Medial temporal lobe (MTL) is generally thought to be a principal site of long term memory (LTM) process, and isn’t usually associated with short term memory (STM). Some recent work have suggested a role for MTL in STM when binding of different elements is required. This study looked at the association of MTL structures with STM performance in memory for objects, location, and most critically, a conjunction of both, in a population of mild cognitive impairment (MCI) patients. Patients performed worse than age-matched controls in all tasks. Further, cortical thickness in MTL substructures was dissociably correlated along the long axis of the MTL. The dissociable regions were largely similar to the anterior posterior MTL networks described in older adults and MCI in our previous work.
This work highlights the relatively unexplored role of MTL in STM, in line with the vast literature of its fundamental role in LTM. It also shows a similar division of labor with respect to different types of memory representations along the anterior-posteriors axis of MTL. This project is a collaboration with David Wolk at the Penn Memory Center.