The Development of Rhythmic Categories as Revealed Through an Iterative Production Task

Both humans and some non-human animals (e.g., birds and primates) demonstrate bias toward simple integer ratios in auditory rhythms. In humans, biases are found for small integer-ratio rhythms in general. In addition, there are biases for the specific small integer-ratio rhythms common to one’s cultural listening experience. To better understand the developmental trajectory of these biases, we estimated children’s rhythm priors across the entire human rhythm production space of simple rhythms. North American children aged 6-11 years completed an iterative rhythm production task, in which they tapped in synchrony with repeating three-interval rhythms. For each rhythm, the child’s produced rhythm was presented back to them as the stimulus, and over the course of 5 iterations we used their final reproductions to estimate their rhythmic biases or priors. Results suggest that children’s rhythmic priors are (nearly) integer ratios, and the relative weights of the categories observed in children are highly correlated with those of adults. However, we also observed age-related changes especially for the ratio types that vary most across cultures. In an additional rhythm perception task, children were better at detecting rhythmic disruptions to a culturally familiar rhythm (in 4/4 meter with 2:1:1 ratio pattern) than to a culturally unfamiliar rhythm (7/8 meter with 3:2:2 ratios), and performance in this task was correlated with tapping variability in the iterative task. Taken together, our findings provide evidence that children as young as 6 years old exhibit categorical rhythm priors in their rhythm production that closely resemble those of adults in the same culture.

Rate of infant carrying impacts infant spontaneous motor tempo

Rhythm production is a critical component of human interaction, not least forming the basis of our musicality. Infants demonstrate a spontaneous motor tempo (SMT), or natural rate of rhythmic movement. Here, we ask whether infant SMT is influenced by the rate of locomotion infants experience when being carried. Ten-month-old, non-walking infants were tested using a free drumming procedure before and after 10 min of being carried by an experimenter walking at a slower (98 BPM) or faster (138 BPM) than average tempo. We find that infant SMT is differentially impacted by carrying experience dependent on the tempo at which they were carried: infants in the slow-walked group exhibited a slower SMT from pre-test to post-test, while infants in the fast-walked group showed a faster SMT from pre-test to post-test. Heart rate data suggest that this effect is not due to a general change in the state of arousal. We argue that being carried during caregiver locomotion is a predominant experience for infants throughout the first years of life, and as a source of regular, vestibular, information, may at least partially form the basis of their sense of rhythm.

Rhythmic abilities in humans and non-human animals: a review and recommendations from a methodological perspective

Rhythmic behaviour is ubiquitous in both human and non-human animals, but it is unclear whether the cognitive mechanisms underlying the specific rhythmic behaviours observed in different species are related. Laboratory experiments combined with highly controlled stimuli and tasks can be very effective in probing the cognitive architecture underlying rhythmic abilities. Rhythmic abilities have been examined in the laboratory with explicit and implicit perception tasks, and with production tasks, such as sensorimotor synchronization, with stimuli ranging from isochronous sequences of artificial sounds to human music. Here, we provide an overview of experimental findings on rhythmic abilities in human and non-human animals, while critically considering the wide variety of paradigms used. We identify several gaps in what is known about rhythmic abilities. Many bird species have been tested on rhythm perception, but research on rhythm production abilities in the same birds is lacking. By contrast, research in mammals has primarily focused on rhythm production rather than perception. Many experiments also do not differentiate between possible components of rhythmic abilities, such as processing of single temporal intervals, rhythmic patterns, a regular beat or hierarchical metrical structures. For future research, we suggest a careful choice of paradigm to aid cross-species comparisons, and a critical consideration of the multifaceted abilities that underlie rhythmic behaviour. This article is part of the theme issue ‘Synchrony and rhythm interaction: from the brain to behavioural ecology’.

