The impact of self-distancing on emotion explosiveness and accumulation: An fMRI study.

Emotions unfold over time with episodes differing in explosiveness (i.e., profiles having a steep vs. a gentle start) and accumulation (i.e., profiles increasing over time vs. going back to baseline). In the present fMRI study, we wanted to replicate and extend previous findings on the psychological and neural mechanisms underlying emotion explosiveness and accumulation. Specifically, we aimed to: (a) replicate the finding that different neural mechanisms are associated with emotion explosiveness and accumulation, (b) replicate the finding that adopting a self-distanced (vs. self-immersed) perspective decreases emotion explosiveness and accumulation at the level of self-report, and (c) examine whether adopting a self-distanced (vs. self-immersed) perspective similarly modulates activity in the brain regions associated with emotion explosiveness and accumulation. Participants in an fMRI scanner were asked to adopt a self-immersed or self-distanced perspective while reading and thinking about negative social feedback, and to report on felt changes in negative affect during that period using an emotion intensity profile tracking approach. We replicated previous findings showing that emotion explosiveness and accumulation were related to activity in regions involved in self-referential processing (such as the medial prefrontal cortex) and sustained visceral arousal (such as the posterior insula), respectively. The finding that adopting a self-distanced (vs. self-immersed) perspective lowers emotion explosiveness and accumulation was also replicated at a self-report level. However, perspective taking did not impact activity in the neural correlates of emotion explosiveness and accumulation.

Default mode and task-positive networks connectivity during the N-Back task in remitted depressed patients with or without emotional residual symptoms.

Clinical remission of depression may be associated with emotional residual symptoms. We studied the association of emotional blunting, rumination with neural networks dynamics in remitted depressed patients and cognitive performance during an N-Back task. Twenty-six outpatients in remission of depression (Hamilton Depressive rating scale score <7) performed an N-Back task during fMRI assessment. All patients had been treated by paroxetine for a minimum of 4 months. Two subgroups of patients [Nonemotionally blunted (NEB) = 14 and emotionally blunted (EB) = 12] were determined. To identify functional network maps across participants, the Network Detection using Independent Component Analysis approach was employed. Within and between Task Positive Network (TPN) and Default Mode Network (DMN) connectivity were assessed and related to variability of performance on the N-Back task and rumination. EB and NEB patients were not different for the level of accurate responses at the N-Back. However over the entire working memory task, the negative correlation between DMN and TPN was significantly lower in the EB than NEB group and was differently related to cognitive performance and rumination. The stronger the negative correlation between DMN and TPN was, the less variable the reaction time during 3-Back task in NEB patients. Moreover the greater the negative correlation between DMN and TPN was, the lower the rumination score in EB patients. Emotional blunting may be associated with compromised monitoring of rumination and cognitive functioning in remitted depressed patients through altered cooperation between DMN and TPN. The study suggests clinical remission in depression is associated with biological heterogeneity. Hum Brain Mapp 38:3491-3501, 2017. © 2017 Wiley Periodicals, Inc.

The neural basis of emotions varies over time: different regions go with onset- and offset-bound processes underlying emotion intensity.

According to theories of emotion dynamics, emotions unfold across two phases in which different types of processes come to the fore: emotion onset and emotion offset. Differences in onset-bound processes are reflected by the degree of explosiveness or steepness of the response at onset, and differences in offset-bound processes by the degree of accumulation or intensification of the subsequent response. Whether onset- and offset-bound processes have distinctive neural correlates and, hence, whether the neural basis of emotions varies over time, still remains unknown. In the present fMRI study, we address this question using a recently developed paradigm that allows to disentangle explosiveness and accumulation. Thirty-one participants were exposed to neutral and negative social feedback, and asked to reflect on its contents. Emotional intensity while reading and thinking about the feedback was measured with an intensity profile tracking approach. Using non-negative matrix factorization, the resulting profile data were decomposed in explosiveness and accumulation components, which were subsequently entered as continuous regressors of the BOLD response. It was found that the neural basis of emotion intensity shifts as emotions unfold over time with emotion explosiveness and accumulation having distinctive neural correlates.

Antidepressant short-term and long-term brain effects during self-referential processing in major depression.

Acute depression is associated with impaired self-referential processing. Antidepressant effects on the neural bases of self-referential processing in depression are unknown. This study aimed to assess short- and long-term effects of agomelatine on these neural bases in depressed patients and the association between pre-treatment brain activation and remission of depression 6 months later. We conducted a randomized double-blind, placebo-controlled, functional magnetic resonance imaging (fMRI) study during an emotional self-referential task, including three scanning sessions (baseline, after 1 week, and after 7 weeks). Twenty-five depressed outpatients were included, all treated with agomelatine or placebo for 1 week. Then, all patients received agomelatine for 24 weeks. Fourteen matched healthy volunteers (HV) who received placebo for 1 week were also included. After 7 days, only depressed patients receiving agomelatine significantly deactivated the ventrolateral prefrontal cortex during self-referential processing, as observed in HV at baseline. After 7 weeks, depressed patients significantly increased the activation of the ventral anterior cingulate cortex. Finally dorsomedial prefrontal cortex and precuneus activations at baseline significantly separated remitters from non-remitters at 24 weeks. In depressed patients, agomelatine had short- and long-term effects on brain structures involved in anhedonia and emotional regulation during self-referential processing. Activation of the dorsomedial prefrontal cortex and precuneus could be informative in the development of biomarker-based treatment of major depression.

