Discrete turn strategies emerge in information-limited navigation

TL;DR

This paper investigates how organisms choose navigation strategies based on sensory information, revealing that discrete turn angles and sudden turns are optimal under information constraints, with strategy transitions as information increases.

Contribution

It introduces a framework for understanding strategy choice in sensory-limited navigation, highlighting the emergence of discrete turn strategies and their transitions.

Findings

Sudden turns outperform gradual steering without directional info.

Optimal strategies transition from reversing to re-orienting as information increases.

Discrete turn angles are optimal among complex re-orientation strategies.

Abstract

Navigation up a sensory gradient is one of the simplest behaviours, and the simplest strategy is run and tumble. But some organisms use other strategies, such as reversing direction or turning by some angle. Here we ask what drives the choice of strategy, which we frame as maximising up-gradient speed using a given amount of sensory information per unit time. We find that, without directional information on which way to turn, behavioural strategies which make sudden turns perform better than gradual steering. We see various transitions where a different strategy becomes optimal, such as a switch from reversing direction to fully re-orienting tumbles as more information becomes available. And, among more complex re-orientation strategies, we show that discrete turn angles are best, and see transitions in how many such angles the optimal strategy employs.