Teletext. Notepad. Twitter. A tractor. A pregnancy test. There have been few limits to the weird and wonderful ways that enterprising Doom fans have found to play the seminal FPS over the last 30 years, but this latest one might take the crown for both weirdest and wonderful-est. Someone is teaching a bunch of lab-grown rat neurons to play Doom. Yes, their literal conscious existence is Doom. I told you it was weird.
YouTuber The Thought Emporium’s recent video details – with the emphasis on detail – their process of growing a network of rat neurons, with the ambition of ultimately hooking the brain-like creation to a computer running Doom and teaching it to master the shooter.(Thanks , PC Gamers.)
While the YouTuber has previously performed experiments with neurons derived from human stem cells, apparently cortical rat neurons are cheaper, easier to source (you can apparently just buy millions of neurons online, which is a thing I learned today) and are smart enough to learn Doom.
The neurons are placed into a set of small jar-like containers, where they are fed with a very specific solution to allow them to grow and crawl (!!!), gradually forming connected networks that can then be hooked up to a PC via an electrode array. (As a slightly disconcerting sidenote, there is regular reference to a fridge-like machine called a Meatcubator used to help prepare the neurons.)
The plan is to train the network of neurons to successfully blast cacodemons by using electrical noise that the neurons “like” and “dislike”, rewarding them for killing enemies while punishing them for dying – effectively Pavlovian conditioning for neurons. The video admits that there’s no consensus on whether the nice noise feels closer to a treat or an orgasm, which is quite the thing to imagine while teaching a brain in a jar to play Doom.
While it might seem far-fetched for a bunch of neurons in a dish to master a fast-paced first-person shooter, The Thought Emporium explains that Doom’s lack of up and down aiming means it can actually be vastly simplified – enough that it becomes a very basic set of instructions to turn left and right, move forward and shoot as delivered through “yes” and “no” commands to the neurons.
“The reason we chose Doom is because it’s a sufficiently complex task to be impressive but it can be deconstructed into a simple signal problem if you set it up properly,” they explain. “Doom only looks 3D. in reality[,] the character is basically just an arrow, enemies are circles, hazards are just shapes, all on a 2D surface. The game just renders it to look 3D.”
The first video in the planned series outlines how the neurons are being grown, but they’re yet to actually log on and start learning Doom. The next steps require finding a way to receive signals out of the neuron array, because the neurons can start to control Doom and be taught to improve. The team also hopes to find a way to grow neurons from human skin samples in order to make a steady, affordable supply of neurons. (They add that blending a rat would also work, but they’re not about to do that.)
Whatever the ultimate outcome of this experiment, it’s hard to deny it’s a fascinating and slightly terrifying raising of the bar for ways to play Doom.