Commonality and variation in mental representations of music revealed by a cross-cultural comparison of rhythm priors in 15 countries.

Music is present in every known society but varies from place to place. What, if anything, is universal to music cognition? We measured a signature of mental representations of rhythm in 39 participant groups in 15 countries, spanning urban societies and Indigenous populations. Listeners reproduced random 'seed' rhythms; their reproductions were fed back as the stimulus (as in the game of 'telephone'), such that their biases (the prior) could be estimated from the distribution of reproductions. Every tested group showed a sparse prior with peaks at integer-ratio rhythms. However, the importance of different integer ratios varied across groups, often reflecting local musical practices. Our results suggest a common feature of music cognition: discrete rhythm 'categories' at small-integer ratios. These discrete representations plausibly stabilize musical systems in the face of cultural transmission but interact with culture-specific traditions to yield the diversity that is evident when mental representations are probed across many cultures.

Consequences of Contracting COVID-19 or Taking the COVID-19 Vaccine for Individuals with a History of Lyme Disease.

Individuals with Lyme disease can be very symptomatic. This survey compares the burden of illness for individuals with a history of Lyme disease (HLD) with individuals with a HLD who have either contracted COVID-19 or who have taken the COVID-19 vaccine. The findings describe the relative symptom burden among these three groups using a cross-sectional descriptive survey investigating the burden of Lyme disease in a pandemic. The survey includes the General Symptom Questionnaire-30 (GSQ-30), a brief self-report scale designed to assess the symptom burden in Lyme disease (LD). The results of this survey show that the overall burden of illness among individuals with HLD is not significantly different after contracting COVID-19 or after COVID-19 vaccination. A new survey will be needed to better understand why one in five individuals with a HLD reported long COVID after contracting COVID-19. These results should help clinicians and their patients to discuss the consequences of contracting a COVID-19 infection or being vaccinated against COVID-19.

The complexity-aesthetics relationship for musical rhythm is more fixed than flexible: Evidence from children and expert dancers.

The urge to move to music (groove) depends in part on rhythmic syncopation in the music. For adults, the syncopation-groove relationship has an inverted-U shape: listeners want to move most to rhythms that have some, but not too much, syncopation. However, we do not know whether the syncopation-groove relationship is relatively sensitive to, or resistant to, a listener's experience. In two sets of experiments, we tested whether the syncopation-groove relationship is affected by dance experience or changes through development in childhood. Dancers and nondancers rated groove for 50 rhythmic patterns varying in syncopation. Dancers' and nondancers' ratings did not differ (and Bayesian tests provided substantial evidence that they were equivalent) in terms of mean groove and the optimal level of syncopation. Similarly, ballet and hip-hop dancers' syncopation-groove relationships did not differ. However, dancers had more robust syncopation-groove relationships (higher goodness-of-fit) than nondancers. Children (3-6 years old) completed two tasks to assess their syncopation-groove relationships: In a 2-alternative-forced choice task, children compared rhythms from 2 of 3 possible levels of syncopation (low, medium, and high) and chose which rhythm in a pair was better for dancing. In a dance task, children danced to the same rhythms. Results from both tasks indicated that for children, as for adults, medium syncopation rhythms elicit more groove than low syncopation rhythms. A follow-up experiment replicated the 2-alternative-forced choice task results. Taken together, the results suggest the optimal level of syncopation for groove is resistant to experience, although experience may affect the robustness of the inverted-U relationship. RESEARCH HIGHLIGHTS: In Experiment 1, dancers and nondancers rated groove (the urge to move) for musical rhythms, demonstrating the same inverted-U relationships between syncopation and groove. In Experiment 2, children and adults both chose rhythms with moderate syncopation more than low syncopation as more groove-inducing or better for dancing. Children also danced more for moderate than low syncopation, showing a close perception-behavior relationship across tasks. Similarities in the syncopation-groove relationship regardless of dance training and age suggest that this perceptual and behavioral groove response to rhythmic complexity may be quite resistant to experience.

Collective dynamics support group drumming, reduce variability, and stabilize tempo drift.

Humans are social animals who engage in a variety of collective activities requiring coordinated action. Among these, music is a defining and ancient aspect of human sociality. Human social interaction has largely been addressed in dyadic paradigms, and it is yet to be determined whether the ensuing conclusions generalize to larger groups. Studied more extensively in non-human animal behavior, the presence of multiple agents engaged in the same task space creates different constraints and possibilities than in simpler dyadic interactions. We addressed whether collective dynamics play a role in human circle drumming. The task was to synchronize in a group with an initial reference pattern and then maintain synchronization after it was muted. We varied the number of drummers from solo to dyad, quartet, and octet. The observed lower variability, lack of speeding up, smoother individual dynamics, and leader-less inter-personal coordination indicated that stability increased as group size increased, a sort of temporal wisdom of crowds. We propose a hybrid continuous-discrete Kuramoto model for emergent group synchronization with a pulse-based coupling that exhibits a mean field positive feedback loop. This research suggests that collective phenomena are among the factors that play a role in social cognition.

