Final answer:
Dopamine, norepinephrine, and phenylethylamine (PEA) are referred to as the brain's 'love chemicals' due to their roles in pleasure, attraction, and emotional processing.
Step-by-step explanation:
Scientists describe dopamine, norepinephrine, and phenylethylamine (PEA) as the brain's “love chemicals”. These neurotransmitters are associated with feelings of pleasure, attraction, and emotional response, and play key roles in brain function and behavior. Dopamine, for instance, is crucial in the reward and pleasure systems of the brain, influencing both movement and emotional responses. It is part of intricate pathways like the mesocorticolimbic system that affect cognition, affective states, and behavioral disorders. Norepinephrine acts as both a hormone and a neurotransmitter, involved in arousal and alertness, while phenylethylamine has been associated with the feelings that come with romantic love, elevating mood and increasing focus.