Seeing how complex movement is has yet again made me gawk at the fact that we are able to move at all, let alone think or do other "higher order" processes. Since so many things must go right in the nervous system just to move a leg, it seems that our notion of lower organisms as simple needs to be placed in a new context. Also, it is now clear to me why the idea of a reflex is not only wrong but grossly misleading. Not only is a reflex not "reflexive" as per the harvard law, but movement such as leg withdrawl is a highly complex ordered procedure.

As a sci-fi aside: I wonder about wet-wires as in William Gibson's classic "Neuromancer". For neural systems that are highly ordered (and generally linear??) such as for visual input or the activation of a central movement pattern, would it be possible to "wire in" false neurons that could be used to artificially control the motor pattern or translate the visual input to a processor and video card and display it on a monitor? Theoretically, it seems that this would be plausible so long as we can read the membrane potentials of specific neurons and if we know where those neurons recieve input from. This latter problem of where the input came from should be simplified in the two above cases. Neurons normally receive input from thousands of other neurons, but in cases where the nervous sytem is operating in a linear fashion, such as very low level visual input and motor output, perhaps the pathways could be determined and mapped in an individual brain. The trouble would be that neuromechanical interface- the so-called wet-wire. But what with advances in brain surgery and the 3D stereotaxic (sp?) imaging equipment available, who knows? Here are some related links:

Check out the first project: Bioelectronics and Neurobioengineering Group, University of Genova, Italy
and Neuronal Pattern Analysis Group, University of Illinois

Thanks. Try out the links, they should work. As should Serendip's list of neurobiology places. Yes, the complexity indeed contributes to making "reflex" a misleading concept. And to uncertainties about the likelihood of Gibson's cyberspace visions. It is not that one can't do implants which affect nervous system activity (one can, and its done fairly routinely in a number of cases). The difficulty (as with many really interesting biological phenomena) is the inordinate three dimensional precision with which one has to produce multiple effects in order for the result to be coherent. PG