Individual differences associated with treatment adherence and transfer effects following gamified web-based cognitive control training for repetitive negative thinking

Recent research suggests beneficial effects of cognitive control training (CCT) on repetitive negative thinking (RNT), a key risk factor for internalizing symptomatology. However, relatively little is known regarding predictors of adherence to internet-delivered CCT as well as moderators of treatment effects for this intervention. Answering these questions could improve efficiency of clinical implementation of CCT as an eHealth intervention. The current pre-registered single-arm trial set-out to address these questions using a web-based gamified CCT procedure based on the adaptive Paced Auditory Serial Addition Task. Participants (N = 382) entered the internet-based study, where we observed considerable drop-out during the assessment phase and the first training sessions. Emotional stability and resilience emerged as predictors for deciding not to commence the intervention. Drop-out throughout the course of CCT was explained by age, emotion regulation-, and personality factors. We used latent profile analysis, a probabilistic modeling approach, to identify clusters of participants (User Profiles) based on indicators of baseline cognitive- and emotional functioning, training progress, and user experience. We obtained three User Profiles, reflecting low-, moderate-, and high-risk status. Effortful control, emotion regulation, internalizing symptomatology, resilience, and emotional stability played a central role in these User Profiles. Interestingly, User Profile predicted training related cognitive gains, as well as effects of CCT on anxiety- and stress symptoms, and reappraisal. Our findings suggest that CCT is most effective for the moderate- and high-risk groups. In addition, the high-risk group would likely benefit from a more intensive training procedure or repeated administration of the training procedure over time to foster long-term retention of training related gains.

Functional connectivity–based prediction of global cognition and motor function in riluzole-naive amyotrophic lateral sclerosis patients

Amyotrophic lateral sclerosis (ALS) is increasingly recognized as a multisystem disorder accompanied by cognitive changes. To date, no effective therapy is available for ALS patients, partly due to disease heterogeneity and an imperfect understanding of the underlying pathophysiological processes. Reliable models that can predict cognitive and motor deficits are needed to improve symptomatic treatment and slow down disease progression. This study aimed to identify individualized functional connectivity–based predictors of cognitive and motor function in ALS by using multiple kernel learning (MKL) regression. Resting-state fMRI scanning was performed on 34 riluzole-naive ALS patients. Motor severity and global cognition were separately measured with the revised ALS functional rating scale (ALSFRS-R) and the Montreal Cognitive Assessment (MoCA). Our results showed that functional connectivity within the default mode network (DMN) as well as between the DMN and the sensorimotor network (SMN), fronto-parietal network (FPN), and salience network (SN) were predictive for MoCA scores. Additionally, the observed connectivity patterns were also predictive for the individual ALSFRS-R scores. Our findings demonstrate that cognitive and motor impairments may share common connectivity fingerprints in ALS patients. Furthermore, the identified brain connectivity signatures may serve as novel targets for effective disease-modifying therapies.

Amyotrophic lateral sclerosis is recognized as a multisystem disorder, and currently no effective therapy is available for this devastating disease. Reliable models that can predict disease progression may facilitate the development of more efficient symptomatic treatment. This study used multiple kernel learning algorithm to identify a potential functional connectivity–based marker for cognitive and motor functioning in ALS. The results show that cognitive decline and motor progression could be predicted by seed-based functional connectivity from the medial prefrontal cortex/posterior cingulate cortex to the sensorimotor network, fronto-parietal network, and salience network. The identified brain connectivity signatures may serve as novel targets for effective disease-modifying therapies.

Combined effects of theta-burst stimulation with transcranial direct current stimulation of the prefrontal cortex: study protocol of a randomized, double-blinded, sham-controlled trial using 99mTc-ECD SPECT

Introduction

Non-invasive brain stimulation (NIBS) as monotherapy has been increasingly used to enhance the activity of brain networks. However, it is unclear whether a combination of distinct NIBS approaches could enhance prefrontal cortical (PFC) activity.

Objective

We propose to investigate the combined and standalone effects of two NIBS modalities on the PFC through a working memory task, single photon emission computed tomography (SPECT), and salivary cortisol. We hypothesize that the combined protocol will provoke greater changes in the collected measures compared to the remining protocols.

