Lexical competition in phonological priming: Assessing the role of phonological match and mismatch lengths between primes and targets

In five experiments, we examined lexical competition effects using the phonological priming paradigm in a shadowing task. Experiments 1A and 1B replicate and extend Slowiaczek and Hamburger's (1992) observation that inhibitory effects occur when the prime and the target share the first three phonemes (e.g., /bRiz/-/bRik/) but not when they share the first two phonemes (e.g., /bRepsilonz/-/bRik/). This observation suggests that lexical competition depends on the length of the phonological match between the prime and the target. However, Experiment 2 revealed that an overlap of two phonemes is sufficient to cause an inhibitory effect provided that the primes mismatched the targets only on the last phoneme (e.g., /b[symbol: see text]l/-/b[symbol: see text]t/). Conversely, with a three-phoneme overlap, no inhibition was observed in Experiment 3 when the primes mismatched the targets on the last two phonemes (e.g., /bagepsilont/-/baga3/). In Experiment 4, an inhibitory effect was again observed when the primes mismatched the targets on the last phoneme but not when they mismatched the targets on the last two phonemes when the time between the offset of overlapping segments in the primes and the onset of overlapping segments in the targets was controlled for. The data thus indicate that what essentially determines prime-target competition effects in word-form priming is the number of mismatching phonemes.     

Phoneme‐Order Encoding During Spoken Word Recognition: A Priming Investigation

In three experiments, we examined priming effects where primes were formed by transposing the first and last phoneme of tri‐phonemic target words (e.g., /byt/ as a prime for /tyb/). Auditory lexical decisions were found not to be sensitive to this transposed‐phoneme priming manipulation in long‐term priming (Experiment 1), with primes and targets presented in two separated blocks of stimuli and with unrelated primes used as control condition (/mul/‐/tyb/), while a long‐term repetition priming effect was observed (/tyb/‐/tyb/). However, a clear transposed‐phoneme priming effect was found in two short‐term priming experiments (Experiments 2 and 3), with primes and targets presented in close temporal succession. The transposed‐phoneme priming effect was found when unrelated prime‐target pairs (/mul/‐/tyb/) were used as control and more important when prime‐target pairs sharing the medial vowel (/pys/‐/tyb/) served as control condition, thus indicating that the effect is not due to vocalic overlap. Finally, in Experiment 3, a transposed‐phoneme priming effect was found when primes sharing the medial vowel plus one consonant in an incorrect position with the targets (/byl/‐/tyb/) served as control condition, and this condition did not differ significantly from the vowel‐only condition. Altogether, these results provide further evidence for a role for position‐independent phonemes in spoken word recognition, such that a phoneme at a given position in a word also provides evidence for the presence of words that contain that phoneme at a different position.     

Temporary ambiguity in whispered word recognition: a semantic priming study

We examined whether listeners use acoustic correlates of voicing to resolve lexical ambiguities created by whispered speech in which a key feature, the voicing, is missing. Three associative priming experiments were conducted. The results showed a priming effect with whispered primes that included an intervocalic voiceless consonant (/petal/ “petal”) when the visual targets (FLEUR “flower”) were presented at the offset of the primes. A priming effect emerged with whispered primes that included a voiced intervocalic consonant (/pedal/ “pedal”) when the delay between the offset of the primes and the visual targets (VELO “bike”) was increased by 50 ms. In none of the experiments, the voiced primes (/pedal/) facilitated the processing of the targets (FLEUR) associated with the voiceless primes (/petal/). Our results suggest that the acoustic correlates of voicing are used by listeners to recover the intended words. Nonetheless, the retrieval of the voiced feature is not immediate during whispered word recognition.     

Inhibitory phonetic priming: Where does the effect come from?

