Certainly there will be structures dedicated to particular tasks. If in nature these emerge spontaneously or are preconstructed I couldn’t say, but for sure I will need to architect these structures myself in order to short circuit the learning process which is still poorly understood.
I am hoping a suitably interconnected group of general purpose artificial neurons with a variety of activation functions will be sufficient to represent a limb, or a more general concept such as
the ground, or an object that can can be manipulated.
Take the limb for example, which is where I am starting. Live sensory data indicates how each of the servo joints is positioned, power data indicates how much effort is being expended to keep it there, and touch data indicates when the foot is on the ground. The model for what it feels like to walk, for this one limb, is the pattern of sensory data the limb is expected to generate as it moves through the walking motion over a period of time - the all important temporal aspect.
If the sensory pattern deviates from the anticipated pattern, if the limb hits an obstacle and the power spikes or the ground is felt sooner than expected or not at all (like when you think you’re on the last step of a staircase and you’re not) then other neurons will spike triggering response behaviour.
A higher level will coordinate all of the limbs into a walking motion using similar neural structures
and combining IMU sensory data. Here there will need to be a model representing the limb’s position relative to the entire body.
In answer to your question about modelling time, I don’t think there is anything special about it. I think our concept of time is determined by the speed at which our neurons operate (in the tens of milliseconds) and that imposes natural limits on our perception of the world.
For an emulation of a brain-like neural network running on a non-real time computer I will need to distribute a time sense signal to all neurons to simulate the passage of time similar to that experienced by a biological brain.
On your last point I think it is too early in the development of Artificial General Intelligence to make any proclamations about the correct way in which to implement it. I would like to create some real world behavioural capabilities (as opposed to humanoid shaped machines carefully configured to simulate human behaviour) and see what is learned on the journey.
Innate structures or behaviours will be required, not least to motivate the artificial creature to get up off the charging station and go explore its environment.