Neural correlates of "Theory of Mind" in very preterm born children

Characterising the spatial and oscillatory unfolding of Theory of Mind in adults using fMRI and MEG

Theory of Mind (ToM) is a core social cognitive skill that refers to the ability to attribute mental states to others. ToM involves understanding that others have beliefs, thoughts and desires that may be different from one's own and from reality. ToM is crucial to predict behaviour and navigate social interactions. This study employed the complementary methodological advantages of both functional MRI (fMRI) and magnetoencephalography (MEG) to examine the neural underpinnings of ToM in adults. Twenty healthy adults were first recruited to rate and describe 28 videos (15s long), each containing three moving shapes designed to depict either social interactions or random motion (control condition). The first sample of adults produced consistent narratives for 6 of those social videos and of those, 4 social videos and 4 control videos were chosen to include in the neuroimaging study. Another sample of twenty-five adults were then recruited to complete the neuroimaging in MEG and fMRI. In fMRI, we found increased activation in frontal-parietal regions in the social compared to the control condition corroborating previous fMRI findings. In MEG, we found recruitment of ToM networks in the social condition in theta, beta and gamma bands. The right supramarginal and angular gyri (right temporal parietal junction), right inferior parietal lobe and right temporal pole were recruited in the first 5s of the videos. Frontal regions such as the superior frontal gyrus were recruited in the second time window (5–10s). Brain regions such as the bilateral amygdalae were also recruited (5–10s), indicating that various social processes were integrated in understanding the social videos. Our study is one of the first to combine multi-modal neuroimaging to examine the neural networks underlying social cognitive processes, combining the strengths of the spatial resolution of fMRI and temporal resolution of MEG. Understanding this information from both modalities helped delineate the mechanism by which ToM processing unfolds over time in healthy adults. This allows us to determine a benchmark against which clinical populations can be compared.

Adult outcome of preterm birth: Implications for neurodevelopmental theories of psychosis

Preterm birth is associated with an elevated risk of developmental and adult psychiatric disorders, including psychosis. In this review, we evaluate the implications of neurodevelopmental, cognitive, motor, and social sequelae of preterm birth for developing psychosis, with an emphasis on outcomes observed in adulthood. Abnormal brain development precipitated by early exposure to the extra-uterine environment, and exacerbated by neuroinflammation, neonatal brain injury, and genetic vulnerability, can result in alterations of brain structure and function persisting into adulthood. These alterations, including abnormal regional brain volumes and white matter macro- and micro-structure, can critically impair functional (e.g. frontoparietal and thalamocortical) network connectivity in a manner characteristic of psychotic illness. The resulting executive, social, and motor dysfunctions may constitute the basis for behavioural vulnerability ultimately giving rise to psychotic symptomatology. There are many pathways to psychosis, but elucidating more precisely the mechanisms whereby preterm birth increases risk may shed light on that route consequent upon early neurodevelopmental insult.

Multimodal classification of extremely preterm and term adolescents using the fusiform gyrus: A machine learning approach

OBJECTIVE

Extremely preterm birth has been associated with atypical visual and neural processing of faces, as well as differences in gray matter structure in visual processing areas relative to full-term peers. In particular, the right fusiform gyrus, a core visual area involved in face processing, has been shown to have structural and functional differences between preterm and full-term individuals from childhood through early adulthood. The current study used multiple neuroimaging modalities to build a machine learning model based on the right fusiform gyrus to classify extremely preterm birth status.

METHOD

Extremely preterm adolescents (n = 20) and full-term peers (n = 24) underwent structural and functional magnetic resonance imaging. Group differences in gray matter density, measured via voxel-based morphometry (VBM), and blood-oxygen level-dependent (BOLD) response to face stimuli were explored within the right fusiform. Using group difference clusters as seed regions, analyses investigating outgoing white matter streamlines, regional homogeneity, and functional connectivity during a face processing task and at rest were conducted. A data driven approach was utilized to determine the most discriminative combination of these features within a linear support vector machine classifier.

RESULTS

Group differences in two partially overlapping clusters emerged: one from the VBM analysis showing less density in the extremely preterm cohort and one from BOLD response to faces showing greater activation in the extremely preterm relative to full-term youth. A classifier fit to the data from the cluster identified in the BOLD analysis achieved an accuracy score of 88.64% when BOLD, gray matter density, regional homogeneity, and functional connectivity during the task and at rest were included. A classifier fit to the data from the cluster identified in the VBM analysis achieved an accuracy score of 95.45% when only BOLD, gray matter density, and regional homogeneity were included.

