Semester

Summer

Date of Graduation

2023

Document Type

Dissertation

Degree Type

PhD

College

Eberly College of Arts and Sciences

Department

Biology

Committee Chair

Gary Marsat

Committee Member

Kevin Daly

Committee Member

Andrew Dacks

Committee Member

Sadie Bergeron

Committee Member

Charles Anderson

Abstract

Organisms rely on sensory systems to gather information about their environment. Localizing the source of a signal is key in guiding the behavior of the animal successfully. Localization mechanisms must cope with the challenges of representing the spatial information of weak, noisy signals. In this dissertation, I investigate the spatial dynamics of natural stimuli and explore how the electrosensory system of weakly electric fish encodes these realistic spatial signals. To do so In Chapter 2, I develop a model that examines the strength of the signal as it reaches the sensory array and simulates the responses of the receptors. The results demonstrate that beyond distances of 20 cm, the signal strength is only a fraction of the self-generated signal, often measuring less than a few percent. Chapter 2 also focuses on modeling a heterogeneous population of receptors to gain insights into the encoding of the spatial signal perceived by the fish. The findings reveal a significant decrease in signal detection beyond 40 cm, with a corresponding decrease in localization accuracy at 30 cm. Additionally, I investigate the impact of receptor density differences between the front and back on both signal detection and resolution accuracy. In Chapter 3, I analyze distinct movement patterns observed during agonistic encounters and their correlation with the estimated range of receptor sensitivity. Furthermore, I uncover that these agonistic interactions follow a classical pattern of cumulative assessment of competitors' abilities. The outcome of this research is a comprehensive understanding of the spatial dynamics of social interactions and how this information is captured by the sensory system. Moreover, the research contributed to the development of a range of tools and models that will play crucial roles in future investigations of sensory processing within this system.

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