the hippocampus is coupled with the default network during memory retrieval but not during memory encoding海马体是加上默认网络在记忆检索但不是在记忆编码.pdf

The Hippocampus Is Coupled with the Default Network during Memory Retrieval but Not during Memory Encoding 1 1 2,3 1 Willem Huijbers , Cyriel M. A. Pennartz , Roberto Cabeza , Sander M. Daselaar * 1 Swammerdam Institute for Life Sciences, Faculty of Science, University of Amsterdam, Amsterdam, The Netherlands, 2 Center for Cognitive Neuroscience, Duke University, Durham, North Carolina, United States of America, 3 Department for Psychology and Neuroscience, Duke University, Durham, North Carolina, United States of America Abstract The brain’s default mode network (DMN) is activated during internally-oriented tasks and shows strong coherence in spontaneous rest activity. Despite a surge of recent interest, the functional role of the DMN remains poorly understood. Interestingly, the DMN activates during retrieval of past events but deactivates during encoding of novel events into memory. One hypothesis is that these opposing effects reflect a difference between attentional orienting towards internal events, such as retrieved memories, vs. external events, such as to-be-encoded stimuli. Another hypothesis is that hippocampal regions are coupled with the DMN during retrieval but decoupled from the DMN during encoding. The present fMRI study investigated these two hypotheses by combining a resting-state coherence analysis with a task that measured the encoding and retrieval of both internally-generated and externally-presented events. Results revealed that the main DMN regions were activated during retrieval but deactivated during encoding. Counter to the internal orienting hypothesis, this pattern was not modulated by whet