Recollection is more than retrieving context or source memory: evidence from ERPs of Recognition and Source Memory combinations

The goal of this study was to investigate a relatively unstudied memory condition for paradoxical combinations of item + source memory confidence responses, which challenged the conventional views of the memory processes supporting item and source memory judgments. We studied instances in which people provided accurate source memory judgments (conventionally ascribed as representing recollection) after having first produced low- confidence item recognition hits for the same items (conventionally thought to reflect familiarity-based processing). This paradoxical combination does not fit traditional accounts of being recollection (because it had low-confidence recognition) nor accounts of familiarity (since it had accurate source memory), and event-related potentials (ERPs) were used to adjudicate which processes support these kinds of memories. ERP results were unlike the conventional ERP effects of memory, lacking both an FN400 and the parietal old-new effect (LPC), and instead exhibited a significant negative-going ERP effect occurring later in time (800-1200ms) in central-parietal sites. Behavioral measures of response times revealed a crossover interaction: low confident recognition hits were slower during recognition but faster during source memory when compared to the opposite pattern seen for instances of high confident hits. Results provide a comprehensive characterization of the individual variability of the FN400 and LPC effects of memory, while adding the behavioral and physiological characterization of a late negative-going ERP effect for accurate source memory without recollection. Conclusions indicated that episodic context could be retrieved independently from recollection, while suggesting a role for a process of context familiarity that is independent from item-familiarity. HighlightsO_LIRecollection is often defined as remembering the source or context of information C_LIO_LIPrior work used ERPs to identify times when source memory did not have recollection C_LIO_LICurrent work replicated ERPs with added response times and measures of variance C_LIO_LIRecollection was not evident in certain source memories, which had a negative ERP C_LIO_LIRecollection is independent of context and is more than just remembering sources C_LI Graphical Abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=182 SRC="FIGDIR/small/339697v1_ufig1.gif" ALT="Figure 1"> View larger version (69K): org.highwire.dtl.DTLVardef@4926f8org.highwire.dtl.DTLVardef@9d87d4org.highwire.dtl.DTLVardef@40a701org.highwire.dtl.DTLVardef@9460f1_HPS_FORMAT_FIGEXP M_FIG C_FIG