The answer is by better emulating the outputs of all of the core human systems based on input. We need an endocrine system analog as much as we need a neural analog.

When we encounter something that invokes fear, our brain tells our body to create adrenaline, the adrenaline makes our brain and body go faster, the brain going faster and being more scared tells the body to make more adrenaline, and so on until attenuation of the cycle is triggered by removal of the threat.

We can't do any of this by focusing on neuronal analogs alone.