1. PHOBIAS AND THE BRAIN Azila Ariffin, Nurul Jawahir Mohd Zohdi 4 th year General Medicine 2014

2.  Phobia is sensation of extreme fear with stimulus  Physical manifestation  There are 3 basic type of phobia 1)Agoraphobia (fear of situation in which escape maybe find difficult) 2) Social phobia 3) Specific phobia Phobia

3.  Majority people have phobia without come in contact with their stimulus  Evolutionary development to avoid danger in order to improve survival  Fear conditioning experiment ( rhesus monkey) Theories of phobia

4.  Hyper activation of amygdala ( lateral nucleus)  LeDoux- 2 separate neurological pathway 1)Sensory thalamus – amygdala – quick response, imprecise information. 2)Goes straight away to sensory cortex – slow response, more detail understanding. Brain and phobias

5.  Lesions in the amygdala central nucleus interfere with every measure of uncontrolled fear  Abnormalities in the hippocampus ( memory) and the medial prefrontal cortex ( phenomenon of extinction) – persistence fear Phobic people

6.  Mutation in chromosome 15  Only manifest in later life  personality traits, culture  Example 1)agoraphobia (> in US than in Mongolia) 2)Taijin kyofusho – the fear of offending others through one’s social incapability ( in Japan only) Genetic role of phobic people

7.  Behavior therapy (exposure therapy) 1) Flooding 2) Modeling  Relaxation and hypnosis therapy  Cognitive therapy  Drugs – 1)Anti-anxiety agent ( benzodiazepine – Xanax and valium) 2)Beta blockers 3)Serotonin specific reuptake inhibitor ( Prozac, Paxil, Zoloft) Treatment

8.  MRI  CT  PET Imaging techniques

9. http://serendip.brynmawr.edu/bb/neuro/neuro02/web3/ mwhite.html Reference