Motion patterns of cognitive odour source search behaviours

Odour Source Localisation (OSL) is the process of finding the origin of releasing events by tracking chemical cues dispersed throughout the environment. Cognitive search strategies performed by mobile agents are reliable in turbulent environments where measurements are sparse and intermittent. These methods estimate a belief over the source location using Bayesian inference and guide movement by evaluating expected entropy reduction at admissible locations, enabling informed decisions instead of reacting to direct sensor readings. However, the computational cost of estimating information gains is often prohibitive for real-time use with resource-constrained agents. Interestingly, search trajectories generated by cognitive methods often resemble those of small insects. Given that these organisms achieve effective search despite limited processing capabilities, analysing cognitive decisions could enable the synthesis of efficient bio-inspired behaviours. This work investigates this possibility by analysing trajectories from cognitive OSL algorithms such as Infotaxis, aiming to identify informative movement patterns and search behaviours. Results from 600 simulation experiments across three environmental scenarios (stable flow, moderate turbulence and high turbulence) show that motion pattern direction and length can be systematically related to the agent’s belief state and plume geometry. Markov chain analysis reveals context-dependent behavioural adaptation and the spontaneous emergence of behaviours similar to bio-inspired motions. These findings support the feasibility of synthesizing reliable and computationally efficient hybrid search strategies. • Informative motion patterns and search behaviours emerge from cognitive decisions • Cognitive OSL decisions can be decomposed into parametric belief-state functions • Movement angle correlates with belief uncertainty, step length with plume width • Markov chains model adaptive behavioural transitions • Bio-inspired behaviours arise naturally from information-theoretic decisions