Neuroendocrine perspectives on social attachment and love

Oxytocin, vasopressin, and human social behavior

There is substantial evidence from animal research indicating a key role of the neuropeptides oxytocin (OT) and arginine vasopressin (AVP) in the regulation of complex social cognition and behavior. As social interaction permeates the whole of human society, and the fundamental ability to form attachment is indispensable for social relationships, studies are beginning to dissect the roles of OT and AVP in human social behavior. New experimental paradigms and technologies in human research allow a more nuanced investigation of the molecular basis of social behavior. In addition, a better understanding of the neurobiology and neurogenetics of human social cognition and behavior has important implications for the current development of novel clinical approaches for mental disorders that are associated with social deficits (e.g., autism spectrum disorder, social anxiety disorder, and borderline personality disorder). This review focuses on our recent knowledge of the behavioral, endocrine, genetic, and neural effects of OT and AVP in humans and provides a synthesis of recent advances made in the effort to implicate the oxytocinergic system in the treatment of psychopathological states.

Optimizing learning and quality of life throughout the lifespan: a global framework for research and application

This overview surveys the new optimism about the aging mind/brain, focusing on the potential for self-regulation practices to advance research in stress-protection and optimal health. It reviews recent findings and offers a research framework. The review links the age-related biology of stress and regeneration to the variability of mind/brain function found under a range of conditions from trauma to enrichment. The framework maps this variation along a biphasic continuum from atrophic dysfunction to peak performance. It adopts the concept of allostatic load as a measure of the wear-and-tear caused by stress, and environmental enrichment as a measure of the use-dependent enhancement caused by positive reinforcement. It frames the dissociation, aversive affect and stereotyped reactions linked with stress as cognitive, affective and behavioral forms of allostatic drag; and the association, positive affect, and creative responses in enrichment as forms of allostatic lift. It views the human mind/brain as a heterarchy of higher intelligence systems that shift between a conservative, egocentric mode heightening self-preservation and memory and a generative, altruistic mode heightening self-correction and learning. Cultural practices like meditation and psychotherapy work by teaching the self-regulation of shifts from the conservative to the generative mode. This involves a systems shift from allostatic drag to allostatic lift, minimizing wear-and-tear and optimizing plasticity and learning. For cultural practices to speed research and application, a universal typology is needed. This framework includes a typology aligning current brain models of stress and learning with traditional Indo-Tibetan models of meditative stress-cessation and learning enrichment.

Modeling dad: animal models of paternal behavior

In humans, paternal behaviors have a strong influence on the emotional and social development of children. Fathers, more frequently than mothers, leave the family nucleus, and/or become abusive, leading to offspring that are more likely to grow under stressful conditions and greater susceptibility to abnormal health and social outcomes. Literature on parental behaviors, human or animal, has primarily focused on the interactions between mothers and offspring, with little research directed at understanding paternal behavior. In animal studies, experimenters correlate paternal behaviors with those seen in rodent or primate mothers, often under situations in which behaviors such as nest protection, huddling, pup grooming, and retrieval are artificially induced. In humans, the majority of the studies have looked at paralleling hormonal changes in fathers with those occurring in mothers, or observed paternal behaviors in populations with specific anthropological backgrounds. These studies reveal commonalities in parental behaviors and their underlying neural circuits. However, this work highlights the possibility that paternal behavior has components that are strictly masculine with unique neurobiological mechanisms. This review summarizes this information and provides a current view of a topic that needs further exploration.

Early stress exposure: concepts, findings, and implications, with particular emphasis on attachment disturbances

BACKGROUND

Early intervention and preventive interventions are attracting increasing attention in the child and adolescent mental health field because recent research findings offer new insights into risk mechanisms and because of the growing expectation that they may hold clues to reducing suffering and health cost burdens for society and the individual.

METHODS

A selective review of the literature is provided to examine alternative models for understanding the impact of early risk exposure and how these findings may be translated to intervention and prevention; we pay particular attention to the role of child-parent attachment relationship quality as a major potential source of risk or protection.

RESULTS

In this qualitative review, we conclude that sharply contrasting models for understanding early exposure to risk have not been adequately empirically examined in human work. In the case of attachment disturbances, one good context for studying early risk and intervention, sizable questions remain about conceptual models and assessment practices.

CONCLUSION

Implications of these findings, and limits of the findings, for existing conceptual models of child and adolescent psychopathology and clinical practice are highlighted.

Detection of salivary oxytocin levels in lactating women

Oxytocin is a neuropeptide with widespread influence on many physiological and social functions including: labor and birth, lactation, sexual behavior, nurturing maternal behaviors, and stress reduction. However, our understanding of oxytocin's roles has been hampered by lack of noninvasive methods for assessing oxytocin levels. The goal of the present study was to assess whether oxytocin could be detected in saliva and whether changes occurred in the pattern of oxytocin release among lactating women from before, at initiation and after breast feeding. Using a prospective repeated measures design, 11 research participants each provided 18 saliva samples during three feeding cycles (before, at initiation and after breast feeding) for two 24-hr data collection periods (Days 1 and 2). Within each day, saliva was collected at late evening, early morning, and late morning. Salivary samples were concentrated fourfold by dehydration prior to analysis and oxytocin was measured in saliva using an enzyme immunoassay (EIA). Salivary oxytocin values, when reconverted to their original levels, ranged from 6.44 to 61.05 pg/ml. Oxytocin values in saliva varied significantly as a function of the breast feeding cycle, but did not show reliable differences as a function of the time of feeding. Oxytocin was highest before feeding, followed by a decrease at initiation of feeding, and an increase at 30 min after feeding. The findings suggest that oxytocin release into saliva increases in anticipation of feedings. This study also supports the potential usefulness of salivary measures of oxytocin as a noninvasive index of changes in this peptide.

