Research in our laboratory examines how memories acquired long ago are represented in the brain.  Damage to the hippocampus results in severe amnesia, but there is controversy surrounding the specific types of memory that are compromised.  Some believe that the hippocampus is always necessary for finding one’s way in an environment (spatial memory), whereas others view this structure as necessary for re-experiencing the details of personal life events (episodic memory).  Still, others believe that it plays a time-limited role in all sorts of declarative memories, similar to its role in representing knowledge about the world that is not tied to any one event (semantic memory). 

Our work addresses the following questions:

1.  What is the role of the hippocampus and other memory structures in storing and retrieving very old memories?  For example, is the hippocampus always necessary for re-experiencing the details of personal life events? 

2.  How is spatial memory related to memory for personal events and for facts?

3.  How does reconstructing past autobiographical episodes relate to non-mnemonic abilities, such as imagining events that have never occurred or deciphering other people’s current mental states? 

Methods of investigation include neuropsychological testing of patients with damage to the medial temporal lobes and prefrontal cortex, and structural and functional MRI of patient and healthy populations.  Findings from this research will hopefully add to our understanding of the relationship among different types of memory and their breakdown following brain damage.