Pre-experimental Familiarization Increases Hippocampal Activity for Both Targets and Lures in Recognition Memory: An fMRI Study

摘要

In the present study, items pre-exposed in a familiarizationnseries were included in a list discrimination task to manipulatenmemory strength. At test, participants were required to discriminatenstrong targets and strong lures from weak targets and newnlures. This resulted in a concordant pattern of increased “old”nresponses to strong targets and lures. Model estimates attributednthis pattern to either equivalent increases in memory strengthnacross the two types of items (unequal variance signal detectionnmodel) or equivalent increases in both familiarity and recollectionn(dual process signal detection [DPSD] model). Hippocampalnactivity associated with strong targets and lures showednequivalent increases compared with missed items. This remainednthe case when analyses were restricted to high-confidence responsesnconsidered by the DPSD model to reflect predominantlynrecollection. A similar pattern of activity was observed in parahippocampalncortex for high-confidence responses. The presentnresults are incompatible with “noncriterial” or “false” recollectionnbeing reflected solely in inflated DPSD familiarity estimates andnsupport a positive correlation between hippocampal activity andnmemory strength irrespective of the accuracy of list discrimination,nconsistent with the unequal variance signal detectionnmodel account.