Undetectable very-low frequency sound increases dancing at a live concert.

Does low frequency sound (bass) make people dance more? Music that makes people want to move tends to have more low frequency sound, and bass instruments typically provide the musical pulse that people dance to1. Low pitches confer advantages in perception and movement timing, and elicit stronger neural responses for timing compared to high pitches2, suggesting superior sensorimotor communication. Low frequency sound is processed via vibrotactile3 and vestibular4 (in addition to auditory) pathways, and stimulation of these non-auditory modalities in the context of music can increase ratings of groove (the pleasurable urge to move to music)3, and modulate musical rhythm perception4. Anecdotal accounts describe intense physical and psychological effects of low frequencies, especially in electronic dance music5, possibly reflecting effects on physiological arousal. We do not, however, know if these associations extend to direct causal effects of low frequencies in complex, real-world, social contexts like dancing at concerts, or if low frequencies that are not consciously detectable can affect behaviour. We tested whether non-auditory low-frequency stimulation would increase audience dancing by turning very-low frequency (VLF) speakers on and off during a live electronic music concert and measuring audience members' movements using motion-capture. Movement increased when VLFs were present, and because the VLFs were below or near auditory thresholds (and a subsequent experiment suggested they were undetectable), we believe this represents an unconscious effect on behaviour, possibly via vestibular and/or tactile processing.

Comparison of Spontaneous Motor Tempo during Finger Tapping, Toe Tapping and Stepping on the Spot in People with and without Parkinson's Disease.

OBJECTIVE: Spontaneous motor tempo (SMT), observed in walking, tapping and clapping, tends to occur around 2 Hz. Initiating and controlling movement can be difficult for people with Parkinson's (PWP), but studies have not identified whether PWP differ from controls in SMT. For community-based interventions, e.g. dancing, it would be helpful to know a baseline SMT to optimize the tempi of cued activities. Therefore, this study compared finger tapping (FT), toe tapping (TT) and stepping 'on the spot' (SS) in PWP and two groups of healthy controls [age-matched controls (AMC) and young healthy controls (YHC)], as SMT is known to change with age. METHODS: Participants (PWP; n = 30, AMC; n = 23, YHC; n = 35) were asked to tap or step on the spot at a natural pace for two trials lasting 40 seconds. The central 30 seconds were averaged for analyses using mean inter-onset intervals (IOI) and coefficient of variation (CoV) to measure rate and variability respectively. RESULTS: PWP had faster SMT than both control groups, depending on the movement modality: FT, F(2, 87) = 7.92, p < 0.01 (PWP faster than YHC); TT, F(2, 87) = 4.89, p = 0.01 (PWP faster than AMC); and SS, F(2, 77) = 3.26, p = 0.04 (PWP faster than AMC). PWP had higher CoV (more variable tapping) than AMC in FT only, F(2, 87) = 4.10, p = 0.02. CONCLUSION: This study provides the first direct comparison of SMT between PWP and two control groups for different types of movements. RESULTS: suggest SMT is generally faster in PWP than control groups, and more variable when measured with finger tapping compared to stepping on the spot.

Neural entrainment is associated with subjective groove and complexity for performed but not mechanical musical rhythms.

Both movement and neural activity in humans can be entrained by the regularities of an external stimulus, such as the beat of musical rhythms. Neural entrainment to auditory rhythms supports temporal perception, and is enhanced by selective attention and by hierarchical temporal structure imposed on rhythms. However, it is not known how neural entrainment to rhythms is related to the subjective experience of groove (the desire to move along with music or rhythm), the perception of a regular beat, the perception of complexity, and the experience of pleasure. In two experiments, we used musical rhythms (from Steve Reich's Clapping Music) to investigate whether rhythms that are performed by humans (with naturally variable timing) and rhythms that are mechanical (with precise timing), elicit differences in (1) neural entrainment, as measured by inter-trial phase coherence, and (2) subjective ratings of the complexity, preference, groove, and beat strength of rhythms. We also combined results from the two experiments to investigate relationships between neural entrainment and subjective perception of musical rhythms. We found that mechanical rhythms elicited a greater degree of neural entrainment than performed rhythms, likely due to the greater temporal precision in the stimulus, and the two types only elicited different ratings for some individual rhythms. Neural entrainment to performed rhythms, but not to mechanical ones, correlated with subjective desire to move and subjective complexity. These data, therefore, suggest multiple interacting influences on neural entrainment to rhythms, from low-level stimulus properties to high-level cognition and perception.

