Neuroimaging Research on Empathy and Shared Neural Networks

Understanding other people’s feelings and perspectives is an important part of effective social communication and interaction. Empathy is the phenomenon that enables us to infer the feelings of others and understand their mental states. It aids in social learning and bonding and is thought to be impaired in individuals with social deficits like schizophrenia and autism spectrum disorder (ASD). Advances in neuroimaging technology have allowed social neuroscientists to study brain activity during this complex social process. A growing body of empathy literature demonstrates that multiple brain regions are involved in empathy. Current theories propose that empathy is enabled through the activation of various dynamic neural networks, each made up of several different regions. These networks respond differently depending on specific contexts and available information. This chapter reviews the networks involved in empathy and highlights the current theories and limitations of empathy research

Empathy and the somatotopic auditory mirror system in humans

SummaryHow do we understand the actions of other individuals if we can only hear them? Auditory mirror neurons respond both while monkeys perform hand or mouth actions and while they listen to sounds of similar actions [1, 2]. This system might be critical for auditory action understanding and language evolution [1–6]. Preliminary evidence suggests that a similar system may exist in humans [7–10]. Using fMRI, we searched for brain areas that respond both during motor execution and when individuals listened to the sound of an action made by the same effector. We show that a left hemispheric temporo-parieto-premotor circuit is activated in both cases, providing evidence for a human auditory mirror system. In the left premotor cortex, a somatotopic pattern of activation was also observed: A dorsal cluster was more involved during listening and execution of hand actions, and a ventral cluster was more involved during listening and execution of mouth actions. Most of this system appears to be multimodal because it also responds to the sight of similar actions. Finally, individuals who scored higher on an empathy scale activated this system more strongly, adding evidence for a possible link between the motor mirror system and empathy

Common Premotor Regions for the Perception and Production of Prosody and Correlations with Empathy and Prosodic Ability

Background: Prosody, the melody and intonation of speech, involves the rhythm, rate, pitch and voice quality to relay linguistic and emotional information from one individual to another. A significant component of human social communication depends upon interpreting and responding to another person’s prosodic tone as well as one’s own ability to produce prosodic speech. However there has been little work on whether the perception and production of prosody share common neural processes, and if so, how these might correlate with individual differences in social ability. Methods: The aim of the present study was to determine the degree to which perception and production of prosody rely on shared neural systems. Using fMRI, neural activity during perception and production of a meaningless phrase in different prosodic intonations was measured. Regions of overlap for production and perception of prosody were found in premotor regions, in particular the left inferior frontal gyrus (IFG). Activity in these regions was further found to correlate with how high an individual scored on two different measures of affective empathy as well as a measure on prosodic production ability. Conclusions: These data indicate, for the first time, that areas that are important for prosody production may also be utilized for prosody perception, as well as other aspects of social communication and social understanding, such as aspect

Congruent Embodied Representations for Visually Presented Actions and Linguistic Phrases Describing Actions

SummaryThe thesis of embodied semantics holds that conceptual representations accessed during linguistic processing are, in part, equivalent to the sensory-motor representations required for the enactment of the concepts described [1–6]. Here, using fMRI, we tested the hypothesis that areas in human premotor cortex that respond both to the execution and observation of actions—mirror neuron areas [7–18]—are key neural structures in these processes. Participants observed actions and read phrases relating to foot, hand, or mouth actions. In the premotor cortex of the left hemisphere, a clear congruence was found between effector-specific activations of visually presented actions and of actions described by literal phrases. These results suggest a key role of mirror neuron areas in the re-enactment of sensory-motor representations during conceptual processing of actions invoked by linguistic stimuli

The Importance of Sensory Processing in Mental Health: A Proposed Addition to the Research Domain Criteria (RDoC) and Suggestions for RDoC 2.0

The time is ripe to integrate burgeoning evidence of the important role of sensory and motor functioning in mental health within the National Institute of Mental Health’s [NIMH] Research Domain Criteria [RDoC] framework (National Institute of Mental Health, n.d.a), a multi-dimensional method of characterizing mental functioning in health and disease across all neurobiological levels of analysis ranging from genetic to behavioral. As the importance of motor processing in psychopathology has been recognized (Bernard and Mittal, 2015; Garvey and Cuthbert, 2017; National Institute of Mental Health, 2019), here we focus on sensory processing. First, we review the current design of the RDoC matrix, noting sensory features missing despite their prevalence in multiple mental illnesses. We identify two missing classes of sensory symptoms that we widely define as (1) sensory processing, including sensory sensitivity and active sensing, and (2) domains of perceptual signaling, including interoception and proprioception, which are currently absent or underdeveloped in the perception construct of the cognitive systems domain. Then, we describe the neurobiological basis of these psychological constructs and examine why these sensory features are important for understanding psychopathology. Where appropriate, we examine links between sensory processing and the domains currently included in the RDoC matrix. Throughout, we emphasize how the addition of these sensory features to the RDoC matrix is important for understanding a range of mental health disorders. We conclude with the suggestion that a separate sensation and perception domain can enhance the current RDoC framework, while discussing what we see as important principles and promising directions for the future development and use of the RDoC

