Day 15 + 16: La Gaïté Haptique

I know, I missed a day. Deal with it.

First and foremost, just listen to this sound.



I know, right? Turn up the bass for added punch. So that sound, that thing you just listened to, that's the sound of a high-bandwidth (40-400 Hz) accelerometer reading played back at audio rate, fed through a delay line whose delay time varies from about 1 millisecond to 500 milliseconds over the course of a second. Why, you might ask? Haptics, my good man, haptics.

Working for Cycling '74 is a bit like working with Max itself: you make a small sacrifice in terms of knowing what the hell you're supposed to be doing in return for absolute creative agency. As a consequence the company attracts people with a huge range of interests and passions, unified solely by their desire to make cool stuff and see cool stuff happen. So when I head out to meet a fellow cyclist, I never know quite what's going to happen. When I drove up to Boston to meet Matthew Davidson I had no idea I'd spend the afternoon drinking tea in the shadow of his Ozymandi-esque modular synthesizer.

Above: Yes

 When I made my way to Greenpoint to chat with Luke DuBois over Balkan cuisine I had no idea we'd launch into a discussion about his planned documentary of the challenges of being a child named Luke in the age of Star Wars. Knowing what I know about the people who work at Cycling '74, I was not at all surprised to learn that Joshua (head of the engineering team) did in fact know some people I could hang out with in Paris, and that one of those people was Yon Vissel.

Vissel is a postdoc at the Institut des Systèmes Intelligents et de Robotique at the Université Pierre et Marie Curie here in Paris. Like any good researcher, Vissel matches a seemingly endless CV with an equally impressive passion for his field, which in his case is haptics, the study of touch. In case the relationship between haptics and Marie Curie isn't obvious, I'll remind you that haptics is the science of understanding and simulating the sense of touch, and that Marie Curie basically died because radioactive material, while very interesting, sort of has some problems with intimacy. This was not true of Pierre, who I'm to understand was quite the romantic.

Having already written his thesis on the geometry of string theory and spent his "wild years" writing signal processing code for a little piece of mom-n-pop software called Ableton Live, Vissel focuses his efforts these days on exploring how people use touch to build a sense of the world around them. In my opinion this is a nice way of saying that haptics research focuses on eroding your sense of self by demolishing your ability to trust your senses. Vissel's most recent project simulates the effect of walking on various materials using a grid of vibrating tiles. Stepping down on a tile causes the tile to vibrate in a way correlated with changes in force, and let me tell you the effect is downright spooky. Tweaked one way the tile gives an unmistakable sense of walking in snow, set another way you'd swear you were stepping on a thin sheet of ice. Of course, for Vissel the science is much more important than any petty feelings of discomfort I might feel trying out his experiments. "I'm not even sure I know what's real anymore," I say. "Hmm," Vissel nods, "interesting."

My visit to the lab happened to coincide with planning for haptics outreach event at Gaïté Lyrique, a sort of exhibition space in roughly Centre-Ville. That plans were underway for such an even was surprising for a number of reasons, not the least of which was that this is Gaïté Lyrique,

which to me looks more like the fever dream of a neglected Tamagotchi than an institute of cultural outreach. But then I've been made to understand that people have a much different relationship to academia here in France than they do back in the states. Academics are not brainy, out of touch atheists worthy of mockery and distrust, though nor are they inaccessible towers of knowledge. Rather, science itself is viewed more as a plaything, a source of entertainment that should be put on display and talked about. Many people try to maintain some kind of scientific awareness in much the same way that one might follow basketball or politics. So when I as an American asked the inevitable, "Are people really going to show up to this thing?" the answer was unanimous: "This is Paris, people go to shit."

As someone who wanted to get a sense of as much of the scope of the lab as possible in a short period of time I probably couldn't have picked a better time to visit; not only was everyone in the lab busy figuring out how they could demonstrate their work but also the informal workshop setting meant I would actually get to participate. I was to show off an effect called La Tasse Magique, or The Magic Cup, wherein you the subject, presumably in the rôle of a pan handler, are made to feel that you have been given some small amount of change when in fact you have been given nothing (finally, someone has the balls to knock panhandlers off their pedestal). The basic setup for the illusion looks something like this:

My workspace in the basement of the Université

I intended to focus on the accelerometer but I guess we're going to look at shoes instead

Custom-made, custom-awesome vibrators

 I should mention a couple of things about this setup. First, if at all possible, do not try to get your dry run set up in the basement of the Institut, which is a realm where the non-deaf dare not travel. My work companion was another grad student who had been banished underground for making too much noise. That noise? A little something like this:



They say god is just and merciful but I just don't know, man. Apparently that horrible tone needs to be passed through this small piece of hardware for days on end in order to wear all the parts in correctly. Anyway the second thing to keep in mind is that you need a special kind of vibrator for this experiment. This ain't your mom's vibrator (gross). See, most vibrators, like the kind we've got in our cell phones (also dildos) work by rotating an unbalanced mass at high speeds. This works fine when all you need to do is vary your vibration along one dimension: is my shit vibrating a lot or a little? The downside though is that slow rotations mean small vibrational amplitude and fast rotations mean large amplitude; you can't decouple frequency and amplitude. For this experiment you need something with a bit more fidelity, which is why I made use of the sweet custom vibrator pictures above. Amir, one of the grad students at the Institut, makes these little bundles of joy himself by encasing a rare earth magnet in a diaphragm, wrapping it in copper wire and submerging the whole thing in epoxy. You can see the end result pictured above, and if you're thinking you've found the perfect stocking stuffer then Amir would be happy to make one for you, provided you can cough up 200 euro. Anyway, the final setup:

The idea is this: you take two cups, an accelerometer and a vibrator and you wire them together so that any acceleration in one cup will trigger vibrations in the other. Then if you tell someone else to hold the cup with the vibrator and drop some coins into the cup with the accelerometer. What's not surprising is that the other person can feel something happening. The strength of the illusion, however, really needs to be felt to be believed. The sense that actual coins have been dropped into the cup is unmistakable, so much so that, when I showed people the experiment at Gaïté Lyrique they would look into the cup afterwards to verify that I hadn't put anything in there. They would even say that they felt their cup was heavier after the illusory coins had been dropped, an amazing result that I did not expect in any way.

Holy shit look: People

Vissel's Tile of Unease

Turns out I can explain haptics in French without understanding haptics or speaking French

 So what's the future of La Tasse Magique? Honestly, man, you could do anything. I was thinking it would be really cool to strap a vibrator to a Wacom pen to give the impression of paper texture, which evidently someone else though would be cool to because they did just that. Beyond that there's a ton of investigation yet to be done in the area of multi-modal sensory integration. One thing that struck me over and over again in this workshop was the degree to which these illusions rely on the integration and simultaneity of stimuli for full effect. My magic cup requires the subject to feel the vibration in the cup and to hear the jingling of the change at the same time; take away either and the illusion vanishes. The strength of Vissel's "Eerie Tiles" comes from the tight coupling between the effort of pushing down on the tile and the resulting vibration; the two are paired in such a way that the effect is completely natural and cannot help but produce the illusory sense of walking in snow. The remaining task is to probe just how deep these relationships between the senses go. What if Vissel's tiles are configured to vibrate like crunchy snow but the subject is shown video of walking on pavement? What if the Magic Cup played different sounds on top of the vibrational pattern of dropped coins? And finally, how can we exploit our human sensitivity (some might even say susceptibility) to correlation between the senses to create a sense of virtual reality? Or to create art?

jit.gl.mindblown