Evaluating Affordable Cranial Ultrasonography in East African Neonatal Intensive Care Units.

Neuroimaging is a valuable diagnostic tool for the early detection of neonatal brain injury, but equipment and radiologic staff are expensive and unavailable to most hospitals in developing countries. We evaluated an affordable, portable ultrasound machine as a quantitative and qualitative diagnostic tool and to establish whether a novice sonographer could effectively operate the equipment and obtain clinically important information. Cranial ultrasonography was performed on term healthy, pre-term and term asphyxiated neonates in Rwandan and Kenyan hospitals. To evaluate the detection of ventriculomegaly and compression injuries, we measured the size of the lateral ventricles and corpus callosum. The images were also assessed for the presence of other cerebral abnormalities. Measurements were reliable across images, and cases of clinically relevant ventriculomegaly were detected. A novice sonographer had good-to-excellent agreement with an expert. This study demonstrates that affordable equipment and cranial ultrasound protocols can be used in low-resource settings to assess the newborn brain.

The Effect of Dopaminergic Medication on Beat-Based Auditory Timing in Parkinson's Disease.

Parkinson's disease (PD) adversely affects timing abilities. Beat-based timing is a mechanism that times events relative to a regular interval, such as the "beat" in musical rhythm, and is impaired in PD. It is unknown if dopaminergic medication influences beat-based timing in PD. Here, we tested beat-based timing over two sessions in participants with PD (OFF then ON dopaminergic medication) and in unmedicated control participants. People with PD and control participants completed two tasks. The first was a discrimination task in which participants compared two rhythms and determined whether they were the same or different. Rhythms either had a beat structure (metric simple rhythms) or did not (metric complex rhythms), as in previous studies. Discrimination accuracy was analyzed to test for the effects of beat structure, as well as differences between participants with PD and controls, and effects of medication (PD group only). The second task was the Beat Alignment Test (BAT), in which participants listened to music with regular tones superimposed, and responded as to whether the tones were "ON" or "OFF" the beat of the music. Accuracy was analyzed to test for differences between participants with PD and controls, and for an effect of medication in patients. Both patients and controls discriminated metric simple rhythms better than metric complex rhythms. Controls also improved at the discrimination task in the second vs. first session, whereas people with PD did not. For participants with PD, the difference in performance between metric simple and metric complex rhythms was greater (sensitivity to changes in simple rhythms increased and sensitivity to changes in complex rhythms decreased) when ON vs. OFF medication. Performance also worsened with disease severity. For the BAT, no group differences or effects of medication were found. Overall, these findings suggest that timing is impaired in PD, and that dopaminergic medication influences beat-based and non-beat-based timing differently. Judging the beat in music does not appear to be affected by PD or by dopaminergic medication.

Cross-cultural influences on rhythm processing: reproduction, discrimination, and beat tapping.

The structures of musical rhythm differ between cultures, despite the fact that the ability to entrain movement to musical rhythm occurs in virtually all individuals across cultures. To measure the influence of culture on rhythm processing, we tested East African and North American adults on perception, production, and beat tapping for rhythms derived from East African and Western music. To assess rhythm perception, participants identified whether pairs of rhythms were the same or different. To assess rhythm production, participants reproduced rhythms after hearing them. To assess beat tapping, participants tapped the beat along with repeated rhythms. We expected that performance in all three tasks would be influenced by the culture of the participant and the culture of the rhythm. Specifically, we predicted that a participant's ability to discriminate, reproduce, and accurately tap the beat would be better for rhythms from their own culture than for rhythms from another culture. In the rhythm discrimination task, there were no differences in discriminating culturally familiar and unfamiliar rhythms. In the rhythm reproduction task, both groups reproduced East African rhythms more accurately than Western rhythms, but East African participants also showed an effect of cultural familiarity, leading to a significant interaction. In the beat tapping task, participants in both groups tapped the beat more accurately for culturally familiar than for unfamiliar rhythms. Moreover, there were differences between the two participant groups, and between the two types of rhythms, in the metrical level selected for beat tapping. The results demonstrate that culture does influence the processing of musical rhythm. In terms of the function of musical rhythm, our results are consistent with theories that musical rhythm enables synchronization. Musical rhythm may foster musical cultural identity by enabling within-group synchronization to music, perhaps supporting social cohesion.

