Virginia E. Sturm

A central unresolved issue in affective neuroscience is whether human emotions have unique biological signatures in the brain and body. Despite decades of debate, a consensus is lacking on whether emotions are patterned (similar across contexts and characterized by distinct features) or flexible (variable across contexts and lacking distinct features). Studies in other species have revealed the ubiquity of autonomic and motor patterns, and these investigations have elucidated the biology of central pattern generation at the levels of networks, neurons, and synapses. Here, we integrate the knowledge gained from this research and introduce the Dynamic Emotion Fabric Theory (DEFT), a new model of emotions biology. DEFT proposes that, just as fabrics are comprised of both patterns and textures, emotions are accompanied by stereotyped responses that are distinct and recognizable, yet also nuanced and malleable. A neurobiological system that is both automatic—generating patterned reactions essential for survival—and flexible—texturizing each response in context—is equipped to produce the spectrum of human emotions. DEFT provides new insights into the biological basis of emotions and identifies novel areas that warrant further study in humans and other species. This framework has implications for basic affective neuroscience and clinical studies of affective symptoms.

Accurate diagnosis of frontotemporal dementia (FTD) with right anterior temporal lobe (RATL) predominance remains challenging due to lack of clinical characterization, and standardized terminology. The recent research of the International Working Group (IWG) identified common symptoms but also unveiled broad terminologies lacking precision and operationalization, with risk of misdiagnoses, inappropriate referrals and poor clinical management. Based on the published evidence (91267 articles screened) and expert opinion (105 FTD specialists across 52 centers) by using the nominal group technique, the IWG delineates three primary domains of impairment causing behavioral, memory and language problems: (i) multimodal knowledge of non-verbal information including people, living beings, landmarks, flavors/odors, sounds, bodily sensations, emotions and social cues; (ii) socioemotional behavior encompassing emotion expression, social response and motivation; and (iii) prioritization for focus on specific interests, hedonic valuation and personal preferences. This study establishes a consensus on clinical profile, phenotypic nomenclature, and future directions to enhance diagnostic precision and therapeutic interventions.

Emotion regulation emerges during childhood and engages prefrontal brain systems. While most developmental studies focus on the neural underpinnings of negative emotion regulation, less is known about the neuroanatomical correlates of positive emotion regulation. In adults, prefrontal areas in the left hemisphere are critical for positive emotion regulation, but whether this association is present in children is unknown. We investigated whether smaller gray matter volume in left prefrontal regions related to worse positive emotion regulation in children with and without dyslexia. Because dyslexia is a neurodevelopmental disorder of reading in which there may be greater variability in left prefrontal structures, it offers a unique window into the neural basis of positive emotion regulation. Sixty-nine children (ages 7–13) were asked to hide their feelings while watching film clips that elicited either amusement or disgust, and evaluate their emotion regulation performance. Parents reported on children’s everyday emotion regulation. Across the sample, children with smaller volumes in left prefrontal regions (i.e., lateral orbitofrontal cortex and dorsolateral prefrontal cortex) had greater facial behavior (i.e., suggesting worse positive emotion regulation) yet more positive self-reported emotion regulation success during the amusement trial (i.e., suggesting more favorable self-evaluation). These regions did not relate to disgust regulation, however. Children with more positive views of their emotion regulation success also had better everyday parent-reported emotion regulation. Results suggest that positive emotion regulation in childhood relies on left prefrontal regions and a more optimistic view of one’s emotion regulation abilities, regardless of one’s actual emotional behavior, may confer real-world advantages.

Dyslexia is a neurodevelopmental condition characterized by reading difficulties, yet there is growing evidence for coinciding social and emotional strengths. In our previous work, we found children with dyslexia displayed greater emotional facial behavior to affective stimuli than their well-reading peers, an enhancement that related to better social skills. Traditional measures provide static “snapshots” of emotional facial behavior but overlook important dynamic information about the face’s movements that may confer interpersonal advantages. Here, we examined whether variability in emotional facial behavior was heightened in children with dyslexia and associated with social communication benefits. We coded the second-by-second intensities of ten emotional facial behaviors in 54 children (ages 7–14) with (n = 33) and without (n = 21) dyslexia while they watched five emotion-inducing film clips. For each trial, we calculated two facial behavior variability scores: a within-emotion variability score (the second-by-second intensity changes within each category of emotional behavior) and a between-emotions variability score (the total number of changes between categories of emotional behavior). Parents also reported on children’s real-world communication skills. Linear mixed-effects models (controlling for age, sex, and total facial behavior) revealed that children with dyslexia had higher within-emotion facial behavior variability but not higher between-emotions facial behavior variability than those without dyslexia. Across the sample, greater total within-emotion facial behavior variability correlated with higher parent-reported functional communication—the ability to express ideas in ways that others can easily understand. These findings suggest nuanced emotional facial behavior dynamics contribute to social strengths in dyslexia.