Mutation analysis of oxytocin gene in individuals with adult separation anxiety

Individuals with a diagnosis of adult separation anxiety (ASAD) have extreme anxiety about separations, actual or imagined, from major attachment figures. ASAD might represent a psychological/behavioral model for research probably involving a dysregulation of those neurobiological mechanisms of attachment, in particular central oxytocin (OT), described in numerous animal studies. As experimental strategy, we chose the nucleotidic sequencing of the human OT gene of patients with ASAD to evaluate whether OT mutations were related to potential alteration of its production. With this aim, mutation scanning of proximal promoter and untranslated and coding regions of the OT gene was carried out in 36 patients with ASAD, 14 patients without ASAD, and 26 controls. No mutations were found in promoter and coding regions of the OT gene in our population. One rare 3'UTR single nucleotide variant (rs17339677) and one intron 2 molecular variant (rs34097556), which showed a high frequency, were evidenced. There was no significant difference in the genotype distribution of this intron 2 polymorphism between patients and healthy individuals. Further research is needed to investigate the association between ASAD and OT peptide and receptor polymorphisms.

The mechanism of life-threatening water imbalance in schizophrenia and its relationship to the underlying psychiatric illness

Impaired water excretion was noted to coincide with psychotic exacerbations in the first decades of the past century. In the ensuing decades, life-threatening water intoxication and elevated plasma levels of the antidiuretic hormone, arginine vasopressin (AVP) were reported in a subset of persons with schizophrenia. Subsequent studies demonstrated that the osmotic set point for AVP secretion was transiently reset in these patients by an unknown process and that this was further exacerbated by acute psychosis. More recent studies indicate that the AVP dysfunction is a manifestation of a hippocampal-mediated impairment in the regulation of both AVP and HPA axis responses to psychological, but not other types of, stimuli. Of potential significance, is that schizophrenic patients without water imbalance exhibit the opposite pattern of responses. Preliminary data indicate those with water imbalance also demonstrate a closely linked deficit in central oxytocin activity which may account for their diminished social function. These latter behavioral deficits are perhaps the most disabling and treatment resistant features of schizophrenia, which recent studies suggest, may respond to oxytocin agonists. Together these findings support the view that schizophrenia is a heterogeneous disorder, and provide novel biomarkers and approaches for exploring the pathophysiology and treatment of severe mental illness.

Passionate love and relationship thinkers: experimental evidence for acute cortisol elevations in women

We assessed the impact of an individual difference variable, relationship-focused thinking, on women's acute salivary cortisol responses during and after a guided imagery task. Specifically, 29 healthy women, all of whom were experiencing high levels of passionate love, but varied on levels of relationship-focused thinking, were assigned to one of two experimental conditions: a partner reflection condition or a cross-sex friend reflection condition. Results indicated that women experiencing passionate love evidenced increased cortisol levels when asked to reflect on their romantic partner and relationship relative to women asked to reflect on a cross-sex friendship, but this difference was particularly pronounced and relatively long-lasting for those women characterized by a high amount of relationship-focused thinking. Our study significantly expands extant work on the passionate love-cortisol link by isolating the impact of a specific psychological variable, relationship-focused thinking, on the physiological experience of falling in love. We believe our work highlights the advances that can be made when established work in the close relationships and neuroendocrine fields are integrated.

Consequences of early experiences and exposure to oxytocin and vasopressin are sexually dimorphic

In the socially monogamous prairie vole, we have observed that small changes in early handling, as well as early hormonal manipulations can have long-lasting and sexually dimorphic effects on behavior. These changes may be mediated in part by changes in parental interactions with their young, acting on systems that rely on oxytocin (OT) and arginine vasopressin (AVP). Knowledge of both endogenous and exogenous influences on systems that rely on OT and AVP may be helpful in understanding sexually dimorphic developmental disorders, such as autism, that are characterized by increased anxiety and deficits in social behavior.

Social closeness increases salivary progesterone in humans

We examined whether interpersonal closeness increases salivary progesterone. One hundred and sixty female college students (80 dyads) were randomly assigned to participate in either a closeness task with a partner versus a neutral task with a partner. Those exposed to the closeness induction had higher levels of progesterone relative to those exposed to the neutral task. Across conditions, progesterone increase one week later predicted the willingness to sacrifice for the partner. These results are discussed in terms of the links between social contact, stress, and health.

Poverty-alleviation program participation and salivary cortisol in very low-income children

Correlational studies have shown associations between social class and salivary cortisol suggestive of a causal link between childhood poverty and activity of the stress-sensitive hypothalamic-pituitary-adrenocortical (HPA) system. Using a quasi-experimental design, we evaluated the associations between a family's participation in a large-scale, conditional cash transfer program in Mexico (Oportunidades, formerly Progresa) during the child's early years of life and children's salivary cortisol (baseline and responsivity). We also examined whether maternal depressive symptoms moderated the effect of program participation. Low-income households (income <20th percentile nationally) from rural Mexico were enrolled in a large-scale poverty-alleviation program between 1998 and 1999. A comparison group of households from demographically similar communities was recruited in 2003. Following 3.5 years of participation in the Oportunidades program, three saliva samples were obtained from children aged 2-6 years from intervention and comparison households (n=1197). Maternal depressive symptoms were obtained using the Center for Epidemiologic Studies-Depression Scale (CES-D). Results were that children who had been in the Oportunidades program had lower salivary cortisol levels when compared with those who had not participated in the program, while controlling for a wide range of individual-, household- and community-level variables. Reactivity patterns of salivary cortisol did not differ between intervention and comparison children. Maternal depression moderated the association between Oportunidades program participation and baseline salivary cortisol in children. Specifically, there was a large and significant Oportunidades program effect of lowering cortisol in children of mothers with high depressive symptoms but not in children of mothers with low depressive symptomatology. These findings provide the strongest evidence to date that the economic circumstances of a family can influence a child's developing stress system and provide a mechanism through which poverty early in life could alter life-course risk for physical and mental health disorders.

