Dr. Bowling is an instructor in the department of Psychiatry and Behavioral Sciences at Stanford University School of medicine. His research is focused on auditory-vocal communication in social functioning and mental health.
Dr. Bowling earned his PhD in Neurobiology from Duke University School of Medicine, going on to complete postdoctoral and fellowship work at the University of Vienna in Austria. He holds graduate certificates in Cognitive Neuroscience and Translational Medicine, and undergraduate degrees in Biological Psychology and Neurophilosophy. He joined Stanford in December of 2018.
Dr. Bowling has published over 30 scientific articles in journals such as Science, PNAS, Trends in Cognitive Science, Scientific Reports, Proceedings of the Royal Society B, and PLoS Biology. His work has been recognized with plaudits including an innovation award from the Social and Affective Neuroscience society, a young investigator award from the faculty of life science at the University of Vienna, and awards for best talk and best poster at international conferences. He has received funding at institutional and federal levels in the United States and in Austria.
Instructor, Psychiatry and Behavioral Sciences
Selection on vocal output affects laryngeal morphology in rats.
Journal of anatomy
Although laryngeal morphology often reflects adaptations for vocalization, the structural consequences of selection for particular aspects of vocal behavior remain poorly understood. In this study, we investigated the effects of increased ultrasonic calling in pups on the adult larynx morphology in selectively bred rat lines. Laryngeal morphology was assessed using multiple techniques: mineralized cartilage volumes were compared in 3D-models derived from microCT scans, internal structure was compared using clearing and staining procedures combined with microscopy, cellular structure was compared using histology and microscopy, and element composition was assessed with scanning energy dispersive X-ray spectroscopy. Our results show that adult rats from lines bred to produce ultrasonic calls at higher rates as pups have shorter vocal folds and a more mineralized thyroid cartilage compared to rats bred to produce ultrasonic calls at lower rates. The change in vocal fold length appears to account for differences in low-frequency calls in these two rat lines. We suggest that the observed increases in mineralization of the thyroid cartilage in the high-ultrasound lineage provide increased reinforcement of the laryngeal structure during ultrasonic call production. Our findings therefore demonstrate an effect of selection for vocal behavior on laryngeal morphology, with acoustic consequences.
View details for DOI 10.1111/joa.13366
View details for PubMedID 33480050
Is consonance attractive to budgerigars? No evidence from a place preference study.
Consonant tone combinations occur naturally in the overtone series of harmonic sounds. These include sounds that many non-human animals produce to communicate. As such, non-human animals may be attracted to consonant intervals, interpreting them, e.g., as a feature of important social stimuli. There is preliminary evidence of attraction to consonance in various bird species in the wild, but few experimental studies with birds. We tested budgerigars (Melopsittacus undulatus) for attraction to consonant over dissonant intervals in two experiments. In Experiment 1, we tested humans and budgerigars using a place preference paradigm in which individuals could explore an environment with multiple sound sources. Both species were tested with consonant and dissonant versions of a previously studied piano melody, and we recorded time spent with each stimulus as a measure of attraction. Human females spent more time with consonant than dissonant stimuli in this experiment, but human males spent equal time with both consonant and dissonant stimuli. Neither male nor female budgerigars spent more time with either stimulus type. In Experiment 2, we tested budgerigars with more ecologically relevant stimuli comprised of sampled budgerigar vocalizations arranged into consonant or dissonant chords. These stimuli, however, also failed to produce any evidence of preference in budgerigar responses. We discuss these results in the context of ongoing research on the study of consonance as a potential general feature of auditory perception in animals with harmonic vocalizations, with respect to similarities and differences between human and budgerigar vocal behaviour, and future methodological directions.
View details for DOI 10.1007/s10071-020-01404-0
View details for PubMedID 32572655
- Claims of categorical primacy for musical affect are confounded by using language as a measure. Proceedings of the National Academy of Sciences of the United States of America 2020
Rapid evolution of the primate larynx?
