Richard, Any ideas on what do such 10^5 neuron cortical columns represent? For example, how do they relate to the multiple topological maps in the brain? They all represent just one concept, or do they represent families of related concepts? Or perhaps do the neurons of each maxi-column act in unison as one cell assemblies, so that subsets of the roughly one million of them can be selected to create unique coding for any one of millions or billions of episodic or pattern memories?
Is there relatively clear demarcation between such columns (i.e., a surrounding surface were the number of interconnects are much lower than similar surfaces within the column), or is it such that any given location on the surface of the cortex the neurons directly below it would be connected to the nearest 10^5 neurons? Ed Porter -----Original Message----- From: Richard Loosemore [mailto:[EMAIL PROTECTED] Sent: Wednesday, November 28, 2007 3:25 PM To: [email protected] Subject: Cortical Columns [WAS Re: [agi] Funding AGI research] Benjamin Goertzel wrote: >> ED>>>>>I must admit, I have never heard cortical column described as >> containing 10^5 neurons. The figure I have commonly seen is 10^2 neurons >> for a cortical column, although my understanding is that the actual number >> could be either less or more. I guess the 10^5 figure would relate to >> so-called hypercolumns. > > The term "cortical column" is vague > > http://en.wikipedia.org/wiki/Cortical_column > > There are minicolumns (around 100 neurons each) and hypercolumns > (around 100 minicolumns each). Both are called columns.. Ben, It is true that there is enormous ambiguity and confusion about the definition. However, a number of people believe that the best compromise values for column size and number are 10,000 neurons per column and 1 million columns. I came to this conclusion after looking into it for my own purposes, then was gratified that Henry Markham quoted the same numbers: http://video.google.com/videoplay?docid=-2874207418572601262 Henry Markram, EPFL/BlueBrain: The Emergence of Intelligence in the Neocortical Microcircuit. Richard Loosemore ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?&; ----- This list is sponsored by AGIRI: http://www.agiri.org/email To unsubscribe or change your options, please go to: http://v2.listbox.com/member/?member_id=8660244&id_secret=69841725-e13379
