apparent complexity of the relations between temperament, attentional breadth, and ER and point out the need for further research in order to inform early intervention.

Digitalized transcranial electrical stimulation: A consensus statement

OBJECTIVE

Although relatively costly and non-scalable, non-invasive neuromodulation interventions are treatment alternatives for neuropsychiatric disorders. The recent developments of highly-deployable transcranial electric stimulation (tES) systems, combined with mobile-Health technologies, could be incorporated in digital trials to overcome methodological barriers and increase equity of access. The study aims are to discuss the implementation of tES digital trials by performing a systematic scoping review and strategic process mapping, evaluate methodological aspects of tES digital trial designs, and provide Delphi-based recommendations for implementing digital trials using tES.

METHODS

We convened 61 highly-productive specialists and contacted 8 tES companies to assess 71 issues related to tES digitalization readiness, and processes, barriers, advantages, and opportunities for implementing tES digital trials. Delphi-based recommendations (>60% agreement) were provided.

RESULTS

The main strengths/opportunities of tES were: (i) non-pharmacological nature (92% of agreement), safety of these techniques (80%), affordability (88%), and potential scalability (78%). As for weaknesses/threats, we listed insufficient supervision (76%) and unclear regulatory status (69%). Many issues related to methodological biases did not reach consensus. Device appraisal showed moderate digitalization readiness, with high safety and potential for trial implementation, but low connectivity.

CONCLUSIONS

Panelists recognized the potential of tES for scalability, generalizability, and leverage of digital trials processes; with no consensus about aspects regarding methodological biases.

SIGNIFICANCE

We further propose and discuss a conceptual framework for exploiting shared aspects between mobile-Health tES technologies with digital trials methodology to drive future efforts for digitizing tES trials.

Eight items of the ruminative response scale are sufficient to measure weekly within-person variation in rumination

The Ruminative Response Scale (RRS) is commonly used to measure people’s general tendency to ruminate. In this study, we explored whether only few items from the RRS can be used to capture within-person variation in rumination in intensive longitudinal studies. Such a short RRS version would allow, for example, monitoring the development of rumination during clinical interventions. We measured rumination on five occasions, with at least one week in between. We used multilevel analyses to analyze the data at the within- and between-person level. Using only eight RRS items, we successfully modeled a reflective self-regulation and depressive brooding factor, similar to the two subfacets of rumination as distinguished by Treynor et al. (2003). We also established convergent validity of depressive brooding at the within- and between-person level of analysis and convergent validity of reflection at the between-person level. We thus introduced a short form of the RRS that captures within-person variation in depressive brooding and reflection well. The short RRS is readily applicable in studies on within-person variation or change in rumination.

Treatment experiences during a cognitive behaviour therapy group intervention targeting repetitive negative thinking: A qualitative study

OBJECTIVES

Treatment of repetitive negative thinking (RNT) focuses rather on individual than group cognitive behaviour therapy (CBT) treatment. Additionally, little is known on how clients experienced these interventions. This study investigates clients' experiences on participating in a CBT group intervention targeting RNT (RNT-G).

DESIGN

Of the 80 participants, 11 were randomly selected for an in-depth, semi-structured interview after treatment. Interviews focused on what participants experienced as important on group aspects, offered interventions, homework tasks, and possible changes.

METHODS

All participants were adults, diagnosed with major depressive disorder and/or generalized anxiety disorder and being currently in mental health care treatment. After transcribing the interviews, analyses were performed according to the guidelines of thematic analysis.

RESULTS

Four major themes were identified. First, the group format itself was experienced as an important factor of change. The experiences about the different offered interventions during the group formed a second theme. A third theme related to changes in family or professional life and dealing with RNT as a result of the intervention. Finally, group participation, social interactions, and mental health care treatment were experienced as mutually influencing during the intervention.

CONCLUSIONS

The results of this study shed some light on which treatment interventions were perceived as beneficial during the RNT-G and should therefore be emphasized in treatment. Further, they indicate that the treatment in a group format was experienced as helpful by the participants. Finally, a positive mutual influence between the group intervention and the ongoing individual treatment was experienced.

Are Emotion Regulation Strategies Associated With Visual Attentional Breadth for Emotional Information in Youth?

