Chimpanzees can navigate virtual environments
In search of virtual fruit, chimpanzees used landscape features for better orientation
Using touchscreen technology, six zoo-housed primates learned to navigate towards a distant virtual tree with different types of fruit underneath it, even working out how to find the landmark from different starting locations. Led by Matthias Allritz and Josep Call from the University of St Andrews and Francine Dolins at the University of Michigan-Dearborn, this is the first empirical study of how chimpanzees navigate an open-field naturalistic, virtual environment. It shows that chimpanzee navigation in the virtual world shares several key features with real-life navigation.
“Tracking primate navigation in the wild has many challenges, including not knowing what landmark information they use as the basis for making spatial decisions,” says Francine Dolins, principal investigator and associate professor at the University of Michigan-Dearborn. “Virtual reality affords greater control over what landmarks are presented and where they are located in relation to the virtual foraging sites, like a fruiting tree.”
Three adult male and three adult female chimpanzees housed at the Wolfgang Köhler Primate Research Center (WKPRC) at Leipzig Zoo, Germany, participated in the study. All six chimpanzees had prior experience with using touchscreens, and five of them had limited experience with 3D video games at the time the study began. All testing was conducted in the apes’ familiar testing areas at WKPRC, where they are given access to touchscreen tasks regularly.
Learning to navigate virtual environments
A new custom VR application, the APExplorer 3D, was created for the study, presenting the primates with a virtual environment through which an invisible, first-person character could be steered to explore and interact with objects in a three-dimensional cartoon style. “Our main goal in designing the app was to create a rich and complex, colourful, engaging 3D environment for the chimpanzees that would be easy to navigate by simply touching the screen,” says lead software developer Kenneth Schweller at Ape Initiative, Des Moines, Iowa.
Using a touchscreen monitor, the chimpanzees guided the virtual agent through an open space containing grassy hills, trees, rocks and other obstacles. Over a month, the chimpanzees were presented with progressively more challenging navigation tasks, exhibiting several cognitive processes and behavioural signatures within the virtual environment that have been predicted to guide navigation in the wild, such as learning to recognise and search for distinct landmarks and to optimise route efficiency.
Chimpanzees completed spatial tasks at a remarkable speed
Matthias Allritz, a postdoctoral researcher at the University of St Andrews and the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, explains: “Almost all animals navigate their environment to find food, shelter, and mates. Because of the space restrictions in zoos, studying the spatial cognition of nonhuman primates experimentally is notoriously difficult. Using virtual environments allows researchers to create large-scale, controllable environments for primate participants to navigate, including completely novel environments.”
“Beyond the clear goal-orientation in the chimpanzees’ spatial learning, one thing that stood out to us was the remarkable speed at which the chimpanzees learned to control the virtual agent and to complete the spatial tasks. It required less training than I originally thought it would, and certainly less than many of the more traditional touchscreen tasks designed for animals,” adds Allritz.
Navigating virtual environments resembled real-life navigation
Josep Call, co-principal investigator and professor at the University of St Andrews, says: “Our study illustrates that non-invasive experiments in open space virtual environments have great potential to study primate spatial cognition. The chimpanzees in our study learned the basic game mechanics quickly and soon exhibited learning and decision-making patterns that resembled real-life navigation. They learned to recognize certain objects as landmarks and to orient and search for these when they could not see them. And they flexibly adapted when food availability became less predictable – though some of them were clearly faster than others.”
“Provided that future studies can replicate and extend these findings to other primate species, naturalistic virtual environments may become a powerful tool to address longstanding questions in the evolution and development of primate navigation that had previously been difficult to study in captive environments and in the wild,” explains Call.
Understanding the evolution of human navigational abilities
“Chimpanzees are the closest living relatives of humans. So understanding how they make travel decisions and how they recognize, remember and reason about travel routes does not only help us to better understand them. It is also critical for understanding the evolution of navigational abilities in our own species,” adds Allritz
From a welfare perspective, the chimpanzees may also benefit from the cognitive enrichment that virtual environment games may provide, given their creative problem-solving and innovative abilities. “The virtual environment tasks do not just help researchers to study how chimpanzees think about space”, adds Francine Dolins. “Just as importantly, these virtual tasks are enriching and engaging for zoo-housed primates, as they offer them choice and control: free choice of what to look at, where to go, and which areas of the virtual environments to explore.”
To facilitate wider adoption of VR research, the team plans to make a version of the APExplorer 3D app available on the Open Science Framework, allowing other researchers to directly replicate these methods and adapt them for related research questions.
[Uni St. Andrews/SJ]