When studying the behavior of species, the study design is often based on human standards. But, when modeling the behavior of non-human species, these biases can skew the results. Now, a research team has proposed the adoption of “ecologically honest” design principles to better reflect rhythmic behaviors that are constrained by the fitness of any specific species being studied and to account for their temporal differences.
“The failure of a non-human animal to synchronize in an experiment designed to test humans does not mean that it is unable to synchronize. It could also mean that the experiment was not designed appropriately. to test a particular species,” said Koen de Reus of the VUB Artificial Intelligence Laboratory and the Comparative Bioacoustics Group at the Max Planck Institute for Psycholinguistics in the Netherlands.
VUB researcher Koen de Reus is part of an international team exploring how best to study how animals synchronize behaviors such as movement, vocalization and respiration. In humans and other animals, these rhythmic behaviors occur in a variety of contexts: during mating, locomotion, and social coordination, for example. Study design is often based on human standards, but to effectively study synchronization abilities in other animals, researchers must consider a species’ temporal, physical, perceptual, and motivational constraints, which could be similar or different from those of humans.
Picture: A framework for mapping and considering rhythmic abilities across species. Line plots show preferred rates and empirical timing ranges over a sample of species
The research team now proposes that a set of “ecologically honest” design principles, specific to the animal and the context, would give a better picture of its synchronization capabilities. Reviewing the literature, the researchers found that anticipation and flexibility of tempo had previously been recognized as essential characteristics of synchrony, but their opinion piece published in the Royal Society’s Philosophical Transactions B is the first to recognize that an animal’s tempo flexibility is limited to a specific range. This means that scientists must first establish the natural range of tempos at which animals produce rhythmic behaviors, in order to study whether they can synchronize.
According to de Reus, “All animals are temporally bounded by the physical limits of their bodies, their perceptual systems, and their behavioral ecology. The interplay of these three components determines how flexible a species’ tempo is. Although all synchronizing animals demonstrate rhythm flexibility, the degree of flexibility varies by species.A range of rhythm differences have been observed in the behaviors of different animals.Some have very flexible ranges, such as humans and geladas, while others are more restricted, such as bonobos and fiddler crabs.
Motivation is key
The team also found that determining which behavior a synchronization task should test is crucial because some behaviors are more easily synchronized with a stimulus than others. Researchers must therefore consider the modality (acoustic, visual, tactile) with which an animal synchronizes best. For example, humans synchronize better with sounds, but other animals may not. Finally, an animal’s motivation to adopt a specific behavior is highly context-dependent. Individual behavior may only appear when individuals form groups and therefore studying this behavior under controlled laboratory conditions would require multiple individuals.
“An animal will only perceive and be able to synchronize to a stimulus within a species-specific tempo range. However, this does not necessarily mean that if a stimulus is within that range, an animal will synchronize to it. It has to be motivated to do it, and a lot depends on the situational context,” de Reus said.
To improve understanding of synchronization abilities across the animal kingdom, knowledge from laboratory experiments and field studies must be integrated. Laboratory settings allow researchers to control a range of variables that can test the full extent of a species’ ability to synchronize. At the same time, field studies can provide insight into why, when and how animal species synchronize in their natural environment. Observational data allows scientists to identify behaviors a species may naturally produce, which can then inform controlled laboratory experiments.
Read the original article, An ecological approach to measuring synchronization capacities across the animal kingdom published in Philosophical Transactions of the Royal Society B