Methods

A randomized, double-blind, sham-controlled, full-factorial design will be conducted. The effects of transcranial direct current stimulation (tDCS) and intermittent theta-burst stimulation (iTBS) will be investigated over four different sessions (sham tDCS + sham iTBS, anodal tDCS + sham iTBS, anodal tDCS + active iTBS and sham tDCS + active iTBS) in 30 healthy adult volunteers. A 99mTc-ethylene cysteine dimer (99mTC-ECD) will be administered during the NIBS session and neuroimaging will be acquired within one hour. Salivary cortisol will be collected before and after each session and an n-back working memory task will be applied after the end of each NIBS session. The outcomes will be cerebral perfusion alterations (99mTC-ECD SPECT), accuracy and reaction time in the n-back task, and changes in salivary cortisol level.

Conclusion

The results from this trial can guide future therapeutic protocols for NIBS treatments stimulating the PFC by demonstrating that the combination of NIBS techniques is feasible, tolerable, and can lead to greater enhancement of PFC activity.

[Transcranial direct current stimulation in substance use disorders: an update]

BACKGROUND

Existing treatments for substance use disorders are often subject to drop-out or relapse. Transcranial direct current stimulation (tDCS) possibly has a positive effect on this problem.

AIM

To give an updated qualitative review of existing studies investigating the clinical effects of transcranial direct current stimulation for people with a substance use disorder, considering the many recently published studies.

METHOD

Extensive literature search in the electronic database PubMed. We included 43 studies on top of the 7 studies already included in the previous review of Herremans and Baeken (2017) in this journal.

RESULTS

The majority of the studies showed a positive effect of transcranial direct current stimulation on clinical measures as craving and abstinence. However, there was little uniformity in used protocols.

CONCLUSION

Transcranial direct current stimulation can be an effective treatment for people with a substance use disorder. Optimal parameters need to be established to make the treatment maximally effective and adapted to the individual patient.

Auricular transcutaneous vagus nerve stimulation modulates the heart-evoked potential

BACKGROUND

There is active interest in biomarker discovery for transcutaneous auricular vagus nerve stimulation (taVNS). However, greater understanding of the neurobiological mechanisms is needed to identify candidate markers. Accumulating evidence suggests that taVNS influences activity in solitary and parabrachial nuclei, the primary brainstem relays for the transmission of visceral sensory afferents to the insula. The insula mediates interoception, which concerns the representation and regulation of homeostatic bodily states. Consequently, interoceptive pathways may be relevant to taVNS mechanisms of action.

HYPOTHESES

We hypothesized that taVNS would modulate an EEG-derived marker of interoceptive processing known as the heart-evoked potential (HEP). We also hypothesized that taVNS-induced HEP effects would be localizable to the insula.

METHODS

Using a within-subject, sham-controlled design in 43 healthy adults, we recorded EEG and ECG concurrent to taVNS. Using ECG and EEG data, we extracted HEPs. Estimation of the cortical sources of the taVNS-dependent HEP responses observed at the scalp were computed using the Boundary Element Method and weighted Minimum Norm Estimation. Statistics were calculated using cluster-based permutation methods.

RESULTS

taVNS altered HEP amplitudes at frontocentral and centroparietal electrode sites at various latencies. The taVNS-dependent HEP effect was localized to the insula, operculum, somatosensory cortex, and orbital and ventromedial prefrontal regions.

CONCLUSION

The results support the hypothesis that taVNS can access the insula as well as functionally and anatomically connected ventral prefrontal regions. HEPs may serve as an objective, non-invasive outcome parameter for the cortical effects of taVNS.

Individual interregional perfusion between the left dorsolateral prefrontal cortex stimulation targets and the subgenual anterior cortex predicts response and remission to aiTBS treatment in medication-resistant depression: The influence of behavioral inhibition

BACKGROUND

Accelerated intermittent Theta Burst Stimulation (aiTBS) has been put forward as an effective treatment to alleviate depressive symptoms. Baseline functional connectivity (FC) patterns between the left dorsolateral prefrontal cortex (DLPFC) and the subgenual anterior cortex (sgACC) have gained a lot of attention as a potential biomarker for response. However, arterial spin labeling (ASL) - measuring regional cerebral blood flow - may allow a more straightforward physiological interpretation of such interregional functional connections.

OBJECTIVES

We investigated whether baseline covariance perfusion connectivity between the individually stimulated left DLPFC targets and sgACC could predict meaningful clinical outcome. Considering that individual characteristics may influence efficacy prediction, all patients were also assessed with the Behavioral Inhibition System/Behavioral Activation System (BIS/BAS) scale.

