Collaborative Research: NSF-BSF: Neural and perceptual mechanisms that bias mate choice in complex signaling environments

University Of Minnesota-Twin Cities, Minneapolis MN

Investigators

Abstract

Humans and other animals often communicate in complex social environments in which multiple individuals produce series of repeated vocalizations, and listeners respond after assessing signal properties that emerge over long times scales. How listeners track individual signalers through time will determine outcomes of many consequential decisions, especially if too many competing signalers create confusion on the part of listeners. This project investigates the extent to which female frogs choose mates using neural mechanisms that are susceptible versus resistant to confusion to understand how neural mechanisms in listeners shape the evolution of vocal behavior. The research focuses on Cope’s gray treefrog, Hyla chrysoscelis, a species in which prior work shows that females prefer males that produce vocal mating calls at faster and more regular rates. The proposed aims will provide a mechanistic view of the sensory and perceptual biases frequently proposed to impact signaling and mate choice. The aims develop new technological approaches to characterize behavioral responses and record neural activity that will enable new insights into how neural circuits in a listener can track an individual signaler in noisy environments. This project will provide training and career opportunities for postdoctoral fellows who identify as members of historically excluded groups in STEM and for up to 12 undergraduate students each year. Finally, the project will extend a highly successful educational game that teaches undergraduates the fundamentals of neural decision making by having students build creatures with simple neural circuits. This proposal integrates behavioral and neural approaches to determine how receivers evaluate a series of signals in complex signaling environments. Aim 1 will determine how female preferences for male call rate and regularity depend on the number of competing signalers using classical behavioral phonotaxis measures of preference. Aim 2 will use new sensor technology that measures detailed movement dynamics to study the perceptual processes females employ when assessing call rate and regularity. Aim 3 will leverage newly developed flexible electrodes to evaluate how female preferences for series of calls are dynamically coded by neural circuits in a major sensory-motor midbrain region. If the proposed research finds that sexual selection is reduced in complex acoustic environments, the experiments will identify neural mechanisms that constrain the ability to follow signal series through time. Alternatively, if sexual selection operates effectively even with many signalers present, the experiments will identify behavioral and neural mechanisms that support the ability of females to exhibit mate preferences even in active leks. In addition to opening new paths of inquiry into how the capabilities or constraints of neural processing impact mate choice, this project seeks to resolve neuroscience studies demonstrating that repeated stimuli tend to elicit weaker sensory responses over time with behavioral ecological models for sensory and perceptual biases that posit that preferred mating signals are those that that elicit stronger sensory responses in receivers. Probing the intersection of these conflicting expectations will help achieve greater consilience between behavioral ecological and neurobiological approaches to understanding animal behavior. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.