An event-related potential study of cross-modal morphological and phonological priming

Abstract

a b s t r a c tThe current work investigated whether differences in phonological overlap between the past-and present-tense forms of regular and irregular verbs can account for the graded neurophysiological effects of verb regularity observed in past-tense priming designs. Eventrelated potentials were recorded from 16 healthy participants who performed a lexical-decision task in which past-tense primes immediately preceded present-tense targets. To minimize intra-modal phonological priming effects, cross-modal presentation between auditory primes and visual targets was employed, and results were compared to a companion intra-modal auditory study (Justus, T., Larsen, J., de Mornay Davies, P., Swick, D. (2008). Interpreting dissociations between regular and irregular past-tense morphology: evidence from event-related potentials. Cognitive, Affective, Behavioral Neuroscience, 8,[178][179][180][181][182][183][184][185][186][187][188][189][190][191][192][193][194]. For both regular and irregular verbs, faster response times and reduced N400 components were observed for present-tense forms when primed by the corresponding past-tense forms. Although behavioral facilitation was observed with a pseudopast phonological control condition, neither this condition nor an orthographic-phonological control produced significant N400 priming effects. Instead, these two types of priming were associated with a post-lexical anterior negativity (PLAN). Results are discussed with regard to dual-and single-system theories of inflectional morphology, as well as intra-and cross-modal prelexical priming.

The role of Broca's area in regular past-tense morphology: An event-related potential study

“…In our previous studies using this experimental design, priming between corresponding past-and present-tense forms resulted in reductions of the N400, and in some cases, modulations of the late positive component, or LPC (Justus et al, 2008, 2009). The N400 is a negative-going wave that peaks approximately 400 ms after stimulus onset.…”

“…In others it is modulated by repetition and has been linked to explicit memory processes (e.g., Olichney et al, 2000). Using the current experimental design, we previously observed a modulation of the LPC effect over anterior electrodes in response to word-onset ortho-phonological overlap, which we referred to as a post-lexical anterior negativity or PLAN (Justus et al, 2009). Other authors have reported similar reverse-direction repetition effects, including Holcomb et al (2005, Exp.…”

“…Thus, the single dissociation represented by the lack of regular past-tense priming may simply represent a failure to observe a less robust effect (regular-verb priming) due to the additional variability and statistical noise, whereas a more robust effect (irregular-verb priming) continues to be observed. Indeed, one notable aspect of this experimental design is that in healthy controls, irregular verbs consistently prime numerically, and sometimes significantly, more strongly than regular verbs do (Marslen-Wilson & Tyler, 1997; Tyler et al, 2002a; Tyler et al, 2004; Longworth et al, 2005a; Justus et al, 2008, 2009). This pattern is not to be confused with a different dissociation that is sometimes found when there are intervening items between prime and target.…”

“…The literature on phonological priming suggests that a combination of pre-lexical facilitation, lexical inhibition, and post-lexical, strategic processes operate simultaneously in designs employing word-onset overlap (McQueen & Sereno, 2005; see Justus et al, 2009, for a review). However, Tyler and colleagues (2002a) did not observe significant phonological priming in controls using the auditory immediate-priming design with lexical decision, making it difficult to evaluate their claims regarding the special status of the inflectional rhyme pattern in this experimental design.…”

“…This would be most consistent with the dual-system approach, which argues that the rule-based regular affixation pattern either is or is not applicable (Pinker & Ullman, 2002). If, however, the preserved irregular-verb priming were greater for the strong verbs compared to the weak irregular verbs, this would suggest that the regular-irregular dissociation represents a continuous, graded effect (Justus et al, 2008, 2009). Marslen-Wilson and Tyler’s (2007) IRP viewpoint, while still positing a categorical division between regular and irregular verbs, might accommodate some degree of continuity in priming effects given that about half of the weak irregular pasts in English contain the inflectional rhyme pattern.…”