Both phonological and phonetic priming studies reveal inhibitory effects that have been interpreted as resulting from lexical competition between the prime and the target. We present a series of phonetic priming experiments that contrasted this lexical locus explanation with that of a prelexical locus by manipulating the lexical status of the prime and the target and the task used. In the related condition of all experiments, spoken targets were preceded by spoken primes that were phonetically similar but shared no phonemes with the target (/bak/–/dεt/). In Experiments 1 and 2, word and nonword primes produced an inhibitory effect of equal size in shadowing and same–different tasks respectively. Experiments 3 and 4 showed robust inhibitory phonetic priming on both word and nonword targets in the shadowing task, but no effect at all in a lexical decision task. Together, these findings show that the inhibitory phonetic priming effect occurs independently of the lexical status of both the prime and the target, and only in tasks that do not necessarily require the activation of lexical representations. Our study thus argues in favour of a prelexical locus for this effect.     

Perceptual representations of phonotactically illegal syllables

Listeners often categorize phonotactically illegal sequences (e.g., /dla/ in English) as phonemically similar legal ones (e.g., /gla/). In an earlier investigation of such an effect in Japanese, Dehaene-Lambertz, Dupoux, and Gout (2000) did not observe a mismatch negativity in response to deviant, illegal sequences, and therefore argued that phonotactics constrain early perceptual processing. In the present study, using a priming paradigm, we compared the event-related potentials elicited by Legal targets (e.g., /gla/) preceded by (1) phonemically distinct Control primes (e.g., /kla/), (2) different tokens of Identity primes (e.g., /gla/), and (3) phonotactically Illegal Test primes (e.g., /dla/). Targets elicited a larger positivity 200–350 ms after onset when preceded by Illegal Test primes or phonemically distinct Control primes, as compared to Identity primes. Later portions of the waveforms (350–600 ms) did not differ for targets preceded by Identity and Illegal Test primes, and the similarity ratings also did not differ in these conditions. These data support a model of speech perception in which veridical representations of phoneme sequences are not only generated during processing, but also are maintained in a manner that affects perceptual processing of subsequent speech sounds.     

Can the dual-route cascaded computational model of reading offer a valid account of the masked onset priming effect?

The masked onset priming effect (MOPE) refers to the empirical finding that target naming is faster when the target (SIB) is preceded by a briefly presented masked prime that starts with the same letter/phoneme (suf) than when it does not (mof; Kinoshita, 2000, Experiment 1). The dual-route cascaded (DRC) computational model of reading (Coltheart, Rastle, Perry, Langdon, & Ziegler, 2001) has offered an explanation for how the MOPE might occur in humans. However, there has been some empirical discrepancy regarding whether for nonword items the effect is limited to the first-letter/phoneme overlap between primes and targets or whether orthographic/phonological priming effects occur beyond the first letter/phoneme. Experiment 1 tested these two possibilities. The human results, which were successfully simulated by the DRC model, showed priming beyond the first letter/phoneme. Nevertheless, two recent versions of the DRC model made different predictions regarding the nature of these priming effects. Experiment 2 examined whether it is facilitatory, inhibitory, or both, in order to adjudicate between the two versions of the model. The human results showed that primes exert both facilitatory and inhibitory effects.     

Tracking independence and merging of prosodic and phonemic processing across infancy

Recent evidence suggests division of labor in phonological analysis underlying speech recognition. Adults and children appear to decompose the speech stream into phoneme‐relevant information and into syllable stress. Here we investigate whether both speech processing streams develop from a common path in infancy, or whether there are two separate streams from early on. We presented stressed and unstressed syllables (spoken primes) followed by initially stressed early learned disyllabic German words (spoken targets). Stress overlap and phoneme overlap between the primes and the initial syllable of the targets varied orthogonally. We tested infants 3, 6 and 9 months after birth. Event‐related potentials (ERPs) revealed stress priming without phoneme priming in the 3‐month‐olds; phoneme priming without stress priming in the 6‐month‐olds; and phoneme priming, stress priming as well as an interaction of both in 9‐month‐olds. In general the present findings reveal that infants start with separate processing streams related to syllable stress and to phoneme‐relevant information; and that they need to learn to merge both aspects of speech processing. In particular the present results suggest (i) that phoneme‐free prosodic processing dominates in early infancy; (ii) that prosody‐free phoneme processing dominates in middle infancy; and (iii) that both types of processing are operating in parallel and can be merged in late infancy.     

