It presents with similar symptoms of decreased fear and aggression but with the addition of the inability to recognize emotional expressions, especially angry or fearful faces.The amygdalas role in learned fear includes interactions with other brain regions in the neural circuit of fear. While damage in the amygdala can inhibit its ability to recognize fearful stimuli, other areas such as the ventromedial prefrontal cortex and the basolateral nuclei of the amygdala can affect the regions ability to not only become conditioned to fearful stimuli but to extinguish them eventually. Through receiving stimulus info, the basolateral nuclei undergo synaptic changes that allow the amygdala to develop a conditioned response to fearful stimuli. Damage to this area, therefore, have been shown to disrupt the acquisition of learned responses to fear. Likewise, damage in the ventromedial prefrontal cortex (the area responsible for monitoring the amygdala) has been shown to slow down the speed of extinguishing a learned fear response and how effective the extinction is. This suggests there is a pathway or circuit among the amygdala and nearby cortical areas that process emotional stimuli and influence emotional expression, all of which can be disrupted when damage occurs. Diagnosis
It is recommended that the terms distress and impairment take into account the context of the persons environment during diagnosis. The DSM-IV-TR states that if a feared stimulus, whether it be an object or a situation, is absent entirely in an environment, a diagnosis cannot be made.
When dealing with fear, the hippocampus receives impulses from the amygdala that allow it to connect the fear with a certain sense, such as a smell or sound. Amygdala
The amygdala is an almond-shaped mass of nuclei located deep in the brains medial temporal lobe. It processes the events associated with fear and is linked to social phobia and other anxiety disorders. The amygdalas ability to respond to fearful stimuli occurs through fear conditioning. Like classical conditioning, the amygdala learns to associate a conditioned stimulus with a negative or avoidant stimulus, creating a conditioned fear response often seen in phobic individuals. The amygdala is responsible for recognizing certain stimuli or cues as dangerous and plays a role in the storage of threatening stimuli to memory. The basolateral nuclei (or basolateral amygdala) and the hippocampus interact with the amygdala in-memory storage. This connection suggests why memories are often remembered more vividly if they have emotional significance.In addition to memory, the amygdala also triggers the secretion of hormones that affect fear and aggression. When the fear or aggression response is initiated, the amygdala releases hormones into the body to put the human body into an "alert" state, which prepares the individual to move, run, fight, etc. This defensive "alert" state and response are known as the fight-or-flight response.However, inside the brain, this stress response can be observed in the hypothalamic-pituitary-adrenal axis (HPA). This circuit incorporates the process of receiving stimuli, interpreting them, and releasing certain hormones into the bloodstream.