The prefrontal cortex is responsible for 'Task Chunking.' It is supposed to seamlessly compress the 8 micro-steps of taking out the trash into one fluid, automatic action program called "Trash."
In ADHD, the compression software is broken. The brain sees 8 distinct, massive barriers. It calculates the friction of putting on shoes (tactile transition) plus the friction of leaving the house (temperature transition) plus the friction of losing the current dopamine (stopping your video game). The cumulative friction is staggering.
Furthermore, the reward circuitry is completely silent. The basal ganglia does not release dopamine for completing preventative maintenance chores (like preventing a bad smell). Because there is no chemical reward promised at the end of the 8-step marathon, the 'Go' signal generated by the prefrontal cortex is completely ignored by the motor cortex.
