Nonstrategic subjective threshold effects in phonemic masking

Abstract

Three backward-masking experiments demonstrated that the magnitude of the phonemic mask reduction effect (MRE) is a function of subjective threshold and that the magnitude is also independent of stimulus-based response strategies. In all three experiments, a target word (e.g, bake) was backward masked by a graphemically similar nonword (e.g, BAWK), a phonemically similar nonword (e.g., BAlK), or an unrelated control (e.g., CRUG), Experiments 1 and 2 had a low percentage (9O,{,) of trials withphonemic masks and differed only in baseline identification rate, Experiment 3 controlled baseline identification rate at below and above subjective threshold levels, with 90;6 phonemic trials. The results were that identification rates were higher with phonemic masks than with graphemic masks, irrespective of the low percentage of phonemic trials. However, the magnitude of the phonemic MRE became large only when the baseline identification rate was below subjective threshold. The pattern ofthe phonemic MRE was interpreted as a result of rapid automatic phonological activation, independent of stimulusbased processing strategies, Over the last two decades, a number of studies using brief-stimulus-presentation and masked-stimuluspresentation paradigms have reported phonological effects in visual word identification (e.g., Lukatela & Turvey, 1994a, 1994bNaish, 1980;Perfetti & Bell, 1991;Perfetti, Bell, & Delaney, 1988;Perfetti & Zhang, 1991;Van Orden, 1987;Van Orden, Johnston, & Hale, 1988). These effects have been taken as major evidence for a rapid, automatic, and obligatory phonological process during lexical access, However, recently, several researchers have raised questions about these findings, particularly about the phonemic mask reduction effect (MRE) reported in studies using backward-masking paradigms (Brysbaert & Praet, 1992;Verstaen, Humphreys, Olson, & D'Ydewalle, 1995). For example, Brysbaert and Praet (1992) suggested that the phonemic MRE observed with these paradigms may be influenced by stimulus composition. They found that a phonemic MRE occurred when the list contained a high percentage (about 80%) of homophones but not when the percentage of homophones was low (below 18%). This result led Brysbaert and Praet to conclude that the phonemic MRE reported in previous studies might have been due to participants' strategic use ofphonological information instead of an obligatory process of phonology.The study reported in this paper was completed when the first author was at the University of Pittsburgh. The authors would like to thank Guy Van Orden and the two other reviewers for their critique and helpful comments on the manuscript. The authors are also grateful to Robert Lorch for his suggestions for the improvement ofthe manuscript and to Maria Walsh and Mara Georgi for their help in conducting the experiments. Correspondence should be addressed to B. Xu, National Institute of Neurological Disorders and Stroke, National Institutes of Health, 5N 250 Bldg. 10, Center Dr. MSC 140, Bethesda, MD 20892 (e-mail: benx...

Strategic effects in associative priming with words, homophones, and pseudohomophones.

“…Once the stored representation has been activated, additional information about the exact pronunciation and spelling becomes available. In such a view, pre-lexical phonological coding is mandatory but the use of lexically supported phonology may be under strategic control (e.g., Berent & Perfetti, 1995;Frost, 1998;Gibbs & Van Orden, 1998;Xu & Perfetti, 1999). Berent (1997) directly addressed the issue of mandatory pre-lexical phonological assembly versus strategic reliance on post-lexical phonology by running a lexical decision task in which the target words were preceded by masked primes.…”

“…Using a backward masking paradigm, these authors only got a significant phonological masking effect when the majority of trials contained pseudohomophonic masks. Brysbaert and Praet's findings have been criticized on various grounds (e.g., Xu & Perfetti, 1999), but only recently has it become clear that phonological effects in Dutch are difficult to obtain with the backward masking paradigm and can be more easily observed with the masked priming technique (Brysbaert, 2000). Whatever the exact reason of Brysbaert and Praet's (1992) findings, they warn us that nothing sensible can be said about the extension of the phonological priming effect to the lexical decision task, if the effect has not first been replicated with the original naming task.…”

Visual word recognition in bilinguals: Phonological priming from the second to the first language.

“…The prototype of this type of task is the masked priming paradigm. Using that paradigm, researchers have reported a net phonological priming effect under a variety of circumstances that would reduce the reliance on phonological information if the system had any strategic control on the use of this information (Berent, 1997;Brysbaert, 2001;Xu & Perfetti, 1999). Brysbaert et al (1999) reasoned that a strong phonological model of visual word recognition also has implications for bilingual language processing.…”

Prelexical phonological coding of visual words in Dutch: Automatic after all

“…Second, Berent and Perfetti argued that the participants may have partly ignored the masks in the condition with a lot of unrelated masks (a criticism repeated by Ferrand, 1995). Two more criticisms were added by Xu and Perfetti (1999). First, they pointed out that the percentage of target recognition in the unrelated control condition was rather high in Brysbaert and Praet's experiments (more than 50%).…”

“…Because participants in Verstaen et al's (1995) experiments were aware of the fact that a lot of the target words were homophones, many authors have considered this strategic effect as one that is comparable to the strategic effects in naming and lexical decision, the more so because the dependent variable (percentage correct target identification) did not allow on-line measurement of word processing (see, e.g., Xu & Perfetti, 1999). …”