The Society for Neuroscience (SFN) had its annual meeting this past November in San Diego, California. This is typically an enormous event, as 20,000-plus neuroscientists from around the world converge in one of the best cities in the country. San Diego is home to a spacious and well-designed convention center that regularly hosts meetings similar in size to SFN and, with events like Comic-Con, often surpasses that attendance. With such a large group of scientists presenting research, there’s bound to be some great work on almost anything a curious mind can imagine. While the projects presented range in their aims from understanding some key aspect of brain functioning impaired by disease to demonstrating the latest in backyard neuroscience technologies like the Roboroach, there was also some tantalizing information about basic processes in perception.
Magicians are masters of perceptual psychology — some illusions take advantage of the principles upon which our sensory systems process incoming signals. Many of these principles were identified, studied and described by the famous Gestalt psychologists. For instance, the principle of closure describes how our visual systems tend to complete otherwise-incomplete structures, like a circle that isn’t entirely closed and the panda from the WWF logo (World Wildlife Fund, that is). The principle of multistability is a particularly powerful one. This is an effect in which alternative percepts of ambiguous images such as the Necker cube and the Rubin vase pop back and forth from one view to the other. Meaning, in the case of the Rubin vase, you see a vase, then you see two faces, then a vase again, and so on. Another fun example of multistability is the Three-Legged Blivet. The object in the illusion (basically a hair pick with a funky middle leg) is drawn in such a way that the middle leg transitions perceptually as the vase. Incidentally, an object of the sort seen in the illusion was not among the definitions of Blivet provided by wiktionary.org. Furthermore, while the definition provided by urbandictionary.com also did not include such a description, it was a lot more fun to read.