Attentional deployment is currently considered as one of the most central mechanisms in emotion regulation (ER) as it is assumed to be a crucial first step in the selection of emotional information. According to the broaden-and-build theory, positive emotions are associated with attentional broadening and negative emotions with attentional narrowing toward emotional information. Given that ER strategies relying on attentional deployment (i.e., rumination, cognitive reappraisal and distraction) have the possibility to influence positive and negative emotions by (re)directing one's attention, there could be an association with one's attentional scope. The current study investigated the association between the general (trait) use of three specific ER strategies and visual attentional breadth for positive, negative, and neutral information in a selected sample of 56 adolescents (M = 12.54, SD = 1.72; 49% girls) at risk for developing psychopathology. First, participants self-reported on their overall use of different ER strategies. Next, the previously validated Attentional Breadth Task (ABT) was used to measure visual attention breadth toward emotional information. No evidence was found for the relationship between 2 specific ER strategies (i.e., cognitive reappraisal and rumination) and visual attentional breadth for neutral, positive and negative emotional information. Surprisingly, "distraction" was associated with visual attentional narrowing, which was unrelated to the valence of the emotion. These unexpected results indicate the multifaceted relationship between trait ER, distraction specifically, and visual attentional breadth for emotional information. Future research, especially in younger age groups, could further elaborate on this research domain.

Attenuated beta-adrenergic response to stress and increased anticipation and perception of social threat in women high on perceived criticism

A large amount of literature has demonstrated that Perceived Criticism (PC)-that is, how critical a person believes a given relative is of him or her-is associated with negative clinical outcomes in a broad range of psychiatric disorders (e.g., relapse or recurrence of symptoms). A possible mechanism behind the predictive value of PC might be its association with the stress regulation process. This is the first study to investigate differences in the psychophysiological response to a social stress task in young women (mean age = 21.66, SD = 4.33) with high (n = 40) and low (n = 39) PC. The physiological response was investigated by measuring two markers of sympathetic activity mediated by acetylcholine (skin conductance levels; SCL) and adrenaline (pre-ejection period; PEP) levels, respectively, and one marker of the vagally-mediated parasympathetic system (heart rate variability; HRV). Moreover, we investigated the anticipation and perception of social threat, in the form of criticism, during the stressor. No differences in HRV and SCL were observed. However, individuals high in PC mobilized fewer cardiovascular resources to deal with the stressor, reflected in an attenuated beta-adrenergic response (i.e., lower PEP response). Women high in PC also expected and perceived more criticism during the stress task. Together, our results indicate that women high in PC make heightened social threat anticipation and interpretations, and they tend to engage in less active coping when exposed to socially evaluated stressful events. Our findings indicate that PC is associated with underlying stress-related psychobiological vulnerabilities that may contribute to its association with negative clinical outcomes.

Prefrontal tDCS Attenuates Self-Referential Attentional Deployment: A Mechanism Underlying Adaptive Emotional Reactivity to Social-Evaluative Threat

Social-evaluative threat (SET) - a situation in which one could be negatively evaluated by others - elicits profound (psycho)physiological reactivity which, if chronically present and not adaptively regulated, has deleterious effects on mental and physical health. Decreased self-awareness and increased other-awareness are understood to be an adaptive response to SET. Attentional deployment - the process of selectively attending to certain aspects of emotional stimuli to modulate emotional reactivity - is supported by fronto-parietal and fronto-limbic networks, with the dorsolateral prefrontal cortex being a central hub. The primary aim of the current study was to investigate the effects of active (versus sham) prefrontal transcranial direct current stimulation (tDCS) on self and other-attentional deployment during the exposure to a SET context. Seventy-four female participants received active or sham tDCS and were subsequently exposed to a rigged social feedback paradigm. In this paradigm a series of social evaluations were presented together with a photograph of the supposed evaluator and a self- photograph of the participant, while gaze behavior (time to first fixation, total fixation time) and skin conductance responses (SCRs; a marker of emotional reactivity) were measured. For half of the evaluations, participants could anticipate the valence (negative or positive) of the evaluation a priori. Analyses showed that participants receiving active tDCS were (a) slower to fixate on their self-photograph, (b) spent less time fixating on their self-photograph, and (c) spent more time fixating on the evaluator photograph. During unanticipated evaluations, active tDCS was associated with less time spent fixating on the evaluation. Furthermore, among those receiving active tDCS, SCRs were attenuated as a function of slower times to fixate on the self-photograph. Taken together, these results suggest that in a context of SET, prefrontal tDCS decreases self-attention while increasing other-attention, and that attenuated self-referential attention specifically may be a neurocognitive mechanism through which tDCS reduces emotional reactivity. Moreover, the results suggest that tDCS reduces vigilance toward stimuli that possibly convey threatening information, corroborating past research in this area.

