The human capacity to synchronize body movements to an external acoustic beat enables uniquely human behaviors such as music making and dancing. By hypothesis, these first evolved in human cultures as fundamentally social activities. We therefore hypothesized that children would spontaneously synchronize their body movements to an external beat at earlier ages and with higher accuracy if the stimulus was presented in a social context. A total of 36 children in three age groups (2.5, 3.5, and 4.5 years) were invited to drum along with either a human partner, a drumming machine, or a drum sound coming from a speaker. When drumming with a social partner, children as young as 2.5 years adjusted their drumming tempo to a beat outside the range of their spontaneous motor tempo. Moreover, children of all ages synchronized their drumming with higher accuracy in the social condition. We argue that drumming together with a social partner creates a shared representation of the joint action task and/or elicits a specific human motivation to synchronize movements during joint rhythmic activity.

BACKGROUND:While limited evidence suggests that omega-3 supplementation may reduce antisocial behavior in children, studies have not reported on posttreatment follow-up and most treatment periods have been of short duration. This study tests the hypothesis that omega-3 supplementation over 6 months will reduce behavior problems in children both at the end of treatment and at 6 months post treatment.

METHODS:In this randomized, double-blind, placebo-controlled, stratified, parallel-group trial, a community sample of 8-16 year old children were randomized into a treatment group (N = 100) and a placebo-control group (N = 100). The supplementation consisted of a fruit drink containing 1 g/day of omega-3 or a placebo consisting of the same fruit drink without omega-3. Participants, caregivers, and research assistants were blinded to group assignment. The primary outcome measures of externalizing and internalizing behavior problems were reported by both caregivers and their children in a laboratory setting at 0 months (baseline), 6 months (end of treatment) and 12 months (6 months post treatment), together with the secondary outcome measures of parental antisocial behavior. Data were analyzed on an intention-to-treat basis including all participants.

TRIAL REGISTRATION:ClinicalTrials.gov: http://clinicaltrials.gov/ct2/show/NCT02016079?term=mauritius&rank=2 RESULTS: Significant group × time interactions were observed with the treatment group showing long-term improvements in child behavior problems. The average posttreatment effect size was d = -.59. Effects were documented for parent reports, but with the exception of proactive and reactive aggression, child-report data were nonsignificant. Parents whose children took omega-3 showed significant posttreatment reductions in their own antisocial and aggressive behavior. This improvement in caregiver behavior partly mediated the improvements observed in child behavior.

CONCLUSIONS:Findings provide initial evidence that omega-3 supplementation can produce sustained reductions in externalizing and internalizing behavior problems. Results are the first to report improvements in caregiver behavior, and to establish this improvement as a part-mechanism for the efficacy of omega-3.

Why does chanting, drumming or dancing together make people feel united? Here we investigate the neural mechanisms underlying interpersonal synchrony and its subsequent effects on prosocial behavior among synchronized individuals. We hypothesized that areas of the brain associated with the processing of reward would be active when individuals experience synchrony during drumming, and that these reward signals would increase prosocial behavior toward this synchronous drum partner. 18 female non-musicians were scanned with functional magnetic resonance imaging while they drummed a rhythm, in alternating blocks, with two different experimenters: one drumming in-synchrony and the other out-of-synchrony relative to the participant. In the last scanning part, which served as the experimental manipulation for the following prosocial behavioral test, one of the experimenters drummed with one half of the participants in-synchrony and with the other out-of-synchrony. After scanning, this experimenter"accidentally"dropped eight pencils, and the number of pencils collected by the participants was used as a measure of prosocial commitment. Results revealed that participants who mastered the novel rhythm easily before scanning showed increased activity in the caudate during synchronous drumming. The same area also responded to monetary reward in a localizer task with the same participants. The activity in the caudate during experiencing synchronous drumming also predicted the number of pencils the participants later collected to help the synchronous experimenter of the manipulation run. In addition, participants collected more pencils to help the experimenter when she had drummed in-synchrony than out-of-synchrony during the manipulation run. By showing an overlap in activated areas during synchronized drumming and monetary reward, our findings suggest that interpersonal synchrony is related to the brain's reward system.

Low-income youth experience social-emotional problems linked to chronic stress that are exacerbated by lack of access to care. Drumming is a non-verbal, universal activity that builds upon a collectivistic aspect of diverse cultures and does not bear the stigma of therapy. A pretest-post-test non-equivalent control group design was used to assess the effects of 12 weeks of school counselor-led drumming on social-emotional behavior in two fifth-grade intervention classrooms versus two standard education control classrooms. The weekly intervention integrated rhythmic and group counseling activities to build skills, such as emotion management, focus and listening. The Teacher's Report Form was used to assess each of 101 participants (n = 54 experimental, n = 47 control, 90% Latino, 53.5% female, mean age 10.5 years, range 10-12 years). There was 100% retention. ANOVA testing showed that intervention classrooms improved significantly compared to the control group in broad-band scales (total problems (P<.01), internalizing problems (P<.02)), narrow-band syndrome scales (withdrawn/depression (P<.02), attention problems (P<.01), inattention subscale (P<.001)), Diagnostic and Statistical Manual of Mental Disorders-oriented scales (anxiety problems (P<.01), attention deficit/hyperactivity problems (P<.01), inattention subscale (P<.001), oppositional defiant problems (P<.03)), and other scales (post-traumatic stress problems (P<.01), sluggish cognitive tempo (P<.001)). Participation in group drumming led to significant improvements in multiple domains of social-emotional behavior. This sustainable intervention can foster positive youth development and increase student-counselor interaction. These findings underscore the potential value of the arts as a therapeutic tool.