Assessing the neuroendocrine stress response in the functional neuroimaging context

Neural regulation of stress responses, and the feedback of stress hormones to the brain, reflect complex brain-body interactions that may underlie the effects of psychological stress on health. Elucidating the brain circuitry involved in the cortical control of limbic-hypothalamic-pituitary-adrenal axis, and the cortical "targets" of cortisol that in turn modulates brain function, requires careful assessment of glucocorticoid hormones, in the context of the neuroimaging paradigms. Here we discuss approaches for assessment of endocrine function in the context of neuroimaging, including methods of blood and saliva specimen collection, and methods for drug/hormone administration. We also briefly discuss important temporal considerations, including appropriate timing of sample collections for hormones with different time-courses of activation (e.g. ACTH vs. cortisol), the pharmacokinetics of both endogenous hormones and administered agents, and circadian considerations. These are crucial to experimental designs of rhythmic hormonal systems and multiple feedback loops. We briefly address psychological/behavioral 'activation' paradigms used for inducing endogenous LHPA axis responses within or in proximity to scanner, as well as strategies for administration of exogenous hormones or secretagogues. Finally, we discuss some of the analytical issues in terms of hormone responses (e.g. response and area under curve, diurnal variability) and strategies for linking measured levels of peripheral humoral factor to brain activity (e.g. hormone responses as between-subject regressors of BOLD activations, hormone levels as within-subject regressors in analyses of covariance of brain activity over time, etc.).

Genetic, epigenetic and environmental impact on sex differences in social behavior

The field of behavioral neuroendocrinology has generated thousands of studies that indicate differences in brain structure and reactivity to gonadal steroids that produce sex-specific patterns of social behavior. However, rapidly emerging evidence shows that genetic polymorphisms and resulting differences in the expression of neuroactive peptides and receptors as well as early-life experience and epigenetic changes are important modifiers of social behavior. Furthermore, due to its inherent complexity, the neurochemical mechanisms underlying sex differences in social behavior are usually studied in a tightly regulated laboratory setting rather than in complex environments. Importantly, specific hormones may elicit a range of different behaviors depending on the cues present in these environments. For example, individuals exposed to a psychosocial stressor may respond differently to the effects of a gonadal steroid than those not exposed to chronic stress. The objective of this review is not to re-examine the activational effects of hormones on sex differences in social behavior but rather to consider how genetic and environmental factors modify the effects of hormones on behavior. We will focus on estrogen and its receptors but consideration is also given to the role of androgens. Furthermore, we have limited our discussions to the importance of oxytocin and vasopressin as targets of gonadal steroids and how these effects are modified by genetic and experiential situations. Taken together, the data clearly underscore the need to expand research initiatives to consider gene-environment interactions for better understanding of the neurobiology of sex differences in social behavior.

The oxytocin receptor (OXTR) contributes to prosocial fund allocations in the dictator game and the social value orientations task

BACKGROUND

Economic games observe social decision making in the laboratory that involves real money payoffs. Previously we have shown that allocation of funds in the Dictator Game (DG), a paradigm that illustrates costly altruistic behavior, is partially determined by promoter-region repeat region variants in the arginine vasopressin 1a receptor gene (AVPR1a). In the current investigation, the gene encoding the related oxytocin receptor (OXTR) was tested for association with the DG and a related paradigm, the Social Values Orientation (SVO) task.

METHODOLOGY/PRINCIPAL FINDINGS

Association (101 male and 102 female students) using a robust-family based test between 15 single tagging SNPs (htSNPs) across the OXTR was demonstrated with both the DG and SVO. Three htSNPs across the gene region showed significant association with both of the two games. The most significant association was observed with rs1042778 (p = 0.001). Haplotype analysis also showed significant associations for both DG and SVO. Following permutation test adjustment, significance was observed for 2-5 locus haplotypes (p<0.05). A second sample of 98 female subjects was subsequently and independently recruited to play the dictator game and was genotyped for the three significant SNPs found in the first sample. The rs1042778 SNP was shown to be significant for the second sample as well (p = 0.004, Fisher's exact test).

CONCLUSIONS

The demonstration that genetic polymorphisms for the OXTR are associated with human prosocial decision making converges with a large body of animal research showing that oxytocin is an important social hormone across vertebrates including Homo sapiens. Individual differences in prosocial behavior have been shown by twin studies to have a substantial genetic basis and the current investigation demonstrates that common variants in the oxytocin receptor gene, an important element of mammalian social circuitry, underlie such individual differences.

Compassionate mind training with people who hear malevolent voices: a case series report

This paper presents a series of case studies to explore the understanding, acceptance and value of compassionate mind training (CMT) with psychotic voice hearers. We were interested in the degree to which such people are able to access and feel the positive emotions of 'warmth' and 'contentment' to become more self-compassionate. We also explored how CMT affected participants' hostile voices, their levels of anxiety, depression, paranoia and self-criticism. Participants were invited to offer suggestions for tailoring this approach for voice hearers. Results showed decreases for all participants in depression, psychoticism, anxiety, paranoia, Obsessive-Compulsive Disorder and interpersonal sensitivity. All participants' auditory hallucinations became less malevolent, less persecuting and more reassuring.

Intranasal oxytocin increases positive communication and reduces cortisol levels during couple conflict

BACKGROUND

In nonhuman mammals, the neuropeptide oxytocin has repeatedly been shown to increase social approach behavior and pair bonding. In particular, central nervous oxytocin reduces behavioral and neuroendocrine responses to social stress and is suggested to mediate the rewarding aspects of attachment in highly social species. However, to date there have been no studies investigating the effects of central oxytocin mechanisms on behavior and physiology in human couple interaction.

METHODS

In a double-blind placebo-controlled design, 47 heterosexual couples (total n = 94) received oxytocin or placebo intranasally before a standard instructed couple conflict discussion in the laboratory. The conflict session was videotaped and coded for verbal and nonverbal interaction behavior (e.g., eye contact, nonverbal positive behavior, and self-disclosure). Salivary cortisol was repeatedly measured during the experiment.

RESULTS

Oxytocin significantly increased positive communication behavior in relation to negative behavior during the couple conflict discussion (F = 4.18, p = .047) and significantly reduced salivary cortisol levels after the conflict compared with placebo (F = 7.14, p = .011).