Combined effects of tDCS over the left DLPFC and gaze-contingent training on attention mechanisms of emotion regulation in low-resilient individuals

Low resilience is characterized by impairments in attention and emotion regulation mechanisms that depend on prefrontal cortical activity. The aim of this study was to test whether transcranial direct current stimulation (tDCS) over the left dorsolateral prefrontal cortex (DLPFC) can augment the effectiveness of a new computerized mouse-based (gaze)contingent training (MCAT) to improve attention and emotion regulation processes (improved reappraisal, reduced rumination) in individuals reporting low resilience levels. The study used a full-factorial between-subject design combining active and sham MCAT and tDCS interventions. One hundred participants reporting low resilience levels were randomly assigned to receive either a single session of: tDCS with sham MCAT treatment (tDCS group), MCAT with sham tDCS (MCAT group), a combination of tDCS and MCAT (combined group), or sham tDCS and sham MCAT (control group). Transfer to attention regulation, reappraisal success, and state rumination was evaluated using an eye-tracking disengagement task and an emotion regulation paradigm, respectively. MCAT, either alone or combined with tDCS, resulted in improved attention regulation. Furthermore, the group receiving combined MCAT and tDCS also showed some evidence of increased reappraisal ability and reduced rumination. MCAT in combination with left DLPFC neuromodulation has potential to maximize transfer to emotion regulation capacities and to promote resilience.

Prefrontal tDCS attenuates counterfactual thinking in female individuals prone to self-critical rumination

The tendency to ruminate (i.e., repetitive negative self-referential thoughts that perpetuate depressive mood) is associated with (a) an elevated propensity to maladaptively experience counterfactual thinking (CFT) and regret, and (b) hypo-activity of the left dorsolateral prefrontal cortex (DLPFC). The goal of this study was to investigate whether anodal transcranial direct current stimulation (tDCS) over the left DLPFC, in function of self-critical rumination tendencies, momentarily reduces counterfactual thinking and regret (assessed via self-report and psychophysiological indices). Eighty healthy participants with different levels of self-critical rumination received either anodal or sham tDCS while performing a decision making task in which they were repeatedly confronted with optimal, suboptimal, and non-optimal choice outcomes. The results showed that among rumination-prone individuals, anodal (versus sham) tDCS was associated with decreased CFT and attenuated psychophysiological reactivity to the differential choice outcomes. Conversely, among low rumination-prone individuals, anodal (versus sham) tDCS was associated with increased CFT and regret, but in absence of any effects on psychophysiological reactivity. Potential working mechanisms for these differential tDCS effects are discussed. Taken together, these results provide initial converging evidence for the adaptive effects of left prefrontal tDCS on CFT and regret to personal choice outcomes among individuals prone to engage in self-critical rumination.

The relationship between affective flexibility, spontaneous emotion regulation and the response to induced stress

Effective emotion regulation contributes to adapting well to challenging situations. One of the proposed cognitive mechanisms underlying emotion regulation is cognitive flexibility in processing of affective material (i.e. affective flexibility). We investigated (n = 118) effects of affective flexibility on the response to a stressor and on spontaneous use of 'adaptive' and 'maladaptive' emotion regulation strategies. Additionally, we examined how emotion regulation influences stress reactivity and recovery. Affective flexibility was measured with a task-switching paradigm in which participants shift attention between affective and non-affective aspects of emotional material. We investigated changes in emotion and heart rate variability to a stress induction. Affective flexibility did not influence the response to stress, but less efficient shifting of attention towards affective aspects of negative information, and more efficient shifting of attention towards non-affective aspects of positive information were related to more use of maladaptive strategies. Emotion regulation strategy use had limited influence on the perceived and actual physiological response to a stress induction, but especially more use of adaptive regulation strategies reduced negative emotional reactivity. Our findings suggest that individual differences in affective flexibility have limited influence on the (acute) response to a stressful event and recovery afterwards, but do influence spontaneous use of emotion regulation strategies.

Contextual goal-dependent attention flexibility or rule-based learning? An investigation of a new attention flexibility paradigm

BACKGROUND & OBJECTIVES

Deficits in the ability to process contextual changes have been proposed to be crucial for emotion dysregulation. A recent study found evidence for the role of contextual changes in exacerbating attention switching towards valence-specific goals using a novel attention flexibility paradigm. Despite the task indicating good reliability, the role of rule-based learning has not been clarified in this paradigm. Therefore, we examined whether the novel attention flexibility task is an index of context-based attention switching or does it reflect impact of rule-based learning on attention.

METHOD

We employed a neutral version of the attention flexibility task. A sample of dysphoric and non-dysphoric participants were introduced to neutral contexts which required them to shift between neutral categories of pictures depending upon the cueing shape.

