Functional significance of retrieval‐related activity in lateral parietal cortex: Evidence from fMRI and ERPs

Abstract

The present study addressed the question whether neural activity in left lateral parietal cortex is modulated by amount of information recollected. In two experiments (one using fMRI, the other ERPs) subjects first studied pairs of pictures presented for either one or six seconds. They then performed a standard 'Remember/Know' recognition memory test in which the old items comprised one of the pictures from each studied pair. In both experiments, a surprise post-test indicated that subjects recollected more details about the study presentation of the items presented for the longer duration. In the fMRI experiment, recollection-and familiarity-based recognition elicited activity in distinct cortical networks. Additionally, recollection-related activity in left inferior parietal cortex was of greater magnitude for test items presented for six seconds than for one second. In the ERP study the 'left-parietal old/new effect' -a putative correlate of successful recollection -was likewise modulated by amount of information retrieved. Together, these findings provide further support for dual-process models of recognition memory and add weight to the proposal that retrieval-related activity in left inferior parietal cortex reflects processes supporting the online representation of retrieved episodic information.Keywords episodic memory; recognition memory; remember-know; event-related potential; episodic buffer Numerous functional neuroimaging studies have implicated the left posterior parietal cortex in recognition memory (for reviews see Wagner et al., 2005;Skinner & Fernandez, 2007; Ciaramelli, Grady, & Moscovitch, in press; Vilberg & Rugg, in press). Activity in this region has been reported to dissociate according to whether recognition judgments are made on the basis of recollection, when contextual information from a study episode is recovered, as opposed to familiarity, when an item is recognized without contextual retrieval (e.g., Yonelinas et al., 2005;Wheeler & Buckner, 2004; see also Vilberg & Rugg, in press). Whereas recollection-sensitive left parietal activity tends to be located in and slightly posterior to the angular gyrus (Brodmann Area (BA) 39/19), familiarity-sensitive regions are located more superiorly in the vicinity of the intraparietal sulcus (IPS; BA 7). Current evidence suggests that the left parietal region associated with familiarity is actually responding to something akin to the salience of the eliciting test items rather than directly reflecting a memory signal (Vilberg & Rugg, in press), but the functional significance of recollection-related left inferior parietal activity remains unclear.Correspondence: Kaia L. Vilberg, Center for the Neurobiology of Learning and Memory, University of California Irvine, Irvine, CA 92697-3800. Email: E-mail: kvilberg@uci.edu. NIH Public Access NIH-PA Author Manuscript NIH-PA Author Manuscript NIH-PA Author ManuscriptIn a recent study (Vilberg & Rugg, 2007) we attempted to adjudicate between two competing hypotheses regarding the role of the ...

Is a novel conceptual unit more than the sum of its parts?: FMRI evidence from an associative recognition memory study

“…In addition, one cluster in the parahippocampal cortex was revealed only in the reversed > new contrast with an activation pattern that is very similar to the one observed in the hippocampus. All these regions were previously identified as being associated with recollective processing (e.g., Dobbins, Rice, Wagner, & Schacter, 2003;Henson et al, 2005;Henson, Rugg, Shallice, Josephs, & Dolan, 1999;Vilberg & Rugg, 2009;Yonelinas et al, 2005). Thus, these results are in line with the prediction that associative recognition of word pairs which were studied as separate lexical items within sentence frames recruits a network typically associated with recollection.…”

Posterior parietal cortex and episodic retrieval: Convergent and divergent effects of attention and memory

“…The first reports of parietal old/new effects came from studies using electroencephalography, which revealed event-related potentials (ERPs) that differed in amplitude over (primarily left) lateral parietal scalp sites in response to hits relative to CRs, with an onset of around 400 ms post-stimulus (for review, see Rugg and Curran 2007). A rich body of evidence suggests that this effect reflects the recollection of contextual details from an episode, rather than simple item familiarity (e.g., Smith 1993;Wilding et al 1995;Allan et al 1998;Curran 2000;Curran and Cleary 2003;Woodruff et al 2006;Vilberg and Rugg 2008a).…”

Stages of Processing in Associative Recognition: Evidence from Behavior, EEG, and Classification

“…It has been suggested that the effect is sensitive to the amount of information recollected (Vilberg & Rugg, 2009;Vilberg, Moosavi, & Rugg, 2006;Wilding, 2000), although the relevant evidence comes from judgments of recollected details rather than manipulations of associative fan. Likewise, Nyhus and Curran (2009) found that the parietal old/ new effect interacted with associative fan.…”