CONCLUSION

Consistent with previous findings, we observed neural differences in extremely preterm youth in an area that plays an important role in face processing. Multimodal analyses revealed differences in structure, function, and connectivity that, when taken together, accurately distinguish extremely preterm from full-term born youth. Our findings suggest a compensatory role of the fusiform where less dense gray matter is countered by increased local BOLD signal. Importantly, sub-threshold differences in many modalities within the same region were informative when distinguishing between extremely preterm and full-term youth.

Development of the mentalizing network structures and theory of mind in extremely preterm youth

Adolescents born preterm (<37 weeks of gestation) are at elevated risk for deficits in social cognition and peer relationships. Theory of Mind (ToM) is a complex form of social cognition important for regulating social interactions. ToM and the underlying mentalizing network continue to develop across adolescence. The present study recruited 48 adolescents (12-17 years old) who were either born extremely preterm (EPT; <28 weeks of gestation) or full-term (FT) at birth. Cortical thickness, gray matter volume and surface area were measured in four regions of the mentalizing network: the temporoparietal junction, anterior temporal cortex, posterior superior temporal sulcus and frontal pole (mBA10). We also assessed the adolescents' performance on a ToM task. Findings revealed both group differences and group-by-age interaction effects in the gray matter indices within the temporal lobe regions of the mentalizing network. The EPT group also performed significantly worse than the FT group on the ToM task. The cortical structural measures that discriminated the EPT and FT groups were not related to ToM performance. These results highlight altered developmental changes in brain regions underlying mentalizing functions in EPT adolescents relative to FT controls.

Effects of Family Nurture Intervention in the NICU on Theory of Mind Abilities in Children Born Very Preterm: A Randomized Controlled Trial

Preterm infants are at risk for socioemotional deficits, neurodevelopmental disorders, and potentially theory of mind (ToM) deficits. Preterm infants enrolled in a randomized controlled trial in the neonatal intensive care unit (NICU) received Standard Care (SC) or Family Nurture Intervention (FNI). Children (N = 72; median age 61.8 ± 2.6 months; FNI: 35 (55%), SC:2 9 (45%)) completed a ToM task, of whom 64 (54% male; born to White (43.8%), Black (18.7%), and Hispanic (25.0%) mothers) contributed to this analysis. FNI and SC infants born extremely preterm to very preterm differed significantly: 78% (14 of 18) of FNI children passed vs. 30% (3 of 10) SC children (p = 0.01, effect size = 1.06). This large effect size suggests that FNI in the NICU may ameliorate deficits in social-cognitive skills of extreme to very preterm infants by school age.

Early life maltreatment affects intrinsic neural function in mothers

Early life maltreatment (ELM) has an impact on brain functions involved in parenting and is associated with impaired maternal sensitivity. Here, we investigated the influence of ELM on intrinsic neural function and its associations with maternal sensitivity in mothers without a current episode of a mental disorder. Twenty-seven mothers with ELM and 29 mothers without ELM were examined using resting-state functional magnetic resonance imaging, followed by Amplitude of Low Frequency Fluctuations, regional homogeneity and seed-based functional connectivity analyses. Videotaped interactions between mothers and their school-aged children were conducted to assess maternal sensitivity based on the Emotional Availability Scales. Regional and functional connectivity measures were used to investigate associations between intrinsic activity and emotional availability. Mothers with ELM showed reduced maternal sensitivity and lower intrinsic neural activity in the right superior frontal gyrus, the left precuneus, the left middle occipital gyrus, and the parietal cortex (left angular and right supramarginal gyrus) compared to mothers without ELM (p < .001, whole-brain). Amplitude of Low Frequency Fluctuations in the superior frontal gyrus was positively associated with maternal sensitivity across all participants (p = .002). The data suggest a behavioral and neural signature of ELM even in currently mentally healthy mothers. In particular, effects of ELM were found in distinct brain regions involved in social cognition and executive control. These ELM-related alterations may be associated with maternal behavior.

