Humans account for cognitive costs when finding shortcuts: An information-theoretic analysis of navigation

Abstract

When faced with navigating back somewhere we have been before we might either retrace our steps or seek a shorter path. Both choices have costs. In this study, we ask whether it is possible to characterize formally the choice of navigational plans in terms of a bounded rational process that trades off the quality of the plan (e.g., its length) and the cognitive cost required to find and implement it. We analyze the navigation strategies of two groups of people that are firstly trained to follow a "default policy" taking a route in a virtual maze and then asked to navigate to various known goal destinations, either in the way they want ("Go To Goal") or by taking novel shortcuts ("Take Shortcut"). We address these wayfinding problems using InfoRL: an information-theoretic approach that formalizes the cognitive cost of devising a navigational plan, as the informational cost to deviate from a well-learned route (the "default policy"). In InfoRL, optimality does not refer to finding the shortest route, but to the best trade-off between route length and the amount of control information required to find it. We report four main findings. First, the navigational strategies automatically identified by InfoRL correspond closely to different routes (optimal or suboptimal) in the virtual reality map, which were annotated by hand in previous research. Second, people deliberate more in places where the value of investing cognitive resources (i.e., relevant goal information) is greater. Third, the group of people who receive the "Take Shortcut" find shorter solutions compared to those who receive the "Go To Goal" instruction. However, while the former appear to be naively more efficient if one only considers plan length, our bounded rational approach reveals that they invest more cognitive resources and find overall less optimal solutions, reflecting the intrinsic difficulty of finding optimal shortcuts. While prior analysis indicates greater male optimality in short-cut finding, we find that both male and female participants similarly modulate their cognitive resources in a task-dependent way, as formally expressed through our information-theoretic approach. Finally, we found a surprising amount of variability in the choice of navigational strategies and resource investment across trials. Participants do not simply adopt one strategy and maintain it. Taken together, these results illustrate the benefits of using InfoRL to address navigational planning problems from a bounded rational perspective.

The relationship between object-based spatial ability and virtual navigation performance

“…It would also be interesting to consider twin study cohorts where the genetic contribution to performance can be explored, and also expand to incorporate a measure of general cognitive ability (Malanchini et al, 2021). Finally, going beyond scores of task performance to modelling the behaviour using reinforcement learning methods (de Cothi et al, 2022;Lancia et al, 2023) holds much promise for helping obtain a more mechanistic understanding of the processes involved in navigation and visuo-spatial cognition.…”

Strategic Task Decomposition in Joint Action

“…A carryover of old strategies to novel situations could be common to both individual and joint action setups. However, while in individual settings, the carryover could be linked to the cost of devising a novel strategy (Lancia et al, 2022;Todorov, 2009), in joint action settings, it could be additionally due to (or amplified by) the communication costs inherent to strategy change. Distinguishing between these possibilities is an intriguing question for future experimental study.…”

Beyond simple laboratory studies: developing sophisticated models to study rich behavior

“…Another study showed that people are able to flexibly decide between habitual routes and shortcuts when provided with different instructions [138]. The same data were reanalyzed using an information-theoretic computational model (Information reinforcement learning, InfoRL) to quantify the amount of cognitive resources required to form the different plans and how optimally these resources were invested [139]. This re-analysis indicates that not only do people selecting shortcuts invest greater cognitive effort, but they also make less efficient use of cognitive resources, despite following routes that may seem advantageous.…”

“…A large scale study of spatial navigation in a videogame demonstrated how navigation skills are modulated by the interplay of cultural factors and individual factors (like gender and age), with patterns of navigation abilities across the globe which have been shaped by economic wealth and gender inequalities [140]. Other ongoing work is attempting to gather more insights from these datasets using sophisticated models such as the InfoRL adopted in [139].…”