Potential movement biomarkers for autism in children and adolescents

Background -- While social communication deficits are the hallmark of autism spectrum disorders (ASD), motor deficits are known to be common in this population as well. Recently, members of our research team showed that kinematic markers collected by playing a tablet game may be a promising biomarker for identification of ASD as compared to a typically developing population (TD) in children ages 3-6 years old (Anzulewicz et al, 2016). To our knowledge, no one has replicated this finding in an older population. Purpose -- To replicate and extend previous findings of kinematic differences in children with ASD to an older population of children (9-14 years old). Methods -- Four TD children and 5 children with ASD (aged 9-12) played an iPad drawing game (Anzulewicz et al, 2016) that measured gesture kinematics and gesture force using inertial sensors and touch screen touch displacements. 212 features were calculated from the inertial sensor and touch screen data (ibid). A Kolmogorov-Smirnov (K-S) test was run to identify motor features distinct between ASD and TD children. Results -- K-S test identified seven significantly different features (JerkMagnitudeMax, JerkMin_y, JerkRange_y, AttitudeRange_y, RotationRMS_x, RotationStdDev_x, JerkZeroCrossing_x) between ASD and TD groups that represented differences in acceleration of finger movements and the displacement of the iPad during movements. Conclusions -- Results demonstrated inertial movement sensor parameter differences are key identifiers between 8-12 year old ASD and TD children, common to children 3-6 years old. Contact forces and the distribution of forces during coloring may serve as important identifiers of ASD irrespective of age during childhood, while other parameters may be age-dependent. Research Support NIH R01 (1R01HD079432-01A1

Brainstem morphometric differences in children with autism spectrum disorder, developmental coordination disorder, and those typically developing

Background: The brainstem is a neglected topic in autism research, despite major lines of evidence indicating its active involvement in sensory, motor, affect, arousal, and social regulation (Dadalko & Travers, 2018). It is the substrate of what affective neuroscience identifies as the ‘Core Self’ (Alcaro, Carta, & Panksepp, 2017), and disruption to its growth and function appears to disturb core conscious experience in autism (Delafield-Butt & Trevarthen, 2017; Trevarthen & Delafield-Butt, 2013). Yet, although evidence indicates brainstem growth is disrupted in early childhood (Bosco et al., 2018), how these growth differences compare to closely related neurodevelopmental disorders, such a Developmental Coordination Disorder (DCD), is not yet understood. Objectives: To determine brainstem morphometric differences between children with ASD, DCD, and those typically developing (TD). Methods: Study participants were 87 youths ages 8 to 17 assigned to the ASD (n = 30, 7 female), DCD (n =24, 12 female) or TD (n = 33, 12 female) group. Exclusion criteria for all groups included IQ <80. TD were excluded if they had any neuropsychological or psychopathological disorder. DCD eligibility additionally included performance 16th percentile on the MABC-2 and no concern about an ASD diagnosis. ASD participants had a previous clinical diagnosis confirmed by ADOS-2 and ADI-R. Individuals were excluded if they had another neuropsychological disorder, except attention deficit or anxiety disorder. T1-weighted MPRAGE (1mm isotropic resolution) MRI data were acquired on a 3T MAGNETOM Prisma (Siemens). Brainstem morphology was analysed using SPHARM-MAT (http://lishenlab.com/spharm/), a 3D Fourier surface representation method¬¬¬. A typical surface was calculated for the TD group, and distances from this norm computed for each vertex. Mean distances at each vertex were computed for each group (ASD, DCD, TD) and compared, taking into account age, gender and supratentorial volume as covariates. Results: Significant brainstem morphological differences were identified between all three (TD, ASD and DCD; Figure 1). Significant differences between TD and ASD (p<0.01) were identified in a large region of the anterior-most surface, extending caudally along the right posterior surface. Differences between TD and DCD groups were similar with reduced significance (p0.01), and the pattern diverged with more inclusion of the anterior ventricular surface and less pronouncement at the right anterior border. Finally, significant differences were found between ASD and DCD groups (p<0.01), specifically at the anterior midline either side of the ventricular surface, and especially in two long anteroposterior columns on the left side adjacent and parallel to the fourth ventricle. Conclusions: Surface morphology differences indicate alterations in local nuclei and/or tract growth within the brainstem, especially approaching the anterior surface in ASD and DCD children, and differentially between them at the ventricular surface. The former may relate to specific nerve growth of the pons, and the latter to cerebellar peduncle connectivity differences, superficial nuclei growth such as the hypoglossal, intercalatus, or vagus and associated tracts, or deeper nuclei such as the inferior olivary nucleus. Brainstem structural differences likely disturbs the integrative function of the Core Self. Higher resolution 7T MRI is required to resolve the underlying differential composition

Default Network Deactivations Are Correlated with Psychopathic Personality Traits

Background: The posteromedial cortex (PMC) and medial prefrontal cortex (mPFC) are part of a network of brain regions that has been found to exhibit decreased activity during goal-oriented tasks. This network is thought to support a baseline of brain activity, and is commonly referred to as the ‘‘default network’’. Although recent reports suggest that the PMC and mPFC are associated with affective, social, and self-referential processes, the relationship between these default network components and personality traits, especially those pertaining to social context, is poorly understood. Methodology/Principal Findings: In the current investigation, we assessed the relationship between PMC and mPFC deactivations and psychopathic personality traits using fMRI and a self-report measure. We found that PMC deactivations predicted traits related to egocentricity and mPFC deactivations predicted traits related to decision-making. Conclusions/Significance: These results suggest that the PMC and mPFC are associated with processes involving selfrelevancy and affective decision-making, consistent with previous reports. More generally, these findings suggest a link between default network activity and personality traits