 Thus, there might be a particular stage in the memory process that is vulnerable to selective amnesia.The current hypothesis is that this vulnerable stage is located during the transition from active memory to short term memory.In an experiment investigating the functional role of the entorhinal cortex pars medialis in memory formation, Hölscher and Schmidt (1994) found that they could produce selective amnesia for specific types of memories by creating lesions in the brains of rats.