Abstract It is possible that humans may never find a neural mechanism that measures the number of action potentials on the scale of neurons. For the cerebral cortex, neurons are merely geometric points without spatial characteristics. No matter when or from which direction a neural signal arrives, the signal expression of a neuron within a neural region is unique. This unique neural signal expression is determined by the properties of the neuron, which in turn are determined by the neurotransmitters it secretes. In the universe, any complete space can be expressed as z = a + bi, where a is the observable part by humans, the real part of z, and bi is the unobservable part, the imaginary part. In the human brain, the real and imaginary parts can transform into each other, forming neural responses in the brain. If the cerebral cortex is a two-dimensional plane structure, then the neural projection structure constitutes the third dimension, and all the neural inhibitory signals form the fourth-dimensional structure of the human brain. At any given moment in the cerebral cortex, the prerequisites for the existence of consciousness include the following: some excited neurons have consistent action potential waveforms and phases, the structure between the excited neurons is continuous, and the biological characteristics of the neurons are fully expressed