RESULTS

There was an existence of a switch cost for shifting between different rules owing to the features of the rules. Further, non-dysphorics were faster at set-shifting between different rules as compared to dysphoric individuals. However, unlike in the affective version of the attention flexibility task, we found no significant differences between dysphoric and non-dysphoric individuals in attention switching patterns owing to switching between different rules.

LIMITATIONS

Although the current study aimed to replicate the design of the previous study, a depressed patient sample must be employed to further clarify the different aspects of the attention flexibility paradigm.

CONCLUSION

Our findings were able to clarify the non-existent role of rule-based learning in the attention flexibility paradigm.

Early reduction of sensory processing within the visual cortex when switching from internal to external attention

The neurocognitive process underlying attention switches between external (perception-based) and internal (memory-based) attention is poorly characterized. Previous research has found that when participants switch attention either between two perception-based tasks (within-domain switches) or between a memory- and a perception-based task (between-domain switches), a substantial and similar processing cost was observed compared to the repetition of the same task (Verschooren, Schindler, De Raedt, & Pourtois, 2019). Here, we recorded 64-channel EEG while participants carried out within- versus between-domain switches of attention. ERP results showed that during early sensory processing, a marked P1 attenuation was associated with both switch types, suggesting that switching was associated with an early bottleneck during information processing. This early gating effect was stronger when switching from an internal to an external task, compared to switching between external tasks, suggesting different top-down requirements for them. These findings are in line with earlier proposals in the literature.

Cognitive behavioral based group psychotherapy focusing on repetitive negative thinking: Decreased uncontrollability of rumination is related to brain perfusion increases in the left dorsolateral prefrontal cortex

Repetitive negative thinking (RNT) is a core process underlying various psychiatric disorders. 'Uncontrollability of rumination (UOR)' is one the most maladaptive factors of rumination, but little is known on how cognitive behavioral focused RNT psychotherapy may alter brain activity. In a subsample of 47 patients suffering from RNT who also underwent brain imaging (registered RCT trial NCT01983033), we evaluated the effect of cognitive behavioral based group psychotherapy (CBGP) (n = 25) as compared to a delayed treatment control group (DTCG) (n = 22) on frontolimbic brain perfusion with a focus on UOR. This RNT construct was measured using the subscale 'uncontrollability' of the Dutch version of the Rumination on Sadness Scale (LARSS-U). Brain perfusion was assessed with arterial spin labeling (ASL)-fMRI. LARSS-U scale scores significantly decreased in the CBGP cohort whereas no significant changes emerged in the DTCG group. Compared to the DTCG, this decrease on UOR in the CBGP group was related to significant perfusion increases in the left (dorsolateral) prefrontal cortex, part of the executive network. Besides the fact that CBGP significantly reduced RNT, this attenuation of uncontrollable ruminative thoughts was related to brain perfusion increases areas documented to be involved in the top down control of adaptive emotion regulation and the inhibition of ruminative processes.

Effects of combined theta burst stimulation and transcranial direct current stimulation of the dorsolateral prefrontal cortex on stress

OBJECTIVE

Research suggests that the combination of different non-invasive brain stimulation techniques, such as intermittent theta-burst stimulation (iTBS) and transcranial direct current stimulation (tDCS), could enhance the effects of stimulation. Studies investigating the combination of tDCS and iTBS over the dorsolateral prefrontal cortex (DLPFC) are lacking. In this within-subjects study, we evaluated the additive effects of iTBS with tDCS on psychophysiological measures of stress.

METHOD

Sixty-eight healthy individuals were submitted to a _bifrontaltDCS + iTBS and _shamtDCS + iTBS protocol targeting the DLPFC with a one-week interval. The Maastricht Acute Stress Test was used to activate the stress system after stimulation. Stress reactivity and recovery were assessed using physiological and self-report measures.

RESULTS

The stressor evoked significant psychophysiological changes in both stimulation conditions. However, no evidence was found for differences between them in stress reactivity and recovery. Participants reported more pain and feelings of discomfort to the _bifrontaltDCS + iTBS protocol.

CONCLUSION

In this study set-up, iTBS plus tDCS was not superior to iTBS in downregulating stress in healthy subjects.

SIGNIFICANCE

There is no evidence for an effect of combined tDCS-iTBS of the DLPFC on stress according to the parameters employed in our study. Future studies should explore other stimulation parameters, additive approaches and/or neurobiological markers.

