Hypothalamus volume and fatherhood: similarity across men and interindividual differences among dads

Most studies on mammalian caregiving and attachment have focused on the mother-child relationship, particularly in humans. Yet, recent re-considerations of attachment theory and changing societal roles of male caregivers have highlighted the necessity for research with fathers. In this pre-registered study (https://aspredicted.org/5uj5y.pdf), we examined the structure of the hypothalamus – an important subcortical brain area for caregiving and attachment behavior – in a sample of N=95 fathering (child age 5-6 years) and non-fathering men. To do so, we used a recently developed technique to accurately and efficiently identify the human hypothalamus in 3T MRI and calculate hypothalamus volume. Furthermore, we employed several self-report measures to assess interindividual differences in attachment style across all men, and caregiving specifically in fathers. While we found no difference in hypothalamus volume between fathers and non-fathers, fathers' interindividual variation in caregiving style was related to hypothalamus volume. Specifically, we observed that fathers who held greater belief in the importance of their role as a father and reported more enjoyment of interacting with their child had greater total hypothalamus volume. This finding suggests that there is interindividual variability in the association between brain structure and caregiving style in fathers, warranting further research

Differential impact of trait, social, and attachment anxiety on the stare-in-the-crowd effect

Eye gaze conveys crucial information for social interactions, with straight versus averted gaze triggering distinct emotional and cognitive processes. The “stare-in-the-crowd” effect exemplifies such differential visual processing of gaze direction, in more recent reports also in interaction with head orientation. Besides aiming at replicating the “stare-in-the-crowd” effect by means of an eye gaze by head orientation interaction, the present study intended to for the first time testing its susceptibility to inter-individual differences in trait, social, and attachment anxiety. Our findings reveal a significant relation between the “stare-in-the-crowd” effect and social and attachment, but not trait anxiety, and therefore provide preliminary cues for personality influences on visual processing of eye gaze and head orientation

A functional neuro-anatomical model of human attachment (NAMA): Insights from first- and second-person social neuroscience

Attachment theory, developed by Mary Ainsworth and John Bowlby about seventy years ago, has become one of the most influential and comprehensive contemporary psychology theories. It predicts that early social interactions with significant others shape the emergence of distinct self- and other-representations, the latter affecting how we initiate and maintain social relationships across the lifespan. A person's attachment history will therefore associate with inter-individual differences in emotional and cognitive mechanisms sustaining representations, modeling, and understanding of others on the biological and brain level. This review aims at summarizing the currently available social neuroscience data in healthy participants on how inter-individual differences in attachment associate with brain anatomy and activity across the lifespan, and to integrate these data into an extended and refined functional neuro-anatomical model of human attachment (NAMA). We first propose a new prototypical initial attachment pathway and its derivatives as a function of attachment security, avoidance, and anxiety. Based on these pathways, we suggest a neural attachment system composed of two emotional mentalization modules (aversion and approach) and two cognitive mentalization modules (emotion regulation and mental state representation) and provide evidence on their functionality depending on inter-individual differences in attachment. We subsequently expand this first-person social neuroscience account by also considering a second-person social neuroscience perspective comprising the concepts of bio-behavioral synchrony and particularly inter-brain coherence. We hope that such extended and refined NAMA can inform attachment theory and ultimately help devising new prevention and intervention strategies for individuals and families at risk for attachment-related psychopathology

Neural bases of social feedback processing and self–other distinction in late childhood: The role of attachment and age

Attachment plays a key role in how children process information about the self and others. Here, we examined the neural bases of interindividual differences in attachment in late childhood and tested whether social cognition-related neural activity varies as function of age. In a small sample of 8-year-old to 12-year-old children (n = 21/19), we used functional magnetic resonance imaging to measure neural responses during social feedback processing and self–other distinction. Attachment was assessed using child self-report. The social feedback processing task presented smiling and angry faces either confirming or disconfirming written information about participant performance on a perceptual game. In addition to observing main effects of facial emotion and performance, an increase in age was related to a shift from negative (i.e., angry faces/bad performance) to positive (i.e., smiling faces/good performance) information processing in the left amygdala/hippocampus, bilateral fusiform face area, bilateral anterior temporal pole (ATP), and left anterior insula. There were no effects of attachment on social feedback processing. The self–other distinction task presented digital morphs between children’s own faces and faces of their mother or stranger females. We observed differential activation in face processing and mentalizing regions in response to self and mother faces versus morphed faces. Furthermore, left ATP activity was associated with attachment anxiety such that greater attachment anxiety was related to a shift from heightened processing of self and mother faces to morphed faces. There were no effects of age on self–other distinction. We discuss our preliminary findings in the context of attachment theory and previous work on social evaluation and self–other processing

