When we see something
or hear something, firstly, it will travel to the thalamus, and then to the visual
and auditory areas of the cortex. Finally it will be sent to the amygdala of
the limbic system for an emotional reaction: "Is it right or wrong?"
Yet it is later discovered that there is a more direct path - from the thalamus
to the amygdala. In other words, the amygdala responds emotionally to different
objects in the world even before the cortex recognizes them. Most of the lower
animals don't have the cortex, but they still can react emotionally. If a mouse
with its auditory cortex removed, it can still learn to fear the ringing when
they received the shock. They learn to fear the ringing without the cortical
representation of sound.
Many other animals
also will have emotional reactions such as shivering and running away when they
see something that scares them, even a cloud or a little thin twig can also scares
them. Because they don't know what are they and they have the circuits there
to notice the movements of possible predators. Then they will make inappropriate
stimuli and it seems that they are… let's say, kind of stupid. But it is
not worthless actually. Imagine if next time there are real dangers, as they
have 'practiced' so many times before, they become sensitive to the surrounding
environment and as a result, they can escape quickly and easily. It is the same
in the case happened for human beings. Sometimes, we may react emotionally yet
we don't mean to do that. The above example can explain why does this happen
to human beings too.
