The amygdala is the part of our brain’s limbic system responsible for the processing and memory of emotional reactions and triggering the fight, fight, or freeze process for human beings.
In the image below, the amygdala (dark red color) can be seen as part of the limbic system, just below the thalamus (also dark red).
The amygdala has been called the “emotional sentinel” of the human brain because it is primarily responsible for helping us to know when it is safe and unsafe.
The amygdala receives signals from our senses which it quickly evaluates. If the signal is safe, all is good. However, if the amygdala determines the signal to be a threat, it sends a message to the hypthalamus to produce dopamine, epinephrine and norepenephrine which provide the chemical fuel for us to fight, flee or freeze.
The studies related to the amygdala have demonstrated that damage to the amygdala or negative personal experiences can result in such things as an inability to determine safe or unsafe facial expressions, hyperarousal, exaggerated fear responses or absence of fear responses.
So, if you grew up in an abusive, dangerous household, it is likely your amygdala has processed and stored those memories in a way which may keep you hyperaroused and unsure about the intentions of your partner.
Any tension or conflict with your spouse may easily result in a yelling match leaving you both depleted and demoralized.
Biology mixes with personal history, with disastrous results for personal and intimate relationships.