The impact of the COVID-19 pandemic on wellbeing and cognitive functioning of older adults

COVID-19 took a heavy toll on older adults. In Belgium, by the end of August, 93% of deaths due to COVID-19 were aged 65 or older. Similar trends were observed in other countries. As a consequence, older adults were identified as a group at risk, and strict governmental restrictions were imposed on them. This has caused concerns about their mental health. Using an online survey, this study established the impact of the COVID-19 pandemic on adults aged 65 years or older, and which factors moderate this impact. Participants reported a significant decrease in activity level, sleep quality and wellbeing during the COVID-19 pandemic. Depression was strongly related to reported declines in activity level, sleep quality, wellbeing and cognitive functioning. Our study shows that the COVID-19 pandemic had a severe impact on the mental health of older adults. This implies that this group at risk requires attention of governments and healthcare.

Hostility in medication-resistant major depression and comorbid generalized anxiety disorder is related to increased hippocampal-amygdala 5-HT2A receptor density

Major depressive disorder (MDD) and generalized anxiety disorder (GAD) are severe and difficult-to-treat psychiatric illnesses with high rates of comorbidity. Although both disorders are treated with serotonergic based psychotropic agents, little is known on the influence of the serotonergic neurotransmitter system on the occurrence of comorbid GAD when clinically depressed. To investigate this poorly understood clinical question, we examined the involvement of frontolimbic post-synaptic 5-HT_2A receptors in 20 medication-resistant depressed (MRD) patients with half of them diagnosed with comorbid GAD with ¹²³I-5-I-R91150 SPECT. To explore whether 5-HT_2A receptor-binding indices (BI) associated with comorbid GAD could be related to distinct psychopathological symptoms, all were assessed with the symptom Checklist-90-Revised (SCL-90-R). MRD patients with comorbid GAD displayed significantly higher 5-HT_2A receptor BI in the hippocampal-amygdala complex, compared to MRD patients without GAD. Correlation analyses revealed that the 5-HT_2A receptor BI in these areas were significantly related to the SCL-90-R subscale hostility (HOS), especially for those MRD patients with comorbid GAD. Comorbid MRD-GAD may be characterized with increased hippocampal-amygdala 5-HT_2A receptor BI which could represent enhanced levels in hostility in such kinds of patients. Adapted psychotherapeutic interventions may be warranted.

Exposure to Criticism Modulates Left but Not Right Amygdala Functional Connectivity in Healthy Adolescents: Individual Influences of Perceived and Self-Criticism

Background: Frequent exposure to criticism is a known risk factor for various adult psychiatric disorders. Adolescents may be even more vulnerable to (parental) criticism, as their imbalanced brain maturation makes them prone to stronger mood changes and less effective emotional regulation. Identifying which adolescent subgroups are more vulnerable than others could be of great clinical relevance. Perceived criticism (PC) and self-criticism (SC), two related but distinct traits, could well be crucial vulnerability factors. Hypotheses: After exposure to criticism during fMRI scanning, rapid changes in amygdalar functional connectivity (FC) with other brain areas involved in emotion regulation and social cognitive processing will occur. These changes will depend on trait moderators, such as the adolescents' proneness to (a) perceive others as critical of them (PC) or (b) perceive themselves positively or negatively (SC). Methods: Sixty-four healthy 14-17-year-olds were exposed to a series of auditory comments. Changes in mood states were assessed based on the Profile of Mood States (POMS) prior to and after exposure to these segments. Pre- and post-experiment FC of the left and right amygdalae with other brain areas were also measured. Correlates between FC changes and psychometric measures-including the perceived criticism measure (PCM) and self-perception profile for adolescents (SPPA)-were assessed. Results: First, after being criticized, FC increases of the left amygdala seed region with brain areas related to sustained emotional processing were found, but no right amygdalar FC changes. Second, there was a significant positive partial correlation between individual PCM scores and FC changes between the left amygdala seed region and the left precuneus and left superior parietal cortex, both part of the default mode network. Conclusion: Exposure to criticism resulted in a rapid negative mood change accompanied by an increase in FC between the left amygdala and regions known to be involved in sustained emotional processing, but no right amygdalar FC changes. Furthermore, higher PC but not SC was correlated with stronger left amygdalar FC increases with these regions, suggesting an elevated vulnerability for disturbed emotional processing, as observed in mood disorders, in healthy adolescents with higher PCM scores.

