Paraphrasing the model's reply to force myself to learn:

The brain is observed to be cyclical with feedback cycles. (Biological neural networks thus cannot be sufficiently modeled with DAGs. RNN Recurrent Neural Networks do model cycles.)

The brain is actually its own generator.

The oscillations of the brain are measurable with e.g. EEG; and are distinct from the heart, which is measurable or imaged with ECG, for example.

Long term memory depends upon synaptic plasticity, which does not require continued electrical charge, though short term memory does depend upon neuronal oscillations which depend upon continued electrical charge.

The DMN Default Mode Network in the brain is observed to be less active in so-called flow states; and more active during daydreaming, ear worm, rumination, and self-reflection. The DMN is probably feed-forward too.