Jeff Hawkins on Scale and Orientation in Cortical Columns - 30 November, 2020

[Paul_Lamb]

@david.pfx

So describe to me the next bit: how does this group of cells recognise vertical lines, that one does Jennifer Aniston and over there is the smell of lavender and the colour hot pink?

WRT “Jennifer Aniston” cells (i.e. “grandmother cells”), here is my perspective on that.

Does the SDR have to be binary?

Old topic, I know, but thought I’d add my two cents on the “grandmother cells” idea. There isn’t going to be “A” grandmother cell (i.e that cell dies, you forget about grandma). The representation for an abstract concept of “grandmother” (the whole concept, not simply the word) will consist of many active cells, with the normal noise and error tolerances that come with SDRs. Most of the cells in the representation will NOT only be active for the concept of “grandmother”. The majority of the …

I believe this is actually a similar problem to recognizing vertical lines. There is an intimate relationship between topology and semantics. Using hexagonal grids, one can, for example, take a series of randomly distributed SDRs with semantic overlap and transform them into a line with an orientation. I’ve been meaning to post some visuals on this, but I can describe this in a little more detail here if you are interested.

As far as the qualia question (why the color pink doesn’t smell like lavender), while an interesting discussion, is ultimately less important from my perspective than the fact that both end up becoming semantics encoded into SDRs by the time they are being processed in cortical columns.