Testing the neurocognitive framework for regulation expectation: The relationship between actual/ideal self-esteem and proactive/reactive autonomic stress regulation

BACKGROUND AND OBJECTIVES

According to the Neurocognitive Framework for Regulation Expectation (NFRE), actual and ideal self-esteem are related to how individuals anticipate and respond to a stressful event. Based on this framework, we investigated whether in individuals with low ideal self-esteem (moderator), a positive relationship between actual self-esteem and reactive autonomic regulation would be mediated by the amount of anticipatory autonomic regulation.

METHODS

Forty-five healthy females prepared a speech (i.e., anticipation) and performed it in front of a camera (i.e., stressor). Actual and ideal self-esteem were measured with the Implicit Relational Assessment Procedure. Anticipatory and reactive autonomic stress regulation were indexed by heart rate variability, and affective responses were assessed via self-report.

RESULTS

Results were in line with predictions based on the NFRE: when ideal self-esteem was low, higher actual self-esteem was associated with higher reactive autonomic regulation, and this association was mediated by higher anticipatory autonomic regulation.

LIMITATIONS

Because only female undergraduates were recruited, replication within a more heterogeneous sample is necessary to further generalize these findings.

CONCLUSIONS

These results support the hypothesis, based on the NFRE, that actual and ideal self-esteem interact in predicting the relationship between anticipatory and reactive stress regulation, and are a step forward in the understanding of the mechanisms underlying successful stress regulation.

Combined transcranial direct current stimulation and psychological interventions: State of the art and promising perspectives for clinical psychology

Recent literature shows great heterogeneity in the reported efficacy of transcranial direct current stimulation (tDCS) as a stand-alone psychiatric treatment. Aiming to increase its efficacy, tDCS has been combined with psychological interventions. Our state-of-the-art overview of such combined treatment trials indicates, however, that these usually do not elicit synergistic clinical effects. We therefore explored more basic mechanisms related to the brain state-dependency of tDCS. Importantly, based on our overview, the efficacy of combined interventions may depend on whether individual patients present with endophenotypes that are implicated in the development and maintenance of psychopathology, such as prefrontal-mediated cognitive dysfunction. We discuss how future studies may contribute to the development of personally-tailored dual active treatments by adhering to the Research Domain Criteria (RDoC) framework. RDoC-based mechanistic research may reveal alternative neural circuits that should be functionally targeted by both tDCS and psychological interventions, with promising avenues for clinical psychological science and practice.

Cognitive remediation following electroconvulsive therapy in patients with treatment resistant depression: randomized controlled trail of an intervention for relapse prevention - study protocol

BACKGROUND

Major depressive episode (MDE) is worldwide one of the most prevalent and disabling mental health conditions. In cases of persistent non-response to treatment, electroconvulsive therapy (ECT) is a safe and effective treatment strategy with high response rates. Unfortunately, longitudinal data show low sustained response rates with 6-month relapse rates as high as 50% using existing relapse prevention strategies. Cognitive side effects of ECT, even though transient, might trigger mechanisms that increase relapse in patients who initially responded to ECT. Among these side effects, reduced cognitive control is an important neurobiological driven vulnerability factor for depression. As such, cognitive control training (CCT) holds promise as a non-pharmacological strategy to improve long-term effects of ECT (i.e., increase remission, and reduce depression relapse).

METHOD/DESIGN

Eighty-eight patients aged between 18 and 70 years with MDE who start CCT will be included in this randomized controlled trial (RCT). Following (partial) response to ECT treatment (at least a 25% reduction of clinical symptoms), patients will be randomly assigned to a computer based CCT or active placebo control. A first aim of this RCT is to assess the effects of CCT compared to an active placebo condition on depression symptomatology, cognitive complaints, and quality of life. Secondly, we will monitor patients every 2 weeks for a period of 6 months following CCT/active placebo, allowing the detection of potential relapse of depression. Thirdly, we will assess patient evaluation of the addition of cognitive remediation to ECT using qualitative interview methods (satisfaction, acceptability and appropriateness). Finally, in order to further advance our understanding of the mechanisms underlying effects of CCT, exploratory analyses will be conducted using video footage collected during the CCT/active control phase of the study.

DISCUSSION

Cognitive remediation will be performed following response to ECT, and an extensive follow-up period will be employed. Positive findings would not only benefit patients by decreasing relapse, but also by increasing acceptability of ECT, reducing the burden of cognitive side-effects.

TRIAL REGISTRATION

The study is registered with ClinicalTrials.gov . Study ID: NCT04383509 Trial registration date: 12.05.2020.

