Information Processing in Complex Environments: Insights from Treefrog Communication

Abstract

Many animals use sounds to perform critical biological functions, such as choosing a mate or evading a predator, in environments where multiple sound sources are simultaneously active. Discerning a sound of interest in such complex acoustic environments, however, is not a trivial task. It requires animals to perceptually organize mixtures of auditory input into meaningful information about their external environment. In this dissertation research, my broad aim was to understand how animals parse their complex acoustic environments to perform acoustically guided behaviors. Using Cope’s gray treefrogs (Hyla chrysoscelis) as a model system, I investigated how animals accomplish the different perceptual tasks that are required for recognizing and responding to a signal of interest in noisy social environments. I discovered some of the processes that act together to extract information and facilitate signal recognition. Specifically, I found a perceptual mechanism that allows animals to perceive the different vocal signals in their environment as distinct sounds. I also found specific neural adaptations that allow them to extract and recognize biologically meaningful information from their vocal signals. Additionally, my research reveals that despite the evolution of these perceptual and sensorineural mechanisms, background sounds present in the social environment can interfere with the information processing capacity of animals, and thus, can critically constrain their ability to perform important biological functions. This research opens up an exciting and unknown question of how animals are evolutionarily adapted to overcome the limitations in information processing to perform acoustically guided behaviors.