HTM only focuses on the sparse representation of neurons and simply uses binary to represent the firing of neurons.
But real nerve firing in brain is not only binary but also rate oriented(frequency is informative, not irregular).
In explaining many principles, rate coding is more convincing than SDR. such as color perception: Cone cells respond differently to light of different wavelengths.
The nerve firing frequency is a scalar. Is it more appropriate to use it for calculations?
We already know that sparse coding/grid cells exist in the neural network, but rate coding cannot be ignored.
Thus, how do they collaborate?