The role of cognitive reappraisal and expectations in dealing with social feedback

Whereas emotion regulation (ER) in response to distressing events is widely studied, the mechanisms underlying adaptive ER while anticipating these events are still unknown. In this study, we investigated how ER strategies and expectation influence (a) individuals' anticipatory and online processing of self-relevant events, and (b) their affective response to them. Sixty-one healthy female participants were exposed to bogus positive and negative social feedback under reappraisal (regulation) and watch (no regulation) instructions. During the anticipatory period, participants were either expecting negative feedback or they had no expectation regarding the valence of the upcoming self-relevant feedback. Hence, negative feedback was, respectively, expected or unexpected. Participants' affective responses were collected via self-report and electromyographic (EMG) activity over the corrugator muscle. Results showed that participants' negative affect (based on both self-reports and EMG) was reduced by the instructions to reappraise as compared to the watch condition. Yet, such beneficial effect of reappraisal was: (a) not observed during the anticipation phase, and (b) less effective when social feedback was expected (as compared to not expected) prior to its presentation. Possibly, cognitive reappraisal might be less able to overcome the influence of negative forecasting of self-relevant negative emotional stimuli. Research findings are discussed in light of potential mechanisms underlying impaired adaptive ER in patients vulnerable for mood disorders. (PsycInfo Database Record (c) 2020 APA, all rights reserved).

Flexibility as a Mediator between Personality and Well-Being in Older and Younger Adults: Findings from Questionnaire Data and a Behavioral Task

BACKGROUND

Personality is a predictor of subjective well-being in older and younger adults, but less is known about the underlying mechanisms. One possible mechanism is psychological flexibility, which is the ability to keep an open mind-set in order to make flexible choices adapted to the situation at hand.

METHODS

We recruited 60 younger and 60 older adults and measured personality and well-being by questionnaires. To assess psychological flexibility we used questionnaires and a behavioral task assessing flexibility in information acquisition when making choices.

RESULTS

Based on indirect effect analysis of the questionnaire data, in line with former research, our data show that in both age groups, the relationship between personality and well-being runs through psychological flexibility.

CONCLUSION

This implies that training psychological flexibility may be a promising approach to increase well-being in both older and younger adults. This effect could not be demonstrated with our choice flexibility task, thus more research is needed to uncover why this could not be measured at the behavioral level.

The effect of HF-rTMS over the left DLPFC on stress regulation as measured by cortisol and heart rate variability

The prefrontal cortex, and especially the Dorsolateral Prefrontal Cortex (DLPFC), plays an inhibitory role in the regulation of the Hypothalamic-Pituitary-Adrenal (HPA) axis under stressful situations. Moreover, recent evidence suggests that a sustained DLPFC activation is associated with adaptive stress regulation in anticipation of a stressful event, leading to a reduced stress-induced amygdala response, and facilitating the confrontation with the stressor. However, studies using experimental manipulation of the activity of the DLPFC before a stressor are scarce, and more research is needed to understand the specific role of this brain area in the stress-induced physiological response. This pre-registered study investigated the effect on stress regulation of a single excitatory high frequency (versus sham) repetitive transcranial magnetic stimulation (HF-rTMS) session over the left DLPFC applied before the Trier Social Stress Test in 75 healthy young women (M = 21.05, SD = 2.60). Heart rate variability (HRV) and salivary cortisol were assessed throughout the experimental protocol. The active HF-rTMS and the sham group showed a similar cognitive appraisal of the stress task. No differences in HRV were observed during both the anticipation and the actual confrontation with the stress task and therefore, our results did not reflect DLPFC-related adaptive anticipatory adjustments. Importantly, participants in the active HF-rTMS group showed a lower cortisol response to stress. The effect of left prefrontal HF-rTMS on the stress system provides further critical experimental evidence for the inhibitory role played by the DLPFC in the regulation of the HPA axis.

Effects of HF-rTMS over the left and right DLPFC on proactive and reactive cognitive control

Previous research supports the distinction between proactive and reactive control. Although the dorsolateral prefrontal cortex (DLPFC) has been consistently related to these processes, lateralization of proactive and reactive control is still under debate. We manipulated brain activity to investigate the role of the left and right DLPFC in proactive and reactive cognitive control. Using a single-blind, sham-controlled crossover within-subjects design, 25 young healthy females performed the 'AX' Continuous Performance Task after receiving sham versus active High-Frequency repetitive Transcranial Magnetic Stimulation (HF-rTMS) to increase left and right DLPFC activity. RTs and pupillometry were used to assess patterns of proactive and reactive cognitive control and task-related resource allocation respectively. We observed that, compared to sham, HF-rTMS over the left DLPFC increased proactive control. After right DLPFC HF-rTMS, participants showed slower RTs on AX trials, suggesting more reactive control. However, this latter result was not supported by RTs on BX trials (i.e. the trial that specifically assess reactive control). Pupil measures showed a sustained increase in resource allocation after both active left and right HF-rTMS. Our results with RT data provide evidence on the role of the left DLPFC in proactive control and suggest that the right DLPFC is implicated in reactive control.

