Sonification of experimental parameters as a new method for efficient coding of behavior

Cognitive research is often focused on experimental condition-driven reactions. Ethological studies frequently rely on the observation of naturally occurring specific behaviors. In both cases, subjects are filmed during the study, so that afterwards behaviors can be coded on video. Coding should typically be blind to experimental conditions, but often requires more information than that present on video. We introduce a method for blindcoding of behavioral videos that takes care of both issues via three main innovations. First, of particular significance for playback studies, it allows creation of a “soundtrack” of the study, that is, a track composed of synthesized sounds representing different aspects of the experimental conditions, or other events, over time. Second, it facilitates coding behavior using this audio track, together with the possibly muted original video. This enables coding blindly to conditions as required, but not ignoring other relevant events. Third, our method makes use of freely available, multi-platform software, including scripts we developed

More than one way to see it: Individual heuristics in avian visual computation

Comparative pattern learning experiments investigate how different species find regularities in sensory input, providing insights into cognitive processing in humans and other animals. Past research has focused either on one species’ ability to process pattern classes or different species’ performance in recognizing the same pattern, with little attention to individual and species-specific heuristics and decision strategies. We trained and tested two bird species, pigeons (Columba livia) and kea (Nestor notabilis, a parrot species), on visual patterns using touch-screen technology. Patterns were composed of several abstract elements and had varying degrees of structural complexity. We developed a model selection paradigm, based on regular expressions, that allowed us to reconstruct the specific decision strategies and cognitive heuristics adopted by a given individual in our task. Individual birds showed considerable differences in the number, type and heterogeneity of heuristic strategies adopted. Birds’ choices also exhibited consistent species-level differences. Kea adopted effective heuristic strategies, based on matching learned bigrams to stimulus edges. Individual pigeons, in contrast, adopted an idiosyncratic mix of strategies that included local transition probabilities and global string similarity. Although performance was above chance and quite high for kea, no individual of either species provided clear evidence of learning exactly the rule used to generate the training stimuli. Our results show that similar behavioral outcomes can be achieved using dramatically different strategies and highlight the dangers of combining multiple individuals in a group analysis. These findings, and our general approach, have implications for the design of future pattern learning experiments, and the interpretation of comparative cognition research more generally

Chorusing, synchrony, and the evolutionary functions of rhythm

A central goal of biomusicology is to understand the biological basis of human musicality. One approach to this problem has been to compare core components of human musicality (relative pitch perception, entrainment, etc.) with similar capacities in other animal species. Here we extend and clarify this comparative approach with respect to rhythm. First, whereas most comparisons between human music and animal acoustic behavior have focused on spectral properties (melody and harmony), we argue for the central importance of temporal properties, and propose that this domain is ripe for further comparative research. Second, whereas most rhythm research in non-human animals has examined animal timing in isolation, we consider how chorusing dynamics can shape individual timing, as in human music and dance, arguing that group behavior is key to understanding the adaptive functions of rhythm. To illustrate the interdependence between individual and chorusing dynamics, we present a computational model of chorusing agents relating individual call timing with synchronous group behavior. Third, we distinguish and clarify mechanistic and functional explanations of rhythmic phenomena, often conflated in the literature, arguing that this distinction is key for understanding the evolution of musicality. Fourth, we expand biomusicological discussions beyond the species typically considered, providing an overview of chorusing and rhythmic behavior across a broad range of taxa (orthopterans, fireflies, frogs, birds, and primates). Finally, we propose an “Evolving Signal Timing” hypothesis, suggesting that similarities between timing abilities in biological species will be based on comparable chorusing behaviors. We conclude that the comparative study of chorusing species can provide important insights into the adaptive function(s) of rhythmic behavior in our “proto-musical” primate ancestors, and thus inform our understanding of the biology and evolution of rhythm in human music and language

Perceptual tuning influences rule generalization: Testing humans with monkey-tailored stimuli

