Foraging in the Virtual Himalayas: Intrinsic and Extrinsic Factors in Search

AbstractForaging over land for resources was central to the evolution of search processes and decision-making for many organisms, including humans. The processes underlying natural foraging behaviors are foundational to cognition, but in the field, it is difficult to collect detailed and accurate measures of search behaviors, and hard to manipulate search conditions. We used Google Earth and the Unity 3D platform to recreate a patch of the Himalayan foothills with ancient temples used as waypoints for travelers on foot. Two hundred players recruited via MTurk moved over the landscape with realistic speed, energy usage, and perceptual conditions to find as many temples as possible given a limited energy budget. Half were constrained by the need to return to a home base to report found temples, and half were not. When search paths were analyzed in terms of segment distributions, players who found relatively more temples (high scorers) more closely followed the theoretically optimal Lévy walk that balances exploration and exploitation, regardless of the home base. This intrinsic pattern was also found in perceptual search intervals, with high scorers leaning more towards exploration. By contrast, when search paths were analyzed as wholes, an extrinsic pattern was found in that players ranged farther without a home base, and this difference was more pronounced for high scorers. We conclude that Lévy-like patterns are intrinsic and effective in terms of path segments and perceptual intervals, but overall search behavior adapts to extrinsic factors and constraints.

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