From [Marc Abrams (2005.10.19.1417)]
In a message dated 10/19/2005 11:47:14 A.M. Eastern Daylight Time, marken@MINDREADINGS.COM writes:
[From Rick Marken (2005.10.19.0845)]
Wonderful!!!, thank you Rick, you helped eliminate a bit of ignorance and helped advance my learning.
I made an incorrect assertion but it was an honest mistake. I knew of experimental work going on with hyperconplex numbers which are an extension of the more commonly known complex numbers.
A hypercomplex cell is one that fires maximally when a “hypercomplex” pattern (such as a moving line) stimulates its receptive field. The “hypercomplex” cell is
distinguished from the “complex” cell which fires maximally when a less
“complex” pattern (such as a stationary line of a particular orientation)
stimulates the receptive field. The response of the hypercomplex cell seems
to be hierarchically related to that of the complex cell. That’s why I
brought it up. This single cell work strikes me as pretty good physiological
evidence in support of the hierarchical PCT model of perception.
This is not quite the description I dug up on the web;
Rick, you may want to go and take a look to get rid of some of your ignorance as well.
I believe this site, if accurate, completely destroys any notion of the existence of a PCT type hierarchy in perceptual development. First, they are not certain about who does what at this point, but it seems a vast complex network is involved and not a hierarchy.
I clipped a snippet of the opening lines of the web page for you perusal.
This is all very interesting stuff. So while it seems a PCT type hierarchy is not the answer, maybe Bill was not far off the mark to begin with after all.
There seems to be some truth to the notion of dependency between functions and not just influence, but that is not clear. There also seems to be feedback involved between some but not all of the functional area’s.
In this brief summary notice the very last sentence. If you assume sensation & intensity as the first two functional kinds of areas and then add orientation and position. It seems you have at least 4 dependent functions. But all hell seems to break loose after this and the neurons actually start to fire.
And remember folks, this just accounts for sight. So a blind person could not possibly have access to these first four ‘levels’, yet as has been shown they can perceive shapes, colors and even perspectives in their minds. How is this possible?
Some interesting food for thought, so thanks Rick for setting me straight and turning me on to some previously unknown info.
THE VISUAL ASSOCIATION AREAS
SIMPLE, COMPLEX, LOWER- & HIGHER ORDER HYPERCOMPLEX FEATURE DETECTORS
The visual cortex is made up of a variety of cell types each of which is concerned with the analysis of different visual features (Ferster, et al., 1996; Hubel & Wiesel, 1959, 1962, 1968; Kaas & Krubitzer 1991; Sereno et al. 1995). These include simple, complex, and (higher & lower order) hypercomplex cells which are distributed disproportionately throughout areas 17,18, 19.
To briefly summarize, simple cells appear to be involved in the initial analysis of incoming visual cortical input, and are most sensitive to slowly moving stimuli. They are found predominantly within area 17 and in layer IVa,b,c,. Some are sensitive to stimuli moving in one direction, whereas others may respond to stimuli moving in any direction. In fact, almost 95% of the neurons in area 17 are responsive to stimuli moving only in one direction, but not the direction of movement. In addition, simple cells are responsive to the particular position and orientation a stimulus may take. However, for a simple cell to fire, a stimulus must assume a specific orientation and position. …
You also might want to check out;
This site provides some interesting mathematical modeling for;
NEURAL DYNAMICS OF 3-D SURFACE PERCEPTION:
FIGURE-GROUND SEPARATION AND LIGHTNESS PERCEPTION