A motion compensation treadmill for untethered wood ants (Formica rufa): evidence for transfer of orientation memories from free-walking training

Abstract

The natural scale of insect navigation during foraging makes it challenging to study under controlled conditions. Virtual reality and trackball setups have offered experimental control over visual environments while studying tethered insects, but potential limitations and confounds introduced by tethering motivates the development of alternative untethered solutions. In this paper, we validate the use of a motion compensator (or ‘treadmill’) to study visually driven behaviour of freely moving wood ants (Formica rufa). We show how this setup allows naturalistic walking behaviour and preserves foraging motivation over long time frames. Furthermore, we show that ants are able to transfer associative and navigational memories from classical maze and arena contexts to our treadmill. Thus, we demonstrate the possibility to study navigational behaviour over ecologically relevant durations (and virtual distances) in precisely controlled environments, bridging the gap between natural and highly controlled laboratory experiments.

Trajectory Recording and Analysis System for Cockroach Robot

“…On this basis, scientists proposed air-cushion trackballs to record insect trajectories [18] , which effectively avoided the problem of mechanical resistance. Later, a virtual reality trackball system was proposed [29,30] , which virtualized a natural environment to enable insects to go about their movements in a familiar environment and record their trajectories through trackballs. While recording insect trajectories with trackballs may have problems such as inertia, this paper constructs a system software module that can more intuitively see the trajectories of cockroaches' movements through the projector's interface projection on the infrared touchpad, and record and store the trajectories of cockroaches in real-time, which simplifies the recording method of trackballs, so there are no problems such as inertia and friction, and there is no need to tether the cockroaches, and the system is relatively accurate and can immediately .…”

“…On this basis, scientists proposed air-cushion trackballs to record insect trajectories [18] , which effectively avoided the problem of mechanical resistance. Later, a virtual reality trackball system was proposed [29,30] ,…”

“…On account of the tethering problem, a tetherless trackball recording method has recently been proposed to record the trajectories of ants. This system uses a motion-compensated treadmill combined with a high-speed camera to track ants [29] . However, if the mass of the trackball tied to the animal is more than 1.5 times that of the animal in the process of rotating motion, there will be problems in controlling the inertia of the trackball [30,31] .…”

Motion cues from the background influence associative color learning of honey bees in a virtual-reality scenario

“…In these setups, the walking movements of the insect under study are constantly monitored and translated into displacements of surrounding visual cues (closed-loop conditions). The insect can be either free 10 , 11 or immobilized 12 – 16 by a tether glued onto its body surface (typically on the thorax). In both cases, the insect walks stationary on a treadmill whose movements are recorded by captors placed lateral or ventral to the treadmill.…”