2020; 18 (8): e3000764
Tissue vibrations in the larynx produce most sounds that comprise vocal communication in mammals. Larynx morphology is thus predicted to be a key target for selection, particularly in species with highly developed vocal communication systems. Here, we present a novel database of digitally modeled scanned larynges from 55 different mammalian species, representing a wide range of body sizes in the primate and carnivoran orders. Using phylogenetic comparative methods, we demonstrate that the primate larynx has evolved more rapidly than the carnivoran larynx, resulting in a pattern of larger size and increased deviation from expected allometry with body size. These results imply fundamental differences between primates and carnivorans in the balance of selective forces that constrain larynx size and highlight an evolutionary flexibility in primates that may help explain why we have developed complex and diverse uses of the vocal organ for communication.
View details for DOI 10.1371/journal.pbio.3000764
View details for PubMedID 32780733
- Pupillometry of Groove: Evidence for Noradrenergic Arousal in the Link Between Music and Movement FRONTIERS IN NEUROSCIENCE 2019; 12
Temporal modulation in speech, music, and animal vocal communication: evidence of conserved function.
Annals of the New York Academy of Sciences
Speech is a distinctive feature of our species. It is the default channel for language and constitutes our primary mode of social communication. Determining the evolutionary origins of speech is a challenging prospect, in large part because it appears to be unique in the animal kingdom. However, direct comparisons between speech and other forms of acoustic communication, both in humans (music) and animals (vocalization), suggest that important components of speech are shared across domains and species. In this review, we focus on a single aspect of speech-temporal patterning-examining similarities and differences across speech, music, and animal vocalization. Additional structure is provided by focusing on three specific functions of temporal patterning across domains: (1) emotional expression, (2) social interaction, and (3) unit identification. We hypothesize an evolutionary trajectory wherein the ability to identify units within a continuous stream of vocal sounds derives from social vocal interaction, which, in turn, derives from vocal emotional communication. This hypothesis implies that unit identification has parallels in music and precursors in animal vocal communication. Accordingly, we demonstrate the potential of comparisons between fundamental domains of biological acoustic communication to provide insight into the evolution of language.
View details for DOI 10.1111/nyas.14228
View details for PubMedID 31482571
Comparing Chalk With Cheese-The EGG Contact Quotient Is Only a Limited Surrogate of the Closed Quotient
JOURNAL OF VOICE
2017; 31 (4): 401–9
The electroglottographic (EGG) contact quotient (CQegg), an estimate of the relative duration of vocal fold contact per vibratory cycle, is the most commonly used quantitative analysis parameter in EGG. The purpose of this study is to quantify the CQegg's relation to the closed quotient, a measure more directly related to glottal width changes during vocal fold vibration and the respective sound generation events. Thirteen singers (six females) phonated in four extreme phonation types while independently varying the degree of breathiness and vocal register. EGG recordings were complemented by simultaneous videokymographic (VKG) endoscopy, which allows for calculation of the VKG closed quotient (CQvkg). The CQegg was computed with five different algorithms, all used in previous research. All CQegg algorithms produced CQegg values that clearly differed from the respective CQvkg, with standard deviations around 20% of cycle duration. The difference between CQvkg and CQegg was generally greater for phonations with lower CQvkg. The largest differences were found for low-quality EGG signals with a signal-to-noise ratio below 10 dB, typically stemming from phonations with incomplete glottal closure. Disregarding those low-quality signals, we found the best match between CQegg and CQvkg for a CQegg algorithm operating on the first derivative of the EGG signal. These results show that the terms "closed quotient" and "contact quotient" should not be used interchangeably. They relate to different physiological phenomena. Phonations with incomplete glottal closure having an EGG signal-to-noise ratio below 10 dB are not suited for CQegg analysis.
View details for DOI 10.1016/j.jvoice.2016.11.007
View details for Web of Science ID 000406147000002
View details for PubMedID 28017461