Enhanced timing abilities in percussionists generalize to rhythms without a musical beat.

The ability to entrain movements to music is arguably universal, but it is unclear how specialized training may influence this. Previous research suggests that percussionists have superior temporal precision in perception and production tasks. Such superiority may be limited to temporal sequences that resemble real music or, alternatively, may generalize to musically implausible sequences. To test this, percussionists and nonpercussionists completed two tasks that used rhythmic sequences varying in musical plausibility. In the beat tapping task, participants tapped with the beat of a rhythmic sequence over 3 stages: finding the beat (as an initial sequence played), continuation of the beat (as a second sequence was introduced and played simultaneously), and switching to a second beat (the initial sequence finished, leaving only the second). The meters of the two sequences were either congruent or incongruent, as were their tempi (minimum inter-onset intervals). In the rhythm reproduction task, participants reproduced rhythms of four types, ranging from high to low musical plausibility: Metric simple rhythms induced a strong sense of the beat, metric complex rhythms induced a weaker sense of the beat, nonmetric rhythms had no beat, and jittered nonmetric rhythms also had no beat as well as low temporal predictability. For both tasks, percussionists performed more accurately than nonpercussionists. In addition, both groups were better with musically plausible than implausible conditions. Overall, the percussionists' superior abilities to entrain to, and reproduce, rhythms generalized to musically implausible sequences.

Evidence assessments and guideline recommendations in Lyme disease: the clinical management of known tick bites, erythema migrans rashes and persistent disease.

Evidence-based guidelines for the management of patients with Lyme disease were developed by the International Lyme and Associated Diseases Society (ILADS). The guidelines address three clinical questions - the usefulness of antibiotic prophylaxis for known tick bites, the effectiveness of erythema migrans treatment and the role of antibiotic retreatment in patients with persistent manifestations of Lyme disease. Healthcare providers who evaluate and manage patients with Lyme disease are the intended users of the new ILADS guidelines, which replace those issued in 2004 (Exp Rev Anti-infect Ther 2004;2:S1-13). These clinical practice guidelines are intended to assist clinicians by presenting evidence-based treatment recommendations, which follow the Grading of Recommendations Assessment, Development and Evaluation system. ILADS guidelines are not intended to be the sole source of guidance in managing Lyme disease and they should not be viewed as a substitute for clinical judgment nor used to establish treatment protocols.

Lyme disease and pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS): an overview.

Lyme disease (LD) is a complex, multisystemic illness. As the most common vector- borne disease in the United States, LD is caused by bacterial spirochete Borrelia burgdorferi sensu stricto, with potential coinfections from agents of anaplasmosis, babesiosis, and ehrlichiosis. Persistent symptoms and clinical signs reflect multiorgan involvement with episodes of active disease and periods of remission, not sparing the coveted central nervous system. The capability of microorganisms to cause and exacerbate various neuropsychiatric pathology is also seen in pediatric autoimmune neuropsychiatric disorders associated with streptococcal infections (PANDAS), a recently described disorder attributed to bacterium Streptococcus pyogenes of group A beta-hemolytic streptococcus in which neurologic tics and obsessive-compulsive disorders are sequelae of the infection. In the current overview, LD and PANDAS are juxtaposed through a review of their respective infectious etiologies, clinical presentations, mechanisms of disease development, courses of illness, and treatment options. Future directions related to immunoneuropsychiatry are also discussed.

Proof that chronic lyme disease exists.

The evidence continues to mount that Chronic Lyme Disease (CLD) exists and must be addressed by the medical community if solutions are to be found. Four National Institutes of Health (NIH) trials validated the existence and severity of CLD. Despite the evidence, there are physicians who continue to deny the existence and severity of CLD, which can hinder efforts to find a solution. Recognizing CLD could facilitate efforts to avoid diagnostic delays of two years and durations of illness of 4.7 to 9 years described in the NIH trials. The risk to society of emerging antibiotic-resistant organisms should be weighed against the societal risks associated with failing to treat an emerging population saddled with CLD. The mixed long-term outcome in children could also be examined. Once we accept the evidence that CLD exists, the medical community should be able to find solutions. Medical professionals should be encouraged to examine whether: (1) innovative treatments for early LD might prevent CLD, (2) early diagnosis of CLD might result in better treatment outcomes, and (3) more effective treatment regimens can be developed for CLD patients who have had prolonged illness and an associated poor quality of life.

