RESUMEN

Cooperation and mutual trust are essential in our society, yet not everybody is trustworthy. In this fMRI study, 62 healthy volunteers performed a repeated trust game, placing trust in a trustworthy or an untrustworthy player. We found that the central amygdala was active during trust behavior planning while the basolateral amygdala was active during outcome evaluation. When planning the trust behavior, central and basolateral amygdala activation was stronger for the untrustworthy player compared to the trustworthy player but only in participants who actually learned to differentiate the trustworthiness of the players. Independent of learning success, nucleus accumbens encoded whether trust was reciprocated. This suggests that learning whom to trust is not related to reward processing in the nucleus accumbens, but rather to engagement of the amygdala. Our study overcomes major empirical gaps between animal models and human neuroimaging and shows how different subnuclei of the amygdala and connected areas orchestrate learning to form different subjective trustworthiness beliefs about others and guide trust choice behavior.

Asunto(s)

RESUMEN

Previous research indicates that the size of interpersonal space at which the other is perceived as intrusive (permeability) and the ability to adapt interpersonal distance based on contextual factors (flexibility) are altered in Autism Spectrum Disorder (ASD). However, the neurophysiological basis of these alterations remains poorly understood. To fill this gap, we used fMRI and assessed interpersonal space preferences of individuals with ASD before and after engaging in cooperative and non-cooperative social interactions. Compared to matched controls, ASDs showed lower comfort in response to an approaching confederate, indicating preference for larger interpersonal space in autism (altered permeability). This preference was accompanied by reduced activity in bilateral dorsal intraparietal sulcus (dIPS) and left fusiform face area (FFA), regions previously shown to be involved in interpersonal space regulation. Furthermore, we observed differences in effective connectivity among dIPS, FFA, and amygdala in ASDs compared to controls, depending on the level of experienced comfort. No differences between groups were observed in interpersonal space regulation after an experienced social interaction (flexibility). Taken together, the present findings suggest that a dysregulation of the activity and connectivity of brain areas involved in interpersonal space processing may contribute to avoidance of physical proximity and social impairments in ASD.

Asunto(s)

RESUMEN

Trust and betrayal are central to our social world, and adaptive responses to generous and selfish behavior are crucial to our economic and social well-being [1]. We learn about others' trustworthiness through trial and error during repeated interactions [2]. By reinforcing and suppressing behavior during positive and negative interactions with conspecifics, rodent research has established a crucial role for the basolateral amygdala (BLA) in social experiential learning [3, 4]. The human BLA has undergone a reorganization with massive expansion relative to other amygdala nuclei [5], and there is no translational research on its role in experiential learning. The human amygdala is traditionally researched as a single structure [6], neglecting the sub-nuclei's structural und functional differences [7], which might explain inconsistent findings in research on social interactions [8, 9]. Here, we study whether the human BLA is necessary for social and non-social experiential learning by testing a group of five humans with selective bilateral damage to the BLA. We compared their learning behavior in a repeated trust game, and a non-social control task, to healthy, matched controls. Crucially, BLA-damaged subjects, unlike control subjects, completely failed to adapt their investments when interacting with a trustworthy and an untrustworthy partner. In the non-social task, BLA-damaged subjects learned from positive outcomes but differed from the controls by not learning from negative outcomes. Our data extend findings in rodent research by showing that the human BLA is essential for social experiential learning and provide confirmatory evidence of divergent mechanisms for differentially valenced outcomes in non-social learning.