CONCLUSIONS

These results are in line with animal studies indicating that central oxytocin facilitates approach and pair bonding behavior. Our findings imply an involvement of oxytocin in couple interaction and close relationships in humans.

Oxytocin: the great facilitator of life

Oxytocin (Oxt) is a nonapeptide hormone best known for its role in lactation and parturition. Since 1906 when its uterine-contracting properties were described until 50 years later when its sequence was elucidated, research has focused on its peripheral roles in reproduction. Only over the past several decades have researchers focused on what functions Oxt might have in the brain, the subject of this review. Immunohistochemical studies revealed that magnocellular neurons of the hypothalamic paraventricular and supraoptic nuclei are the neurons of origin for the Oxt released from the posterior pituitary. Smaller cells in various parts of the brain, as well as release from magnocellular dendrites, provide the Oxt responsible for modulating various behaviors at its only identified receptor. Although Oxt is implicated in a variety of "non-social" behaviors, such as learning, anxiety, feeding and pain perception, it is Oxt's roles in various social behaviors that have come to the fore recently. Oxt is important for social memory and attachment, sexual and maternal behavior, and aggression. Recent work implicates Oxt in human bonding and trust as well. Human disorders characterized by aberrant social interactions, such as autism and schizophrenia, may also involve Oxt expression. Many, if not most, of Oxt's functions, from social interactions (affiliation, aggression) and sexual behavior to eventual parturition, lactation and maternal behavior, may be viewed as specifically facilitating species propagation.

Oxytocin makes a face in memory familiar

Social recognition is the basis of all social interactions. Here, we show that, in humans, the evolutionarily highly conserved neuropeptide oxytocin, after intranasal administration, specifically improves recognition memory for faces, but not for nonsocial stimuli. With increased oxytocin levels, previously presented faces were more correctly assessed as "known," whereas the ability of recollecting faces was unchanged. This pattern speaks for an immediate and selective effect of the peptide strengthening neuronal systems of social memory.

Mother-infant interactions in free-ranging rhesus macaques: relationships between physiological and behavioral variables

Studies of mother-infant relationships in nonhuman primates have increasingly attempted to understand the neuroendocrine bases of interindividual variation in mothering styles and the mechanisms through which early exposure to variable mothering styles affects infant behavioral development. In this study of free-ranging rhesus macaques on Cayo Santiago, Puerto Rico, we aimed to: 1) compare lactating and nonlactating females to investigate whether lactation is associated with changes in plasma cortisol, prolactin and oxytocin, as well as changes in CSF levels of serotonin and dopamine metabolites (5-HIAA and HVA); 2) examine the extent to which interindividual variation in maternal physiology is associated with variation in maternal behavior; 3) examine the extent to which interindividual variation in infant physiology and behavior is accounted for by variation in maternal physiology and behavior. Lactating females had higher plasma concentrations of cortisol, prolactin, and oxytocin but lower CSF concentrations of HVA than nonlactating females. Variation in maternal rejection behavior was positively correlated with variation in maternal plasma cortisol levels and in CSF 5-HIAA levels while variation in the time spent nursing and grooming was associated with maternal plasma oxytocin levels. Infants who were protected more by their mothers had higher cortisol levels than those who were protected less, while infants who were rejected more had lower CSF 5-HIAA than infants who were rejected less. Since exposure to high levels of maternal protectiveness and rejection is known to affect the offspring's behavior and responsiveness to the environment later in life, our results are consistent with the hypothesis that these effects are mediated by long-term changes in the activity of the offspring's HPA axis and brain serotonergic system.

Caregiving behavior is associated with decreased mortality risk

Traditional investigations of caregiving link it to increased caregiver morbidity and mortality, but do not disentangle the effects of providing care from those of being continuously exposed to an ailing loved one with serious health problems. We explored this possible confound in a national, longitudinal survey of elderly married individuals (N= 3,376). Results showed that spending at least 14 hr per week providing care to a spouse predicted decreased mortality for the caregiver, independently of behavioral and cognitive limitations of the care recipient (spouse), and of other demographic and health variables. These findings suggest that it may be premature to conclude that health risks for caregivers are due to providing active help. Indeed, under some circumstances, caregivers may actually benefit from providing care.

Temporal changes in functional magnetic resonance imaging activation of heterosexual couples for visual stimuli of loved partners

OBJECTIVE

Previous neuroimaging studies on romantic love have focused on determining how the visual stimuli that serve as a representation of loved ones induce the neural activation patterns of romantic love. The purpose of this study was to investigate the temporal changes in romantic love over a period of 6 months and their correlated neurophysiological changes.

METHODS

Five heterosexual couples (n=10, mean age 21.1+/-1.97) who started dating not less than 100 days previously were recruited to measure their blood oxygen level dependent (BOLD) signals using functional magnetic resonance imaging (fMRI) while showing them pictures of their loved ones and their previously identified, opposite-sex friends. Subsequently, the subjects were scanned under the same experimental conditions to assess possible changes in their brain activities after 180 days.

RESULTS

WE FOUND THAT THEIR PASSIONATE LOVE SCORE (PLS) VALUES (M: 118.6+/-9.1, F: 120.2+/-7.0) were significantly reduced after 6 months (M: 110.8+/-4.0, F: 106.2+/-3.0). Furthermore, significantly increased activations were found in the cingulate gyri, inferior frontal gyri, supramarginal gyri, etc., after 6 months, whereas the head and tail of the right caudate nucleus were deactivated, which is indicative of the inhibition of expression and sensory neglect.

CONCLUSION

These findings suggest that dynamic neural processes in the cortical-subcortical regions are involved in temporal changes in romantic love.