Rhythmic abilities in humans and non-human animals: A review and recommendations from a methodological perspective

Rhythmic behavior is ubiquitous in both human and non-human animals, but it is unclear whether the cognitive mechanisms underlying the specific rhythmic behaviors observed in different species are related. Lab experiments combined with highly controlled stimuli and tasks can be very effective in probing the cognitive architecture underlying rhythmic abilities. Rhythmic abilities have been examined in the lab with explicit and implicit perception tasks, and with production tasks, such as sensorimotor synchronization, with stimuli ranging from isochronous sequences of artificial sounds to human music. Here, we provide an overview of experimental findings on rhythmic abilities in human and non-human animals, while critically considering the wide variety of paradigms used. We identify several gaps in what is known about rhythmic abilities. Many bird species have been tested on rhythm perception, but research on rhythm production abilities in the same birds is lacking. In contrast, research in mammals has primarily focused on rhythm production rather than perception. Many experiments also do not differentiate between possible components of rhythmic abilities, such as processing of single temporal intervals, rhythmic patterns, a regular beat, or hierarchical metrical structures. For future research, we suggest a careful choice of paradigm to aid cross-species comparisons, and a critical consideration of the multifaceted abilities that underlie rhythmic behavior.

Rate of infant carrying predicts infant spontaneous motor tempo

Rhythm production is a critical component of human interaction, not least forming the basis of our musicality. Infants demonstrate a Spontaneous Motor Tempo (SMT), or natural rate of rhythmic movement. Here we ask whether infant SMT is influenced by the rate of loco- motion infants experience when being carried. Ten-month-old, non-walking infants were tested using a free drumming procedure before and after ten minutes of being carried by an experimenter walking at a slower (98 BPM) or faster (138 BPM) than average tempo. We find that infant SMT is differentially impacted by carrying experience dependent on the tempo at which they were carried: Infants in the slow-walked group exhibited a slower SMT from pre-test to post-test, whilst infants in the fast-walked group showed a faster SMT from pre-test to post-test. Heart rate data suggest that this effect is not due to a general change in state of arousal. We argue that being carried during caregiver locomotion is a predominant experience for infants throughout the first years of life, and as a source of regular, vestibular, information, may at least partially form the basis of their sense of rhythm.

Spontaneous grouping of saccade timing in the presence of task-irrelevant objects

Sequential movements are often grouped into several chunks, as evidenced by the modulation of the timing of each elemental movement. Even during synchronized tapping with a metronome, we sometimes feel subjective accent for every few taps. To examine whether motor segmentation emerges during synchronized movements, we trained monkeys to generate a series of predictive saccades synchronized with visual stimuli which sequentially appeared for a fixed interval (400 or 600 ms) at six circularly arranged landmark locations. We found two types of motor segmentations that featured periodic modulation of saccade timing. First, the intersaccadic interval (ISI) depended on the target location and saccade direction, indicating that particular combinations of saccades were integrated into motor chunks. Second, when a task-irrelevant rectangular contour surrounding three landmarks ("inducer") was presented, the ISI significantly modulated depending on the relative target location to the inducer. All patterns of individual differences seen in monkeys were also observed in humans. Importantly, the effects of the inducer greatly decreased or disappeared when the animals were trained to generate only reactive saccades (latency >100 ms), indicating that the motor segmentation may depend on the internal rhythms. Thus, our results demonstrate two types of motor segmentation during synchronized movements: one is related to the hierarchical organization of sequential movements and the other is related to the spontaneous grouping of rhythmic events. This experimental paradigm can be used to investigate the underlying neural mechanism of temporal grouping during rhythm production.

Rhythmic Abilities Correlate with L2 Prosody Imitation Abilities in Typologically Different Languages

While many studies have demonstrated the relationship between musical rhythm and speech prosody, this has been rarely addressed in the context of second language (L2) acquisition. Here, we investigated whether musical rhythmic skills and the production of L2 speech prosody are predictive of one another. We tested both musical and linguistic rhythmic competences of 23 native French speakers of L2 English. Participants completed perception and production music and language tests. In the prosody production test, sentences containing trisyllabic words with either a prominence on the first or on the second syllable were heard and had to be reproduced. Participants were less accurate in reproducing penultimate accent placement. Moreover, the accuracy in reproducing phonologically disfavored stress patterns was best predicted by rhythm production abilities. Our results show, for the first time, that better reproduction of musical rhythmic sequences is predictive of a more successful realization of unfamiliar L2 prosody, specifically in terms of stress-accent placement.