Amygdala

psychology assignment

1. AMYGDALA Done by Sara Seif

2. What is the amygdala Amygdala is an almond shape set of neurons located deep in the brains medical temporal lobe. There are 2 amygdalae per person. Forms part of the limbic system( a complex set of nerves and networks in the brain concerned with instinct and mood. It controls the basic emotions such as fear, pleasure and anger, and drives the desire of hunger, sex, dominance, and care of an offspring.)

3. Function of the amygdala Plays a key role in detecting fear and preparation for emergency events, in addition to controlling aggression. Helps store memories of events and emotions in order to recognize similar events in the future. For example, if you once got bit by a snake, the amygdala would help alerting this incident when you see another snake which causes your fear for snakes.

4. It plays another role in sexual activity and libido(sex drive). It changes in size based on age, hormonal activity, and gender of an individual. For example, males who have low levels of testosterone or may have had their testicles removed (transgender) tend to have a smaller amygdalae and as a result could have a lower sex drive.

5. The main function of the amygdala is whenever our bodies sense a change in our surroundings that could be harmful, the amygdala is responsible for preparing the body either to fight or flight. This part of the body is known as the startle circuit of the brain which controls our response to being startled😓. Our response involves the activation of the s ympathetic division of the peripheral nervous system which results in accelerated heart rate, d ilated pupils, and increase in blood flow.

6. Amygdala is only able to process sensory information and initiate behavior responses before the information reaches awareness in the center of the brain. It revives sensory information from 2 separate pathways: Short route: when the message is first sent to the thalamus then directly to the amygdala. (fast reaction) Long route: when the message travels from the cortex where it is evaluated then sent to the thalamus then the amygdala. ( slow reaction)

7. The amygdala also gets input from the medial prefrontal cortex, which is involved in the planning phase of the response, after the initial reflexive reactions, when you have to choose the best course of action to get you out of danger. While the amygdala is fully developed at birth, the prefrontal cortex does not mature until early adulthood. Because of this, children and adolescents do not always make rational decisions and cannot always control their emotions.

8. Importance of the amygdala A case study performed in the late 90's by John Downer at university collage London demonstrated the importance of the amygdala in aggressive behavior. Downer removed one amygdalae in rhesus (used in experimental medicine) monkeys, at the same time he transected the optic chasm and commissures that link the 2 hemispheres. So he basically produced an animal with a single amygdalae that has access only to visual inputs from the same side of the head. He found that the animals behavior depended on which eye was used to view the world. When the eye that the inspected amygdala views from was covered the monkey would behave with some respect; however, if the eye that the amygdala views from would be covered the monkey would act aggressive.

9. Results In the absence of an amygdalae, a monkey doesn‘t interpret the significance of the visual stimulus presented by an approaching human in the same way as a normal animal. Thus if the animal was touched on either side, a full aggressive reaction occurred, implying somatic sensory information about both sides had access to the remaining amygdalae. The amygdala processes that invest sensory experience with emotional significance.

10. A brain without an amygdala It is said that a brain without amygdala could still sense panic and fear as there other regions provide input to the amygdala therefor it is not the center of fear. (hippocampus) However, a case study published by neuroscience news on December 17,2010 states that a women SM with bilateral damage to the amygdala seems to be able to experience emotions such as happiness and sadness normally, but shows no sign of fear.

11. Case study of SM the emotional life of a unique individual who completely lacks the function of an almond-shaped structure in the brain known as the amygdala. Studies over the last 50 years have shown that the amygdala plays a central role in generating fear reactions in animals from rats to monkeys. Based on the detailed case study of the woman identified only as SM, it now appears that the same is true of humans . The finding offers a powerful take on the connection between the brain and behavior, specifically in the context of situations that would normally evoke fear, the researchers say . refer to handout. http://neurosciencenews.com/sm-fearless-woman-missing-amygdala/

12. THANK YOUUU!!!!😚❤