Asunto(s)

RESUMEN

Psychopathic offenders have a high propensity to violate social norms, as indicated for instance by their widespread lying and cheating behaviour. The reasons for their norm violations are not well understood, though, as they are able to recognise norms in a given situation and also punish norm violators. In this study, we investigated whether psychopathic offenders would violate fairness norms during a repeated trust game because of increased profit-maximising concerns. We measured back-transfer decisions in the repeated trust game, and affective arousal by means of skin conductance responses (SCR) in violent offenders with varying degrees of psychopathy, and non-offenders with low-trait psychopathy. Psychopathy in offenders was measured with the Psychopathy Checklist-Revised (PCL-R). In the task, a participant and an interaction partner entrusted each other money for multiple rounds with the goal to earn as much money as possible. Fairness norm violations were positively associated with Factor 2 scores (the lifestyle/anti-social psychopathy subscale) of the PCL-R, but this was not accompanied by clear profit-maximising behaviour. In addition, anticipatory arousal to self-advantageous decisions was higher in all offenders, independent of their degree of psychopathy, compared with non-offenders. The results of our study widen our understanding of social decision-making in psychopathy. They also suggest treatment possibilities in offenders scoring high on Factor 2, targeting empathic concern and related prosocial intentions to overcome norm-violating behaviour.

Asunto(s)

RESUMEN

BACKGROUND: Current treatment options for knee osteoarthritis have limited effectiveness and potentially adverse side effects. Massage may offer a safe and effective complement to the management of knee osteoarthritis. OBJECTIVE: Examine effects of whole-body massage on knee osteoarthritis, compared to active control (light-touch) and usual care. DESIGN: Multisite RCT assessing the efficacy of massage compared to light-touch and usual care in adults with knee osteoarthritis, with assessments at baseline and weeks 8, 16, 24, 36, and 52. Subjects in massage or light-touch groups received eight weekly treatments, then were randomized to biweekly intervention or usual care to week 52. The original usual care group continued to week 24. Analysis was performed on an intention-to-treat basis. PARTICIPANTS: Five hundred fifty-one screened for eligibility, 222 adults with knee osteoarthritis enrolled, 200 completed 8-week assessments, and 175 completed 52-week assessments. INTERVENTION: Sixty minutes of protocolized full-body massage or light-touch. MAIN MEASURES: Primary: Western Ontario and McMaster Universities Arthritis Index. Secondary: visual analog pain scale, PROMIS Pain Interference, knee range of motion, and timed 50-ft walk. KEY RESULTS: At 8 weeks, massage significantly improved WOMAC Global scores compared to light-touch (- 8.16, 95% CI = - 13.50 to - 2.81) and usual care (- 9.55, 95% CI = - 14.66 to - 4.45). Additionally, massage improved pain, stiffness, and physical function WOMAC subscale scores compared to light-touch (p < 0.001; p = 0.04; p = 0.02, respectively) and usual care (p < 0.001; p = 0.002; p = 0.002; respectively). At 52 weeks, the omnibus test of any group difference in the change in WOMAC Global from baseline to 52 weeks was not significant (p = 0.707, df = 3), indicating no significant difference in change across groups. Adverse events were minimal. CONCLUSIONS: Efficacy of symptom relief and safety of weekly massage make it an attractive short-term treatment option for knee osteoarthritis. Longer-term biweekly dose maintained improvement, but did not provide additional benefit beyond usual care post 8-week treatment. TRIAL REGISTRATION: clinicaltrials.gov NCT01537484.

Asunto(s)

RESUMEN

Field studies have demonstrated that humans become more generous, helpful and compliant after having been touched by another person. Here, we explored whether these effects are larger for touch activating the C-tactile (CT) fibres, as it is ascribed a particular role in establishing and maintaining bonds and affiliative interactions. The role of CT-targeted and non-targeted touch on prosocial behaviour was investigated in three different experiments using a trust game and a task measuring individual differences in social value orientations (the SVO task). Whereas participants in general acted prosocially, there was no influence of CT-targeted touch on prosocial behaviour, both in comparison to non-CT-targeted control touch and visual (non-tactile) stimulation. The null findings were further corroborated by Bayesian statistics. Thus, under the controlled laboratory conditions employed, CT-targeted touch did not play a particular role in prosocial behaviour. This indicates that touch does not increase prosocial behaviour in the absence of meaningful social and psychological connotations. Any touch related effects on prosocial behaviour likely depends on the ecological validity of the situation.

