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result(s) for
"Viviani, Roberto"
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Neurobiological models of emotion regulation: a meta-analysis of neuroimaging studies of acceptance as an emotion regulation strategy
by
Grecucci, Alessandro
,
Viviani, Roberto
,
Messina, Irene
in
Brain
,
Brain research
,
Emotional regulation
2021
Abstract
Emotional acceptance is an important emotion regulation strategy promoted by most psychotherapy approaches. We adopted the Activation Likelihood Estimation technique to obtain a quantitative summary of previous fMRI (functional Magnetic Resonance Imaging) studies of acceptance and test different hypotheses on its mechanisms of action. The main meta-analysis included 13 experiments contrasting acceptance to control conditions, yielding a total of 422 subjects and 170 foci of brain activity. Additionally, subgroups of studies with different control conditions (react naturally or focus on emotions) were identified and analysed separately. Our results showed executive areas to be affected by acceptance only in the subgroup of studies in which acceptance was compared to natural reactions. In contrast, a cluster of decreased brain activity located in the posterior cingulate cortex (PCC)/precuneus was associated with acceptance regardless of the control condition. These findings suggest that high-level executive cortical processes are not a distinctive feature of acceptance, whereas functional deactivations in the PCC/precuneus constitute its specific neural substrate. The neuroimaging of emotional acceptance calls into question a key tenet of current neurobiological models of emotion regulation consisting in the necessary involvement of high-level executive processes to actively modify emotional states, suggesting a complementary role for limbic portions of the default system.
Journal Article
The fMRI global signal and its association with the signal from cranial bone
by
Labek, Karin
,
Viviani, Roberto
,
Orsini, Chiara
in
Adult
,
Autonomic nervous system
,
Bone imaging
2024
•The fMRI global signal is a proxy for the mean signal from cerebral cortex.•The global signal is thought to contain neural and vascular signal.•It is shown that the global signal is highly correlated from that of cranial bone.•Finding suggests the origin of global signal to be prevalently vascular.
The nature of the global signal, i.e. the average signal from sequential functional imaging scans of the brain or the cortex, is not well understood, but is thought to include vascular and neural components. Using resting state data, we report on the strong association between the global signal and the average signal from the part of the volume that includes the cranial bone and subdural vessels and venous collectors, separated from each other and the subdural space by multispectral segmentation procedures. While subdural vessels carried a signal with a phase delay relative to the cortex, the association with the cortical signal was strongest in the parts of the scan corresponding to the laminae of the cranial bone, reaching 80% shared variance in some individuals. These findings suggest that in resting state data vascular components may play a prominent role in the genesis of fluctuations of the global signal. Evidence from other studies on the existence of neural sources of the global signal suggests that it may reflect the action of multiple mechanisms (including cerebrovascular reactivity and autonomic control) concurrently acting to regulate global cerebral perfusion.
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Journal Article
Neural Correlates of Psychotherapy in Anxiety and Depression: A Meta-Analysis
2013
Several studies have used neuroimaging methods to identify neural change in brain networks associated to emotion regulation after psychotherapy of depression and anxiety. In the present work we adopted a meta-analytic technique specific to neuroimaging data to evaluate the consistence of empirical findings and assess models of therapy that have been proposed in the literature. Meta-analyses were conducted with the Activation Likelihood Estimation technique, which evaluates the overlap between foci of activation across studies. The analysis included 16 studies found in Pubmed (200 foci of activation and 193 patients). Separate meta-analyses were conducted on studies of 1) depression, post-traumatic stress disorder and panic disorder investigated with rest state metabolism (6 studies, 70 patients); 2) depression, post-traumatic stress disorder and panic disorder investigated with task-related activation studies (5 studies, 65 patients); 3) the previous studies considered jointly; and 4) phobias investigated with studies on exposure-related activation (5 studies, 57 patients). Studies on anxiety and depression gave partially consistent results for changes in the dorsomedial prefrontal cortex and in the posterior cingulated gyrus/precuneus. Several areas of change in the temporal lobes were also observed. Studies on the therapy of phobia were consistent with a reduction of activity in medial temporal areas. The cluster of change in the prefrontal cortex may refer to increased recruitment of control processes, as hypothesized by influential models of emotion regulation changes due to psychotherapy. However, not all areas associated with controlled emotion regulation were detected in the meta-analysis, while involvement of midline structures suggested changes in self-related information processing. Changes in phobia were consistent with reduced reactivity to phobic stimuli.
