Unraveling the cognitive map: feature-positive discrimination in spatial search

Abstract

The ability to use cues to navigate through the environment is a trait shared by all mobile organisms. This dissertation focused on spatial search behavior in two mammalian species (rats and humans) and an avian species (pigeons) to explore similarities and differences in learning and memory. A major aim of the project was to explore the role of conditioning (feature-positive discrimination) in building allocentric representations of space. The experiments were implemented on either a two-dimensional touchscreen monitor (humans and pigeons), three-dimensional open field task (humans and rats), or a VR equipped (Oculus Rift) video game (humans). We hypothesized that a conditional background could un-gate spatial information about a landmark, allowing the organism to integrate the cues, and search accurately. The results indicated that trained conditional cues could readily transfer their spatial information to novel pairings with familiar landmarks at test. This ease of transfer indicates that feature-positive discriminations do play an important role in modifying our search decisions in the presence of landmarks. Making species comparisons during search tasks will further elucidate the true psychological mechanism backing our extraordinary ability to navigate through space. The search tasks developed in this dissertation hold potential to guide future diagnostic measurements that can detect decrements in spatial cognition, and distinguish individual differences in strategy.