Processing fluency hinders subsequent recollection: an electrophysiological study

Separating the role of perceptual and conceptual fluency on masked word priming using event-related potentials

Masked word repetition increases "old" responses on an episodic recognition test (Jacoby & Whitehouse, 1989). This effect is commonly attributed to perceptual fluency; that is, unconscious perception of the prime speeds reading of the target and this fluency leads to elevated familiarity. Two experiments directly tested the claim that perceptual fluency is responsible for word priming effects. Experiment 1 held prime-target meaning constant and altered the physical characteristics of match primes (e.g., "RIGHT" primes "RIGHT") by including both lowercase (e.g, "right") and mixed case primes (e.g., "rIgHt"). If word priming effects are due to perceptual fluency, then lowering the perceptual overlap between the prime and target should decrease or eliminate word priming effects. Instead, all three conditions showed robust priming effects in the behavioral and ERP (i.e., N400) measures. Experiment 2 equated the prime-target perceptual features and lowered the conceptual overlap by using orthographically similar nonwords as primes (e.g., "JIGHT" primes "RIGHT"). Removing prime-target conceptual overlap eliminated behavioral evidence of priming and N400 ERP differences correlated with priming. The evidence suggests that word priming effects on episodic recognition memory are more likely a product of conceptual fluency than perceptual fluency.

Event-Related Potential (ERP) evidence for fluency and disfluency effects on recognition memory

Masked priming is used in recognition memory studies to alter fluency and create familiarity. Primes are flashed briefly before target words that are considered for a recognition judgment. Matching primes are hypothesized to produce greater familiarity by increasing the perceptual fluency of the target word. Experiment 1 tested this claim by contrasting match primes (i.e., "RIGHT" primes "RIGHT"), semantic primes (e.g., "LEFT" primes "RIGHT"), and orthographically similar (OS) primes (e.g., "SIGHT" primes "RIGHT") while recording event-related potentials (ERPs). Relative to match primes, OS primes elicited fewer "old" responses and more negative ERPs during the interval associated with familiarity (300-500 ms). This result was replicated when control primes consisting of unrelated words (Experiment 2) or symbols (Experiment 3) were inserted into the sequence. The behavioral and ERP evidence suggest that word primes are perceived as a unit and the prime word activation will affect target fluency and recognition judgments. When the prime matches the target, fluency is increased and more familiarity experiences are created. When the primes are words that do not match the target, fluency is decreased (disfluency) and fewer familiarity experiences result. This evidence suggests that the effects of disfluency on recognition should be carefully considered.

Neural correlates of the Dunning-Kruger effect

The Dunning-Kruger effect (DKE) is a metacognitive phenomenon of illusory superiority in which individuals who perform poorly on a task believe they performed better than others, yet individuals who performed very well believe they under-performed compared to others. This phenomenon has yet to be directly explored in episodic memory, nor explored for physiological correlates or reaction times. We designed a novel method to elicit the DKE via a test of item recognition while electroencephalography (EEG) was recorded. Throughout the task, participants were asked to estimate the percentile in which they performed compared to others. Results revealed participants in the bottom 25th percentile over-estimated their percentile, while participants in the top 75th percentile under-estimated their percentile, exhibiting the classic DKE. Reaction time measures revealed a condition-by-group interaction whereby over-estimators responded faster than under-estimators when estimating being in the top percentile and responded slower when estimating being in the bottom percentile. Between-group EEG differences were evident between over-estimators and under-estimators during Dunning-Kruger responses, which revealed FN400-like effects of familiarity supporting differences for over-estimators, whereas "old-new" memory event-related potential effects revealed a late parietal component associated with recollection-based processing for under-estimators that was not evident for over-estimators. Findings suggest over- and under-estimators use differing cognitive processes when assessing their performance, such that under-estimators may rely on recollection during memory while over-estimators may draw upon excess familiarity when over-estimating their performance. Episodic memory thus appears to play a contributory role in metacognitive judgements of illusory superiority.

The effect of conceptual priming on subsequent familiarity: Behavioral and electrophysiological evidence

Previous studies on the neural mechanisms of how priming influences subsequent recognition memory have mainly focused on repetition priming, whereas the neural mechanisms of how conceptual priming affects subsequent recognition memory is still not clear. The present study investigated the electrophysiological correlates of how conceptual priming influences subsequent recognition memory. The behavioral results showed that conceptual priming only affected subsequent familiarity. The ERP results showed that conceptual priming was associated with reduced N400, and that the N400 conceptual priming effect predicted the behavioral effect of conceptual priming on subsequent familiarity. These results indicated that conceptual priming could influence subsequent familiarity by facilitating semantic processing in the encoding phase.

