2015-05-06 17:27 GMT+02:00 cogmission (David Ray) < [email protected]>:
> Valentin, > > >> Perhaps, I have some crazy idea about what is going on. I think that the >> notion of "t" and "t-1", implicitly asumes a synchronous circuit. >> Nevertheless, biology don't have any clock around... definitely is >> asynchronous. Under such assumption the previous sequence is not possible, >> since all the repeated values are the same. Therefore, I think that the "t" >> and "t-1" should be redefined as the time where the "input changed". If we >> feed the memory with the same input sequence in t and t-1 something is >> going to be bad at the end. > > > HTM Theory does not have any real "time" so to speak. We're talking about > sequences, and yes in the biology (I just recently overheard this), there > are "serial" cell/column events. Now, "t-1" refers to the state the > cell/column was left in during the previous activation - cells "depolarize" > making them quicker to fire (and subsequently beat out the race against > inhibitory cell activations); the resulting "depolarization" is what is > modeled as the state in t-1 (AFAIK). > >> > Thanks David. I understand now (being used to circuits, this is a bit hard for me :-) Nevertheless, in this case, it looks like the implementation should "protect" that. I.e. don't perform compute() in temporalMemory if activeColumns in "t" are equal to "t-1". -- vpuente PS: Perhaps the implementation is too "time-driven". I think that a "event-driven" approach could be more close to the reality (besides have better performance... especially given the sparsity of the problem).
