That's the title of an Economist article about synaesthesia.
http://www.economist.com/science/displaystory.cfm?story_id=9217798
A few times in my life I've met people who say that particular letters or words are associated with colors, or sometimes tastes--words that ordinarily would not evoke colors or tastes. That's called synaesthesia. The article refers to a Nature Neuroscience study that uses a particular type of brain analysis. "Diffusion-tensor imaging measures the direction of movement of water molecules. Since the filaments that connect distant nerve cells are surrounded by fatty sheaths which restrict the movement of water, such molecules tend to move along a filament rather than out of it. The upshot is that the technique can detect bundles of such filaments running from one part of the brain to another." Although the researchers did find atypical connections between two areas of the brain, "...the phenomenon is more complex than had been appreciated." (The Economist, May 24, 2007)
Synaesthetes show more connectivity than other people; these people have cases of certain senses being blended or woven together.
Just out of curiosity, does anyone on CL2.0 experience synaesthesia?
Or, to take this just one step further and propose a preposterous question, through active participation in Web 2.0 technologies, are we all developing a new kind of sense, which may possibly be called "thinking in linking"? (And is that sort of thinking any different than regular thinking, anyway?)
OK, shoot me now. Another off-beat topic. Just for fun.