think or thwim

In this TED presentation, Dan Dennett argues that we don’t really understand our consciousness. We consist of about 100 trillion stupid cells who individually have no way to comprehend what they are a part of. Our perceptions of consciousness amount to a bunch of parlor tricks performed by those 100 trillion cellular robots. I think he needed about two more hours to make his point, but it’s a very interesting set of examples.

I think Jeff Hawkins’ model of sensory processing fits pretty well with Dennett’s demonstrations and the ant colonies and slime molds I’ve been writing about. However, there is a difference. Hawkins argues that neurons in the neocortex do have a hierarchy.

Signals from our sensors, like eyes and ears, are transmitted to the lowest level of neurons in the neocortex. Those neurons fire when they see a familiar pattern. For instance, one set of neurons may fire whenever it recognizes a horizontal line. Another set might be programmed to recognize the color blue. The pattern of firing lower level neurons is output to the next higher level, and the higher level neurons process those input patterns into more complex patterns and pass those up. This continues up the six levels of the hierarchy until the top level has the big picture.

Hawkins also theorizes that our brains use a feedback loop to control what the lower levels do and avoid unnecessary calculations. The upper level neurons send signals back down to the lower levels predicting the inputs they should see next. The lower level neurons ignore data that matches the predictions and concentrate on novel inputs. If the inputs don’t differ enough from the predictions to trigger a closer examination, we’ll be oblivious to the changes.

If you think of ant colonies as a higher level in the hierarchy of ants and slime molds as a higher level in the hierarchy of simple cellular organisms, they seem analogous to simple brains.