Neonatal White Matter Microstructure and Emotional Development during the Preschool Years in Children Who Were Born Very Preterm

Children born very preterm (<33 weeks of gestation) are at a higher risk of developing socio-emotional difficulties compared with those born at term. In this longitudinal study, we tested the hypothesis that diffusion characteristics of white matter (WM) tracts implicated in socio-emotional processing assessed in the neonatal period are associated with socio-emotional development in 151 very preterm children previously enrolled into the Evaluation of Preterm Imaging study (EudraCT 2009-011602-42). All children underwent diffusion tensor imaging at term-equivalent age and fractional anisotropy (FA) was quantified in the uncinate fasciculus (UF), inferior fronto-occipital fasciculus (IFOF), inferior longitudinal fasciculus (ILF), and superior longitudinal fasciculus (SLF). Children's socio-emotional development was evaluated at preschool age (median = 4.63 years). Exploratory factor analysis conducted on the outcome variables revealed a three-factor structure, with latent constructs summarized as: "emotion moderation," "social function," and "empathy." Results of linear regression analyses, adjusting for full-scale IQ and clinical and socio-demographic variables, showed an association between lower FA in the right UF and higher "emotion moderation" scores (β = -0.280; p < 0.001), which was mainly driven by negative affectivity scores (β = -0.281; p = 0.001). Results further showed an association between higher full-scale IQ and better social functioning (β = -0.334, p < 0.001). Girls had higher empathy scores than boys (β = -0.341, p = 0.006). These findings suggest that early alterations of diffusion characteristics of the UF could represent a biological substrate underlying the link between very preterm birth and emotional dysregulation in childhood and beyond.

The preterm social brain: altered functional networks for Theory of Mind in very preterm children

Neurodevelopmental difficulties emerge in very preterm born children (<32-week gestation) in infancy and continue to early adulthood but little is known about their social-cognitive development. This study utilized the complementary methodological advantages of both functional MRI and magnetoencephalography to examine the neural underpinnings of Theory of Mind in very preterm birth. Theory of Mind, one of the core social-cognitive skills, is the ability to attribute mental states to others, and is crucial for predicting others’ behaviours in social interactions. Eighty-three children (40 very preterm born, 24 boys, age = 8.7 ± 0.5 years, and 43 full-term born, 22 boys, age = 8.6 ± 0.5 years) completed the study. In functional MRI, both groups recruited classic Theory of Mind areas, without significant group differences. However, reduced Theory of Mind connectivity in the very preterm born group was found in magnetoencephalography in distinct theta, alpha and beta-band networks anchored in a set of brain regions that comprise the social brain. These networks included regions such as the angular gyrus, the medial pre-frontal cortex, the superior temporal gyrus and the temporal poles. Very preterm born children showed increased connectivity compared to controls in a network anchored in the occipital gyri rather than classical social-processing regions. Very preterm born children made significantly more attribution errors and mis-construed the social scenarios. Findings offer novel insight into the neural networks, supporting social cognition in very preterm born children and highlight the importance of multimodal neuroimaging to interrogate the social brain in clinical populations.

Extremely preterm children demonstrate hyperconnectivity during verb generation: A multimodal approach

Children born extremely preterm (EPT, <28 weeks gestation) are at risk for delays in development, including language. We use fMRI-constrained magnetoencephalography (MEG) during a verb generation task to assess the extent and functional connectivity (phase locking value, or PLV) of language networks in a large cohort of EPT children and their term comparisons (TC). 73 participants, aged 4 to 6 years, were enrolled (42 TC, 31 EPT). There were no significant group differences in age, sex, race, ethnicity, parental education, or family income. There were significant group differences in expressive language scores (p < 0.05). Language representation was not significantly different between groups on fMRI, with task-specific activation involving bilateral temporal and left inferior frontal cortex. There were group differences in functional connectivity seen in MEG. To identify a possible subnetwork contributing to focal spectral differences in connectivity, we ran Network Based Statistics analyses. For both beta (20-25 Hz) and gamma (61-70 Hz) bands, we observed a subnetwork showing hyperconnectivity in the EPT group (p < 0.05). Network strength was computed for the beta and gamma subnetworks and assessed for correlation with language performance. For the EPT group exclusively, strength of the subnetwork identified in the gamma frequency band was positively correlated with expressive language scores (r = 0.318, p < 0.05). Thus, hyperconnectivity is positively related to language for EPT children and might represent a marker for resiliency in this population.