Journal Article
Functional imaging of time on task and the involvement of dopaminergic and cholinergic substrates in cognitive effort and reward
2026
Neuroimaging studies have identified the neural substrates associated with sustained cognitive efforts and control and their modulation by rewards. Different lines of evidence implicate the prefrontal cortex (especially the anterior cingulate cortex, ACC), dopaminergic, and cholinergic substrates in this modulation. We studied here the activity of these substrates at increasing time on task (requiring increasing levels of cognitive effort) in trials within blocks with differing reward levels. In the cortex, while peaking in the ACC, activity associated with time on task was extensive, also including activity decrements outside the default mode network, primarily involving motor and somatosensory regions. Information about reward levels was carried in the ventral striatum, consistent with its motivational role, but did not reflect trade-offs with increasing efforts during time on task. Instead, the ventral tegmental area and parts of the basal forebrain (BF) corresponding to the cholinergic Ch4 nuclei increased in activity with time on task and were sensitive to reward levels. This BF activity is consistent with a cholinergic role in driving compensatory efforts modulated by reward levels. These findings identify the BF as a neuroimaging phenotype associated with sustaining task sets and cognitive efforts.
Journal Article
Changing views of emotion regulation and neurobiological models of the mechanism of action of psychotherapy
by
Viviani, Roberto
,
Messina, Irene
,
Sambin, Marco
in
Behavioral Science and Psychology
,
Brain - diagnostic imaging
,
Brain - physiopathology
2016
Influential neurobiological models of the mechanism of action of psychotherapy attribute its success to increases of activity in prefrontal areas and decreases in limbic areas, interpreted as the successful and adaptive recruitment of controlled processes to achieve emotion regulation. In this article, we review the behavioral and neuroscientific evidence in support of this model and its applicability to explain the mechanism of action of psychotherapy. Neuroimaging studies of explicit emotion regulation, evidence on the neurobiological substrates of implicit emotion regulation, and meta-analyses of neuroimaging studies of the effect of psychotherapy consistently suggest that areas implicated in coding semantic representations play an important role in emotion regulation not covered by existing models based on controlled processes. We discuss the findings that implicate these same areas in supporting working memory, in encoding preferences and the prospective outcome of actions taken in rewarding or aversive contingencies, and show how these functions may be integrated into process models of emotion regulation that depend on elaborate semantic representations for their effectiveness. These alternative models also appear to be more consistent with internal accounts in the psychotherapeutic literature of how psychotherapy works.
Journal Article
Reassessing the Neural Correlates of Social Exclusion: A Replication Study of the Cyberball Paradigm Using Arterial Spin Labeling
2024
Background/Objectives: The cyberball paradigm has been used in numerous neuroimaging studies to elicit activation in neural substrates of social exclusion, which have been interpreted in terms of activity associated with “social pain”. The objectives of the study were to assess not only the replicability but also the specificity of the areas activated by this paradigm. Methods: Functional imaging with arterial spin labeling, an approach to image longer mental states. Results: We replicated findings of previous meta-analyses of this paradigm in the inferior frontal gyrus and ventral cingular cortex. However, these areas were also active in a watch condition (in which participants were not excluded), although less so. Conclusions: These findings relativize a simple and specific interpretation of these areas as the neural substrates of social exclusion and social pain, as in previous studies. In a broader experimental context, similar activations have been reported by neuroimaging studies when semantic disambiguation and evaluation of action goals are required, an interpretation that may also apply to the effects elicited by this paradigm.
