 According to Searle, no mathematical function can be used to connect a known VIN with its LPN, but the process of assignment is quite simple—namely, "first come, first served"—and can be performed entirely by a computer.Penrose and Stuart Hameroff have constructed the Orch-OR theory in which human consciousness is the result of quantum gravity effects in microtubules.However, in 2000, Max Tegmark calculated in an article he published in "Physical Review E" that the time scale of neuron firing and excitations in microtubules is slower than the decoherence time by a factor of at least 1010.