They seem to all walk in a straight line. Are they not able to make turns? It’s hard to tell if they’re even perceiving the VR environment or just doing their own thing on the sphere.
I suspect that TFA's author is aware of this, but rats' vision is so poor that I'm not certain VR is the correct modality for them. IIRC they rely on smell, primarily, along with touch, to navigate their environment. I imagine that the rat just decided to accept the likely-ineffective vagaries of the experimental setup, because the smell of food was tantalizingly nearby.
VR has become a pretty popular tool in neuroscience.
Rodents can be trained to follow cues shown in VR, or even navigate to specific virtual locations by running on the sphere, so they can certainly perceive something.
That said, vision is certainly not their primary sense and the organization of their visual system is...dissimilar from humans and other primates.
Eh, it’s partly marketing, but there are some neat tricks that make it more immersive.
Some groups put the rodent at the center of a translucent hemisphere, then reverse-project the scene onto it. This can completely fill its field of view, and looks pretty good if you get the transform right. It’s also not too hard to make walking on the ball control the camera, so that objects approach faster when the animal runs, or the scene swivels as the animal turns. This article has a few videos of the setup: https://www.nature.com/articles/d41586-019-00791-w
I doubt the mouse is totally fooled (but neither are you with an Oculus). I think someone has done some cross-over experiments: mazes learned virtually transfer over to physical contraptions and vice versa. Unfortunately, I’m blanking on who might have done this.
Did not Feynman use rat experiments in his book to lay heavily into social studies? As i recall in the book, there was only one guy whose rat/mouse experiments had enough rigour, eliminating data disturbing experiment influences, systematically.
The moral of that story, IMO, is not "don't do experiments with rodents" or even "bio/psych is nonsense."
Instead, the point is that a good scientist has to aggressively consider possible explanations for your data and possible experimental confounds. This is much, much harder when studying subjects that have some agency of their own, like rats or humans.
It gets even worse outside of science. I'm sure most people who've been in the business world long have noticed that attempts to eliminate confounding factors when drawing conclusions are rarely even attempted unless the results contradict what the highest-on-the-org-chart interested party wants it to be (and even then, they're usually just ignored rather than any attack on their validity actually being made).
For all the attempts to measure stuff and be "scientific", businesses mostly run on gut feelings, even when they're doing "experiments" or "collecting data in order to make informed decisions" or whatever. Often it's really easy to spot problems with these processes, but no-one cares as long as the PowerPoint slides say what they want them to say and pretend to be backed by data.
A paper found that in order to prevent rats cheating the floor needed to have sand to prevent them picking up on vibrations. The result should've been that experiments began incorporating this measure in their own setups, but instead the paper went ignored
Amusingly this VR direction could also be a useful method to limit the rat's perceptions to the experiment. But first it'd need to have the rat trained to explore a 3d environment & be fed by collecting food in the 3d environment
From the article: "Although the mechanisms to train left-right turning was present, I did not have time to train movements with turns included, so in most sessions only one axis of motion was registered."