Contributions Of The Medial Prefrontal Cortex To Managing Memory And Resolving Mnemonic Interference
Mnemonic interference is the failure to retrieve a target memory due to the presence of other memories. Interference indicates underlying principles of memory organization, most notably that there is an interdependent structure to memories. Interference is potentially problematic for retrieval in systems that store many memories, yet there is substantial evidence for neural mechanisms dedicated to managing interference in support of memory retrieval. This evidence indicates that the prefrontal cortex (PFC) is a critical structure for combatting interference. However, the majority of this evidence is derived from human imaging studies and behavior studies involving human subjects with non-specific PFC damage, which lack the experimental control to examine the precise neural operations that manage interference. Surprisingly, few animal models exist that explicitly examine the role of the PFC in managing mnemonic interference. This discrepancy may be due to a diverse literature on the functional contribution of the PFC, including its involvement in a variety of processes that fall under the broad category of executive control. Animal studies have modeled some of these other executive functions, particularly the PFC role in behavioral flexibility and task switching. This thesis argues that many executive functions attributed to the PFC and modeled in animals involve an underlying need to resolve conflict in neural representations developed over learning. This view may reduce the number of attributes needed to characterize PFC function. I test this hypothesis by examining the role of PFC in resolving mnemonic interference in rats and comparing this evidence to other animal models of PFC function. These studies provide strong evidence that the PFC is critical for the normal management of interference in rats, which is consistent with the human literature. Together this evidence indicates a fundamental role for PFC in managing mnemonic competition, which opens the door for detailed investigations of neural mechanisms of interference resolution in animal models of memory.
Prefrontal Cortex; Mnemonic Interference; Cognitive Flexibility
Cleland,Thomas A.; Cutting,James Eric; Devoogd,Timothy John
Ph. D., Psychology
Doctor of Philosophy
dissertation or thesis