RESUMEN

Objective: We hypothesized that participants receiving Swedish massage would experience benefits such as stress reduction and enhanced quality of life, in addition to the osteoarthritis-specific effects assessed in a randomized controlled clinical trial. Design: Qualitative methods were used to explore a deeper contextual understanding of participants' experiences with massage and osteoarthritis, in addition to the quantitative data collected from primary and secondary outcome measures of the dose-finding study. Setting: Two community hospitals affiliated with academic health centers in Connecticut and New Jersey. Subjects: Eighteen adults who previously participated in a dose-finding clinical trial of massage therapy for osteoarthritis of the knee. Methods: Face-to-face and telephone interviews using a standardized interview guide. Triangulation of qualitative and quantitative data allowed for a more thorough understanding of the effects of massage therapy. Results: Three salient themes emerged from our analysis. Participants discussed 1) relaxation effects, 2) improved quality of life associated with receiving massage therapy, and 3) the accessibility of massage therapy in treating osteoarthritis. Conclusions: Participant responses noted empowerment with an improved ability to perform activities of daily living after experiencing massage therapy. The majority of statements were consistent with their quantitative changes on standard osteoarthritis measures. Future research in pain conditions should include health-related quality of life assessments as well as outcomes related to perceived well-being, along with greater exploration of the concept of salutogenic side effects of an intervention in the context of complementary and integrative therapies.

Asunto(s)

RESUMEN

Neuro-evolutionary theories describe social anxiety as habitual subordinate tendencies acquired through a recursive cycle of social defeat and submissive reactions. If so, the steroid hormone testosterone might be of therapeutic value, as testosterone is a main force behind implicit dominance drive in many species including humans. We combined these two theories to investigate whether the tendency to submit to the dominance of others is an implicit mechanism in social anxiety (Study-1), and whether this can be relieved through testosterone administration (Study-2). Using interactive eye-tracking we demonstrate that socially anxious humans more rapidly avert gaze from subliminal angry eye contact (Study-1). We replicate this effect of implicit subordination in social anxiety in an independent sample, which is subsequently completely abolished after a single placebo-controlled sublingual testosterone administration (Study-2). These findings provide crucial evidence for hormonal and behavioral treatment strategies that specifically target mechanisms of dominance and subordination in social anxiety.

Asunto(s)

RESUMEN

Griffin Hospital, a community hospital affiliated with Yale School of Public Health and Yale School of Medicine, received Health Resources and Services Administration funding to strengthen and improve its combined internal medicine and general preventive medicine residency program by incorporating an integrative medicine curriculum. The purpose of project ASPIRE (Advancing Skills of Preventive medicine residents through Integrative medicine Education, Research and Evaluation) was to create, implement, and evaluate a needs-based, innovative training curriculum in integrative medicine. Through this robust new training, the authors aimed to produce preventive medicine-trained physicians with competencies in integrative medicine to collaboratively work with other integrative medicine practitioners in interdisciplinary teams to provide holistic, patient-centered care. The multifaceted collaborative curriculum was composed of didactics, grand rounds, journal club, objective structured clinical examinations, and two new practicum rotations in integrative medicine. The new practicum rotations included block rotations at the Integrative Medicine Center at Griffin Hospital and the Yale Stress Center. Between 2012 and 2014, three cohorts participated in the curriculum; two of these cohorts included three advanced preventive medicine residents each and the fourth included four residents. Project faculty conducted 14 lectures and journal clubs, and two grand rounds. Six of the ten participating residents (60%) completed integrative medicine clinical rotations. Residents' attitudes toward integrative medicine were evaluated through self-assessment using the Complementary, Alternative, and Integrative Medicine Attitudes Questionnaire; data were analyzed in 2015. This article describes the results of this prospective observational study based on single-institution experience over the course of the 2-year project period.