Subliminal repetition primes help detection of phonemes in a picture: Evidence for a phonological level of the priming effects

In this research, we combine a cross-form word–picture visual masked priming procedure with an internal phoneme monitoring task to examine repetition priming effects. In this paradigm, participants have to respond to pictures whose names begin with a prespecified target phoneme. This task unambiguously requires retrieving the word-form of the target picture's name and implicitly orients participants' attention towards a phonological level of representation. The experiments were conducted within Spanish, whose highly transparent orthography presumably promotes fast and automatic phonological recoding of subliminal, masked visual word primes. Experiments 1 and 2 show that repetition primes speed up internal phoneme monitoring in the target, compared to primes beginning with a different phoneme from the target, or sharing only their first phoneme with the target. This suggests that repetition primes preactivate the phonological code of the entire target picture's name, hereby speeding up internal monitoring, which is necessarily based on such a code. To further qualify the nature of the phonological code underlying internal phoneme monitoring, a concurrent articulation task was used in Experiment 3. This task did not affect the repetition priming effect. We propose that internal phoneme monitoring is based on an abstract phonological code, prior to its translation into articulation.     

注意和非注意条件下的整体和局部性质加工

以往关于整体和局部知觉的研究通常要求被试直接对出现在复合刺激整体或局部水平上的靶目标做反应,因此复合刺激与任务相关并被注意。该研究通过测量复合字母的整体和局部性质对随后出现的探测刺激的启动效应来研究在非注意条件下整体和局部性质加工的差异。实验一发现复合刺激的整体和局部性质对探测刺激产生负启动效应,但二者没有显著差异。实验二缩短了启动刺激与探测刺激之间的时间间隔,复合刺激的整体和局部性质对探测刺激都不再产生启动效应。在实验一、二中,当要求被试直接对复合刺激做反应时,其分辨局部性质的错误率都比分辨整体性质的错误率高。根据这些结果,讨论了在注意和非注意下的整体和局部性质加工的差异。     

Prelexical facilitation and lexical interference in auditory word recognition.

Phonological priming effects were examined in an auditory single-word shadowing task. In 6 experiments, target items were preceded by auditorily or visually presented, phonologically similar, word or nonword primes. Results revealed facilitation in response time when a target was preceded by a word or nonword prime having the same initial phoneme when the prime was auditorily presented but not when it was visually presented. Second, modality-independent interference was observed when the phonological overlap between the prime and target increased from 1 to 3 phonemes for word primes but not for nonword primes. Taken together, these studies suggest that phonological information facilitates word recognition as a result of excitation at a prelexical level and increases response time as a result of competition at a lexical level. These processes are best characterized by connectionist models of word recognition.     

Masked priming with orthographic neighbors: a test of the lexical competition assumption

In models of visual word identification that incorporate inhibitory competition among activated lexical units, a word's higher frequency neighbors will be the word's strongest competitors. Preactivation of these neighbors by a prime is predicted to delay the word's identification. Using the masked priming paradigm (K. I. Forster & C. Davis, 1984, J. Segui and J. Grainger (1990) reported that, consistent with this prediction, a higher frequency neighbor prime delayed the responses to a lower frequency target, whereas a lower frequency neighbor prime did not delay the responses to a higher frequency target. In the present experiments, using English stimuli, it was found that this pattern held only when the primes and targets had few neighbors; when the primes and targets had many neighbors, lower frequency primes delayed responses to higher frequency targets essentially as much as higher frequency primes delayed responses to lower frequency targets. Several possible explanations for these findings are discussed along with their theoretical implications. Considered together, the results are most consistent with activation-based accounts of the masked priming effect.     

The left-to-right nature of the masked onset priming effect in naming

Two experiments were performed to investigate the nature of the masked onset priming effect in naming, that is, the facilitation in naming latency that is observed when a target shares the initial grapheme/phoneme with a masked prime. Experiment 1 showed that the effect is not due to position-independent letter priming, since the naming of nonword targets preceded by masked primes was facilitated only if the prime shared the initial letter with the target (e.g., suf-SIB) and not if the prime shared the final letter (e.g., mub-SIB). Experiment 2 showed that the effect reflects the sharing of onsets rather than the initial letter, since facilitation due to an overlap of the initial letter was observed only for the simple onset target (e.g., penny-PASTE) for which the letter corresponded to the onset, and not for complex onset targets (e.g., bingo-BLISS). It is argued that the serial nature of the masked onset priming effect is best interpreted as the planning of articulation, rather than as the computation of phonology from orthography.     

