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)
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