Hi Laurent, Thank you for sharing this link. I am not a neuroscientist, but here's my take on the article. First, the Salk scientists construe the variation of discrete states and sizes of synapses in the hippocampus to represent "bits" of information, which is pure speculation. Because they are not working with any theoretical framework which defines the way information is represented by neural structures - they conclude that every single discrete variation represents a bit of information; then they extrapolate across the total number of estimated synapses to derive their figures.
To me they are naively stabbing in the dark, with no theoretical framework with which to define capacity or storage. They also mention the 10 to 20% probability of activation of any neuron; and attribute this to a functional "unreliability" which is now "remedied" by their discovery of the existence of 26 discrete synaptic sizes which now (they think) hold information that is independent of dendritic activation. This seems to me to be conjecture with no correlation to an over all theory. In my estimation, and according to what I know about HTM theory, this just simply is not how neural connectivity conveys information, and just simply is not how the brain works. They ignore the significance of sparsity and SDRs (sparse distributed representations); attributing it to "unreliability" which to me underlines the fact that they aren't really working with an understanding with which to attribute their findings as a contribution to an over all theory. I'm couldn't tell you whether their discovery of 26 discrete synaptic sizes in the hippocampus is "useful" and is an important distinction which could add utility to HTM theory or not - that would be left up to the neuroscientifically inclined here; but I really doubt it is even all that useful? There is a lot of biological detail which is overtly and purposefully left out of HTM theory; either because it is only a necessity in an organic context, or it really doesn't convey any significant information within the translation to computer software. This to me would be one of those "details". Anyway, thank you again for sharing this link and contributing new information to the group; it helps our community to thrive that we have people committed to making sure we stay relevant and current. Let's see what others think about this particular article? :-) Cheers, David On Sun, Jan 24, 2016 at 1:48 AM, Laurent Julliard <[email protected]> wrote: > Guys, > > I came across this article ( > http://www.kurzweilai.net/memory-capacity-of-brain-is-10-times-more-than-previously-thought) > and I was wondering if what they discover on synapse behavior could either > improve in any way the current model of synapses in HTM and/or confirm the > way synapses are potentiated today through the management of their > permanence value ? > > -- > Laurent Julliard > Twitter @lrjay > > -- *With kind regards,* David Ray Java Solutions Architect *Cortical.io <http://cortical.io/>* Sponsor of: HTM.java <https://github.com/numenta/htm.java> [email protected] http://cortical.io
