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I just had one of those wonderful moments where a bunch of ideas that had been floating around in my head for a number of years came together and made sense, thanks to a section of Alva Noë’s book Out of Our Heads: Why You Are Not Your Brain, and Other Lessons from the Biology of Consciousness. In Chapter 4, he challenges the common metaphor for the brain as the “Mission Control”  of the body — the place where all stimulation comes in and is noted, processed, and responded to. Instead, he says, our perception, and even our reaction, is distributed throughout our body and even through our environment.  To counter this, he offers the example of a snail’s response to being touched. At first touch, the snail will recoil, but with repeated touches, the snail becomes habituated to the touch, and doesn’t recoil. The sensory neurons in the snail’s nervous system are linked to the motor neurons, and the response to the initial touch is to cue the motor neurons to move the snail away.  As repeated touches occur, the snail’s nervous system learns the pattern as “normal” and the connection between the motor neurons and the sensory stimulus is lessened over time.  There’s no central brain managing this — the change is a result of the connection between the neurons and the patterns of action in the environment in which the snail is embedded, argues Noë. It’s not just about the changing in the coupling between the sensory neurons and the motor neurons, because that change would not occur without the repeated pattern of touch that the snail encounters.  It all happens without a “mission control” brain to process it.