Fynn-Mathis Trautwein

Structural plasticity of the social brain: Differential change after socio-affective and cognitive mental training

Training to understand the feelings and thoughts of others induces structural changes in two divergent social brain networks. Although neuroscientific research has revealed experience-dependent brain changes across the life span in sensory, motor, and cognitive domains, plasticity relating to social capacities remains largely unknown. To investigate whether the targeted mental training of different cognitive and social skills can induce specific changes in brain morphology, we collected longitudinal magnetic resonance imaging (MRI) data throughout a 9-month mental training intervention from a large sample of adults between 20 and 55 years of age. By means of various daily mental exercises and weekly instructed group sessions, training protocols specifically addressed three functional domains: (i) mindfulness-based attention and interoception, (ii) socio-affective skills (compassion, dealing with difficult emotions, and prosocial motivation), and (iii) socio-cognitive skills (cognitive perspective-taking on self and others and metacognition). MRI-based cortical thickness analyses, contrasting the different training modules against each other, indicated spatially diverging changes in cortical morphology. Training of present-moment focused attention mostly led to increases in cortical thickness in prefrontal regions, socio-affective training induced plasticity in frontoinsular regions, and socio-cognitive training included change in inferior frontal and lateral temporal cortices. Module-specific structural brain changes correlated with training-induced behavioral improvements in the same individuals in domain-specific measures of attention, compassion, and cognitive perspective-taking, respectively, and overlapped with task-relevant functional networks. Our longitudinal findings indicate structural plasticity in well-known socio-affective and socio-cognitive brain networks in healthy adults based on targeted short daily mental practices. These findings could promote the development of evidence-based mental training interventions in clinical, educational, and corporate settings aimed at cultivating social intelligence, prosocial motivation, and cooperation.

Socio-Cognitive Phenotypes Differentially Modulate Large-Scale Structural Covariance Networks

Abstract Functional neuroimaging studies have suggested the existence of 2 largely distinct social cognition networks, one for theory of mind (taking others’ cognitive perspective) and another for empathy (sharing others’ affective states). To address whether these networks can also be dissociated at the level of brain structure, we combined behavioral phenotyping across multiple socio‐cognitive tasks with 3‐Tesla MRI cortical thickness and structural covariance analysis in 270 healthy adults, recruited across 2 sites. Regional thickness mapping only provided partial support for divergent substrates, highlighting that individual differences in empathy relate to left insular‐opercular thickness while no correlation between thickness and mentalizing scores was found. Conversely, structural covariance analysis showed clearly divergent network modulations by socio‐cognitive and ‐affective phenotypes. Specifically, individual differences in theory of mind related to structural integration between temporo‐parietal and dorsomedial prefrontal regions while empathy modulated the strength of dorsal anterior insula networks. Findings were robust across both recruitment sites, suggesting generalizability. At the level of structural network embedding, our study provides a double dissociation between empathy and mentalizing. Moreover, our findings suggest that structural substrates of higher‐order social cognition are reflected rather in interregional networks than in the the local anatomical markup of specific regions per se.

Stimulus-driven reorienting impairs executive control of attention: Evidence for a common bottleneck in anterior insula

A classical model of human attention holds that independent neural networks realize stimulus-driven reorienting and executive control of attention. Questioning full independence, the two functions do, however, engage overlapping networks with activations in cingulo-opercular regions such as anterior insula (AI) and a reverse pattern of activation (stimulus-driven reorienting), and deactivation (executive control) in temporoparietal junction (TPJ). To test for independent versus shared neural mechanisms underlying stimulus-driven and executive control of attention, we used fMRI and a task that isolates individual from concurrent demands in both functions. Results revealed super-additive increases of left AI activity and behavioral response costs under concurrent demands, suggesting a common bottleneck for stimulus-driven reorienting and executive control of attention. These increases were mirrored by non-additive decreases of activity in the default mode network (DMN), including posterior TPJ, regions where activity increased with off-task processes. The deactivations in posterior TPJ were spatially separated from stimulus-driven reorienting related activation in anterior TPJ, a differentiation that replicated in task-free resting state. Furthermore, functional connectivity indicated inhibitory coupling between posterior TPJ and AI during concurrent attention demands. These results demonstrate a role of AI in stimulus-driven and executive control of attention that involves down-regulation of internally directed processes in DMN.

Decentering the self? Preliminary evidence for changes in self- vs. other related processing as a long-term outcome of loving-kindness meditation.

Research in social neuroscience provides increasing evidence that self and other are interconnected, both on a conceptual and on an affective representational level. Moreover, the ability to recognize the other as “like the self” is thought to be essential for social phenomena like empathy and compassion. Meditation practices such as loving-kindness meditation (LKM) have been found to enhance these capacities. Therefore, we investigated whether LKM is associated to an increased integration of self–other-representations. As an indicator, we assessed the P300 event-related potential elicited by oddball stimuli of the self-face and a close other’s face in 12 long-term practitioners of LKM and 12 matched controls. In line with previous studies, the self elicited larger P300 amplitudes than close other. This effect was reduced in the meditation sample at parietal but not frontal midline sites. Within this group, smaller differences between self- and other-related P300 were associated with increasing meditation practice. Across groups, smaller P300 differences correlated with self-reported compassion. In meditators, we also investigated the effect of a short LKM compared to a control priming procedure in order to test whether the state induction would additionally modulate self- vs. other-related P300. However, no effect of the priming conditions was observed. Overall, our findings provide preliminary evidence that prolonged meditation practice may modulate self- vs. other-related processing, accompanied by an increase in compassion. Further evidence is needed, however, to show if this is a direct outcome of loving-kindness meditation.

Psychedelics, meditation, and self-consciousness

In recent years, the scientific study of meditation and psychedelic drugs has seen remarkable developments. The increased focus on meditation in cognitive neuroscience has led to a cross-cultural classification of standard meditation styles validated by functional and structural neuroanatomical data. Meanwhile, the renaissance of psychedelic research has shed light on the neurophysiology of altered states of consciousness induced by classical psychedelics, such as psilocybin and LSD, whose effects are mainly mediated by agonism of serotonin receptors. Few attempts have been made at bridging these two domains of inquiry, despite intriguing evidence of overlap between the phenomenology and neurophysiology of meditation practice and psychedelic states. In particular, many contemplative traditions explicitly aim at dissolving the sense of self by eliciting altered states of consciousness through meditation, while classical psychedelics are known to produce significant disruptions of self-consciousness, a phenomenon known as drug-induced ego dissolution. In this article, we discuss available evidence regarding convergences and differences between phenomenological and neurophysiological data on meditation practice and psychedelic drug-induced states, with a particular emphasis on alterations of self-experience. While both meditation and psychedelics may disrupt self-consciousness and underlying neural processes, we emphasize that neither meditation nor psychedelic states can be conceived as simple, uniform categories. Moreover, we suggest that there are important phenomenological differences even between conscious states described as experiences of self-loss. As a result, we propose that self-consciousness may be best construed as a multidimensional construct, and that “self-loss,” far from being an unequivocal phenomenon, can take several forms. Indeed, various aspects of self-consciousness, including narrative aspects linked to autobiographical memory, self-related thoughts and mental time travel, and embodied aspects rooted in multisensory processes, may be differently affected by psychedelics and meditation practices. Finally, we consider long-term outcomes of experiences of self-loss induced by meditation and psychedelics on individual traits and prosocial behavior. We call for caution regarding the problematic conflation of temporary states of self-loss with “selflessness” as a behavioral or social trait, although there is preliminary evidence that correlations between short-term experiences of self-loss and long-term trait alterations may exist.