ERP Evidence for an Interaction between Phonological and Semantic Processes in Masked Priming Tasks

ERP Evidence for an Interaction between Phonological and Semantic Processes in Masked Priming Tasks Caroline Jacquier (jacquier@isc.cnrs.fr) Aicha Rouibah (rouibah@isc.cnrs.fr) Institut des Sciences Cognitives, 67 boulevard Pinel 69500 Bron, France Michel Hoen(hoen@isc.cnrs.fr) Laboratoire Dynamique Du Langage, 14 avenue Berthelot 69007 Lyon, France Thus, phonological processing would be both automatic and obligatory during visual word recognition. Abstract Two masked priming experiments investigated the time- course of phonological and semantic processes implicated in visual word recognition as well as their possible interaction, using event-related brain potentials (ERPs). Participants read target words which were phonologically related, semantically related, both phonologically and semantically related or unrelated to a masked prime word. In experiment 1, participants performed a phonological task (decide whether targets rhymed with a previously heard rhyme). The phonological relation elicited a frontal negativity whereas the semantic relation elicited a left anterior negativity, both followed by an N400 at centro-parietal sites. In experiment 2, participants performed a semantic task (decide whether targets belonged to a previously presented semantic category). In contrast to experiment 1, phonological and semantic relations elicited an N400 over frontal sites. Together, these results demonstrate that phonological and semantic processes interact during visual word recognition. Phonology: a Mediator to Meaning Access Keywords: Word Recognition; Masked Priming; Phonology; Semantic; Event-Related brain Potentials (ERPs). Introduction Phonology: an Obligatory Stage Although many studies were interested in the determining of cognitive processes implicated in printed word recognition, there have yet been few studies dedicated to phonological information processing and its potential interaction with semantic information processing. For a long time, phonological processing was considered as an optional stage during word recognition. But recent studies (Berent & Perfetti, 1995; Van Orden, 1987; Hillinger, 1980) have shown much clearer that phonology might well be an obligatory stage during the processing of visual words. For instance, Berent and Perfetti (1995) have observed that non-word primes, phonologically related to target words, induced better identification rates than non-word primes that were orthographically related to target words. Moreover, phonological processing seems unavoidable because it appears even if phonological manipulations are unconscious and alter subject’s performance (Tanenhaus, Flanigan, & Seidenberg, 1980). Over the past 20 years, the direct access view has been strongly called into question. Van Orden (1987) has reported clear evidence for phonological mediation during meaning access. In a semantic decision task, homophones of words belonging to a semantic category (e.g., MEET the homophone of MEAT), were more often incorrectly classified as belonging to the category FOOD than orthographically similar but non homophone words (e.g., MELT). The false-positive responses suggest that phonological information was activated and used to access meaning. Lesch and Pollatsek (1993) and Lukatela and Turvey (1994) have extended this homophone effect in the context of masked priming paradigms. They have reported that the phonological facilitation effect appeared at short prime exposure durations. And they concluded: “The data thus provide support for a model of word recognition in which meaning is rapidly and automatically accessed through a phonological code” (Lesch & Pollatsek, 1993, p.291). Perfetti, Bell, and Delaney (1988) have suggested that the phonological form of a word is activated automatically and at a very early stage in processing. According to Plaut, McClelland, Seidenberg, and Patterson (1996), an orthography-phonology (OP) and an orthography-semantic-phonology (OSP) pathways would exist. It is generally accepted that at least two pathways exist for reading words, but their exact nature and their mode of interaction are still actively discussed. Interaction between Phonology and Semantic As such, phonological priming effects should generally be observed in masked priming experiments, for tasks such as naming or lexical decision. Thus, the question is whether the same is true in a task for which phonological processing of the target is completely irrelevant. Rouibah, Tiberghien and Lupker (1999) have shown that priming effects based on phonological similarity can be obtained even when the task itself does not require the retrieval of phonological information. They have also tested