Memories, emotions and brain
How it works?
Emotion can have a powerful effect on humans and animals. Numerous studies have shown that the most vivid autobiographical memories tend to be of emotional events, which are likely to be recalled more often and with more clarity and detail than neutral events.
The activity of emotionally enhanced memory retention can be linked to
human evolution; during early development, responsive behavior to
environmental events would have progressed as a process of trial and
error. Survival depended on behavioral patterns that were repeated or
reinforced through life and death situations.
Artificially inducing this instinct through traumatic physical or
emotional stimuli essentially creates the same physiological condition
that heightens memory retention by exciting neuro-chemical activity
affecting areas of the brain responsible for encoding and recalling
memory. This memory-enhancing effect of emotion has been demonstrated in
many laboratory studies, using stimuli ranging from words to pictures to
narrated slide shows, as well as autobiographical memory studies.
Dopamine is a neuromodulatory molecule that plays several important roles in cells. It is an organic chemical of the catecholamine and phenethylamine families. Dopamine constitutes about 80% of the catecholamine content in the brain. It is an amine synthesized by removing a carboxyl group from a molecule of its precursor chemical, L-DOPA, which is synthesized in the brain and kidneys.
Dopamine is also synthesized in plants and most animals. In the brain, dopamine functions as a neurotransmitter—a chemical released by neurons (nerve cells) to send signals to other nerve cells. Neurotransmitters are synthesized in specific regions of the brain, but affect many regions systemically. The brain includes several distinct dopamine pathways, one of which plays a major role in the motivational component of reward-motivated behavior. The anticipation of most types of rewards increases the level of dopamine in the brain, and many addictive drugs increase dopamine release or block its reuptake into neurons following release. Other brain dopamine pathways are involved in motor control and in controlling the release of various hormones. These pathways and cell groups form a dopamine system which is neuromodulatory.