Understanding the proximate mechanisms of caste development in eusocial taxa can reveal how social species evolved from solitary ancestors. In Polistes wasps, the current paradigm holds that differential amounts of nutrition during the larval stage cause the divergence of worker and gyne (potential queen) castes. But nutrition level alone cannot explain how the first few females to be produced in a colony develop rapidly yet have small body sizes and worker phenotypes. Here, we provide evidence that a mechanical signal biases caste toward a worker phenotype. In Polistes fuscatus, the signal takes the form of antennal drumming (AD), wherein a female trills her antennae synchronously on the rims of nest cells while feeding prey-liquid to larvae. The frequency of AD occurrence is high early in the colony cycle, when larvae destined to become workers are being reared, and low late in the cycle, when gynes are being reared. Subjecting gyne-destined brood to simulated AD-frequency vibrations caused them to emerge as adults with reduced fat stores, a worker trait. This suggests that AD influences the larval developmental trajectory by inhibiting a physiological element that is necessary to trigger diapause, a gyne trait.

AIMS:Very little data are available on the physical requirements for drumming and the potential health benefits of particularly djembe drumming. We hypothesized that djembe drumming constitutes low-to-moderate intensity exercise, and that drumming would simultaneously reduce stress and anxiety levels and benefit cardiovascular health.

METHODS:Two study populations, middle-aged experienced drummers and a younger novice group participated in 40-min djembe drumming sessions. Measurements of blood pressure, blood lactate and stress and anxiety levels were taken before and after sessions. Also, heart rate was monitored at 5-s intervals throughout each session.

RESULTS:Participation in drumming significantly decreased the Stress Anxiety Index scores acutely, both in a middle-aged (P < 0.01) and younger population (P < 0.001). SBP was significantly decreased in the older population postdrumming (141 ± 24 vs. 153 ± 26  mmHg; P < 0.01). Blood lactate levels remained below 4  mmol/l in all individuals and together with heart rate suggest that drumming may be categorized as low-to-moderate intensity exercise.

CONCLUSION:Djembe drumming may improve cardiovascular health, without the cardiovascular risks to unhealthy or older populations that are associated with higher intensity exercise, and at the same time may decrease stress and anxiety levels. Furthermore, participation in drumming did not result in acute hypotension in normotensive individuals.

Despite the quintessential role that music plays in human societies by enabling us to release and share emotions with others, traces of its evolutionary origins in other species remain scarce. Drumming like humans whilst producing music is practically unheard of in our most closely related species, the great apes. Although beating on tree roots and body parts does occur in these species, it has, musically speaking, little in common with human drumming. Researchers suggest that for manual beating in great apes to be compared to human drumming, it should at least be structurally even, a necessary quality to elicit entrainment (beat induction in others). Here we report an episode of spontaneous drumming by a captive chimpanzee that approaches the structural and contextual characteristics usually found in musical drumming. This drumming differs from most beating episodes reported in this species by its unusual duration, the lack of any obvious context, and rhythmical properties that include long-lasting and dynamically changing rhythms, but also evenness and leisureliness. This performance is probably the first evidence that our capacity to drum is shared with our closest relatives.

Nonverbal communication of emotion is essential to human interaction and relevant to many clinical applications, yet it is an understudied topic in social neuroscience. Drumming is an ancient nonverbal communication modality for expression of emotion that has not been previously investigated in this context. We investigate the neural response to live, natural communication of emotion via drumming using a novel dual-brain neuroimaging paradigm. Hemodynamic signals were acquired using whole-head functional near-infrared spectroscopy (fNIRS). Dyads of 36 subjects participated in two conditions, drumming and talking, alternating between 'sending' (drumming or talking to partner) and 'receiving' (listening to partner) in response to emotionally salient images from the International Affective Picture System. Increased frequency and amplitude of drum strikes was behaviorally correlated with higher arousal and lower valence measures and neurally correlated with temporoparietal junction (TPJ) activation in the listener. Contrast comparisons of drumming greater than talking also revealed neural activity in right TPJ. Together, findings suggest that emotional content communicated by drumming engages right TPJ mechanisms in an emotionally and behaviorally sensitive fashion. Drumming may provide novel, effective clinical approaches for treating social-emotional psychopathology.

