Function of the left and right Amygdala from birth

The importance of self-regulation, emotions and attachments since birth

  • The central nucleus of the amygdala has direct correlations to the hypothalamus and brainstem – areas directly related to fear and anxiety.
  • Many projection areas of the amygdala are critically involved in specific signs that are used to measure fear and anxiety.
  • There is a direct relationship between the activation of the amygdala and the level of anxiety the subject feels.
  • Feelings of anxiety start with a catalyst – an environmental stimulus that provokes stress. This can include various smells, sights, and internal feelings that result in anxiety.
  • Fear responses can include dizziness, faint, giving up, pleasing others, freeze, startle, high heart rate, etc. (stress cascade response). This can be felt through craniosacral treatment all over their system.
  • Moderate fear level causes a startle reflex, while a bigger fear does not. The amygdala is thought to be involved in enhancing the startle reflex in the moderate fear reaction (Walker).
  • Facial expression of fear or acknowledged fear is connected with the right amygdala. 
  • The right amygdala seems to be more connected and activated with the conditional fear, while the left is more connected with the non-conditional fears.
  • The amygdala in males, is bigger than the female one as the amygdala has got more androgen receptors and therefore testosterone stimulates the amygdala to grow more.
  • There is also difference in the left and right amygdala for both female and male.
  • The left full growth is about 1.5 to 2 years before the right full growth.
  • Right amygdala is connected to the face recognition. 
  • It is thought that the early left amygdala development, is due to giving infants the ability to detect danger (possible connection to primitive brain, the occipital brain). 
  • In childhood, the amygdala is found to react differently to same-sex versus opposite-sex individuals.
  • This reactivity decreases until a person enters adolescence, where it increases dramatically at puberty.
  • So, the amygdala is very important during the most difficult times in teenagers! If you have some now, brace yourself and blame it on the amygdala!
  • Difference in emotional stimulation in men and women have also been found.
  • A recollection of a horror film in women, would activate more the left amygdala, while same thing for men would activate more the right amygdala.
  • The right amygdala has been linked to taking action and to negative emotions. This is one of the reasons that men might fight when scared.
  • This is why men and women also respond differently to stressful stimuli, as the left amygdala allows for the recall of details, but it also results in more thought rather than action.
  • Amygdala can be affected by meditation, possibly resulting in more compassion and connection towards others, according to a study with Buddha Monks.
  • Left amygdala has been connected to anxiety in children.
  • Low activity of the gland in general though, results in more anxiety and depression.
  • The use of serotonin drugs increases the size of the amygdala (as we have mentioned above because of the receptors 5HT for serotonin).
  • Some studies also have connected autism to small left amygdala.