The Polyvagal Theory: phylogenetic contributions to social behavior

A model of preverbal social development and its application to social dysfunctions in autism

Studies of early face perception are used to develop a model of how face expressions might be transduced to initiate consonant internal affect, related outward expressions and other behaviours. Underlying neural mechanisms and processes are identified. The model is generalised to offer an account of aspects of typical preverbal social development. It is then used to develop aetiological hypotheses about the lack of social interest and motivation in autism and to provide a framework for evaluating other theories of autism. Although derived from existing literature, the model offers a distinctive account.

Structural changes in the nucleus ambiguus of the medulla oblongata and intracardiac ganglia in growing rats in immobilization stress

The aim of the present work was to study qualitative and quantitative measures of histological changes in the nucleus ambiguus (NA) of the medulla oblongata and the cardiac autonomic ganglia (CAG) in growing animals in conditions of immobilization stress of different durations. Experiments were performed on 56 mongrel white rats aged 30 days. Immobilization stress was produced by placing rats in a special apparatus with a controllable internal volume for 3, 7, 15, and 30 days. The NA and CAG were studied on paraffin sections using neurohistological methods and quantitative analysis. Morphological and morphometric changes, consisting of a delay in the growth of neurocyte cell and nucleus volumes, as compared with controls, were seen both in the NA of the medulla oblongata and the CAG and were evaluated as impairments in the histogenesis of nerve tissue during postnatal ontogenesis. The extent of structural changes in these components of the autonomous nervous system was directly dependent on the duration of the experimental treatment.

Effects of human contact and vagal regulation on pain reactivity and visual attention in newborns

In two experiments we examined the effects of human contact and vagal regulation on newborns' pain reactivity and visual attention. Baseline cardiac vagal tone was measured during quiet sleep and during the experiment, and vagal withdrawal was indexed as change in vagal tone from baseline to pain (study 1) or attention (study 2). In study 1, 62 healthy newborns were videotaped during a heel-prick procedure and pain reactivity was assessed from micro-level coding of facial expressions, cry behavior, and body movements. Infants were randomly assigned to a contact condition, held by a female assistant, or a no contact condition, on an infant-seat in a similar angle. In study 2, 62 additional healthy newborns, randomly assigned to contact and noncontact conditions, were presented with 2 visual stimuli for a 60 s familiarization period, which were then paired with a novel stimulus. Visual interest, alertness, and novelty preference were coded. Human contact had no effect on the newborns' pain response. Visual attention increased with human contact and newborns in the contact condition looked at the stimuli more frequently, with higher alertness, for longer durations, and had a higher novelty preference. Autonomic reactivity-as indexed by vagal withdrawal-differentiated newborns with intense and mild pain response. Discussion focused on proximity to conspecifics as a contributor to emerging regulatory and adaptive functioning in the human infant.

Maternal care and development of stress responses in baboons

The ability to mount a successful response to threats is critical for an organism's survival. A key element of the stress response is its nonspecificity toward the stress source, with similar endocrine and behavioral changes expected under a variety of stressors. In this project we utilized an experimental design that accounts for multiple sources of variation to further understand the nature of stress responsivity and its relationship to the early rearing environment. A sample of baboons (n=73) was observed during the early phase of life in their social group, and then tested as juveniles in a challenging situation. Maternal cortisol levels were measured during the peripartum period. The challenging situation (individuals were isolated for a few minutes in a single cage) was designed to be a moderate source of psychological stress. Patterns in individual differences during the stress test were "mapped" by means of multidimensional scaling (MDS). After the observation was made, the subject was sedated and a blood sample was taken to measure cortisol levels. Our results indicate that when juvenile baboons are confronted with a source of psychological stress, they show a multidimensional behavioral response, probably mediated by the activation and synergic interaction among different neurohormonal systems that, ultimately, act on the hypothalamus-pituitary-adrenal (HPA) axis. Different components of the multidimensional, or nonspecific, behavioral response are associated with the quality and quantity of interactions with their mothers during early life. Juveniles whose mothers displayed higher levels of positive interaction were characterized by vigilant but less active reactions to the stress test, whereas juveniles of mothers that displayed high levels of stress-related behaviors had higher cortisol and locomotion levels.

Biofeedback and Dance Performance: A Preliminary Investigation

Alpha-theta neurofeedback has been shown to produce professionally significant performance improvements in music students. The present study aimed to extend this work to a different performing art and compare alpha-theta neurofeedback with another form of biofeedback: heart rate variability (HRV) biofeedback. Twenty-four ballroom and Latin dancers were randomly allocated to three groups, one receiving neurofeedback, one HRV biofeedback and one no intervention. Dance was assessed before and after training. Performance improvements were found in the biofeedback groups but not in the control group. Neurofeedback and HRV biofeedback benefited performance in different ways. A replication with larger sample sizes is required.