Asunto(s)

RESUMEN

Research in rodents and humans has shown divergent effects of the glucocorticoids corticosterone and cortisol (CRT) on reward processing. In rodents, administration of CRT increases reward drive by facilitating dopamine release in the ventral striatum. In humans, correspondingly, risky decision-making increases when CRT levels are elevated. Human stress studies contrariwise show that elevated CRT is accompanied by a decrease in reward-related brain activity. There are however no direct insights into how CRT acts on the reward system in the human brain. Accordingly, we used pharmacological functional magnetic resonance imaging (pharmaco-fMRI) to investigate the effects of CRT on the brain's reward system. In a randomized within-subject design we administered a high dose of CRT (40 mg) and placebo to twenty healthy male volunteers on separate days, and used a monetary incentive delay task to assess the effects of the hormone on the striatum and the amygdala in anticipation of potential reward. In contrast to animal studies, we show that this high dose of CRT strongly decreases activity of the striatum in both reward and non-reward conditions. Furthermore, we observed reductions in activity in the basolateral amygdala, a key regulator of the brain's reward system. Crucially, the overall down-regulation of the brain's reward circuit was verified on the subjective level as subjects reported significantly reduced reward preference after CRT. In sum, we provide here direct evidence in humans that CRT acts on brain regions involved in reward-related behavior, that is, the basolateral amygdala and the striatum. Our findings suggest that CRT in the quantity and time course presently used globally down-regulates the reward system, and thereby decreases motivational processing in general.

Asunto(s)

RESUMEN

The timing and developmental factors underlying the establishment of language dominance are poorly understood. We investigated the degree of lateralization of traditional frontotemporal and modulatory prefrontal-cerebellar regions of the distributed language network in children (n = 57) ages 4 to 12--a critical period for language consolidation. We examined the relationship between the strength of language lateralization and neuropsychological measures and task performance. The fundamental language network is established by four with ongoing maturation of language functions as evidenced by strengthening of lateralization in the traditional frontotemporal language regions; temporal regions were strongly and consistently lateralized by age seven, while frontal regions had greater variability and were less strongly lateralized through age 10. In contrast, the modulatory prefrontal-cerebellar regions were the least strongly lateralized and degree of lateralization was not associated with age. Stronger core language skills were significantly correlated with greater right lateralization in the cerebellum.

Asunto(s)

RESUMEN

The South African endemic plant Sceletium tortuosum has a long history of traditional use as a masticatory and medicine by San and Khoikhoi people and subsequently by European colonial farmers as a psychotropic in tincture form. Over the past decade, the plant has attracted increasing attention for its possible applications in promoting a sense of wellbeing and relieving stress in healthy individuals and for treating clinical anxiety and depression. The pharmacological actions of a standardized extract of the plant (Zembrin) have been reported to be dual PDE4 inhibition and 5-HT reuptake inhibition, a combination that has been argued to offer potential therapeutic advantages. Here we tested the acute effects of Zembrin administration in a pharmaco-fMRI study focused on anxiety-related activity in the amygdala and its connected neurocircuitry. In a double-blind, placebo-controlled, cross-over design, 16 healthy participants were scanned during performance in a perceptual-load and an emotion-matching task. Amygdala reactivity to fearful faces under low perceptual load conditions was attenuated after a single 25 mg dose of Zembrin. Follow-up connectivity analysis on the emotion-matching task showed that amygdala-hypothalamus coupling was also reduced. These results demonstrate, for the first time, the attenuating effects of S. tortuosum on the threat circuitry of the human brain and provide supporting evidence that the dual 5-HT reuptake inhibition and PDE4 inhibition of this extract might have anxiolytic potential by attenuating subcortical threat responsivity.