The experience of interpersonal space may be altered in Alzheimer’s disease (AD) due to atrophy in brain systems that support emotion and reward processing. Seventy participants (AD = 36, healthy controls = 34) underwent structural neuroimaging and completed a modified stop-distance paradigm, an established interpersonal distance task, in which they indicated at which distance they preferred to have a conversation with the experimenter. After estimating the distance between themselves and the experimenter, participants rated their emotional experience. Feelings of physical closeness were calculated as the discrepancy between the perceived and actual distance between the participant and experimenter. Participants also estimated their distance from the wall, which served as a non-social control task. Unlike the healthy controls, the participants with AD felt physically closer to the experimenter than they were (despite no differences in objective interpersonal distance) and reported greater positive emotional experience. Voxel-based morphometry analyses revealed greater feelings of physical closeness related to smaller gray matter volume in the right ventral striatum and right medial orbitofrontal cortex (pFWE<.05). These results suggest that reward system atrophy influences how people with AD experience interpersonal space. Individuals with AD may feel physically closer to others than they are and find social proximity more enjoyable than healthy controls.

Introduction: More precise subtyping within dementia syndromes leads to better prediction of pathology, supporting individualized, disease-specific treatments. Notably, studies highlight that identification of the right-temporal or semantic behavioral variant frontotemporal dementia (sbvFTD) subtype relies in part on measuring emotion recognition abilities. Methods: To evaluate the effectiveness of current tools, we compared two dynamic video-based affect labeling tests—the Dynamic Affect Recognition Test (DART) and The Awareness of Social Inference Test-Emotion Evaluation Test (TASIT-EET)—against the static image-based Name Affect subtest of the Comprehensive Affect Testing System (CATS-NA) test. A total of 555 persons with dementia (PwD), in the early stages of neurodegenerative disease (Clinical Dementia Rating ≤ 1; Mini Mental State Examination ≥ 20), diagnosed with Alzheimer’s disease syndrome (AD) (n=154), progressive supranuclear palsy syndrome (PSPS) (n=88), non-fluent variant primary progressive aphasia (nfvPPA) (n=77), semantic variant PPA (n=53), behavioral variant frontotemporal dementia (bvFTD) (n=124), semantic bvFTD (n=65), and 133 healthy older participants underwent emotion testing and structural MRI. Results: All emotion labeling tests differentiated PwD from healthy controls (DART, AUC=0.81; TASIT-EET, AUC=0.84; CATS-NA, AUC=0.72), and FTD with social cognition deficits (sbvFTD, bvFTD, and svPPA) from other PwDs (DART, AUC=0.64; TASIT-EET, AUC=0.66; CATS-NA, AUC=0.63). Dynamic tests outperformed CATS-NA in differentiating sbvFTD from bvFTD and svPPA (DART, AUC=0.79; TASIT-EET, AUC=0.74; CATS-NA, AUC=0.60), whereas DART outperformed TASIT-EET in differentiating sbvFTD from svPPA (DART, AUC=0.73; TASIT-EET, AUC=0.66). Multiple linear regression analysis showed that TASIT-EET performance was predicted by visual memory (Benson-delayed) and verbal semantic (BNT, Animal Fluency) functions (p<0.01) and CATS-NA performance was predicted by visuospatial (CATS-Face matching, Number location) (p<0.001) and executive functions (Modified Trail making speed) (p<0.05), while DART was predicted by only working memory functions (Digit span backward) (p<0.05). DART corresponded to the expected structural anatomy of emotion, including right predominant insula, anterior temporal, and orbitofrontal lobes. While both TASIT-EET and CATS-NA shared that pattern of brain anatomy, TASIT-EET correlated with more left temporal structures than DART, and CATS-NA associated with more dorsal structures than DART. Finally, all emotion labeling tests correlated with real-life empathy deficits measured by a standardized informant-based survey. Conclusion: Tasks showing dynamic audio-visual emotion displays showed better effectiveness for diagnostic differentiation of FTD syndromes than static image-based tasks, and the DART showed better clinical and anatomic precision than the TASIT-EET. Emotion identification deficits are a core feature of dementia syndromes like sbvFTD, but occur in the context of additional cognitive deficits. Therefore, careful selection of tests that reflect the key underlying neural circuits related to emotion, and which minimize demand from other cognitive domains, will result in more accurate diagnoses.

The human face plays a central role in emotions and social communication. The emotional and somatic motor networks generate facial behaviors, but whether facial behaviors have representations in the structural anatomy of the human brain is unknown. We coded 16 facial behaviors in 55 healthy older adults who viewed five videos that elicited emotions and examined whether individual differences in facial behavior were related to regional variation in gray matter volume. Voxel-based morphometry analyses revealed that greater emotional facial behavior during the disgust trial (i.e. greater brow furrowing and eye tightening as well as nose wrinkling and upper lip raising) and the amusement trial (i.e. greater smiling and eye tightening) was associated with larger gray matter volume in midcingulate cortex, supplementary motor area, and precentral gyrus, areas spanning both the emotional and somatic motor networks. When measured across trials, however, these facial behaviors (and others) only related to gray matter volume in the precentral gyrus, a somatic motor network hub. These findings suggest that the emotional and somatic motor networks store structural representations of facial behavior and that the midcingulate cortex is critical for generating the predictable movements in the face that arise during emotions.