Amygdala
The amygdala allows us to react so rapidly to a danger, that only afterwards do we realize what frightened us. How? It connects events with emotions, and helps arouse survival feelings such as fear, pity, outrage.
All messages from the senses go first to the thalamus. From there to the appropriate sensory cortex (visual cortex, auditory cortex, etc.). They assign it a meaning. If the meaning is threatening, the amygdala is informed. It then produces the appropriate emotional responses.
Sometimes, a part of the message received by the thalamus is transferred directly to the amygdala! This shorter route explains the rapid reaction of our natural alarm system.
However, this fast route provides only a crude discrimination of potentially threatening objects. It is the cortex that provides the confirmation, milliseconds later, if there actually was a danger. Those milliseconds are sometimes fatal. If all is OK, we had a good scare, and that’s it.
The two amygdalas (Gr: almond) have an almond shape. They are essential for decoding emotions, particular stimuli that are threatening to the organism, and the ability to feel certain emotions and to perceive them in other people.
Other important events are the presence of food, sexual partners, rivals, children in distress, and so on.
