I've been around and around on the net, and had two neuro-physiologists repeatedly dodge the question, so I open it to the wider population... When one speaks of learning one uses the phrase "adjusting synaptic weights", meaning (I presume) changing the strength of a connection between two neurons. However I have not been able to find a reasonable (or simply stated) estimate of how much these "weights" can be changed. I usually get sidetracked into discussion of whether it's timing or strength that is being changed, or how insects are different from humans, or some other seemingly more interesting topic, and never get to the range and resolution. I wanted to know this in order to make a _very_ rough estimate of the Shannon Information content of the human brain for comparison -- if there could be such -- to some little robot cars that I'm building. So does anyone know offhand how many bits of information are encoded in these putative "synaptic weights"? Or, alternately, can you explain to a (somewhat) sophisticated layman why that is a stupid question to ask?