Edge-enhanced disruptive camouflage is contrast dependent in VR environments

In camouflage research, field studies provide ecological validity but lack experimental control, and computer-based experimental studies have the opposite issue. Virtual reality (VR) systems could potentially allow researchers to have both experimental control and ecological validity. Here we develop a VR environment using Unreal Engine and present it via a head-mounted display (HMD). The HMD affords binocular depth and therefore a more ecologically valid, three-dimensional environment, whilst still maintaining experimental control. Disruptive camouflage interferes with depth-based cues, making it a good candidate for testing within a VR environment. Disruptively camouflaged moth-like targets were presented to human surrogate predators, and their survivability was measured. We show that VR can be used to measure camouflage effectiveness by replicating existing findings showing that edge-enhanced disruptive camouflage (EE-DC) is more effective than disruptive camouflage (DC) alone. Furthermore, we extend these findings to show that the effectiveness of EE-DC is modulated by the relative contrast of the disruptive patches. Specifically, it is more effective when the contrast difference between the patches is low. Additionally, we considered edge-enhancement in isolation and found that it still provided a camouflage benefit even without a DC component. Search paradigms within an immersive VR experimental framework offer a unique opportunity to evaluate camouflage theory in a rigorous, yet ecologically grounded manner.