CONTEXT: Drum circles have been part of healing rituals in many cultures throughout the world since antiquity. Although drum circles are gaining increased interest as a complementary therapeutic strategy in the traditional medical arena, limited scientific data documenting biological benefits associated with percussion activities exist.

OBJECTIVE: To determine the role of group-drumming music therapy as a composite activity with potential for alteration of stress-related hormones and enhancement of specific immunologic measures associated with natural killer cell activity and cell-mediated immunity.

DESIGN: A single trial experimental intervention with control groups.

SETTING: The Mind-Body Wellness Center, an outpatient medical facility in Meadville, Pa.

PARTICIPANTS: A total of 111 age- and sex-matched volunteer subjects (55 men and 56 women, with a mean age of 30.4 years) were recruited.

INTERVENTION: Six preliminary supervised groups were studied using various control and experimental paradigms designed to separate drumming components for the ultimate determination of a single experimental model, including 2 control groups (resting and listening) as well as 4 group-drumming experimental models (basic, impact, shamanic, and composite). The composite drumming group using a music therapy protocol was selected based on preliminary statistical analysis, which demonstrated immune modulation in a direction opposite to that expected with the classical stress response. The final experimental design included the original composite drumming group plus 50 additional age- and sex-matched volunteer subjects who were randomly assigned to participate in group drumming or control sessions.

MAIN OUTCOME MEASURES: Pre- and postintervention measurements of plasma cortisol, plasma dehydroepiandrosterone, plasma dehydroepiandrosterone-to-cortisol ratio, natural killer cell activity, lymphokine-activated killer cell activity, plasma interleukin-2, plasma interferon-gamma, the Beck Anxiety Inventory, and the Beck Depression Inventory II.

RESULTS: Group drumming resulted in increased dehydroepiandrosterone-to-cortisol ratios, increased natural killer cell activity, and increased lymphokine-activated killer cell activity without alteration in plasma interleukin 2 or interferon-gamma, or in the Beck Anxiety Inventory and the Beck Depression Inventory II.

CONCLUSIONS: Drumming is a complex composite intervention with the potential to modulate specific neuroendocrine and neuroimmune parameters in a direction opposite to that expected with the classic stress response.

During social interaction, the behavior of interacting partners becomes coordinated. Although interpersonal coordination is well-studied in adults, relatively little is known about its development. In this project we explored how 2-, 3-, and 4-year-old children spontaneously coordinated their drumming with a peer. Results showed that all children adapted their drumming to their partner's drumming by starting and stopping their drumming in a coordinated fashion, but only 4-year-olds adapted the rhythmic structure of their drumming to their partner's drumming. In all age groups, children showed similarly stable drumming. Typically, it was 1 of the 2 children who initiated drumming throughout the session. The results of this study offer new insights into the development of interpersonal coordination abilities in early childhood. (PsycINFO Database Record

BACKGROUND:Drumming muscles of some sound-producing fish are 'champions' of contraction speed, their rate setting the fundamental frequency. In the piranha, contraction of these muscles at 150 Hz drives a sound at the same frequency. Drumming muscles of different not closely related species show evolutionary convergences. Interestingly, some characters of sonic muscles can also be found in the trunk muscles of newly hatched larvae that are able to maintain tail beat frequencies up to 100 Hz. The aim of this work was to study the development of sound production and sonic and epaxial muscles simultaneously in the red bellied piranhas (Pygocentrus nattereri) to seek for possible common characteristics.

RESULTS:Call, pulse and period durations increased significantly with the fish size, but the call dominant frequencies decreased, and the number of pulses and the call amplitude formed a bell curve. In epaxial muscles, the fibre diameters of younger fish are first positioned in the graphical slope corresponding to sonic muscles, before diverging. The fibre diameter of older fish trunk muscles was bigger, and the area of the myofibrils was larger than in sonic muscles. Moreover, in two of the biggest fish, the sonic muscles were invaded by fat cells and the sonic muscle ultrastructure was similar to the epaxial one. These two fish were also unable to produce any sound, meaning they lost their ability to contract quickly.