METHODS

After baseline ASL scanning, forty-one medication-resistant depressed patients received twenty sessions of neuronavigated left DLPFC aiTBS in an accelerated sham-controlled crossover fashion, where all stimulation sessions were spread over four days (Trial registration: http://clinicaltrials.gov/show/NCT01832805).

RESULTS

Stronger individual baseline interregional covariance perfusion connectivity patterns predicted response and/or remission. Furthermore, responders and remitters with higher BIS scores displayed stronger baseline interregional perfusion connections.

CONCLUSIONS

Targeting the left DLPFC with aiTBS based on personal structural imaging data only may not be the most optimal method to enhance meaningful antidepressant responses. Individual baseline interregional perfusion connectivity could be an important added brain imaging method for individual optimization of more valid stimulation targets within the left DLPFC. Additional therapies dealing with behavioral inhibition may be warranted.

How are OCD Patients and Family Members Dealing with the Waxing and Waning Pattern of the COVID-19 Pandemic? Results of a Longitudinal Observational Study

The current study aimed to investigate the impact of the COVID-19 pandemic on the mental health of people with OCD and the degree of family accommodation (FA) by live-in family members across phases of the lockdown measures imposed by the Belgian government. Forty-nine OCD patients and 26 live-in family members participated in the study. We assessed OCD symptom severity and FA of the live-in family members, as well as depressive symptoms, anxiety and stress levels and COVID-19 related psychological distress of patients and family members at four different timepoints: one month after the start of the lockdown (T₁), during the gradual relaxation (T₂), between the two waves (T₃) and during the second wave (T₄). Results showed that although COVID-19 related stress increased and decreased in accordance with the waxing and waning pattern of the pandemic, OCD symptoms showed an initial slight increase followed by a decrease at T₃ and again at T₄. Changes in family members' accommodation of symptoms followed the same course as the OCD symptoms. Furthermore, OCD symptoms correlated with depressive symptoms, anxiety and stress levels and COVID-19 related distress at all timepoints. It is important to involve family members in the treatment of OCD even during a pandemic. Clinicians should also pay attention to symptoms of depression, anxiety and stress during OCD treatment. Further research is necessary to entangle the causal relationship between OCD symptoms, FA and symptoms of depression, anxiety and stress.

The Involvement of the Posterior Cerebellum in Reconstructing and Predicting Social Action Sequences

Recent advances in social neuroscience have highlighted the critical role of the cerebellum and especially the posterior cerebellar Crus in social mentalizing (i.e., theory of mind). Research in the past 5 years has provided growing evidence supporting the view that the posterior cerebellum builds internal action models of our social interactions to predict how other people's actions will be executed, and what our most likely responses to these actions will be. This paper presents an overview of a series of fMRI experiments on novel tasks involving a combination of (a) the learning or generation of chronological sequences of social actions either in an explicit or implicit manner, which (b) require social mentalizing on another person's mental state such as goals, beliefs, and implied traits. Together, the results strongly confirm the central role of the posterior cerebellar Crus in identifying and automatizing action sequencing during social mentalizing, and in predicting future action sequences based on social mentalizing inferences about others. This research program has important implications: It provides for the first time (a) fruitful starting points for diagnosing and investigating social sequencing dysfunctions in a variety of mental disorders which have also been related to cerebellar dysfunctions, (b) provides the necessary tools for testing whether non-invasive neurostimulation targeting the posterior cerebellum has a causal effect on social functioning, and (c) whether these stimulation techniques and training programs guided by novel cerebellar social sequencing insights, can be exploited to increase posterior cerebellar plasticity in order to alleviate social impairments in mental disorders.

The Role of the Posterior Cerebellum in Dysfunctional Social Sequencing

Recent advances in social neuroscience have highlighted the critical role of the cerebellum in social cognition, and especially the posterior cerebellum. Studies have supported the view that the posterior cerebellum builds internal action models of our social interactions to predict how other people's actions will be executed and what our most likely responses are to these actions. This mechanism allows to better anticipate action sequences during social interactions in an automatic and intuitive way and to fine-tune these anticipations, making it easier to understand other's social behaviors and mental states (e.g., beliefs, intentions, traits). In this paper, we argue that the central role of the posterior cerebellum in identifying and automatizing social action sequencing provides a fruitful starting point for investigating social dysfunctions in a variety of clinical pathologies, such as autism, obsessive-compulsive and bipolar disorder, depression, and addiction. Our key hypothesis is that dysfunctions of the posterior cerebellum lead to under- or overuse of inflexible social routines and lack of plasticity for learning new, more adaptive, social automatisms. We briefly review past research supporting this view and propose a program of research to test our hypothesis. This approach might alleviate a variety of mental problems of individuals who suffer from inflexible automatizations that stand in the way of adjustable and intuitive social behavior, by increasing posterior cerebellar plasticity using noninvasive neurostimulation or neuro-guided training programs.

