So what do light bulbs and ideas have to do with linguistics, you might ask.
Well, if a light bulb is viewed semiotically as a symbol that people use to communicate the concept of "idea", this symbol can be considered a part of our language.
The reason I bring this up is that the May 21st issue of The Week magazine included a report from LiveScience.com, which concludes that "just showing a real light bulb to people can actually trigger insights."
The article further reports that "psychologists at Tufts University gave volunteers a series of puzzles to solve under time pressure. Part way through the test, either a bare light bulb or an overhead fluorescent light was turned on in the room. The researchers found that volunteers exposed to the light bulb were 50 percent to 70 percent more successful at the puzzles than subjects given the fluorescent light."
In other words, the image of a light bulb can be used to semiotically prime (stimulate) people to come up with ideas that solve puzzles.