How Processing Fluency Contributes to the Old/New Effects of Familiarity and Recollection: Evidence From the Remember/Know Paradigm

Abstract

Previous investigations have demonstrated FN400 and LPC, 2 event-related potential old/new effects that respectively reflect familiarity- and recollection-based processes in memory. However, it is unclear whether these effects are susceptible to processing fluency, particularly different types of processing fluency. To address this issue, applying a masked priming paradigm, we conducted an event-related potential experiment by manipulating semantic relations between the prime and the target as identical (reflecting perceptual fluency), thematically and taxonomically related (referring to conceptual fluency), and unrelated. A remember/know (R/K) judgment task in the test phase was used to distinguish familiarity- and recollection-based processes. Behaviorally, both task performance and response speed were modulated by the variables of priming condition, item type, and response type. All 4 priming conditions elicited significant FN400 and LPC. Compared with the K response, the R response was more relevant to the recollection-based processes reflected by LPC. Both FN400 and LPC were modulated by whether there was a response of R, K, or new. The former was susceptible only to conceptual fluency, and the latter was sensitive to both perceptual fluency and conceptual fluency, which offered telling evidence for the dual process model. Considerations for future investigations are proposed. See supplemental materials here: https://www.press.uillinois.edu/journals/ajp/media/evidence_in_remember_know_paradigm/

Differentiation of the Contribution of Familiarity and Recollection to the Old/New Effects in Associative Recognition: Insight from Semantic Relation

“…Before the formal experiment, we collected 1400 colourized pictures. Most of them were taken from the Hemera Photo-Objects Collection (of Canada), as in the previous literature [ 21 , 35 , 41 , 42 ], and a small amount were downloaded from the internet. Picture content included a variety of categories (e.g., people, animals, plants, landscapes, scenes, tools, and food), but they were not repeated, that is, we did not use pictures of different dogs or different pictures of one dog.…”

“…The first effect, which distributes over the central-frontal region during the epoch of approximately 300–500 ms post-stimulus onset (usually largest around 400 ms), manifests waveforms evoked by the correctly rejected novel items that are more negative-going than those by the accurately discriminated old ones, and this effect is also named the FN400 [ 11 , 14 , 15 , 17 , 18 ]. The second effect, which emerges late and is larger over the parietal scalp around the time window of 500–800 ms, commonly presents an enhanced positivity for the accurately identified studied stimuli, and it is also termed the LPC [ 11 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. The FN400 and LPC are thought to be the signals corresponding to familiarity and recollection processes, respectively [ 11 , 12 , 13 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

“…The second effect, which emerges late and is larger over the parietal scalp around the time window of 500–800 ms, commonly presents an enhanced positivity for the accurately identified studied stimuli, and it is also termed the LPC [ 11 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ]. The FN400 and LPC are thought to be the signals corresponding to familiarity and recollection processes, respectively [ 11 , 12 , 13 , 17 , 18 , 19 , 20 , 21 , 22 , 23 ].…”

“…In recent years, semantic relations are subdivided into three different types: thematic, taxonomic, and unrelated [ 21 , 33 , 50 , 51 , 52 ]. Thematic relations generally refers to the relation of different items that play different roles in the same scene, which depends on an individual’s experience and emphasizes the external relations between items.…”

“…For example, “lamp” and “table” hold a spatial relation because the former is usually located on the latter, and “joke” and “laugh” possess a cause-and-effect relation. Taxonomic relations are generally similarity based, where the similarity is defined as the shared attributes and overlapped features across items, such as “potato” and “eggplant” or “pen” and “pencil.” Comparatively, the items that are neither thematically related nor in a taxonomic relation are considered unrelated [ 21 , 33 , 51 , 52 , 53 ].…”