The Influence of Hierarchical Masks on Masked Repetition Priming: Evidence From Event-Related Potential Investigation

The discussion about relationship between prime and target has contributed to the mechanism of priming effect and object recognition. Nevertheless, the role of relationship between mask and target in those cognitive processes remains unquestioned. In the present study, we aim to investigate how mask-target hierarchical relationship may affect word priming and familiarity, by using the masked repetition paradigm and manipulating three hierarchical relationship between mask and target. It is hypothesized that a closer hierarchical relationship between mask and target is associated with a higher mask target similarity, and thereby it leads to a worse recognition performance. Our behavioral results do not support this hypothesis by showing no effect of mask target hierarchical relationship on response time (RT) and accuracy. Event-related potentials (ERPs) indicated that highly similar mask-target triggered (i.e., the subordinate-subordinate-subordinate trials) larger N1 amplitudes, suggesting that it requires more cognitive resource to discriminate the stimuli. In addition, trials with highly similar mask-target hierarchical relationship induced smaller P2 (150–250 ms) and larger mid-frontal FN400 amplitudes than do trials with low mask-target similarity (i.e., the subordinate-basic-subordinate and the subordinate-superordinate-subordinate trials). Our results suggested that the similarity between mask and target may impede conceptual fluency to reduce word priming and familiarity effect.

The temporal dynamics of perceptual and conceptual fluency on recognition memory

Recognition memory can be driven by both perceptual and conceptual fluency, but when and to what extent they contribute to recognition memory remains an open question. The present study used event-related potentials (ERPs) to investigate the neural correlates of perceptual and conceptual fluency, when they gave rise to recognition. We manipulated the perceptual and conceptual fluency of retrieval cues in the recognition test independently to obtain the effects of different types of fluency. Behavioral results showed that perceptual fluency selectively affected K hits, while conceptual fluency affected R hits and K false alarms. In addition, conceptual fluency facilitated the response times of R hits. The ERP results showed that perceptual fluency effect appeared at 100-200 ms and conceptual fluency effect appeared at 300-500 ms. The parietal LPC peaked earlier for conceptually primed trials compared to unprimed trials. These results suggest that perceptual and conceptual fluency had different effects on recognition judgments, and these two types of fluency can be delineated by distinct ERP correlates. The current finding indicates that unconscious memory processes can support recognition and have provided insights into the underlying mechanism involved in recognition memory.

Subliminal Priming-State of the Art and Future Perspectives

The influence of subliminal priming (behavior outside of awareness) in humans is an interesting phenomenon and its understanding is crucial as it can impact behavior, choices, and actions. Given this, research about the impact of priming continues to be an area of investigative interest, and this paper provides a technical overview of research design strengths and issues in subliminal priming research. Efficient experiments and protocols, as well as associated electroencephalographic and eye movement data analyses, are discussed in detail. We highlight the strengths and weaknesses of different priming experiments that have measured affective (emotional) and cognitive responses. Finally, very recent approaches and findings are described to summarize and emphasize state-of-the-art methods and potential future directions in research marketing and other commercial applications.

Separating Event-related Potential Effects for Conceptual Fluency and Episodic Familiarity

ERP old/new effects have been associated with different subprocesses of episodic recognition memory. The notion that recollection is reflected in the left parietal old/new effect seems to be uncontested. However, an association between episodic familiarity and the mid-frontal old/new effect is not uncontroversial. It has been argued that the mid-frontal old/new effect is functionally equivalent to the N400 and hence merely reflects differences in conceptual fluency between old and new items. Therefore, it is related to episodic familiarity only in situations in which conceptual fluency covaries with familiarity. Alternatively, the old/new effect in this time window reflects an interaction of episodic familiarity and conceptual processing with each making a unique functional contribution. To test this latter account, we manipulated conceptual fluency and episodic familiarity orthogonally in an incidental recognition test: Visually presented old and new words were preceded by either conceptually related or unrelated auditory prime words. If the mid-frontal old/new effect is functionally distinguishable from conceptual priming effects, an ERP contrast reflecting pure priming (correct rejections in the related vs. unrelated condition) and a contrast reflecting priming plus familiarity (hits in the related vs. correct rejections in the unrelated condition) should differ in scalp distribution. As predicted, the pure priming contrast had a right-parietal distribution, as typically observed for the N400 effect, whereas the priming plus familiarity contrast was significantly more frontally accentuated. These findings implicate that old/new effects in this time window are driven by unique functional contributions of episodic familiarity and conceptual processing.