To Nicholas Strausfeld, a tiny brain is a beautiful thing. Over his 35-year career, the neurobiologist at the University of Arizona at Tucson has probed the minute brain structures of cockroaches, water bugs, velvet worms, brine shrimp, and dozens of other invertebrates. Using microscopes, tweezers, and hand-built electronics, he and his graduate students tease apart — ever so gently — the cell-by-cell workings of brain structures the size of several grains of salt. From this tedious analysis Strausfeld concludes that insects possess "the most sophisticated brains on this planet."
Strausfeld and his students are not alone in their devotion. Bruno van Swinderen, a researcher at the Neurosciences Institute (NSI) in San Diego, finds hints of higher cognitive functions in insects — clues to what one scientific journal called "the remote roots of consciousness."
"Many people would pooh-pooh the notion of insects having brains that are in any way comparable to those of primates," Strausfeld adds. "But one has to think of the principles underlying how you put a brain together, and those principles are likely to be universal."
The findings are controversial. "The evidence that I've seen so far has not convinced me," says Gilles Laurent, a neuroscientist at Caltech. But some researchers are considering possibilities that would shock most lay observers. "We have literally no idea at what level of brain complexity consciousness stops," says Christof Koch, another Caltech neuroscientist. "Most people say, 'For heaven's sake, a bug isn't conscious.' But how do we know? We're not sure anymore. I don't kill bugs needlessly anymore."
