1
|
Varkevisser JM, Simon R, Mendoza E, How M, van Hijlkema I, Jin R, Liang Q, Scharff C, Halfwerk WH, Riebel K. Adding colour-realistic video images to audio playbacks increases stimulus engagement but does not enhance vocal learning in zebra finches. Anim Cogn 2021; 25:249-274. [PMID: 34405288 PMCID: PMC8940817 DOI: 10.1007/s10071-021-01547-8] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Revised: 07/28/2021] [Accepted: 08/05/2021] [Indexed: 11/30/2022]
Abstract
Bird song and human speech are learned early in life and for both cases engagement with live social tutors generally leads to better learning outcomes than passive audio-only exposure. Real-world tutor–tutee relations are normally not uni- but multimodal and observations suggest that visual cues related to sound production might enhance vocal learning. We tested this hypothesis by pairing appropriate, colour-realistic, high frame-rate videos of a singing adult male zebra finch tutor with song playbacks and presenting these stimuli to juvenile zebra finches (Taeniopygia guttata). Juveniles exposed to song playbacks combined with video presentation of a singing bird approached the stimulus more often and spent more time close to it than juveniles exposed to audio playback only or audio playback combined with pixelated and time-reversed videos. However, higher engagement with the realistic audio–visual stimuli was not predictive of better song learning. Thus, although multimodality increased stimulus engagement and biologically relevant video content was more salient than colour and movement equivalent videos, the higher engagement with the realistic audio–visual stimuli did not lead to enhanced vocal learning. Whether the lack of three-dimensionality of a video tutor and/or the lack of meaningful social interaction make them less suitable for facilitating song learning than audio–visual exposure to a live tutor remains to be tested.
Collapse
Affiliation(s)
| | - Ralph Simon
- Institute of Biology Leiden, Leiden University, Leiden, The Netherlands.,Department of Ecological Science, VU University Amsterdam, Amsterdam, The Netherlands.,Nuremberg Zoo, Nuremberg, Germany
| | - Ezequiel Mendoza
- Institut für Biologie, Freie Universität Berlin, Berlin, Germany
| | - Martin How
- School of Biological Sciences, University of Bristol, Bristol, UK
| | - Idse van Hijlkema
- Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Rozanda Jin
- Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| | - Qiaoyi Liang
- Evolution of Sensory Systems, Max Planck Institute for Ornithology, Seewiesen, Germany
| | | | - Wouter H Halfwerk
- Department of Ecological Science, VU University Amsterdam, Amsterdam, The Netherlands
| | - Katharina Riebel
- Institute of Biology Leiden, Leiden University, Leiden, The Netherlands
| |
Collapse
|
2
|
Abstract
Animal vocalizations serve a wide range of functions including territorial defense, courtship, social cohesion, begging, and vocal learning. Whereas many insights have been gained from observational studies and experiments using auditory stimulation, there is currently no technology available for the selective control of vocal communication in small animal groups. We developed a system for real-time control of vocal interactions among separately housed animals. The system is implemented on a field-programmable gate array (FPGA) and it allows imposing arbitrary communication networks among up to four animals. To minimize undesired transitive sound leakage, we adopted echo attenuation and sound squelching algorithms. In groups of three zebra finches, we restrict vocal communication in circular and in hierarchical networks and thereby mimic complex eavesdropping and middleman situations.
Collapse
|