The ability to identify emotional arousal in heterospecific vocalizations may facilitate behaviors that increase survival opportunities. Crucially, this ability may orient inter-species interactions, par- ticularly be...The ability to identify emotional arousal in heterospecific vocalizations may facilitate behaviors that increase survival opportunities. Crucially, this ability may orient inter-species interactions, par- ticularly between humans and other species. Research shows that humans identify emotional arousal in vocalizations across multiple species, such as cats, dogs, and piglets. However, no previ- ous study has addressed humans＂ ability to identify emotional arousal in silver foxes. Here, we adopted low- and high-arousal calls emitted by three strains of silver fox--Tame, Aggressive, and Unselected--in response to human approach. Tame and Aggressive foxes are genetically selected for friendly and attacking behaviors toward humans, respectively. Unselected foxes show aggres- sive and fearful behaviors toward humans. These three strains show similar levels of emotional arousal, but different levels of emotional valence in relation to humans. This emotional information is reflected in the acoustic features of the calls. Our data suggest that humans can identify high- arousal calls of Aggressive and Unselected foxes, but not of Tame foxes. Further analyses revealed that, although within each strain different acoustic parameters affect human accuracy in identifying high-arousal calls, spectral center of gravity, harmonic-to-noise ratio, and F0 best predict humans＇ ability to discriminate high-arousal calls across all strains. Furthermore, we identified in spectral center of gravity and F0 the best predictors for humans＇ absolute ratings of arousal in each call. Implications for research on the adaptive value of inter-specific eavesdropping are discussed.展开更多
Lepidoptera evolved tympanic ears in response to echolocating bats. Comparative studies have shown that moth ears evolved many times independently from chordotonal organs. With only 1 to 4 receptor cells, they are one...Lepidoptera evolved tympanic ears in response to echolocating bats. Comparative studies have shown that moth ears evolved many times independently from chordotonal organs. With only 1 to 4 receptor cells, they are one of the simplest hearing organs. The small number of receptors does not imply simplicity, neither in behavior nor in the neural circuit. Behaviorally, the response to ultrasound is far from being a simple reflex. Moths＇ escape behavior is modulated by a variety of cues, especially pheromones, which can alter the auditory response. Neurally the receptor cell（s） diverges onto many interneurons, enabling pa- rallel processing and feature extraction. Ascending interneurons and sound-sensitive brain neurons innervate a neuropil in the ventrolateral protocerebrum. Further, recent electrophysiological data provides the first glimpses into how the acoustic response is modulated as well as how ultrasound influences the other senses. So far, the auditory pathway has been studied in noctuids. The findings agree well with common computational principles found in other insects. However, moth ears also show unique mechanical and neural adaptation. Here, we first describe the variety of moths＇ auditory behavior, especially the co-option of ul- trasonic signals for intraspecific communication. Second, we describe the current knowledge of the neural pathway gained from noctuid moths. Finally, we argue that Galleriinae which show negative and positive phonotaxis, are an interesting model species for future electrophysiological studies of the auditory pathway and multimodal sensory integration, and so are ideally suited for the study of the evolution of behavioral mechanisms given a few receptors.展开更多
文摘The ability to identify emotional arousal in heterospecific vocalizations may facilitate behaviors that increase survival opportunities. Crucially, this ability may orient inter-species interactions, par- ticularly between humans and other species. Research shows that humans identify emotional arousal in vocalizations across multiple species, such as cats, dogs, and piglets. However, no previ- ous study has addressed humans＂ ability to identify emotional arousal in silver foxes. Here, we adopted low- and high-arousal calls emitted by three strains of silver fox--Tame, Aggressive, and Unselected--in response to human approach. Tame and Aggressive foxes are genetically selected for friendly and attacking behaviors toward humans, respectively. Unselected foxes show aggres- sive and fearful behaviors toward humans. These three strains show similar levels of emotional arousal, but different levels of emotional valence in relation to humans. This emotional information is reflected in the acoustic features of the calls. Our data suggest that humans can identify high- arousal calls of Aggressive and Unselected foxes, but not of Tame foxes. Further analyses revealed that, although within each strain different acoustic parameters affect human accuracy in identifying high-arousal calls, spectral center of gravity, harmonic-to-noise ratio, and F0 best predict humans＇ ability to discriminate high-arousal calls across all strains. Furthermore, we identified in spectral center of gravity and F0 the best predictors for humans＇ absolute ratings of arousal in each call. Implications for research on the adaptive value of inter-specific eavesdropping are discussed.
文摘Lepidoptera evolved tympanic ears in response to echolocating bats. Comparative studies have shown that moth ears evolved many times independently from chordotonal organs. With only 1 to 4 receptor cells, they are one of the simplest hearing organs. The small number of receptors does not imply simplicity, neither in behavior nor in the neural circuit. Behaviorally, the response to ultrasound is far from being a simple reflex. Moths＇ escape behavior is modulated by a variety of cues, especially pheromones, which can alter the auditory response. Neurally the receptor cell（s） diverges onto many interneurons, enabling pa- rallel processing and feature extraction. Ascending interneurons and sound-sensitive brain neurons innervate a neuropil in the ventrolateral protocerebrum. Further, recent electrophysiological data provides the first glimpses into how the acoustic response is modulated as well as how ultrasound influences the other senses. So far, the auditory pathway has been studied in noctuids. The findings agree well with common computational principles found in other insects. However, moth ears also show unique mechanical and neural adaptation. Here, we first describe the variety of moths＇ auditory behavior, especially the co-option of ul- trasonic signals for intraspecific communication. Second, we describe the current knowledge of the neural pathway gained from noctuid moths. Finally, we argue that Galleriinae which show negative and positive phonotaxis, are an interesting model species for future electrophysiological studies of the auditory pathway and multimodal sensory integration, and so are ideally suited for the study of the evolution of behavioral mechanisms given a few receptors.
