The Brain Controls
Emotions Are Part of What Makes Humans Different
Laughter is one clear difference from animals
("laughing" hyenas are not really laughing). For more on the brain's
role in laughing,
Likewise, emotion-based crying seems unique to humans.
All animals produce tears in response to eye irritants.
Feel excited? ... happy? ... sad? ... depressed? ... mad?
These, and other feelings are called emotions and they are
controlled by the brain. They arise from outside stimulation,
"inside" thoughts that may be influenced by memories.
Emotions are processed by a group of a system of brain areas known as
the limbic system. Some structures are shown in the diagram. When
emotionally relevant stimuli evoke activity in the amygdala, for
example, neurons there send signals to forebrain areas that in turn
trigger avoidance behavior or to the brainstem that trigger fear and
freezing behavior. In both cases, fear and anxiety are part of the
|The limbic system is a highly integrated
set of brain areas that process emotions. What you experience or think
about is processed in this system to generate emotions.
This processing can be over-ridden by
"executive functions" of the cerebral cortex, especially
the part under the forehead ("frontal cortex").
Conscious meditation, for example, can
convert anxiety or fear to calmness.
The Brain Controls
The brain has systems
that cause us
to seek pleasure and to avoid pain or unpleasantness
Pleasure seeking system
Pain/displeasure avoidance area
As seen in a midline slice of human brain, areas
outlined in white contain the indicated system (usually extends out
laterally from the midline)
LEFT- reward/pleasure pathway in brain.
Stimulation along the darkened area of diagram induces pleasure.
RIGHT - Drug addicted rats will work feverishly
to press lever to self-administer the drug into a vein (left). They
do the same if the drug is delivered by way of small tubes implanted
into the "pleasure seeking system" (right). Similar effects can be
produced by implanting small wires into the system that deliver
small electric current stimulation. This reward system has been
confirmed to exist in humans and operate in a similar way.