An integrative theoretical framework for understanding sexual motivation, arousal, and behavior

An integrative theoretical framework and model for understanding sexual motivation, arousal, and behavior is presented, combining the principles of incentive motivation theory and the hierarchical control of behavior. It is intended to stimulate discussion. The framework can serve as a "route map" in understanding the links between different component processes and their interactions, as well as the relations between different academic perspectives on understanding sexuality. It is suggested that both excitation and inhibition of sexual motivation, arousal, and behavior act at various levels in a hierarchical structure, and much confusion can be avoided by distinguishing these levels. The model integrates information from different branches of psychology: biological, evolutionary, clinical, cognitive, developmental, and social. It describes interactions between sexual behavior and anxiety, attachment, aggression, and drug taking; and it is applied to gender differences, evolutionary psychology, sexual deviancy, sexual addiction, and the biological bases of sexuality.

Effects of oxytocin and prosocial behavior on brain responses to direct and vicariously experienced pain

In this study, we tested the validity of 2 popular assumptions about empathy: (a) empathy can be enhanced by oxytocin, a neuropeptide known to be crucial in affiliative behavior, and (b) individual differences in prosocial behavior are positively associated with empathic brain responses. To do so, we measured brain activity in a double-blind placebo-controlled study of 20 male participants either receiving painful stimulation to their own hand (self condition) or observing their female partner receiving painful stimulation to her hand (other condition). Prosocial behavior was measured using a monetary economic interaction game with which participants classified as prosocial (N = 12) or selfish (N = 6), depending on whether they cooperated with another player. Empathy-relevant brain activation (anterior insula) was neither enhanced by oxytocin nor positively associated with prosocial behavior. However, oxytocin reduced amygdala activation when participants received painful stimulation themselves (in the nonsocial condition). Surprisingly, this effect was driven by "selfish" participants. The results suggest that selfish individuals may not be as rational and unemotional as usually suggested, their actions being determined by their feeling anxious rather than by reason.

Romantic love modulates women's identification of men's body odors

Romantic love is one of our most potent and powerful emotions, but very little is known with respect to the hormonal and psychological mechanisms in play. Romantic love is thought to help intimate partners stay committed to each other and two mechanisms have been proposed to mediate this commitment: increased attention towards one's partner or deflected attention away from other potential partners. Both mechanisms find support in the literature. We explored the potential influence of each of these mechanisms by assessing women's ability to identify (ID) body odors originating from their boyfriend, a same-sex friend, and an opposite-sex friend and the relationship between this ability and the degree of romantic love expressed towards their boyfriend. We hypothesized that an increase in attention towards one's partner would render a positive correlation between ID of a boyfriend's body odor and degree of romantic love; conversely, we hypothesized that attention deflected away from other potential partners would render a negative correlation between ID of an opposite-sex friend's body odor and degree of romantic love for the boyfriend. Our results supported the deflection theory as we found a negative correlation between the degree of romantic love for the subjects' boyfriends and their ability to ID the body odor of an opposite-sex friend but not of their boyfriend or same-sex friend. Our results indicate that romantic love deflects attention away from potential new partners rather than towards the present partner. These changes are likely mediated by circulating neuropeptides and a testable model is suggested.

Expression and developmental regulation of oxytocin (OT) and oxytocin receptors (OTR) in the enteric nervous system (ENS) and intestinal epithelium

Although oxytocin (OT) and oxytocin receptor (OTR) are known for roles in parturition and milk let-down, they are not hypothalamus-restricted. OT is important in nurturing and opposition to stress. Transcripts encoding OT and OTR have been reported in adult human gut, and OT affects intestinal motility. We tested the hypotheses that OT is endogenous to the enteric nervous system (ENS) and that OTR signaling may participate in enteric neurophysiology. Reverse transcriptase polymerase chain reaction confirmed OT and OTR transcripts in adult mouse and rat gut and in precursors of enteric neurons immunoselected from fetal rats. Enteric OT and OTR expression continued through adulthood but was developmentally regulated, peaking at postnatal day 7. Coincidence of the immunoreactivities of OTR and the neural marker Hu was 100% in the P3 and 71% in the adult myenteric plexus, when submucosal neurons were also OTR-immunoreactive. Co-localization with NeuN established that intrinsic primary afferent neurons are OTR-expressing. Because OTR transcripts and protein were detected in the nodose ganglia, OT signaling might also affect extrinsic primary afferent neurons. Although OT immunoreactivity was found only in approximately 1% of myenteric neurons, extensive OT-immunoreactive varicosities surrounded many others. Villus enterocytes were OTR-immunoreactive through postnatal day 17; however, by postnatal day 19, immunoreactivity waned to become restricted to crypts and concentrated at crypt-villus junctions. Immunoelectron microscopy revealed plasmalemmal OTR at enterocyte adherens junctions. We suggest that OT and OTR signaling might be important in ENS development and function and might play roles in visceral sensory perception and neural modulation of epithelial biology.

What do people talk about during reflexology? Analysis of worries and concerns expressed during sessions for patients with multiple sclerosis

BACKGROUND

Our previous study evaluated the use of reflexology compared to progressive muscular relaxation in improving the psychological and physical profile associated with multiple sclerosis. In this paper audiotapes from the reflexology sessions have been analysed to give a picture of the nature of interaction between patients and therapists during treatment.

METHODS

A crossover design with two groups was chosen. Each participant received six sessions of both interventions. All reflexology sessions were recorded and the tapes transcribed and analysed.

RESULTS

Analysis of the available audiotapes (n=245) revealed that reflexology provided opportunities for 48 out of the 50 participants to share worries and concerns. Recurring disclosure themes related to physical symptoms and treatment, psychological concerns, home/family worries, and work/leisure issues. Explorative analysis revealed some differences in the amount of disclosure over the weeks, between for example the participant's type of MS and time living with the diagnosis.

CONCLUSIONS

Reflexology appears to have created a space for patients to talk about their worries and concerns, and to receive advice and support from the nurse therapists. This work contributes to the debate about the role of the therapeutic relationship within reflexology practice.