Mind the social feedback: effects of tDCS applied to the left DLPFC on psychophysiological responses during the anticipation and reception of social evaluations

The left dorsolateral prefrontal cortex (lDLPFC) is implicated in anticipatory (i.e. during anticipation of emotional stimuli) and online (i.e. during confrontation with emotional stimuli) emotion regulatory processes. However, research that investigates the causal role of the lDLPFC in these processes is lacking. In this study, 74 participants received active or sham transcranial direct current stimulation (tDCS) over the lDLPFC. Participants were told strangers evaluated them. These (rigged) social evaluations were presented, and in 50% of the trials, participants could anticipate the valence (positive or negative) of the upcoming social feedback. Pupil dilation (a marker of cognitive resource allocation), and skin conductance responses (a marker of arousal) were measured. The results indicate that active (compared to sham) tDCS reduced arousal during the confrontation with anticipated feedback, but only marginally during the confrontation with unanticipated feedback. When participants were given the opportunity to anticipate the social feedback, tDCS reduced arousal, irrespective of whether one was anticipating or being confronted with the anticipated feedback. Moreover, tDCS reduced cognitive resource allocation during anticipation, which was associated with resource allocation increases during the subsequent confrontation. Altogether, results suggest that the lDLPFC is causally implicated in the interplay between anticipatory and online emotion regulatory processes.

The effect of neurostimulation applied to the left dorsolateral prefrontal cortex on post-stress adaptation as a function of depressive brooding

Depressive brooding following a stressful event predicts negative affect and neuroendocrine responses related to psychological stress. The dorsolateral prefrontal cortex (DLPFC) has been associated with the top-down regulation of thoughts and emotions, and abnormal neural activity within this region has been associated with increased psychological stress and ruminative thinking. The aim of this study was to investigate whether the modulation of the DLPFC could have beneficial effects on ruminative thoughts and the endocrine response following a self-relevant stressor. Using a sham-controlled within-subjects crossover-design, two sessions of intermittent theta-burst stimulation (iTBS) were administered over the left DLPFC to thirty-eight healthy-volunteers after they were confronted with a social-evaluative stressor, the Trier Social Stress Test. To assess stress recovery, momentary rumination was measured before and after a resting period subsequent to the encounter with the stressor. In addition, cortisol levels were measured between and after the two iTBS sessions that were applied during the stress recovery phase. Overall, iTBS did not significantly influence ruminative thinking and cortisol secretion during the stress recovery phase. However, taking into account participants ruminative tendencies, our results revealed that for participants with higher levels of brooding ruminative thinking remained stable after iTBS, whereas in the sham condition there was a marginal significant increase in ruminative thinking. Moreover, only after iTBS, there was a significant reduction in cortisol secretion (i.e. a faster return to baseline as compared to sham) for high brooders during the recovery from the stressor. These results show that the prefrontal cortex plays a role in stress recovery mechanisms in individuals who are more vulnerable for psychopathology.

Cortisol response to stress: The role of expectancy and anticipatory stress regulation

An exacerbated physiological response to stress is associated with the development of stress-related disorders (e.g., depression and anxiety disorders). Recently, it has been proposed that individuals with high expectancies of being able to deal with stressful situations will activate regulatory mechanisms during the anticipation of the stressful event that would improve stress regulation. To test this hypothesis, 52 women in young adulthood (M = 21.06; SD = 2.58) anticipated and performed a laboratory-based stress task after receiving positive or negative bogus feedback on their abilities to deal with stressful events. Heart rate variability and salivary cortisol were assessed throughout the experimental protocol. Participants receiving positive bogus feedback (i.e., High Expectancy group) showed a more positive anticipatory cognitive stress appraisal (i.e., they anticipated the stress task as less threatening/challenging, and they perceived that they were more able to deal with it), and they showed a lower cortisol response to stress. Moreover, a more positive anticipatory cognitive stress appraisal was associated with better anticipatory stress regulation (indexed as less decrease in heart rate variability), leading to a lower cortisol response. Our results indicate that people with positive expectancy initiate mechanisms of anticipatory stress regulation that enhance the regulation of the physiological stress response. Expectancy and anticipatory stress regulation may be key mechanisms in the development and treatment of stress-related disorders.