Comparative research investigating how nonhuman animals generalize patterns of auditory stimuli often uses sequences of human speech syllables and reports limited generalization abilities in animals. Here, we reverse this logic, testing humans with stimulus sequences tailored to squirrel monkeys. When test stimuli are familiar (human voices), humans succeed in two types of generalization. However, when the same structural rule is instantiated over unfamiliar but perceivable sounds within squirrel monkeys’ optimal hearing frequency range, human participants master only one type of generalization. These findings have methodological implications for the design of comparative experiments, which should be fair towards all tested species’ proclivities and limitations

I\u27m sometimes sad, but know not why

[Verse 1]I\u27m sometimes sad, but know not why, And weep at evening hour;Then gentlest murmurs whisper by,And stillness wakes her power.I\u27m sometimes sad when Cynthia\u27s beamsThe fountains silver o\u27er;I wander then among the elms,Where shadows hide my tear,Where shadows hide my tear. [Verse 2]I\u27m sometimes sad, when friends that were,My sorrows wake anew;They once were here but now they areWhere weeping willows grow!I\u27m sometimes sad, when friends that be,Excite the tender sigh;For soon a long adieu, they\u27ll say!And so must I, must I And so must I, must I. [Verse 3]I\u27m sometimes sad among the crowd,And in the circle glee;And often when the laugh is loud,I go to bend the knee.I\u27m sometimes sad, and think I\u27ve noneTo shed a tear with me!And who for Welwyneer will mourn,When \u27neath the pendant tree?When \u27neath the pendant tree? [Verse 4]Sad world! where is thy soothing pow\u27r,At morn, or vesper mild?Or where when noontide tells the hour,The charm for sorrows child?Tho\u27 sad I roam, tho\u27 drop the tear\u27Mid light, or shadows gloom,Ere long I\u27ll lay me silent there, Low in the peaceful Tomb, Low in the peaceful Tomb

Dance, Music, Meter and Groove: A Forgotten Partnership

I argue that core aspects of musical rhythm, especially groove and syncopation, can only be fully understood in the context of their origins in the participatory social experience of dance. Musical meter is first considered in the context of bodily movement. I then offer an interpretation of the pervasive but somewhat puzzling phenomenon of syncopation in terms of acoustic emphasis on certain offbeat components of the accompanying dance style. The reasons for the historical tendency of many musical styles to divorce themselves from their dance-based roots are also briefly considered. To the extent that musical rhythms only make sense in the context of bodily movement, researchers interested in ecologically valid approaches to music cognition should make a more concerted effort to extend their analyses to dance, particularly if we hope to understand the cognitive constraints underlying rhythmic aspects of music like meter and groove

The biology and evolution of music: A comparative perspective

Studies of the biology of music (as of language) are highly interdisciplinary and demand the integration of diverse strands of evidence. In this paper, I present a comparative perspective on the biology and evolution of music, stressing the value of comparisons both with human language, and with those animal communication systems traditionally termed &quot;song&quot;. A comparison of the &quot;design features&quot; of music with those of language reveals substantial overlap, along with some important differences. Most of these differences appear to stem from semantic, rather than structural, factors, suggesting a shared formal core of music and language. I next review various animal communication systems that appear related to human music, either by analogy (bird and whale &quot;song&quot;) or potential homology (great ape bimanual drumming). A crucial comparative distinction is between learned, complex signals (like language, music and birdsong) and unlearned signals (like laughter, ape calls, or bird calls). While human vocalizations clearly build upon an acoustic and emotional foundation shared with other primates and mammals, vocal learning has evolved independently in our species since our divergence with chimpanzees. The convergent evolution of vocal learning in other species offers a powerful window into psychological and neural constraints influencing the evolution of complex signaling systems (including both song and speech), while ape drumming presents a fascinating potential homology with human instrumental music. I next discuss the archeological data relevant to music evolution, concluding on the basis of prehistoric bone flutes that instrumental music is at least 40,000 years old, and perhaps much older. I end with a brief review of adaptive functions proposed for music, concluding that no one selective force (e.g., sexual selection) is adequate to explaining all aspects of human music. I suggest that questions about the past function of music are unlikely to be answered definitively and are thus a poor choice as a research focus for biomusicology. In contrast, a comparative approach to music promises rich dividends for our future understanding of the biology and evolution of music. (c) 2005 Elsevier B.V. All rights reserved.</p