Neuroendocrine dysregulation following early social deprivation in children

Human and nonhuman animal studies reveal that early experiences with caregivers shape children's ability to regulate their responses to stress. To understand the effects of early deprivation on the regulation of the hypothalamic-pituitary-adrenal axis following social interactions, we examined urinary cortisol levels in a group of internationally adopted children who had experienced institutional care, and thus, species-atypical attachment relationships, early in life prior to adoption. Cortisol regulation was assessed both basally and following standardized interpersonal interactions between the child and his/her mother and the child and an unfamiliar adult. Postinstitutionalized children showed prolonged elevations in cortisol levels following the mother, but not the stranger, interaction. More severe neglect was associated with the highest basal cortisol levels and the most impaired cortisol regulation following the mother interaction. These results suggest that early social deprivation may contribute to long-term regulatory problems of the stress-responsive system, and that these differences are most evident within the context of ongoing, close interpersonal relationships.

Pharmacology of sexually compulsive behavior

In a meta-analysis on controlled outcomes evaluations of 22,000 sex offenders, Losel and Schmucker found 80 comparisons between treatment and control groups. The recidivism rate averaged 19% in treated groups, and 27% in controls. Most other reviews reported a lower rate of sexual recidivism in treated sexual offenders. Of 2039 citations in this study (including literature in five languages), 60 studies held independent comparisons. Problematic issues included the control groups; various hormonal, surgical, cognitive behavioral, and psychotherapeutic treatments; and sample sizes. In the 80 studies compared after the year 2000, 32% were reported after 2000, 45% originated in the United States, 45% were reported in journals, and 36% were unpublished. Treatment characteristics showed a significant lack of pharmacologic treatment (7.5%), whereas use cognitive and classical behavioral therapy was 64%. In 68% of the studies, no information was available on the integrity of the treatment implementation; 36% of the treatment settings were outpatient only, 31% were prison settings, and 12% were mixed settings (prison, hospital, and outpatient). Integrating research interpretations is complicated by the heterogeneity of sex offenders, with only 56% being adult men and 17.5% adolescents. Offense types reported included 74% child molestation, 48% incest, and 30% exhibitionism. Pedophilia was not singled out. Follow-up periods varied from 12 months to greater than 84 months. The definition of recidivism ran the gamut from arrest (24%), conviction (30%), charges (19%), and no indication (16%). Results were difficult to interpret because of the methodological problems with this type of study. Overall, a positive outcome was noted with sex offender treatment. Cognitive-behavioral and hormonal treatment were the most promising. Voluntary treatment led to a slightly better outcome than mandatory participation. When accounting for a low base rate of sexual recidivism, the reduction was 37%, which included psychological and medical modes of treatment. Which treatments will reduce recidivism rates in sex offenders is extremely difficult to conclude. Some treatment effects are determined from small studies; however, recidivism rates may be based on different criteria. Larger studies tend to be published more frequently than small studies, negative results may be less likely to be reported in published studies, and differences in mandatory versus voluntary treatment may occur. Clearly more high-quality outcome studies are needed to determine which treatments work best for which individuals. One size is unlikely to fit all. However, pharmacologic intervention, although not always the perfect choice, has improved and will continue to advance the treatment of paraphilic, nonparaphilic, and compulsive sexual behaviors.

Synchrony in the triad: a microlevel process model of coparenting and parent-child interactions

Guided by a microanalytic approach to the study of relationships, we assessed parent, infant, and coparental behaviors during triadic interactions in 94 parents and their 5-month-old firstborn child. Relational behaviors in each family subsystem--mother-infant, father-infant, and coparenting--were microcoded. Marital satisfaction and infant temperament were self-reported. No differences were found in the infants' behavior toward mother and father or in the time spent with each parent. Mothers' and fathers' relational behavior during parent-infant episodes were generally comparable, yet mothers vocalized more and the latency to father's displaying positive affect was longer. Conditional probabilities indicated that under conditions of coparental mutuality, fathers showed more positive behaviors than mothers. Lag-sequential analysis demonstrated that change in the infant's social focus between parents followed change in coparental behavior. Fathers' coparental mutuality was independently predicted by maternal behavior during mother-child episodes, father marital satisfaction, and infant difficult temperament, whereas mothers' coparental mutuality was only linked with fathers' relational behavior. Results highlight the importance of including a microlevel perspective on the family system at the first stages of family development.

Influence of a "warm touch" support enhancement intervention among married couples on ambulatory blood pressure, oxytocin, alpha amylase, and cortisol

OBJECTIVE

To investigate whether a support intervention (warm touch enhancement) influences physiological stress systems that are linked to important health outcomes. Growing evidence points to a protective effect of social and emotional support on both morbidity and mortality.

METHODS

In this study, 34 healthy married couples (n = 68), aged 20 to 39 years (mean = 25.2 years), were randomly assigned to a "behavior monitoring" control group or participated in a 4-week intervention study in which clinic levels of plasma oxytocin, 24-hour ambulatory blood pressure, and salivary cortisol and alpha amylase were obtained pre and post intervention, at the same time salivary oxytocin was taken at home during weeks 1 and 4.

RESULTS

Salivary oxytocin was enhanced both early and late in the intervention group and alpha amylase was reduced at post treatment in intervention group husbands and wives relative to controls. Husbands in the intervention group had significantly lower post treatment 24-hour systolic blood pressure than the control group.

CONCLUSION

Increasing warm touch among couples has a beneficial influence on multiple stress-sensitive systems.

The science of interpersonal touch: an overview

Surprisingly little scientific research has been conducted on the topic of interpersonal touch over the years, despite the importance of touch in our everyday social interactions from birth through to adulthood and old age. In this review, we critically evaluate the results of the research on this topic that have emerged from disciplines, such as cognitive and social psychology, neuroscience, and cultural anthropology. We highlight some of the most important advances to have been made in our understanding of this topic: For example, research has shown that interpersonal tactile stimulation provides an effective means of influencing people's social behaviors (such as modulating their tendency to comply with requests, in affecting people's attitudes toward specific services, in creating bonds between couples or groups, and in strengthening romantic relationships), regardless of whether or not the tactile contact itself can be remembered explicitly. What is more, interpersonal touch can be used to communicate emotion in a manner similar to that demonstrated previously in vision and audition. The recent growth of studies investigating the potential introduction of tactile sensations to long-distance communication technologies (by means of mediated or 'virtual' touch) are also reviewed briefly. Finally, we highlight the synergistic effort that will be needed by researchers in different disciplines if we are to develop a more complete understanding of interpersonal touch in the years to come.

