Concepts from the lectures on Information Cascades can be used to model the development of epilepsy from single events of induced seizures.  Seizures are a primary symptom of epilepsy, however, a person can have a seizure without being an epileptic.  Seizures can be induced by rapid consistent cycles of visual or auditory stimulation.  One very strong example of this, in recent history, is a paticular pokeman episode aired in Japan.  In this episode a space ship was blown up and to animate this the animators used repetetive blinking lights and colors.  These blinking lights and colors caused 5,000 Japanese children to have seizures that had never before suffered from seizures.

 Research has shown that induced seizures are due to a excessive excitatory state that is brought on by either low GABA activity (GABA is the inhibitory neurotransmitter) or abnormally high Glutamate levels (Glutamate is the brains excitatory neurotransmitter).  

 According to a lecture given by Ron Hoy a Cornell University P.I. repeated seemingly unrelated events of seizure seem to be able to develop into epilepsy.  This progression is due to neurological pathways reprogramming, sort to speak.  This reprogramming is like neurons ignoring their own signals and following the signals observed from others.  And this reprogramming does not occur following a single event of seizure but comes about after more than one round.  So, neurons observing two overally exitatory states will ignore their own signals and begin to have physiological changes that lead them to ignore their current exitatory states and instead follow this over exited state.  Multiple seizure events then lead to a disease state resembling epilepsy. 

This positive feedback loop can be likened to bubbles in markets thanks to information cascades.  Multiple rounds of market participants ignoring their own signals and choosing to purchase a paticular financial product due to the behavior of others they observe can lead to overpricing like seen in tech stocks at the end of the last century.  I am sure that many would consider disfunctional times like these in markets to be a disease state.