Implicit learning of perceptual sequences is preserved in Parkinson's disease

OBJECTIVE

Various studies investigated implicit sequence learning in Parkinson's disease (PD) by means of the traditional motor Serial Reaction Time (SRT) task and found a general pattern of impaired sequence learning. However, as perceptual and motor sequences of the SRT-task were correlated in previous studies, implicit sequential knowledge acquisition that is tested independently from motor sequences remains to be determined in PD. In this study, we investigated implicit sequence learning independently from motor sequence learning in individuals with PD. To this end, we used a perceptual SRT-task that did not rely upon sequential motor knowledge.

METHOD

We measured response times (RTs) of 19 participants with PD (Hoehn & Yahr II or III; mean age 65) and 18 age-matched healthy controls (HC; mean age 61.5) in a perceptual SRT-task. General learning effects and sequence-specific learning effects were analyzed using repeated measures ANOVAs.

RESULTS

A significant decreasing linear trend (p < .001) in RTs was revealed in both the PD and HC groups as the SRT-task progressed, indicating general learning effects. Notably, a significant, strong main effect of sequence-specific learning occurred (p < .001), irrespective of group (p = .436). Sequence-specific learning did not differ significantly between the PD (M = 156.5 ms; SD = 50.7) and HC group (M = 173.0 ms; SD = 104.2). Bayesian analyses confirmed this as evidence of absence of an effect (B₁₀ = 3.543).

CONCLUSIONS

Our results suggest that, at least in Hoehn & Yahr stages II and III, implicit sequential knowledge acquisition may be preserved in individuals with PD, when tested independently from motor sequence learning. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Social cerebellum in goal-directed navigation

The posterior cerebellum is responsible for the understanding and learning of sequences of actions by others, which are a prerequisite for social understanding. This study investigates this cerebellar function while navigating toward a goal in a social context. Participants undertook a novel social navigation task requiring them to memorize and subsequently reproduce a protagonist's trajectory through a grid toward a desirable goal. As a nonsocial control condition, a ball underwent the same trajectory by passively rolling through the grid toward the same endpoint. To establish that memorizing and reproducing a trajectory is a critical cerebellar function, two non-sequencing control conditions were created, which involved the observation only of the trajectory by the protagonist or ball. Our results showed that the posterior cerebellar Crus II was involved in memorizing both social and nonsocial trajectories, along with the parahippocampal gyrus and other cortical areas involved in social cognition. As hypothesized, cerebellar Crus I was more active when memorizing social as opposed to nonsocial trajectories. Moreover, cerebellar Crus I and II, and lobule VI, were activated when reproducing both social and nonsocial trajectories. These findings highlight the involvement of the posterior cerebellar Crus in supporting human goal-directed social navigation.

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.

Non-invasive vagal nerve stimulation enhances cognitive emotion regulation

Transcutaneous auricular vagus nerve stimulation (taVNS) has been proposed as a potential new tool in the treatment of major depressive disorder. Prior studies have demonstrated that taVNS enhances cognitive control and is able to modulate brain activity in key regions involved in cognitive emotion regulation, such as the anterior cingulate and medial prefrontal cortex, which is known to be impaired in depressed patients. Preclinical studies are lacking but may provide important insights into the working mechanisms of taVNS on cognitive emotion regulatory processes. In this between-subject study, 83 healthy subjects underwent a single-session of active taVNS or sham stimulation, after which cognitive reappraisal was examined using a computer-based cognitive emotion regulation task. Our results indicate that participants receiving active taVNS, compared to sham, were better at using cognitive reappraisal and rated their response to emotion-eliciting pictures as less intense. Yet, even though we found significant differences in behavioral measures of cognitive emotion regulation, no differences between groups were found in terms of physiological responses to the emotional stimuli. Overall, these findings suggest a positive effect of taVNS on the cognitive reappraisal of emotions, but future studies assessing objective measures of neural activity during cognitive emotion regulation following taVNS are warranted.

