Geometry-based navigation in the dark: Layout symmetry facilitates spatial learning in the house cricket,Acheta domesticus, in the absence of visual cues

Abstract

There is heavy debate about the mechanisms of spatial navigation by insects. Researchers tend to focus mainly on vision-based models, neglecting non-visual modalities. The capacity to navigate by layout symmetry has been reported in vertebrates. Nevertheless, there has been no direct evidence for such an ability in insects, especially regarding center finding. To provide novel insight into the ongoing debate, we developed a non-visual paradigm for testing navigation by layout geometry. We tested the house crickets to find a cool spot positioned centrally in heated arenas of different shapes. We found that the symmetry of the arena significantly facilitates how crickets learn to find the center of the arena, both in terms of time spent on the cool spot and the latency of locating it. Because there were no visual cues, this observation challenges visiocentric models. As alternatives, we discuss the possibility of nonvisual space representation, or non-spatial search strategy.