Neuromodulators, Benefits and Side-effects
In the real world, “raw” signals are not continuous. Wind, water flow, stronger smells etc can all make signals short-lived. If a living thing were to only rely on such signals, it would give up way too soon. It is to address these real-world constraints that certain neuromodulators arose, explains Max Bennett in A Brief History of Intelligence . Neuromodulators tune the neural activity across the entire brain, not just in neighbouring neurons. Not surprisingly, they have side-effects. Dopamine is the neuromodulator that says “Keep going” even though the signal that initiated the action is no longer present. The principle behind it is as follows: if the animal got a whiff of food, it is probably nearby. If the signal soon stopped, it is probably because of a change in wind direction or other such variable. Continuing to look makes sense. Dopamine, however, is not about liking something. It is all about wanting something. It is easy to understand th...