Emergent Braitenberg-style Behaviors Enable Efficient Navigation in the ViZDoom 'My Way Home' Labyrinth

Core Concepts

Simple Braitenberg-style heuristics can emerge to efficiently navigate a complex partially observable visual labyrinth task, without the need for complex deep learning architectures or explicit memory mechanisms.

Abstract

The paper investigates the ability to evolve navigation strategies for the ViZDoom 'My Way Home' (MWH) labyrinth task, which requires an agent to navigate through a complex partially observable visual environment to reach a goal. The authors use the Tangled Program Graphs (TPG) genetic programming approach, which is constrained to a simple instruction set of arithmetic operations, to discover emergent Braitenberg-style behaviors for the task.
The key findings are:

TPG agents are able to successfully navigate the MWH labyrinth, while a baseline Deep Q-Network (DQN) agent fails to do so. This suggests that the TPG approach is able to discover simple yet effective navigation heuristics.

Analysis of the TPG champion agents reveals that they have developed Braitenberg-style behaviors, such as:

Seeking out a room's wall after spawning in the center of a room
Alternating the direction of a slow arcing trajectory after pursuing a wall-following behavior
Reorienting after encountering a room's corner

The TPG solutions are remarkably simple, indexing less than 1% of the original high-dimensional visual state space per decision. This is in contrast to previous work that required complex deep learning architectures and memory mechanisms to solve similar tasks.

Further experiments in an empty room scenario without a goal demonstrate that the TPG agent's navigation heuristic is a general reactive behavior, not dependent on the presence of the goal.

The authors conclude that the constraints imposed on the TPG approach, such as the limited instruction set, introduce a bias towards discovering simple Braitenberg-style heuristics for navigation, rather than more complex deep learning solutions. This highlights the potential of such approaches to uncover emergent behaviors that are efficient, interpretable, and suitable for deployment on resource-constrained platforms.

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Key Insights Distilled From

Emergent Braitenberg-style Behaviours for Navigating the ViZDoom `My Way Home' Labyrinth

by Caleidgh Bay... at arxiv.org 04-11-2024

https://arxiv.org/pdf/2404.06529.pdf

Deeper Inquiries

How would the emergent Braitenberg-style behaviors change if the room/corridor sizes or entry/exit points were asymmetric or different from the original MWH labyrinth

In the context of the emergent Braitenberg-style behaviors, asymmetry in room/corridor sizes or entry/exit points would likely lead to adaptations in the navigation strategies developed by the agents. If the room/corridor sizes were asymmetric, the agents might prioritize certain paths over others based on the size and layout of the spaces. This could result in the emergence of more complex behaviors, where the agents learn to adjust their trajectories based on the spatial constraints present in each room or corridor.
Similarly, if the entry/exit points were different from the original MWH labyrinth, the agents would need to adapt their navigation strategies to account for these variations. They might develop specific heuristics for different entry/exit configurations, leading to a more diverse set of behaviors depending on the specific layout of the environment. Overall, asymmetry or changes in entry/exit points would likely influence the emergent behaviors by requiring the agents to develop more flexible and adaptive navigation strategies to successfully navigate the environment.

Can the insights from this work be applied to other partially observable visual reinforcement learning tasks beyond navigation, such as manipulation or exploration

The insights gained from this work on emergent Braitenberg-style behaviors in partially observable visual reinforcement learning tasks can indeed be applied to other domains beyond navigation, such as manipulation or exploration tasks. The key takeaway from this study is the ability of agents to develop simple yet effective heuristics to navigate complex environments with high-dimensional state spaces.
In the context of manipulation tasks, agents could potentially learn to interact with objects in the environment using similar reactive behaviors. For example, they might develop strategies to grasp objects, move them to specific locations, or manipulate them in a controlled manner based on visual cues and partial observations.
Similarly, in exploration tasks, agents could leverage the principles of emergent behaviors to efficiently explore unknown environments and discover new information. By developing simple yet effective exploration strategies, agents could navigate complex spaces, uncover hidden areas, and gather valuable data to achieve their objectives.
Overall, the insights from this study can be generalized to various partially observable visual reinforcement learning tasks, providing a foundation for developing adaptive and efficient agents in diverse domains beyond navigation.

What other types of biases or constraints could be introduced in the TPG framework to encourage the discovery of specific classes of emergent behaviors, beyond just Braitenberg-style heuristics

To encourage the discovery of specific classes of emergent behaviors beyond Braitenberg-style heuristics in the TPG framework, additional biases or constraints could be introduced. These constraints could shape the evolutionary process towards the emergence of desired behaviors, tailored to the requirements of the task at hand.
One approach could be to incorporate task-specific constraints or objectives into the fitness function, guiding the evolution towards behaviors that align with the desired outcomes. For example, constraints related to efficiency, safety, or resource optimization could be introduced to encourage the emergence of behaviors that prioritize these factors.
Furthermore, introducing environmental constraints or limitations, such as restricted movement patterns, limited sensory inputs, or varying levels of uncertainty, could influence the types of behaviors that emerge. By constraining the agents in specific ways, the evolutionary process could be steered towards the discovery of novel and contextually relevant behaviors that go beyond simple reactive strategies.
Additionally, incorporating hierarchical structures or modular architectures within the TPG framework could encourage the emergence of more complex behaviors by allowing for the composition of simpler behaviors into higher-level strategies. By promoting the development of hierarchical behaviors, agents could exhibit more sophisticated decision-making processes and adaptive responses to dynamic environments.
Overall, by introducing tailored biases and constraints into the TPG framework, researchers can explore a wide range of emergent behaviors and advance the capabilities of agents in solving complex tasks across various domains.