CONCLUSIONS:The volume occupied by myofibrils determines the force of contraction, the volume of sarcoplasmic reticulum sets the contraction frequency, and the volume of mitochondria sets the level of sustained performance. The functional outcomes in muscles are all attributable to shifts in the proportions of those structures. A single delay in the development restricts the quantity of myofibrils, maintains a high proportion of space in the sarcoplasm and develops sarcoplasmic reticulum. High-speed sonic muscles could thus be skeletal muscles with delayed development. This hypothesis has the advantage that it could easily explain why high-speed sonic muscles have evolved so many times in different lineages.

Although several behavioural studies demonstrate the ability of insects to localise the source of vibrations, it is still unclear how insects are able to perceive directional information from vibratory signals on solid substrates, because time-of-arrival and amplitude difference between receptory structures are thought to be too small to be processed by insect nervous systems. The termite Macrotermes natalensis communicates using vibrational drumming signals transmitted along subterranean galleries. When soldiers are attacked by predators, they tend to drum with their heads against the substrate and create a pulsed vibration. Workers respond by a fast retreat into the nest. Soldiers in the vicinity start to drum themselves, leading to an amplification and propagation of the signal. Here we show that M. natalensis makes use of a directional vibration sensing in the context of colony defence. In the field, soldiers are recruited towards the source of the signal. In arena experiments on natural nest material, soldiers are able to localise the source of vibration. Using two movable platforms allowing us to vibrate the legs of the left and right sides of the body with a time delay, we show that the difference in time-of-arrival is the directional cue used for orientation. Delays as short as 0.2 ms are sufficient to be detected. Soldiers show a significant positive tropotaxis to the platform stimulated earlier, demonstrating for the first time perception of time-of-arrival delays and vibrotropotaxis on solid substrates in insects.

BACKGROUND:Physical therapy can improve motor function in patients with PD. Music performance may be used to improve motor skills by rhythmic entrainment. Drumming has long been a part of traditional healing rituals worldwide, and is increasingly being utilized as a therapeutic strategy.

METHODS:This pilot controlled prospective cohort trial assessed feasibility and effects of twice-weekly group West African drum circle classes for 6 weeks on PD patients' quality of life, symptoms, motor findings, cognition, and mood. Ten patients with PD were recruited into the drum circle group. Ten patients with PD were matched pairwise to each of the drum circle participants, and enrolled in a no-intervention control group. Both groups completed the PD-specific Parkinson Disease Questionnaire (PDQ)-39 quality of life assessment and the Geriatric Depression Scale (GDS), and underwent motor and cognitive assessments by a rater blinded to group at baseline, 6 weeks, and 12 weeks.

RESULTS:Drummers had significantly improved PDQ-39 scores from baseline to 6 weeks (-5.8, p=0.042), whereas the control group's scores were unchanged. Walking performance was significantly faster at baseline for controls; after 6 weeks of drumming this difference was no longer significant, and remained non-significant at 12 weeks. The drummers trended (p=0.069) toward improvement in walking from baseline to 12 weeks. Other outcomes did not significantly change from baseline to 6 or 12 weeks.

CONCLUSIONS:Drum circle classes significantly and reversibly improved quality of life in patients with PD. This pilot trial's findings merit larger controlled investigations comparing drumming classes to established interventions in PD, such as physical therapy.

Long-term music training has been shown to affect different cognitive and perceptual abilities. However, it is less well known whether it can also affect the perception of emotion from music, especially purely rhythmic music. Hence, we asked a group of 16 non-musicians, 16 musicians with no drumming experience, and 16 drummers to judge the level of expressiveness, the valence (positive and negative), and the category of emotion perceived from 96 drumming improvisation clips (audio-only, video-only, and audiovideo) that varied in several music features (e.g., musical genre, tempo, complexity, drummer's expressiveness, and drummer's style). Our results show that the level and type of music training influence the perceived expressiveness, valence, and emotion from solo drumming improvisation. Overall, non-musicians, non-drummer musicians, and drummers were affected differently by changes in some characteristics of the music performance, for example musicians (with and without drumming experience) gave a greater weight to the visual performance than non-musicians when giving their emotional judgments. These findings suggest that besides influencing several cognitive and perceptual abilities, music training also affects how we perceive emotion from music.

