Distinct brain networks in recognition memory share a defined region in the precuneus

Current models of recognition memory performance postulate that there are two fundamentally distinct retrieval processes, i.e. recollection and familiarity. This view has been challenged and little is known from human research about the functional connectivity of the brain areas involved in these processes. In our study we used a Remember-Know procedure to assess the functional connectivity of brain regions under recognition memory in 30 healthy adults. Using functional magnetic resonance imaging, we analysed the blood oxygen level-dependent responses during correct Remember, correct Know, correct Rejection and missed responses of the subjects during recognition of non-emotional nouns. One activation cluster was found in the left precuneus associated with both recollection and familiarity answers. To acquire information about the way in which activity in one brain region modulates activity in another brain region in response to the active task, we performed a psychophysiological interaction analysis with the left precuneus as a seed region. This analysis revealed functionally distinct networks of brain areas underlying recollection and familiarity. Furthermore, we discuss the differential involvement of the hippocampus in a recollection network as compared with a familiarity network. In summary, our results further strengthen the assumptions of a dual-process view of recognition memory [e.g. H. Eichenbaum et al. (2007) Annual Review of Neuroscience, 30, 123-152; A.P. Yonelinas (2001) Philosophical Transactions of the Royal Society London B Biological Sciences, 356, 1363-1374] and add empirical findings about the functional interconnectivity of brain regions supporting either recollection or familiarity.