The digital dualism of the rodent mind


“It’s a really welcome addition to the growing field of rodent virtual reality.” So says Northwestern University neurobiologist Daniel Dombeck in commenting on a new study, published yesterday by Science, that compares what goes on in rats’ brains when they navigate digitally created spaces with what goes on in their noggins when they navigate the real world. Rats, like humans, have place cells, which are neurons that fire reliably at particular locations and, it’s believed, play a key role in the brain’s creation of cognitive maps. The study reveals that place cells are considerably less active in virtual reality (VR) than in the real world (RW):

When Mayank Mehta, a neurophysicist at the University of California (UC), Los Angeles, compared the activity of place cells in rats running along a real, linear track with place cell activity in the rats running in virtual reality, he saw some surprising differences. In the real world, about 45% of the rats’ place cells fired at some point along the track. In virtual reality, only 22% did. “Half of the neurons just shut up,” he says.

Individual place cells also behaved radically differently in VR than they do in RW:

On a real track, [a particular place cell] would fire when [the rat] had taken two steps away from the start [of the track], and then again when the animal reached the same spot on its return trip. But in virtual reality, something odd happened. Rather than firing a second time when the rat reached the same place on its return trip, [the cell] fired when the rat was two steps away from the opposite end of the track … That’s like the same place cell in your brain firing when you’ve taken two steps away from your door and then when you’ve taken two steps away from your car. Instead of encoding a position in absolute space, the place cell seems to be keeping track of the rat’s relative distance along the (virtual) track. [Mehta] says, “This never happens in the real world.”

Mehta thinks that the difference may stem from the lack of “proximal cues” — environmental smells, sounds, and textures that provide clues to location — in the digital world:

And considering that when those cues disappear, the rat’s cognitive map appears to change from one based on absolute space to one based on relative distance, proximal cues might be the key component to how those mental maps work in the real world.

Rats’ sensory perception of the world differs from that of people — rats don’t see very well, for instance — and that (among other things) makes it hard to know whether human brains react to VR and RW in the same way. But the study at least hints at the richness of our perception of the world — a richness that is very much embodied in our physical being even though it may be hidden from our conscious mind. To me, this raises an important but rarely heard question about so-called augmented reality (AR), particularly the use of computers to add an extra layer of visual information to our conscious perception of the world: Is augmented reality also diminished reality? In other words, by adding input to one (conscious) layer of perception, do you end up degrading other (conscious and/or unconscious) layers of perception?

Is RW + AR > RW or is RW + AR < RW?

And does it matter?

Photo by UCLA Neurology.

6 thoughts on “The digital dualism of the rodent mind

  1. Daniel Cole

    The proponents of the “augmented reality” idea either miss or ignore a lot by emphasizing that we’ve always “augmented” ourselves. It reminds me of Chomsky’s comment that technology is neutral; you can use a hammer to build something or to bash someone’s head in. Disregarding that I think this is precisely the wrong way to think about technology, it illustrates why it’s presumptuous to make such judgements about “technology” in the aggregate. There’s an obvious difference in the cognitive perspectives that a hammer promotes and those promoted by a telephone, automobile or computer. Likewise, our history of “augmenting” even with something as clever as eye glasses in no way dismisses things like virtual reality or the internet as just another tool.

    At any rate, it’s no surprise that a visually specialized virtual reality still comes up short compared to the RW. I expect the worst to come when they find ways to fool the rat completely, by incorporating the rest of the senses. Once the kinks in that are worked out, perhaps people will never have to leave the comfort of their own minds again. Or at least plenty won’t want to.

  2. Elly/Quiet Riot Girl

    DC: ‘perhaps people will never have to leave the comfort of their own minds again. Or at least plenty won’t want to.’

    Whilst I am quite a ‘cerebral’ person, I find my own mind the scariest ‘place’ I have ever been. See Robert Frost: ‘I have it in me so much nearer home
    To scare myself with my own desert places.’

    But I have found solace/escape from my mind’s tricks both ‘IRL’ and online. The internet is after all, a very social, very externally stimulating set of mechanisms and data etc.

    Having said that, I also do tai chi and don’t think I’ll ever find a ‘virtual’ equivalent of that.

  3. Tim

    It matters.
    We can discuss the possibilities that lay ahead, however, currently I believe our culture, and certainly our educational system, is attempting to portray VR = RW or that VR>RW. However it really is very clear that synthetic experience isn’t the same as real experience and when we build something in the real world the experience of building in the real world teaches us how different VR is from RW. At best VR is the visualization of the concept of RW.
    A hundred years ago Dewey was fighting for real experience as the primary means by which children should be educated, now, for some reason VR is seen as a far more convenient tool for the delivery of educational substance. I think this study is most illuminating as it suggests that when we use virtual devices in education we may be training our students to discount the whole scope of their critical senses and only use a diminished number of clues to reach conclusions that might not be reached in the real world.

  4. yt75

    Let’s not forget that one thing “virtual reality” cannot provide is the feeling of acceleration, that is the result of energy.
    However “realistic” a flight simulator is, it won’t provides you with g feeling.
    The rape of the virtual adjective is the most pathetic thing in the XX/XXI century turn.
    Michey mouse in 3D through gglass is still mickey mouse.
    The period is in full regression mode.

  5. Linda Holliday

    I will forever have to preface my comments with the caveat that I am a classicist and a hedonist. I prefer paper to digital and believe the tactile features of paper currently create superior memorability and cognition.
    However–are we comparing the best of the old with the weakest of the new? If something mighty powerful–even addictive weren’t firing in kids brain (in the digital mazes referred to as Video Games) I doubt they would clock the 10,000 hours they do. I don’t know how convincing the VR used in the study was, but it’s not irrelevant. I would think the characterization of that “reality” would be essential to the findings. Digital environments are not all equally created.

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