Extremely Preterm Children Demonstrate Interhemispheric Hyperconnectivity During Verb Generation: a Multimodal Approach

Children born extremely preterm (EPT, <28 weeks gestation) are at risk for delays in development, including language. We use fMRI-constrained magnetoencephalography (MEG) during a verb generation task to assess the extent and functional connectivity (phase locking value, or PLV) of language networks in a large cohort of EPT children and their term comparisons (TC). 73 participants, aged 4 to 6 years, were enrolled (42 TC, 31 EPT). There were no significant group differences in age, sex, race, ethnicity, parental education, or family income. There were significant group differences in expressive language scores (p<0.05). Language representation was not significantly different between groups on fMRI, with task-specific activation involving bilateral temporal and left inferior frontal cortex. There were group differences in functional connectivity seen in MEG. To identify a possible subnetwork contributing to focal spectral differences in connectivity, we ran Network Based Statistics analyses. For both beta (20-25 Hz) and gamma (61-70 Hz) bands, we observed a subnetwork showing hyperconnectivity in the EPT group (p<0.05). Network strength was computed for the beta and gamma subnetworks and assessed for correlation with language performance. For the EPT group, exclusively, strength of the subnetwork identified in the gamma frequency band was positively correlated with expressive language scores (r=0.318, p<0.05). Thus, interhemispheric hyperconnectivity is positively related to language for EPT children and might represent a marker for resiliency in this population.

[Formula: see text] Social cognition, adaptive functioning, and behavior problems in preschoolers born extremely preterm

Despite medical advances, prematurity is associated with a higher risk of neurodevelopmental problems. Although social impairments are commonly reported in preterm children, their origins are not clearly determined though they may be associated with the integrity of social cognitive skills, such as theory of mind. This study aimed to assess social cognitive, social adaptive, and social behavior functioning in children born extremely prematurely. Thirty children born between 22 and 28 weeks of gestation and 30 children born at term completed measures of social cognition (theory of mind, affect recognition) between 4:6, 5:11 years of age (mean = 5.29, standard deviation = 0.28 years). Parents completed questionnaires measuring their child's adaptive social functioning and social behavior. Analyses of covariance controlling for cognitive, attentional, executive, sociodemographic, and perinatal characteristics were performed. Children born between 22 and 28 weeks displayed poorer theory of mind (p < 0.01) and affect recognition (p < 0.01) than term controls, and their parents reported lower adaptive social functioning (p < 0.01) and prosocial behavior (p = 0.04). Social cognitive, adaptive, and behavior functioning appear to be affected by extreme preterm birth. These findings may explain the social challenges experienced by extremely preterm children and provide potential loci for targeted interventions to optimize social functioning.

Altered Connectivity During a False-Belief Task in Adults With Autism Spectrum Disorder

BACKGROUND

Deficits in social communication are one of the main features of autism spectrum disorder (ASD). Adults with ASD show atypical brain activity during false-belief understanding, an aspect of social communication involving the ability to infer that an individual can have an incorrect belief about a situation. Our study is the first to investigate whether adults with ASD exhibit differences in frequency-specific functional connectivity patterns during false-belief reasoning.

METHODS

We used magnetoencephalography to contrast functional connectivity underlying false-belief understanding between 40 adults with ASD and 39 control adults. We examined whole-brain phase synchrony measures during a false-belief task in 3 frequency bands: theta (4-7 Hz), alpha (8-14 Hz), and beta (15-30 Hz).

RESULTS

Adults with ASD demonstrated reduced theta-band connectivity compared with control adults between several right-lateralized and midline regions such as the medial prefrontal cortex, right temporoparietal junction, right inferior frontal gyrus, and right superior temporal gyrus. During false-belief trials, they also recruited a network in the beta band that included primary visual regions such as the bilateral inferior occipital gyri and the left anterior temporoparietal junction.

CONCLUSIONS

Reduced theta-band synchrony between areas associated with mentalizing, inhibition, and visual processing implies some difficulty in communication among these functions in ASD. This impairment in top-down control in the theta band may be counterbalanced by their engagement of a beta-band network because both the left anterior temporoparietal junction and beta-band oscillations are associated with attentional processes. Thus, adults with ASD demonstrate alternative neural mechanisms for successful false-belief reasoning.