Early detection of core deficits in autism

The goal of this review of the research literature is to discuss approaches to the early detection of autism in infancy. Early detection would enable diagnoses to be made before 18 months of age rather than at 24-30 months, the age where diagnoses start to be made now. After summarizing the criteria for a deficit to be considered "core" to the disorder, the literature on research strategies used in early detection is examined. In order to guide the design of future studies, the review then turns to an overview of what is known about the processes of early social development in typically developing children that underlie the domains in which core deficits are manifested in young children with autism. The social domains covered in the review are those that show development in typically developing infants below 18 months of age: dyadic interaction and imitation; emotion discrimination; and attachment. The review concludes that all of these areas are worthy of investigation in young children, particularly those at higher risk of showing some of the core deficits of autism such as the infant siblings of children with autism.

Neuroimaging in disorders of social and emotional functioning: what is the question?

Social and emotional processing uses neural systems involving structures ranging from the brain stem to the associational cortex. Neuroimaging research has attempted to identify abnormalities in components of these systems that would underlie the behavioral abnormalities seen in disorders of social and emotional processing, notably autism spectrum disorders, the focus of this review. However, the findings have been variable. The most replicated anatomic finding (a tendency toward large brains) is not modular, and metabolic imaging and functional imaging (although showing substantial atypicality in activation) are not consistent regarding specific anatomic sites. Moreover, autism spectrum disorder demonstrates substantial heterogeneity on multiple levels. Here evidence is marshaled from a review of neuroimaging data to support the claim that abnormalities in social and emotional processing on the autism spectrum are a consequence of systems disruptions in which the behaviors are a final common pathway and the focal findings can be variable, downstream of other pathogenetic mechanisms, and downstream of more pervasive abnormalities.

Insomnia causes, consequences, and therapeutics: an overview

There is growing interest in insomnia both from the perspective of recent advances in clinical management as well as research aimed at elucidating its pathophysiology. This theoretical overview of insomnia describes the negative impact, etiological considerations, and pharmacological and behavioral treatments for the disorder, with an emphasis on areas receiving increased research attention. Insomnia, the most prevalent sleep disorder, affects 10-15% of the general population. In population-based studies severe insomnia has been shown to last for a median of 4 years. In addition, insomnia has a significant negative impact on an individual's work, physical, and social performance as well as overall quality of life. Furthermore, the economic cost of insomnia related to lost productivity, work-related accidents, absenteeism, and health-care costs are enormous. There is increasing evidence linking the precipitation of insomnia to stress, and converging evidence from cognitive, endocrine, neurological, and behavioral domains provide clear evidence for hyper-arousal in insomnia. However, there remains no consensus regarding the specific etiological mechanisms of this disorder. Although the pathophysiology of primary insomnia remains an enigma, numerous treatments both pharmacological and behavioral have been developed and found to be efficacious in controlled studies. Despite the wide availability of pharmacological treatments and increased knowledge of behavioral interventions, the vast majority of individuals with insomnia do not appear to be receiving adequate treatment. The inadequate treatment of insomnia leads to several important and under-recognized consequences including subsequent development of psychiatric disease and increased substance use.

Modulation of autonomic balance by tumors and viruses

Autonomic balance, a function generally under host control, is subject to modulation by other signalers. In some cases, modulation of host autonomic function through behavioral and physical stressors exerted by another individual may have negative consequences for the stress recipient by inducing sympathetic bias. Modulation of autonomic function may sometimes benefit one party at the expense of another. Tumors and HIV are examples of illegitimate signalers who may induce host sympathetic bias to promote their own growth and evade host immune surveillance. Paraneoplastic and paraviral syndromes such as hypertrophic osteoarthopathy, QTc prolongation, insomnia, and cachexia could be viewed as epiphenomena related to the tumoral and viral manipulation of host autonomic balance. In a more general framework, other paraneoplastic and paraviral syndromes may represent epiphenomena related to modulation of endocrine, cytokine, and autonomic functions by tumors and viruses to promote their own survival. Spatial distribution of cancers and viruses within the host may reflect affinity for strategic locations that facilitate manipulation of a variety of host functions including autonomic, endocrine, and cytokine regulation. A more general for understanding spatial distribution of diseases based on gradients of autonomic balance in the body are explored. Darwinian perspectives are discussed.