Positive couple interactions and daily cortisol: on the stress-protecting role of intimacy

OBJECTIVE

To determine whether intimacy might be associated with reduced daily salivary cortisol levels in couples, thereby adding to the epidemiologic literature on reduced health burden in happy couples.

METHODS

A total of 51 dual-earner couples reported time spent on intimacy, stated their current affect quality, and provided saliva samples for cortisol estimation approximately every 3 hours in a 1-week time-sampling assessment. In addition, participants provided data on chronic problems of work organization.

RESULTS

Multilevel analyses revealed that intimacy was significantly associated with reduced daily salivary cortisol levels. There was an interaction effect of intimacy with chronic problems of work organization in terms of their relationship with cortisol levels, suggesting a buffering effect of intimacy on work-related elevated cortisol levels. Above this, the association between intimacy and cortisol was mediated by positive affect. Intimacy and affect together explained 7% of daily salivary cortisol variance.

CONCLUSIONS

Our results are in line with previous studies on the effect of intimacy on cortisol stress responses in the laboratory as well as with epidemiologic data on health beneficial effects of happy marital relationships.

Association between the oxytocin receptor (OXTR) gene and autism: relationship to Vineland Adaptive Behavior Scales and cognition

Evidence both from animal and human studies suggests that common polymorphisms in the oxytocin receptor (OXTR) gene are likely candidates to confer risk for autism spectrum disorders (ASD). In lower mammals, oxytocin is important in a wide range of social behaviors, and recent human studies have shown that administration of oxytocin modulates behavior in both clinical and non-clinical groups. Additionally, two linkage studies and two recent association investigations also underscore a possible role for the OXTR gene in predisposing to ASD. We undertook a comprehensive study of all 18 tagged SNPs across the entire OXTR gene region identified using HapMap data and the Haploview algorithm. Altogether 152 subjects diagnosed with ASDs (that is, DSM IV autistic disorder or pervasive developmental disorder--NOS) from 133 families were genotyped (parents and affected siblings). Both individual SNPs and haplotypes were tested for association using family-based association tests as provided in the UNPHASED set of programs. Significant association with single SNPs and haplotypes (global P-values <0.05, following permutation test adjustment) were observed with ASD. Association was also observed with IQ and the Vineland Adaptive Behavior Scales (VABS). In particular, a five-locus haplotype block (rs237897-rs13316193-rs237889-rs2254298-rs2268494) was significantly associated with ASD (nominal global P=0.000019; adjusted global P=0.009) and a single haplotype (carried by 7% of the population) within that block showed highly significant association (P=0.00005). This is the third association study, in a third ethnic group, showing that SNPs and haplotypes in the OXTR gene confer risk for ASD. The current investigation also shows association with IQ and total VABS scores (as well as the communication, daily living skills and socialization subdomains), suggesting that this gene shapes both cognition and daily living skills that may cross diagnostic boundaries.

Genetic correlates of adult attachment style

Attachment theory attempts to explain effects of social experiences, not genes, on personality development. Most studies of the development of attachment insecurities support this emphasis on social experiences rather than genes, although there are exceptions. In the present study, the authors examine associations between attachment insecurities and particular genetic polymorphisms related to emotions and social behavior. They find that (a) anxious attachment is associated with a polymorphism of the DRD2 dopamine receptor gene, (b) avoidant attachment is associated with a polymorphism of the 5HT2A serotonin receptor gene, and (c) the rs53576 A polymorphism of the OXTR oxytocin receptor gene is not associated with attachment insecurities. These findings suggest that attachment insecurities are partially explained by particular genes, although there is still a great deal of individual difference variance that remains to be explained by other genes or social experiences.

Mechanisms underlying altered mood and cardiovascular dysfunction: the value of neurobiological and behavioral research with animal models

A bidirectional association between mood disorders and cardiovascular diseases has been described in humans, yet the precise neurobiological mechanisms that underlie this association are not fully understood. This article is focused on neurobiological processes and mediators in mood and cardiovascular disorders, with an emphasis on common mechanisms including stressor reactivity, neuroendocrine and neurohumoral changes, immune alterations, autonomic and cardiovascular dysregulation, and central neurotransmitter and neuropeptide dysfunction. A discussion of the utility of experimental investigations with rodent models, including those in rats and prairie voles (Microtus ochrogaster), is presented. Specific studies using these models are reviewed, focusing on the analysis of behavioral, physiological and neural mechanisms underlying depressive disorders and cardiovascular disease. Considered in combination with studies using human samples, the investigation of mechanisms underlying depressive behaviors and cardiovascular regulation using animal models will enhance our understanding of the association of depression and cardiovascular disease, and will promote the development of improved interventions for individuals with these detrimental disorders.

Oxytocin shapes the neural circuitry of trust and trust adaptation in humans

Trust and betrayal of trust are ubiquitous in human societies. Recent behavioral evidence shows that the neuropeptide oxytocin increases trust among humans, thus offering a unique chance of gaining a deeper understanding of the neural mechanisms underlying trust and the adaptation to breach of trust. We examined the neural circuitry of trusting behavior by combining the intranasal, double-blind, administration of oxytocin with fMRI. We find that subjects in the oxytocin group show no change in their trusting behavior after they learned that their trust had been breached several times while subjects receiving placebo decrease their trust. This difference in trust adaptation is associated with a specific reduction in activation in the amygdala, the midbrain regions, and the dorsal striatum in subjects receiving oxytocin, suggesting that neural systems mediating fear processing (amygdala and midbrain regions) and behavioral adaptations to feedback information (dorsal striatum) modulate oxytocin's effect on trust. These findings may help to develop deeper insights into mental disorders such as social phobia and autism, which are characterized by persistent fear or avoidance of social interactions.

Is there a place for sexuality in the holistic care of patients in the palliative care phase of life?