Exposure to repetitive drumming combined with instructions for shamanic journeying has been associated with physiological and therapeutic effects, such as an increase in salivary immunoglobulin A. In order to assess whether the combination of repetitive drumming and shamanic instructions is specifically associated with these effects, we compared the effect of listening to either repetitive drumming or instrumental meditation music for 15 minutes on salivary cortisol concentration and on self-reported physiological and psychological states. For each musical style, two groups of participants were exposed to two conditions: instructions for shamanic journeying or relaxation instructions. A total of 39 participants (24 females) inexperienced in shamanic journeying completed the experiment. Salivary cortisol concentrations were measured before and after exposure to music. In addition, participants filled out a mood questionnaire before and after the experiment and completed a post experiment questionnaire on their experiences. A significant decrease in the concentration in salivary cortisol was observed across all musical styles and instructions, indicating that exposure to 15 minutes of either repetitive drumming or instrumental meditation music, while lying down, was sufficient to induce a decrease in cortisol levels. However, no differences were observed across conditions. Significant differences in reported emotional states and subjective experiences were observed between the groups. Notably, participants exposed to repetitive drumming combined with shamanic instructions reported experiencing heaviness, decreased heart rate, and dreamlike experiences significantly more often than participants exposed to repetitive drumming combined with relaxation instructions. Our findings suggest that the subjective effects specifically attributed to repetitive drumming and shamanic journeying may not be reflected in differential endocrine responses.

As a species-typical trait of Homo sapiens, musicality represents a cognitively complex and biologically grounded capacity worthy of intensive empirical investigation. Four principles are suggested here as prerequisites for a successful future discipline of bio-musicology. These involve adopting: (i) a multicomponent approach which recognizes that musicality is built upon a suite of interconnected capacities, of which none is primary; (ii) a pluralistic Tinbergian perspective that addresses and places equal weight on questions of mechanism, ontogeny, phylogeny and function; (iii) a comparative approach, which seeks and investigates animal homologues or analogues of specific components of musicality, wherever they can be found; and (iv) an ecologically motivated perspective, which recognizes the need to study widespread musical behaviours across a range of human cultures (and not focus solely on Western art music or skilled musicians). Given their pervasiveness, dance and music created for dancing should be considered central subcomponents of music, as should folk tunes, work songs, lullabies and children's songs. Although the precise breakdown of capacities required by the multicomponent approach remains open to debate, and different breakdowns may be appropriate to different purposes, I highlight four core components of human musicality--song, drumming, social synchronization and dance--as widespread and pervasive human abilities spanning across cultures, ages and levels of expertise. Each of these has interesting parallels in the animal kingdom (often analogies but in some cases apparent homologies also). Finally, I suggest that the search for universal capacities underlying human musicality, neglected for many years, should be renewed. The broad framework presented here illustrates the potential for a future discipline of bio-musicology as a rich field for interdisciplinary and comparative research.

BACKGROUND:Huntington's disease (HD) is an autosominal dominant neurodegenerative condition that leads to progressive loss of motor and cognitive functions. Early symptoms in HD include subtle executive dysfunction related to white and grey matter loss in cortico-striatal-thalamic loops. There is no cure for HD and hence a significant need for early intervention with the potential to delay the clinical onset of the disease.

OBJECTIVE:The objective of the present pilot study was to devise a novel behavioural intervention involving drumming and rhythm exercises that targets early dysexecutive problems, such as difficulties in sequence and reversal learning, response speed, timing, and dual tasking.

METHOD:One preclinical person and nine people with early to advanced stages of HD were recruited of whom five completed the two months intervention. The effects of rhythm exercise on executive function, basal ganglia volume, and white matter microstructure in the anterior corpus callosum, the anterior thalamic radiation, and the cortico-spinal tract were assessed post- relative to pre-training.

RESULTS:After two months training, improvements in executive function and changes in white matter microstructure, notably in the genu of the corpus callosum that connects prefrontal cortices of both hemispheres, were observed. No changes in basal ganglia volume were present.

