Definition
The limbic system is not a single organ but a loose coalition of brain regions that, together, do the work of emotion. It includes the amygdala, hippocampus, hypothalamus, and parts of the cortex, all densely interconnected and sitting beneath the wrinkled outer cortex.
Behave treats the limbic system as one of the brain's three broad functional layers — the emotional layer, mediating between automatic bodily regulation below it and deliberate cognition above it. When you feel afraid, attached, disgusted, or aroused, the limbic system is generating that feeling.
Why it matters
How it works
The limbic regions exchange constant signals with each other and with the rest of the brain. The hypothalamus connects emotion to the body, triggering hormonal and autonomic changes. The hippocampus binds emotion to memory, which is why emotionally charged events are remembered vividly. The amygdala feeds threat and salience information into the network.
Critically, the limbic system is wired bidirectionally to the frontal cortex. Emotion is not a primitive force the cortex merely suppresses; it is information. Good decisions depend on the limbic system supplying the cortex with what matters and how much.