A Guide to Parent-Child fNIRS Hyperscanning Data Processing and Analysis

The use of functional near-infrared spectroscopy (fNIRS) hyperscanning during naturalistic interactions in parent–child dyads has substantially advanced our understanding of the neurobiological underpinnings of human social interaction. However, despite the rise of developmental hyperscanning studies over the last years, analysis procedures have not yet been standardized and are often individually developed by each research team. This article offers a guide on parent–child fNIRS hyperscanning data analysis in MATLAB and R. We provide an example dataset of 20 dyads assessed during a cooperative versus individual problem-solving task, with brain signal acquired using 16 channels located over bilateral frontal and temporo-parietal areas. We use MATLAB toolboxes Homer2 and SPM for fNIRS to preprocess the acquired brain signal data and suggest a standardized procedure. Next, we calculate interpersonal neural synchrony between dyads using Wavelet Transform Coherence (WTC) and illustrate how to run a random pair analysis to control for spurious correlations in the signal. We then use RStudio to estimate Generalized Linear Mixed Models (GLMM) to account for the bounded distribution of coherence values for interpersonal neural synchrony analyses. With this guide, we hope to offer advice for future parent–child fNIRS hyperscanning investigations and to enhance replicability within the field

Conceptual analysis: A Social neuroscience approach to interpersonal interaction in the context of disruption and disorganization of attachment (NAMDA)

Humans are strongly dependent upon social resources for allostasis and emotion regulation. This applies especially to early childhood because humans-as an altricial species-have a prolonged period of dependency on support and input from caregivers who typically act as sources of co-regulation. Accordingly, attachment theory proposes that the history and quality of early interactions with primary caregivers shape children's internal working models of attachment. In turn, these attachment models guide behavior, initially with the set goal of maintaining proximity to caregivers but eventually paving the way to more generalized mental representations of self and others. Mounting evidence in non-clinical populations suggests that these mental representations coincide with differential patterns of neural structure, function, and connectivity in a range of brain regions previously associated with emotional and cognitive capacities. What is currently lacking, however, is an evidence-based account of how early adverse attachment-related experiences and/or the emergence of attachment disorganization impact the developing brain. While work on early childhood adversities offers important insights, we propose that how these events become biologically embedded crucially hinges on the context of the child-caregiver attachment relationships in which the events take place. Our selective review distinguishes between direct social neuroscience research on disorganized attachment and indirect maltreatment-related research, converging on aberrant functioning in neurobiological systems subserving aversion, approach, emotion regulation, and mental state processing in the wake of severe attachment disruption. To account for heterogeneity of findings, we propose two distinct neurobiological phenotypes characterized by hyper- and hypo-arousal primarily deriving from the caregiver serving either as a threatening or as an insufficient source of co-regulation, respectively

Association of Short-term Change in Leukocyte Telomere Length With Cortical Thickness and Outcomes of Mental Training Among Healthy Adults

Importance:Telomere length is associated with the development of age-related diseases and structural differences in multiple brain regions. It remains unclear, however, whether change in telomere length is linked to brain structure change, and to what extent telomere length can be influenced through mental training. Objectives:To assess the dynamic associations between leukocyte telomere length (LTL) and cortical thickness (CT), and to determine whether LTL is affected by a longitudinal contemplative mental training intervention. Design, Setting, and Participants:An open-label efficacy trial of three 3-month mental training modules with healthy, meditation-naive adults was conducted. Data on LTL and CT were collected 4 times over 9 months between April 22, 2013, and March 31, 2015, as part of the ReSource Project. Data analysis was performed between September 23, 2016, and June 21, 2019. Of 1582 eligible individuals, 943 declined to participate; 362 were randomly selected for participation and assigned to training or retest control cohorts, with demographic characteristics matched. The retest control cohorts underwent all testing but no training. Intention-to-treat analysis was performed. Interventions:Training cohort participants completed 3 modules cultivating interoception and attention (Presence), compassion (Affect), or perspective taking (Perspective). Main Outcomes and Measures:Change in LTL and CT. Results:Of the 362 individuals randomized, 30 participants dropped out before study initiation (initial sample, 332). Data were available for analysis of the training intervention in 298 participants (n = 222 training; n = 76 retest control) (175 women [58.7%]; mean [SD] age, 40.5 [9.3] years). The training modules had no effect on LTL. In 699 observations from all 298 participants, mean estimated changes in the relative ratios of telomere repeat copy number to single-copy gene (T/S) were for no training, 0.004 (95% CI, -0.010 to 0.018); Presence, -0.007 (95% CI, -0.025 to 0.011); Affect, -0.005 (95% CI, -0.019 to 0.010); and Perspective, -0.001 (95% CI, -0.017 to 0.016). Cortical thickness change data were analyzed in 167 observations from 67 retest control participants (37 women [55.2%], mean [SD] age, 39.6 [9.0] years). In this retest control cohort subsample, naturally occurring LTL change was related to CT change in the left precuneus extending to the posterior cingulate cortex (mean t161 = 3.22; P < .001; r = 0.246). At the individual participant level, leukocyte telomere shortening as well as lengthening were observed. Leukocyte telomere shortening was related to cortical thinning (t77 = 2.38; P = .01; r = 0.262), and leukocyte telomere lengthening was related to cortical thickening (t77 = 2.42; P = .009; r = 0.266). All analyses controlled for age, sex, and body mass index. Conclusions and Relevance:The findings of this trial indicate an association between short-term change in LTL and concomitant change in plasticity of the left precuneus extending to the posterior cingulate cortex. This result contributes to the evidence that LTL changes more dynamically on the individual level than previously thought. Further studies are needed to determine potential long-term implications of such change in relation to cellular aging and the development of neurodegenerative disorders. No effect of contemplative mental training was noted in what may be, to date, the longest intervention with healthy adults. Trial Registration:ClinicalTrials.gov identifier: NCT01833104