The dark side of self-focus: brain activity during self-focus in low and high brooders.

There are two distinct modes of self-focus: analytical self-focus is abstract, general and evaluative whereas experiential self-focus is concrete, specific and non-evaluative. Using functional magnetic resonance imaging (fMRI), we investigated the neural bases of these two modes of self-focus in relation with brooding, the maladaptive form of rumination. Forty-one French-speaking right-handed healthy young adults (10 men, mean age ± s.d.: 21.8 ± 2.3 years) engaged in analytical and experiential self-focus triggered by verbal stimuli during fMRI. Brooding was measured with the 22-item Rumination Response Style scale. Individuals with lower brooding scores showed greater activation of the posterior cingulate cortex/precuneus during analytical than experiential self-focus, whereas individuals with higher brooding scores did not. This is consistent with the hypothesis that brooding is associated with less control over the nature of the self-focus engaged. These findings may help to refine our understanding of how rumination promotes depression through maladaptive self-focus.

The eye of the self: precuneus volume and visual perspective during autobiographical memory retrieval.

Visual perspective (i.e. first-person versus third-person perspective) during autobiographical memory (AM) retrieval plays a role in both emotional regulation and self-related processes. However, its neural underpinnings remain mostly unexplored. Visual perspective during AM retrieval was assessed in two independent datasets of 45 and 20 healthy young adults with two different AM retrieval tasks. Diffeomorphic anatomical registration using exponentiated lie algebra and voxel-based morphometry were used to assess individual differences in the precuneus grey matter volume. The spontaneous tendency to recall memories from a first-person perspective was positively correlated with the right precuneus volume among the two independent datasets. Whole-brain analyses revealed that these results were relatively specific to the anterior part of the right precuneus. Our results provide first evidence for the role of the precuneus in egocentric spatial processing in the context of AM retrieval among healthy subjects.

Reciprocal imitation: toward a neural basis of social interaction.

Social interaction is a coregulated coupling activity that involves at least 2 autonomous agents. Numerous methodological and technical challenges impede the production of natural social interaction within an Magnetic Resonance Imaging environment under controlled conditions. To overcome the obstacle, we chose a simple format of social interaction, namely "interactive imitation" through a double-video system. We registered blood oxygen level-dependent activity of 23 participants during 2 imitative conditions: free (F) and instructed (I) episodes of imitating (i) and of being imitated (bi). In addition to the areas classically reported in instructed imitation tasks, 2 activation patterns were found, which differentiate the subconditions. Firstly, brain areas involved during decisional and attentional processes (dorsolateral prefrontal cortex , dorsal part of anterior cingulate gyrus [dACC], pre-SMA) were activated during all conditions except for instructed imitation-classically used in neuroimaging studies of imitation. Second, a greater activation in dACC and insula combined with an increased deactivation in the default mode network was observed when subjects were imitated compared with when they imitated. We suggest that these 2 patterns reflect the anticipation of the other's behavior and the engagement with others required by social interaction.

Medial prefrontal cortex and the self in major depression.

Self-focus (i.e. the process by which one engages oneself in self-referential processing) is a core issue in the psychopathology of major depression. The cortical midline structures, including the medial prefrontal cortex (MPFC), play a key role in self-referential processing in healthy subjects. Four functional magnetic resonance imaging studies recently found either an increased or a decreased MPFC activation during self-referential processing in depressed patients compared to healthy controls. Building on critical differences in experimental settings, we argue that these conflicting results are indeed consistent with two modes of elevated MPFC activation in major depression. An elevated tonic ventral MPFC activation, as uncovered by an event-related design, may embody automatic aspects of depressive self-focus, such as attracting attention to self-relevant incoming information. An elevated phasic dorsal MPFC activation, as uncovered by a block-based design, may embody more strategic aspects of depressive self-focus, such as comparing the self with inner standards. Additionally, strategic self-focus in depression may recruit the anterior cingulate cortex and more lateral regions of the prefrontal cortex. An aberrant functional connectivity of the dorsal MPFC may underlie this lack of reciprocal inhibition between the cognitive control network and the default mode network. Altogether, these results suggest that self-focus in depression may emerge as a process competing for brain resources due to a lack of inhibition of the default mode network, resulting in detrimental effects on externally-oriented cognitive processes. Follow-up studies are warranted to determine the trait vs. state nature of these biomarkers and their ability to predict treatment outcome.

Different brain structures related to self- and external-agency attribution: a brief review and meta-analysis.

Several neuroimaging studies have consistently shown activations of areas surrounding the temporo-parietal junction (TPJ) during tasks exploring the sense of agency. Beyond TPJ, activations in different structures, such as the dorsolateral prefrontal cortex (dLPFC), the pre-supplementary motor area (pre-SMA), the insula and the precuneus have been reported. Moreover, a possible dissociation between self- and external-agency attribution has been suggested. To test the hypothesis of distinct neural correlates for self- and external-agency attribution a quantitative meta-analysis, based on activation likelihood estimation (ALE) method, across 15 PET and fMRI studies (228 subjects) was conducted. Results show converging activations including the TPJ, pre-SMA, precuneus and dorsomedial prefrontal cortex (dMPFC) in external-agency, while insula activation was related to self-agency. We discuss these findings, highlighting the role of the insula, and calling for the use of alternative paradigms such as intentional binding and interactive imitation to study agency.