Abstract
Memory retrieval is thought to involve an interaction between a retrieval cue (or some elements of a memory) and a full memory trace. Memory models have proposed that the hippocampus plays a critical role in binding together the diverse elements of a memory, allowing holistic recollection of all elements. To investigate how the presented cue and the linked elements of a memory are represented in the hippocampus and cortical areas, we conducted an event-related functional magnetic resonance imaging (fMRI) experiment with a simple object association task. The task was comprised of separate learning and retrieval sessions. During the learning session, outside the scanner participants were trained to memorize object pairs for about one hour. During the retrieval session, one day after the learning session, participants were scanned, and instructed to see a cue object image (one of the learned objects), followed by a test phase. In the test phase, they were asked to decide whether the test object is paired with the cue object. Every participant showed good performance in the test (> 90% correct on average). Using multi-voxel pattern analysis, we found that during the presentation of a cue object, the response patterns of hippocampus showed greater similarity between paired objects compared to unpaired objects, while the response of object-selective visual cortex could be mainly used to decode the identity of the cue objects. These results suggest that hippocampal representation reflects integrative information of related objects even when incomplete information exists. This work was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI) funded by the Ministry of Health & Welfare, Republic of Korea (HI15C3175), and the National Research Foundation of Korea (NRF) grant funded by the Korea government (MSIP) (2016R1C1B2010726).
Meeting abstract presented at VSS 2017