Lexical enhancement during prime–target integration: ERP evidence from matched-case identity priming

Abstract

A number of experiments have revealed that matched-case identity PRIME-TARGET pairs are responded to faster than mismatched-case identity prime-TARGET pairs for pseudowords (e.g., JUDPE-JUDPE < judpe-JUDPE), but not for words (JUDGE-JUDGE = judge-JUDGE). These findings suggest that prime-target integration processes are enhanced when the stimuli tap onto lexical representations, overriding physical differences between the stimuli (e.g., case). To track the time course of this phenomenon, we conducted an event-related potential (ERP) masked-priming lexical decision experiment that manipulated matched versus mismatched case identity in words and pseudowords. The behavioral results replicated previous research. The ERP waves revealed that matched-case identity-priming effects were found at a very early time epoch (N/P150 effects) for words and pseudowords. Importantly, around 200 ms after target onset (N250), these differences disappeared for words but not for pseudowords. These findings suggest that different-case word forms (lower-and uppercase) tap into the same abstract representation, leading to prime-target integration very early in processing. In contrast, different-case pseudoword forms are processed as two different representations. This word-pseudoword dissociation has important implications for neural accounts of visual-word recognition.Keywords Masked priming . ERP correlates . N250 . Visual-word recognition Despite the variability in physical appearance of a written word (e.g., house, HOUSE, house), skilled readers are able to access the appropriate lexical entry in a few hundreds of milliseconds. When and how the stimulus features are coded in an abstract manner are the main questions in this article. These are not trivial issues, since this process of abstraction might take place at an individual-letter level, at a graphemic level, at a whole-word level, or even at a semantic level. To make matters even more complex, feedforward and feedback connections might also exist among the levels.There is some consensus among researchers that a word's constituent letters are coded in an abstract form that is independent of its physical features (see Bowers, 2000, andThompson, 2009, for reviews). Although initially the wordprocessing system is sensitive to differences in the visual features of stimuli, these differences are quickly diffused by mapping these features onto unique orthographic abstract representations (see Dehaene, Cohen, Sigman, &Vinckier, 2005, andGrainger, Rey, &Dufau, 2008, for neurally motivated accounts of this phenomenon). The assumption that abstract representations are rapidly accessible during visualword recognition has come mainly from previous experimental evidence using the masked-priming technique (Forster & Davis, 1984; see Grainger, 2008, for a review; see Dehaene et al

Evidence from masked‐priming that initial identification of brand names is via abstract letter identities

“…(), who found that for pseudo‐words, but not for words, matched‐case identity PRIME–TARGET pairs were responded to faster than mismatched‐case identity prime–TARGET pairs. A similar finding was also reported by Vergara‐Martínez, Gómez, Jiménez, and Perea (). The explanation of these case‐specific identity priming effects for pseudo‐words and pseudo‐brands is not entirely clear, but presumably reflects non‐lexical processing (we return to this issue in the General Discussion).…”

“…() and Vergara‐Martínez et al . (). One possible explanation for the interaction of Prime Type and Target Case for pseudo‐brands is that it could reflect differences in the evidence accumulation process.…”

Do Diacritical Marks Play a Role at the Early Stages of Word Recognition in Arabic?

“…For instance, in a masked priming experiment, Jacobs et al (1995) found that the lowercase prime judge and the uppercase prime JUDGE were equally effective at activating the target word JUDGE (i.e., there was no advantage of the physically identical condition over the nominally identical condition). In an electrophysiological experiment, Vergara-Martínez et al (2015) replicated this behavioral phenomenon and found a difference between judge - JUDGE and JUDGE - JUDGE in an early (visual) ERP component (N/P150)—this difference completely disappeared in orthographical-lexical components (N250 and N400). Similarly, Bowers et al (1998) found an equivalent magnitude of masked identity priming, relative to an unrelated condition, for words that look visually similar across case (e.g., kiss - KISS ) and for cross-case words that look visually dissimilar across case (e.g., gale - GALE ).…”

The role of letter features in visual-word recognition: Evidence from a delayed segment technique

“…It appears that capacity benefits because of lexicality expressed in RT distributions can't accumulate unless a continuation of form constraint at the level of stroke-units is met. Importantly, the differences across the terminals-deleted, midsegments-deleted and junctions-deleted conditions -highlighted above -did not appear for nonword stimuli, which suggests either that top-down processes from lexical levels may be at play here (e.g., see Perea, Jiménez, & Gomez, 2014;Perea, Marcet, & Vergara-Martínez, 2016;Vergara-Martínez, Gomez, Jiménez, & Perea, 2015), or that already well before 60 ms after stimulus onset (cf. van Leeuwen, 2015) the activity of early neurons in visual cortex may become dependent on that of their neighbours through within-layer horizontal connections for familiar words.…”