Insufficient evidence to deny antibiotic treatment to chronic Lyme disease patients.

BACKGROUND: The severity, length of illness, and cost of chronic Lyme disease (CLD) have been well described. A number of oral, intravenous, and intramuscular antibiotics have been prescribed for CLD. Surprisingly few antibiotic schedules prescribed for the treatment of CLD have been evaluated in randomized double-blind placebo-controlled clinical trials (RCTs). Physicians have increasingly turned to clinical treatment guideline (CPG) panels to judge the mixed results of the evidence. Two CPG panels have looked at the evidence only to reach opposite conclusions: (1) antibiotic therapy for CLD is not effective and (2) antibiotic therapy for CLD is effective. Physicians have been advised by guideline developers to use clinical discretion in diagnosing and treating CLD. Nevertheless, many health insurers - relying exclusively upon only one CPG - have a policy of automatically denying antibiotics to CLD patients regardless of the specifics of each case or the recommendations of the patient's physician. HYPOTHESES: This paper examined the eight limitations of the evidence used to conclude that antibiotics therapy for CLD is not effective in forming the following hypothesis: insufficient evidence to deny antibiotic treatment to CLD patients. EVIDENCE FOR THE HYPOTHESIS: There are eight limitations that support the hypothesis: (1) the power of the evidence is inadequate to draw definite conclusions, (2) the evidence is too heterogeneous to make strong recommendations, (3) the risk to an individual of facing a long-term debilitating illness has not been considered, (4) the risk to society of a growing chronically ill population has not been considered, (5) treatment delay has not been considered as a confounder, (6) co-infections have not been considered as a confounder, (7) the design of RCTs did not address the range of treatment options in an actual practice, and (8) the findings cannot be generalized to actual practice. IMPLICATIONS OF THE HYPOTHESES: This hypothesis suggests that physicians should consider the limitations of the evidence before denying antibiotic treatment for CLD. Physicians who deny antibiotic treatment to CLD patients might inform their patients that there are some clinicians who disagree with that position, and then offer to refer them for a second opinion to a doctor who could potentially present a different point of view. The hypothesis also suggests that health care insurers should consider the limitations of the evidence before adopting policies that routinely deny antibiotic treatment for CLD patients and should expand coverage of CLD to include clinical discretion for specific clinical situations.

Clinical trials validate the severity of persistent Lyme disease symptoms.

BACKGROUND: Persistent Lyme Disease Symptoms (PLDS) have included fatigue, headaches, poor concentration and memory, lightheadedness, joint pain, and mood disturbances. Evidence-based guidelines committees disagree over the severity of PLDS. The 2004 International Lyme and Associated Diseases Society (ILADS) concluded that PLDS are severe. The 2006 Infectious Disease Society of America (IDSA) guidelines committee concluded that PLDS are nothing more than the "aches and pains of daily living" and an ad hoc International Lyme group concluded that PLDS are "symptoms common in persons who have never had Lyme disease." HYPOTHESIS: Clinical trials validate the severity of persistent Lyme disease symptoms. EVALUATION OF THE HYPOTHESIS: There are 22 standardized instruments used to measure the severity of PLDS among the four published National Institutes of Health (NIH) sponsored double-blind randomized placebo-controlled trials (RCTs). VALIDATING THE HYPOTHESIS: All four NIH sponsored RCTs validate the severity of PLDS. PLDS are as severe as symptoms seen in other serious chronic illnesses, and result in a quality of life lower than for the general population as determined by 22 standardized measures of QOL, including fatigue, pain, role function, psychopathology, and cognition. None of the four RCTs support the IDSA hypothesis that PLDS are nothing more than "the aches and pains of daily living" nor the ad hoc International Lyme group conclusion that PLDS are "symptoms common in persons who have never had Lyme disease." IMPLICATIONS OF THE HYPOTHESIS: If the QOL of life for these patients is as poor as for patients with other serious chronic diseases, their symptoms need to be addressed by their doctors. Studies differ as to the precise cause of PLDS, the most effective treatments, and whether a cure is possible. But the fact that there is disagreement is not a license for physicians to ignore or turn away patients complaining of PLDS, or to dismiss their symptoms as purely psychosomatic. For physicians, the goal or purpose of treating PLDS should be the same as their purpose in treating other chronic illnesses that result in a poor QOL: vigorous pursuit of a cure, and where a cure proves impossible, amelioration of patients' symptoms and suffering. Even if this hypothesis fails to be apply to more than a fraction of the total Lyme disease population, this still represents a significant number of patients, and these findings could address a neglected aspect of caring for patients with Lyme disease.