When you walk into Elisabeth Murray’s office, you can see a 3-D model of the brain belonging to Patient H.M. (Henry Gustav Molaison), a man well known by students in psychology and neuroscience. In 1953, surgeons removed his medial temporal lobe in an attempt to stop his epileptic seizures. Although the surgery helped, there was an unfortunate side effect: He was unable to form new memories about individuals, objects, or events. He did, however, retain most of his memories formed prior to the procedure and could carry on a normal conversation, solve math problems, and write sentences. Based on this evidence, the prevailing dogma when Murray began her postdoctoral training in 1979 with Mortimer Mishkin at the National Institute of Mental Health (NIMH) was that specific areas within the medial temporal lobe—the hippocampus and amygdala—were the seeds of memory formation for previously encountered objects and people.
But when Murray began investigating the neural substrates of this recognition memory in the 1990s, she showed that the amygdala and hippocampus were not key for object-memory formation, but that two other regions within the medial temporal lobe—the entorhinal and perirhinal cortex—were. Her studies overturned long-standing theories about neurobiology at the time.