Journal Article
Cognitions in antisocial personality and their association with “dark” traits
2024
Unlike the cognitions associated with depressive symptoms, little is known about those associated with antisocial personality and with its related traits (“dark traits”). Using the scrambled sentences task, an instrument from depression research, we investigated cognitions such as justifications (external blaming for one’s behavior) and harm to others (based on the notion that some of these individuals enjoy harming or humiliating others) that we hypothesized may be prevalent in those high in antisocial personality traits. Confirming our hypothesis, these cognitions were associated with ratings on different antisocial personality scales and with antisocial and detachment scores in the alternative model of personality disorders of the DSM-5 (AMPD) in three non-clinical samples, but not with depressive symptoms or neuroticism. Cognitions including harm to others were differentially associated with high sadism. These findings empirically characterize classes of cognitions that are shared by individuals with antisocial tendencies, and that differ from those associated with depressive symptoms.
Journal Article
Segregation, connectivity, and gradients of deactivation in neural correlates of evidence in social decision making
2020
Functional imaging studies of sensory decision making have detected a signal associated with evidence for decisions that is consistent with data from single-cell recordings in laboratory animals. However, the generality of this finding and its implications on our understanding of the organization of the fMRI signal are not clear. In the present functional imaging study, we investigated decisions in an elementary social cognition domain to identify the neural correlates of evidence, their segregation, connectivity, and their relationship to task deactivations. Besides providing data in support of an evidence-related signal in a social cognition task, we were interested in embedding these neural correlates in models of supramodal associative cortex placed at the top of a hierarchy of processing areas. Participants were asked to decide which of two depicted individuals was saddest based on information rich in sensory features (facial expressions) or through contextual cues suggesting the mental state of others (stylized drawings of mourning individuals). The signal associated with evidence for the decision was located in two distinct networks differentially recruited depending on the information type. Using the largest peaks of the signal associated with evidence as seeds in a database of connectivity data, these two networks were retrieved. Furthermore, the hubs of these networks were located near or along a ribbon of cortex located between task activations and deactivations between areas affected by perceptual priming and the deactivated areas of the default network system. In associative cortex, these findings suggest gradients of progressive relative deactivation as a possible neural correlate of the cortical organization envisaged by structural models of cortical organization and by predictive coding theories of cortical function.
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Journal Article
Dealing with adverse drug reactions in the context of polypharmacy using regression models
2024
Polypharmacy in older adults increases the risk of adverse drug reactions (ADRs), but studying this relationship is complex. In real-world data, the high number of medications, coupled with rare drug combinations, results in high-dimensional datasets that are difficult to analyze using conventional statistical methods. This study applies horseshoe and lasso regression for analyzing rare events in polypharmacy contexts, focusing on severe ADRs such as falls and bleedings. These regression models are executed on a multi-center dataset compiling 7175 cases from the ADRED project to detect potential ADR-associated drugs among 100 most common drugs in emergency department admissions. Positive predictors are classified by using 50% and 90% credibility intervals. This study demonstrates that regression models with horseshoe or lasso priors are effective for analyzing ADRs, providing a comprehensive consideration of multiple factors in large, sparse datasets and improving signal detection in polypharmacy, addressing a significant challenge in pharmacovigilance. Both priors yielded consistent and clinically meaningful results. The horseshoe regression resulted in fewer potential positive predictors overall, which could make it suitable as a diagnostic tool. While these regressions generate valuable information, there are still challenges in setting appropriate thresholds for determining and interpreting the positive results.
Journal Article
Resting State Functional Connectivity in Perfusion Imaging: Correlation Maps with BOLD Connectivity and Resting State Perfusion
2011
Functional connectivity is a property of the resting state that may provide biomarkers of brain function and individual differences. Classically, connectivity is estimated as the temporal correlation of spontaneous fluctuations of BOLD signal. We investigated differences in connectivity estimated from the BOLD and CBF signal present in volumes acquired with arterial spin labeling technique in a large sample (N = 265) of healthy individuals. Positive connectivity was observable in both BOLD and CBF signal, and was present in the CBF signal also at frequencies lower than 0.009 Hz, here investigated for the first time. Negative connectivity was more variable. The validity of positive connectivity was confirmed by the existence of correlation across individuals in its intensity estimated from the BOLD and CBF signal. In contrast, there was little or no correlation across individuals between intensity of connectivity and mean perfusion levels, suggesting that these two biomarkers correspond to distinct sources of individual differences.
Journal Article