Being diagnosed with a life-limiting condition is a traumatic event. The journey to the moment of death is usually only done once--so it is a time of fears and uncertainty. Sexuality is particularly vulnerable at this time. It may be difficult for both patient and partner to deal with the changes in sexuality without professional assistance. It is "sexuality" rather than "sex" that defines the meaningful relationships people have with themselves and significant others. When sexuality is lost or changed, important benefits may be lost. Studies show that many patients do value sexuality and want assistance in making the best of their sexual potential during the palliative care phase. Health professionals regularly acknowledge the importance of sexuality for their patients but have difficulties acting on their beliefs. Sexuality, within the patient's functional ability and desire for it, must be acknowledged and included in holistic management. It is the health professional's responsibility to raise this issue.

Focused grooming networks and stress alleviation in wild female baboons

We examine the relationship between glucocorticoid (GC) levels and grooming behavior in wild female baboons during a period of instability in the alpha male rank position. All females' GC levels rose significantly at the onset of the unstable period, though levels in females who were at lower risk of infanticide began to decrease sooner in the following weeks. Three factors suggest that females relied on a focused grooming network as a coping mechanism to alleviate stress. First, all females' grooming networks became less diverse in the weeks following the initial upheaval. Second, females whose grooming had already focused on a few predictable partners showed a less dramatic rise in GC levels than females whose grooming network had been more diverse. Third, females who contracted their grooming network the most experienced a greater decrease in GC levels in the following week. We conclude that close bonds with a few preferred partners allow female baboons to alleviate the stress associated with social instability.

The acute effects of intranasal oxytocin administration on endocrine and sexual function in males

The role of the neuropeptide oxytocin (OT) ranges from the modulation of neuroendocrine physiological effects to the establishment of complex social and bonding behaviours. Experimental studies in animals, as well as case reports in humans, suggest that OT affects different aspects of sexual behaviour and has predominantly facilitating properties for sexual appetence and performance. Using a previously established experimental paradigm of sexual arousal and masturbation-induced orgasm, this study investigated the acute effects of intranasal OT application (24I.U.) on endocrine parameters and measures of sexual appetence and function in healthy men (n=10). In a double-blind, placebo-controlled, balanced cross-over design, sexual arousal, and orgasm were induced by an erotic film and masturbation. In addition to the continuous recording of endocrine (OT, cortisol, prolactin, epinephrine, norepinephrine) and cardiovascular data (heart rate), parameters of appetitive, consummatory, and refractory sexual behaviour were assessed using the acute sexual experience scale (ASES). OT plasma levels were significantly elevated after intranasal OT throughout the whole experiment (>60 min). In addition, OT treatment induced significantly higher increases in epinephrine plasma levels during sexual activity without affecting cortisol levels, prolactin levels or heart rate. OT treatment did not alter appetitive, consummatory, and refractory sexual behaviour according to the ASES. However, when subjects were asked about their subjective perception of whether OT or placebo had been applied, eight out of 10 subjects in the OT group answered correctly, thus pointing to an altered perception of arousal. In conclusion, intranasally administered OT leads to a marked increase in OT plasma levels together with increased secretion of catecholamines when subjects are engaged in sexual activity in a laboratory setting. As the effects of OT on sexual behaviour were equivocal, future studies should examine possible facilitating effects further by including males, females, and couples in a field setting, taking into account that OT exerts the most prominent behavioural effects in pair bond formations.

Ethnicity is associated with alterations in oxytocin relationships to pain sensitivity in women

It is well established that African Americans (AA) experience greater pain associated with a variety of clinical conditions, and greater pain sensitivity to experimental pain tasks relative to non-Hispanic Whites (W). Notably, African Americans do not show the same relationships involving endogenous pain regulatory mechanisms and pain sensitivity documented in Caucasians, including positive associations between blood pressure, norepinephrine, cortisol and greater pain tolerance.

OBJECTIVES

The purpose of this study was to examine the relationship between plasma oxytocin (OT) and pain sensitivity and to explore the relation of OT to other factors known to influence pain perception.

DESIGN

OT concentration and sensitivity to ischemic, cold pressor, and thermal pain tasks were assessed in African American (n=25) and non-Hispanic White (n=23) pre-menopausal women.

RESULTS

African American women demonstrated significantly lower pain tolerance across tasks compared with Whites (F(1,46)=6.31, p=0.0156) and also exhibited lower plasma OT levels (AA: 3.90, W: 7.05 pg/mL; p=0.0014). Greater OT levels were correlated with greater tolerance to ischemic pain (r=0.36, p=0.013) and accounted for a marginally significant portion of the ethnic difference in ischemic pain tolerance (B=+0.29, p=0.06). Greater OT was also correlated with greater tolerance of cold pressor pain (r=0.31, p=0.03); however, this association was no longer seen after the variance due to ethnicity was accounted for.

CONCLUSION

These data suggest that reduced oxytocinergic function may be one of multiple biological factors contributing to the greater sensitivity to experimental ischemic pain, and to the greater burden of some types of clinical pain experienced by African Americans compared with Whites.

Coregulation, Dysregulation, Self-Regulation: An Integrative Analysis and Empirical Agenda for Understanding Adult Attachment, Separation, Loss, and Recovery

An integrative framework is proposed for understanding how multiple biological and psychological systems are regulated in the context of adult attachment relationships, dysregulated by separation and loss experiences, and, potentially, re-regulated through individual recovery efforts. Evidence is reviewed for a coregulatory model of normative attachment, defined as a pattern of interwoven physiology between romantic partners that results from the conditioning of biological reward systems and the emergence of felt security within adult pair bonds. The loss of coregulation can portend a state of biobehavioral dysregulation, ranging from diffuse psychophysiological arousal and disorganization to a full-blown (and highly organized) stress response. The major task for successful recovery is adopting a self-regulatory strategy that attenuates the dysregulating effects of the attachment disruption. Research evidence is reviewed across multiple levels of analysis, and the article concludes with a series of testable research questions on the interconnected nature of attachment, loss, and recovery processes.