Berlin cognitive science safari: report

So I’m back from my time in Berlin at the BMW Guggenheim Lab. As announced previously, I was there to give a talk about how perception works, and how cities control our perception. If you’re a regular mindhacks.com reader nothing I said would have been earth-shattering – it was a tour through some basics of perception and attention. I’ll just highlight two points:

Perception is about meaning. We so effortlessly transform visual input into percepts that we can forget what a difficult task it is. Fortunately we have a heap of dedicated brain machinery to do this for us. A common mistake is to think of perception as mere projection on an inner screen. Part of this fallacy is to think that perception is trivial, but another important part is to think that perception is about the production of images of some sort. Perception is the production of meaning, not the production of images. Our associations and experience are incorporated in the act of perception, so that they are intrinsic to the perceptual act (not somehow added “on top”, or as an after thought). This goes so way to explaining why foreigners appear so stupid in cities. In know that personally I feel my IQ drop at least 15 points as soon as the plane touches down in a foreign country. Native city dwellers have learn to read the city, through experience forming webs of association that build up into symbols. This allows them to instantly perceive what different scenes in the city mean for how they should act. Here’s an example I used in my talk.

Outside Berlin Zoo, looking for the underground: which way should I go? The visual sign for the U-bahn actually forms a tiny fraction of the visual field, so small that I’d bet it is invisible to the majority of my peripheral vision. To a resident of Berlin the way to the tube is obvious, perceptual learning ensures that they don’t even have to think about which symbol to look for, or what it means. The accumulation of thousands of pieces of perceptual expertise is what makes us natives in a city, and what renders us flailing when abroad.

Attention is co-constituted with history and the environment. What we notice depends on what we are seeking, what we have previously experienced and the world around us. We can choose to look for something, or concentrate on something, but our attention can also be driven by factors outside of our
direct control. Advertisers know this, and hence we get bright adverts, moving adverts, and the plethora of adverts which use faces and particularly eyes. Light contrasts, movement and human eyes are all elements which are fundamentally wired into the operation of our visual system. Advertisers are using them to perform a subcortical hijack of what we look at as we navigate the city. The psychology of advertising is a different talk, in Berlin it occurred to me that attention could be a useful, concrete, model generally for thinking about how our agency is spread between self and world.

After the talk was the real highlight – a cognitive science safari where we went out into the city and tried out some interventions based on classic experiments from psychology. Demonstration of strange allure of a crowd all looking the same way worked reasonably well (looking up is definitely more attention-capturing than horizontal gaze). So did ‘reading’ someone’s country of origin from their appearance alone, but the real treat of the tour was the change blindness ‘door’ experiment

This video shows one run of the experiment (thanks to tour particpant Hans Huett for taking it. Jump to about 0:50 for the action). We can see Matt Craddock and another volunteer (sorry, I didn’t catch your name) waiting for an unsuspecting member of the public. After engaging him in asking for directions, Yunus (my Berlin fixer) and Jakub Limanowski (mindhacks.com reader and volunteer), arrive from around the corner, carrying the door. After swopping Matt for Jakub we can see the member of the public continuing giving directions as if nothing has happened – he was blind to the change! Later we tried a more extreme change, swopping an older, shorter, beardless gentleman into Matt’s place – again it worked, asking the question of just how extreme a change you could make and the phenomenon still work.

The moral of this story is not that many people are stupid, just that attention is a double-edged sword. The good citizens of Berlin focus hard on giving directions, not on monitoring the identity of their interlocutor for signs of an improbable change. Yes, the phenomenon shows how much of the environment we are not aware, but it is also a back-handed tribute to our ability to focus our attention where we want.