Dissociating Empathy From Perspective-Taking: Evidence From Intra- and Inter-Individual Differences Research

Humans have the capacity to share others' emotions, be they positive or negative. Elicited by the observed or imagined emotion of another person, an observer develops a similar emotional state herself. This capacity, empathy, is one of the pillars of social understanding and interaction as it creates a representation of another's inner, mental state. Empathy needs to be dissociated from other social emotions and, crucially, also from cognitive mechanisms of understanding others, the ability to take others' perspective. Here, we describe the conceptual distinctions of these constructs and review behavioral and neural evidence that dissociates them. The main focus of the present review lies on the intraindividual changes in empathy and perspective-taking across the lifespan and on interindividual differences on subclinical and clinical levels. The data show that empathy and perspective-taking recruit distinct neural circuits and can be discerned already during early and throughout adult development. Both capacities also vary substantially between situations and people. Differences can be systematically related to situational characteristics as well as personality traits and mental disorders. The clear distinction of affect sharing from other social emotions like compassion and from cognitive perspective-taking, argues for a clear-cut terminology to describe these constructs. In our view, this speaks against using empathy as an umbrella term encompassing all affective and cognitive routes to understanding others. Unifying the way we speak about these phenomena will help to further research on their underlying mechanisms, psychopathological alterations, and plasticity in training and therapy.

The metabolic basis of psychosis in bipolar disorder: A positron emission tomography study

OBJECTIVES

Psychotic symptoms are a common feature in bipolar disorder (BD), especially during manic phases, and are associated with a more severe course of illness. However, not all bipolar subjects experience psychosis during the course of their illness, and this difference often guides assessment and pharmacological treatment. The aim of the present study is to elucidate, for the first time, the FDG uptake dysfunctions associated with psychosis in BD patients with and without a history of past psychotic symptoms, through a positron emission tomography (PET) approach.

METHODS

Fifty BD patients with lifetime psychotic symptoms, 40 BD patients without lifetime psychotic symptoms and 27 healthy controls (HC) were recruited and underwent an 18F-FDG-PET session.

RESULTS

Compared to HC, BD subjects shared common FDG uptake deficits in several brain areas, including insula, inferior temporal gyrus and middle occipital gyrus. Moreover, we found that BD patients with a history of past psychotic symptoms had a unique FDG uptake alteration in the right fusiform gyrus compared to both BD patients without lifetime psychotic symptoms and HC (all P < 0.01, cFWE corrected).

CONCLUSIONS

Overall, our results suggest that FDG uptake alterations in brain regions involved in emotion regulation are a key feature of BD, regardless the presence of past psychosis. Finally, we demonstrated that the FDG uptake reduction in fusiform gyrus is associated with the presence of past psychotic symptoms in BD, ultimately leading towards the idea that the fusiform gyrus might be considered a putative biomarker of psychosis.

Delayed theory of mind development in children born preterm: A longitudinal study

BACKGROUND

Children born preterm are at high risk of developmental delay in various cognitive domains. Moreover, problems in social interaction are more frequently reported in preterm children than in their full-term peers. These difficulties can be observed at two years of age and seem to persist until school age. Although closely linked to social acceptance, remarkably little research has focused on social-cognitive skills such as Theory of Mind in preterm children.

AIM

The aim of the current study was to assess Theory-of-Mind development in preterm (n = 34) and full-term (n = 38) children over the course of two years.

METHODS

A Theory-of-Mind scale was administered at the children's age of 3, 4, and 5 years, and we additionally assessed and controlled for general cognitive development.

RESULTS

At the age of 3, mean Theory-of-Mind scores were 1.23 (SD = 0.65) for preterm and 1.58 (SD = 0.76) for full-term children. By the age of 5, preterm children's performance (M = 3.50, SD = 1.16) was similar to that of full-term children (M = 3.52, SD = 0.98), revealing a significant interaction effect between birth status and time of measurement, F(1, 44.424) = 4.76, p = .035.

CONCLUSION

The interaction effect indicates that preterm children show a delay rather than a general deficit in Theory-of-Mind development. Mechanisms underlying this course of development are still unknown. To examine why problems in social interaction persist despite improving Theory-of-Mind abilities, future research should extend the focus to implicit mental reasoning in preterm children.