Effective connectivity predicts cognitive empathy in cocaine addiction: a spectral dynamic causal modeling study

Social cognition plays a crucial role in the development and treatment of cocaine dependence. However, studies investigating social cognition, such as empathy and its underlying neural basis, are lacking. To explore the neural interactions among reward and memory circuits, we applied effective connectivity analysis on resting-state fMRI data collected from cocaine-dependent subjects. The relationship between effective connectivity within these two important circuits and empathy ability - evaluated with the Interpersonal Reactivity Index (IRI) - was assessed by machine learning algorithm using multivariate regression analysis. In accordance with the neurocircuitry disruptions of cocaine addiction, the results showed that cocaine-dependent subjects relative to healthy controls had altered resting state effective connectivity between parts of the memory and reward systems. Furthermore, effective connectivity between the memory and reward system could predict the fantasy empathy (FE) subscale scores in cocaine dependence. Overall, our findings provide further evidence for the neural substrates of social cognition in cocaine-dependent patients. These new insights could be useful for the development of new treatment programs for this substance dependency disorder.

Social Thinking is for Doing: The Posterior Cerebellum Supports Prediction of Social Actions Based on Personality Traits

Can we predict the future by reading others’ minds? This study explores whether attributing others’ personality traits facilitates predictions about their future actions and the temporal order of these future actions. Prior evidence demonstrated that the posterior cerebellar crus is involved in identifying the temporal sequence of social actions and the person’s traits they imply. Based on this, we hypothesized that this area might also be recruited in the reverse process; that is, knowledge of another person’s personality traits supports predictions of temporal sequences of others’ actions. In this study, participants were informed about the trait of a person and then had to select actions that were consistent with this information and arrange them in the most likely temporal order. As hypothesized, the posterior cerebellar crus 1 and crus 2 were strongly activated when compared to a control task which involved only the selection of actions (without temporal ordering) or which depicted non-social objects and their characteristics. Our findings highlight the important function of the posterior cerebellar crus in the prediction of social action sequences in social understanding.

Increased brain reactivity to gambling unavailability as a marker of problem gambling

The unprecedented development and ubiquity of sports betting constitute an emerging public health concern. It is crucial to provide markers that could help to better identify people experiencing sports betting-related harms. The current study investigated whether problem gambling status, sports betting passion, and trait-self-control modulate brain reactivity to sports betting cues. Sixty-five frequent sports bettors (35 "nonproblem bettors" and 30 "problem bettors") were exposed to cues representing real upcoming sport events (with varying levels of winning confidence) that were made available or blocked for betting, during functional magnetic resonance imaging (fMRI) recording. Sports betting passion and trait-self-control were assessed using self-report scales. Sport events nonavailable for betting elicited higher insular and striatal activation in problem bettors, as compared with nonproblem bettors. Within a large cluster encompassing the ventral striatum, hippocampus, and amygdala, lower trait-self-control was associated with increased brain reactivity to sport events with high levels of winning confidence that were nonavailable for betting. No significant effect of sports betting passion was observed. These findings suggest that sports bettors' brain reactivity to gambling unavailability might be a relevant marker of sports betting-related harms, as well as of blunted trait-self-control.

Registered report: Does transcranial direct current stimulation of the primary motor cortex improve implicit motor sequence learning in Parkinson's disease?

Implicit motor sequence learning (IMSL) is a cognitive function that is known to be directly associated with impaired motor function in Parkinson's disease (PD). Research on healthy young participants shows the potential for transcranial direct current stimulation (tDCS), a noninvasive brain stimulation technique, over the primary motor cortex (M1) to enhance IMSL. tDCS has direct effects on the underlying cortex, but also induces distant (basal ganglia) network effects-hence its potential value in PD, a prime model of basal ganglia dysfunction. To date, only null effects have been reported in persons with PD. However, these studies did not determine the reacquisition effects, although previous studies in healthy young adults suggest that tDCS specifically exerts its beneficial effects on IMSL on reacquisition rather than acquisition. In the current study, we will therefore establish possible reacquisition effects, which are of a particular interest, as long-term effects are vital for the successful functional rehabilitation of persons with PD. Using a sham-controlled, counterbalanced design, we will investigate the potential of tDCS delivered over M1 to enhance IMSL, as measured by the serial reaction time task, in persons with PD and a neurologically healthy age- and sex-matched control (HC) group. Multilevel Mixed Models will be implemented to analyze the sequence-specific aspect of IMSL (primary outcome) and general learning (secondary outcome). We will determine not only the immediate effects that may occur concurrently with the application of tDCS but also the short-term (5 min post-tDCS) and long-term (1 week post-tDCS) reacquisition effects.

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.