Asunto(s)

RESUMEN

BACKGROUND: Clinical trial design of manual therapies may be especially challenging as techniques are often individualized and practitioner-dependent. This paper describes our methods in creating a standardized Swedish massage protocol tailored to subjects with osteoarthritis of the knee while respectful of the individualized nature of massage therapy, as well as implementation of this protocol in two randomized clinical trials. METHODS: The manualization process involved a collaborative process between methodologic and clinical experts, with the explicit goals of creating a reproducible semi-structured protocol for massage therapy, while allowing some latitude for therapists' clinical judgment and maintaining consistency with a prior pilot study. RESULTS: The manualized protocol addressed identical specified body regions with distinct 30- and 60-min protocols, using standard Swedish strokes. Each protocol specifies the time allocated to each body region. The manualized 30- and 60-min protocols were implemented in a dual-site 24-week randomized dose-finding trial in patients with osteoarthritis of the knee, and is currently being implemented in a three-site 52-week efficacy trial of manualized Swedish massage therapy. In the dose-finding study, therapists adhered to the protocols and significant treatment effects were demonstrated. CONCLUSIONS: The massage protocol was manualized, using standard techniques, and made flexible for individual practitioner and subject needs. The protocol has been applied in two randomized clinical trials. This manualized Swedish massage protocol has real-world utility and can be readily utilized both in the research and clinical settings. TRIAL REGISTRATION: Clinicaltrials.gov NCT00970008 (18 August 2009).

Asunto(s)

RESUMEN

Listening and reading comprehension of paragraph-length material are considered higher-order language skills fundamental to social and academic functioning. Using ecologically relevant language stimuli that were matched for difficulty according to developmental level, we analyze the effects of task, age, neuropsychological skills, and post-task performance on fMRI activation and hemispheric laterality. Areas of supramodal language processing are identified, with the most robust region being left-lateralized activation along the superior temporal sulcus. Functionally, this conjunction has a role in semantic and syntactic processing, leading us to refer to this conjunction as "comprehension cortex." Different from adults, supramodal areas for children include less extensive inferior frontal gyrus but more extensive right cerebellum and right temporal pole. Broader neuroanatomical pathways are recruited for reading, reflecting the more active processing and larger set of cognitive demands needed for reading compared to listening to stories. ROI analyses reveal that reading is a less lateralized language task than listening in inferior frontal and superior temporal areas, which likely reflects the difficulty of the task as children in this study are still developing their reading skills. For listening to stories, temporal activation is stable by age four with no correlations with age, neuropsychological skills or post-task performance. In contrast, frontal activation during listening to stories occurs more often in older children, and frontal activation is positively correlated with better performance on comprehension questions, suggesting that the activation of frontal networks may reflect greater integration and depth of story processing.

Asunto(s)

RESUMEN

Functional magnetic resonance imaging (fMRI) in children is increasingly used in clinical application and in developmental research; however, little is known how pediatric patient and typically developing populations successfully complete studies. We examined pediatric success rates with epilepsy, attention deficit/hyperactivity disorder (ADHD), autism spectrum disorders (ASD), and typically developing children (TYP). We also examined the affect of age, and, for ADHD populations, medication status on success rates. We defined a successful fMRI individual run when the data were interpretable and included in group statistics. For unsuccessful runs, datasets with excessive motion or floor task performance were categorized when possible. All clinical groups scanned less successfully than controls; medication status did not affect ADHD success (epilepsy, 80%; ADHD (off methylphenidate), 77%; ADHD (on methylphenidate), 81%; ASD, 70%; TYP, 87%). Ten to 18-year-old had a significantly greater scan success rate than 4- to 6-year-old; adolescents (13- to 18-year-old) demonstrated greater scan success rates than 7- to 9-year-old. Success rate for completing an entire battery of experimental runs (n = 2-6), varied between 50-59% for patient populations and 69% for TYP (79% when excluding 4- to 6-year-old). Success rate for completing one run from a battery was greater than 90% for all groups, except for ASD (81%). These data suggest 20-30% more children should be recruited in these patient groups, but only 10-20% for TYP for research studies. Studies with 4- to 6-year-olds may require 20-40% additional participants; studies with 10- to 18-year-olds may require 10-15% additional participants.

Asunto(s)