CONCLUSION:This pilot study provides novel preliminary evidence that carefully targeted behavioural stimulation in HD can result in cognitive enhancement and improvements in callosal white matter microstructure.

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 music-making interventions are increasingly recognised as enhancing mental health, little is known of why music may engender such benefit. The objective of this article is to elucidate the features of a programme of group drumming known to enable mental health recovery.

METHODS:Qualitative research was conducted with 39 mental health patients and carers who had demonstrated recovery following engagement with a programme of group djembe drumming in the UK. Data were collected through semi-structured individual interviews and focus group interviews designed to understand the connection between drumming and recovery and analysed using Interpretative Phenomenological Analysis (IPA).

RESULTS:Results revealed three overarching features of the drumming intervention: (1) the specific features of drumming, including drumming as a form of non-verbal communication, as a connection with life through rhythm, and as a grounding experience that both generates and liberates energy; (2) the specific features of the group, including the group as a space of connection in and through the rhythmic features of the drumming, as well as facilitating feelings of belonging, acceptance, safety and care, and new social interactions; (3) the specific features of the learning, including learning as an inclusive activity in which the concept of mistakes is dissolved and in which there is musical freedom, supported by an embodied learning process expedited by the musical facilitator.

CONCLUSION:The findings provide support for the conceptual notion of 'creative practice as mutual recovery', demonstrating that group drumming provides a creative and mutual learning space in which mental health recovery can take place.

Salient sounds such as those created by drumming can serve as means of nonvocal acoustic communication in addition to vocal sounds. Despite the ubiquity of drumming across human cultures, its origins and the brain regions specialized in processing such signals remain unexplored. Here, we report that an important animal model for vocal communication, the macaque monkey, also displays drumming behavior, and we exploit this finding to show that vocal and nonvocal communication sounds are represented by overlapping networks in the brain's temporal lobe. Observing social macaque groups, we found that these animals use artificial objects to produce salient periodic sounds, similar to acoustic gestures. Behavioral tests confirmed that these drumming sounds attract the attention of listening monkeys similarly as conspecific vocalizations. Furthermore, in a preferential looking experiment, drumming sounds influenced the way monkeys viewed their conspecifics, suggesting that drumming serves as a multimodal signal of social dominance. Finally, by using high-resolution functional imaging we identified those brain regions preferentially activated by drumming sounds or by vocalizations and found that the representations of both these communication sounds overlap in caudal auditory cortex and the amygdala. The similar behavioral responses to drumming and vocal sounds, and their shared neural representation, suggest a common origin of primate vocal and nonvocal communication systems and support the notion of a gestural origin of speech and music.

The purpose of this article is to report a case study of the effect of therapeutic drumming on motor, communication skills, and behavior of a preteen diagnosed with agenesis of the corpus callosum. This 12-year-old participated in 30- to 45-minute weekly sessions over a 12-month period in which rudimentary drumming exercises were used to analyze and then measure any changes in equilibrium reactions, postural transfers, and trunk control. Measurable documentation evidenced marked improvement in motor skills while suggesting communication and behavioral improvement. The findings support the theory that therapeutic drumming would benefit preteens with agenesis of the corpus callosum, which provides promising evidence to other neurologic developmental diagnoses and therefore indicates a need for further research. While the therapeutic nature of music is well documented, how the listener participates can influence the effect of the music. For example, passive music listening can improve pain or anxiety, however, active music listening with expected intentional action may improve physical, mental, behavioral, and spiritual healing. Active music listening could be a valuable holistic nursing intervention.

It is well known that music arouses emotional responses. In addition, it has long been thought to play an important role in creating a sense of community, especially in small scale societies. One mechanism by which it might do this is through the endorphin system, and there is evidence to support this claim. Using pain threshold as an assay for CNS endorphin release, we ask whether it is the auditory perception of music that triggers this effect or the active performance of music. We show that singing, dancing and drumming all trigger endorphin release (indexed by an increase in post-activity pain tolerance) in contexts where merely listening to music and low energy musical activities do not. We also confirm that music performance results in elevated positive (but not negative) affect. We conclude that it is the active performance of music that generates the endorphin high, not the music itself. We discuss the implications of this in the context of community bonding mechanisms that commonly involve dance and music-making.