Interpersonal neurobehavioral synchrony during father-child problem solving: An fNIRS hyperscanning study

Interpersonal neural synchrony (INS) has been previously evidenced in mother-child interactions, yet findings concerning father-child interaction are wanting. The current experiment examined whether fathers and their 5- to 6-year-old children (N=66) synchronize their brain activity during a naturalistic interaction, and addressed paternal and child factors related to INS. Compared to individual problem-solving and rest, father-child dyads showed increased INS in bilateral dorsolateral prefrontal cortex and left temporo-parietal junction during cooperative problem-solving. Furthermore, the father’s attitude toward his role as a parent was positively related to INS during the cooperation condition. These results highlight the implication of the father’s attitude to parenting in INS processes for the first time

Neural synchrony in mother-child conversation: Exploring the role of communicative features

Conversations are an essential form of communication in daily family life. Specific patterns of caregiver-child conversations have been linked to children’s socio-cognitive development and child relationship quality beyond the immediate family environment. Recently, interpersonal neural synchronization has been proposed as a neural mechanism supporting conversation. Here, we present a functional near-infrared spectroscopy (fNIRS) hyperscanning study looking at the temporal dynamics of neural synchrony during mother-child conversation. Preschoolers (20 boys and 20 girls; M age 5;07 years) and their mothers (M age 36.37 years) were tested simultaneously with fNIRS hyperscanning while engaging in a free verbal conversation lasting for four minutes. Neural synchrony (using wavelet transform coherence analysis) was assessed over time. Furthermore, each conversational turn was coded for conversation patterns comprising turn-taking, relevance, contingency, and intrusiveness. Results from linear mixed-effects modeling revealed that turn-taking, but not relevance, contingency, or intrusiveness predicted neural synchronization during the conversation over time. Results are discussed to point out possible variables affecting parent-child conversation quality and the potential functional role of interpersonal neural synchronization for parent-child conversation

Neuroimaging of emotional dysregulation in multiple sclerosis: relationship with alexithymia

Patients with multiple sclerosis (MS) often show alexithymia, but the brain mechanisms underlying this emotional disorder remains unknown. We used functional magnetic resonance imaging (fMRI) to investigate alterations of emotion processing and emotion regulation in patients with MS, and their relationships with alexithymia. Nineteen MS patients with minimal disability and twenty healthy control (HC) participants took part in this cross-sectional study. During fMRI, participants viewed scenes conveying negative or positive emotions, and were asked to rate the intensity of their emotional state (1) after spontaneous viewing and (2) after emotion regulation (cognitive reappraisal). Self-reported questionnaires targeting alexithymia and other affective disorders were collected, in addition to functional and anatomical MRI. We compared brain activity and functional connectivity between each group during emotion processing and reappraisal. Moreover, we performed correlation analyses between affective questionnaire scores, subjective emotion ratings, brain activity, and structural integrity. Results showed a higher rate of alexithymia in MS patients. Globally, subjective ratings of emotional state were similar between MS and HC during both spontaneous perception and reappraisal. However, in both task conditions, the MS group showed increased responses to emotional scenes in the orbital inferior frontal gyrus, compared with controls. Moreover, during the reappraisal of negative scenes, these regions displayed increased functional connectivity with the amygdala, whose activity was positively correlated with alexithymia severity in MS. Our findings suggest a direct relationship between alexithymia and a lack of down-regulation of amygdala activity in response to negative emotions during reappraisal in MS. Moreover, they highlight compensatory mechanisms in minimally disabled MS patients, recruiting fronto-striatal circuits, which may serve to preserve homeostasis of amygdala activity and affective state