Jeff, wouldn't boosting essentially be similar to neurotransmitter recovery in synapses? In short term a pre-senaptic axon would be less likely to excite a post-synaptic dendrite due to the lack of neurotransmitter. So it's sort of a boosting mechanism but is inverted. There is also boosting in some of the mechanisms of how the short term memory works, but I guess it does the opposite, as it's job is to remember rather then to achieve sparsity.
On Dec 11, 2013, at 3:55 AM, Jeff Hawkins <[email protected]> wrote: > Great question. > > Boosting or something like it is essential. Without boosting it is possible > for some columns to never win (become active) and others to win too much. We > started without boosting but quickly saw that the spatial pooler would have > this problem of columns that never won and were essentially wasted resources. > So we added boosting to solve the problem. > > I am not aware of anything in the biological literature that relates directly > to our method of boosting, but I haven’t looked either. However, a general > observation is that most excitatory neurons have a low background firing > rate, maybe once a second or slower. Although this has been observed and > noted by many neuroscientists, I am not aware of anyone studying the > mechanisms that might cause it. It is possible that low background firing > rates could achieve the same result as boosting. All cells will fire > sometime and therefore be given a chance to learn. > > Jeff. > > From: nupic [mailto:[email protected]] On Behalf Of Marek Otahal > Sent: Wednesday, December 11, 2013 12:11 AM > To: NuPIC general mailing list. > Subject: [nupic-discuss] Boosting: biological support? > > Hello, > > I understand why boosting is needed and how is it implemented > (algorithmically), my problem is: does it have an analogy in real brains? > > I'm comparing it with the inhibition (where boosting is like a counterpart) > which is known (local inh) from the real brains and we just implement it. Or > is boosting a new, artificial concept added for an improved performance? > > Thanks, Mark > > -- > Marek Otahal :o) > _______________________________________________ > nupic mailing list > [email protected] > http://lists.numenta.org/mailman/listinfo/nupic_lists.numenta.org
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