^{8}Calculating this number can be a challenge. Typical
methods are to calculate the number of signal transitions that a
neuron can do multiplied by the number of neurons that are
active. If, for example, Roger Penrose is right that human brains
can do signiﬁcant quantum computations, then the human brain
may be able to do many more calculations, which would push back
the dates for when computers match or exceed human intelligence.