Does Talker‐Specific Information Influence Lexical Competition? Evidence From Phonological Priming

In this study, we examined whether the lexical competition process embraced by most models of spoken word recognition is sensitive to talker‐specific information. We used a lexical decision task and a long lag priming experiment in which primes and targets sharing all phonemes except the last one (e.g., /bagaR/“fight” vs. /baga?/“luggage”) were presented in two separate blocks of stimuli. In Experiment 1, the competitor prime block was presented only once to listeners, and no modulation of the competitor priming effect as a function of a talker change between the primes and targets was observed. However, attenuation in the competitor priming effect in the case of a talker change between the primes and targets was observed in Experiment 2 in which the competitor prime block was presented five times to listeners. We discuss our findings in reference to hybrid models of spoken word recognition in which repetition of words with the same talker could be a key factor in the formation and access to talker‐dependent representations.     

Subthreshold semantic priming: Not a context effect

Bernstein, Bissonnette, Vyas, and Barclay (1989) showed that masked primes can be recognized more often when followed by a related target than when followed by an unrelated target. They suggested that this effect may allow subjects in subthreshold semantic priming experiments to recognize the masked primes on the related semantic priming trials, even when the subjects cannot recognize masked primes presented alone. The present experiment found that when masked primes are presented at recognition rates comparable to those used in published studies of subthreshold masked priming, the forced choice recognition of masked primes followed by related targets was similar to that of masked primes presented alone (25% vs. 22%). In addition, the recognition of masked primes on the forced choice trials was highly predictive of masked prime recognition on the semantic priming trials.     

Cognate status and cross-script translation priming

Greek-French bilinguals were tested in three masked priming experiments with Greek primes and French targets. Related primes were the translation equivalents of target words, morphologically related to targets, or phonologically related to targets. In Experiment 1, cognate translation equivalents (phonologically similar translations) showed facilitatory priming, relative to matched phonologically related primes, in conditions in which morphologically related primes showed no effect (50-msec prime exposure). Cross-language morphological priming emerged at longer prime exposure durations (66 msec), but cognate primes continued to generate more priming than did those in the morphological condition. In Experiments 2 and 3, the level of phonological overlap across translation equivalents was varied, and priming effects were measured against those for matched phonologically related primes and those in an unrelated prime condition. When measured against the unrelated baseline, cognate primes showed the typical advantage over noncognate primes. However, this cognate advantage disappeared when priming was measured against the phonologically related prime condition. The results are discussed in terms of how translation equivalents are represented in bilingual memory.     

Processing of distractors inside and outside the attentional focus in a priming procedure

A priming procedure was used to study the processing of distractors located either inside (between the location of two targets) or outside (peripherally to the locations of the targets) the focus of attention. The stimuli were five-letter arrays, and participants had to decide whether two marked target letters were the same or different. In Experiments 1 and 2, positive priming was obtained both when targets and in-distractors in primes repeated as targets in probes; negative priming was found when out-distractor primes repeated as targets in probes. In Experiment 3, we also manipulated the match in letter case from primes to probes. In-distractors produced reliable positive priming, irrespective of whether the letters matched in case. In contrast out-distractors produced negative priming but only when the letters had the same case in primes and probes. These results are attributed to a spatial attention process operating (in this case) on low-level visual features, and an object-based selection process that enables more abstract information to be processed for selected stimuli.     

Center-surround or spreading inhibition: which mechanism caused the negative effect from repeated masked semantic primes?

In the paradigm of repeated masked semantic priming (Wentura & Frings. 2005), prime and mask are repeatedly and rapidly interchanged. Using this technique in a semantic priming task with category labels as primes and category exemplars as targets (related, e.g.. BIRD - swan --> BIRD - finch; unrelated, e.g., BIRD - lily --> FRUIT - finch), Wentura and Frings found a negatively signed priming effect. Here we used the repeated masking technique with category exemplars as targets and primes (i.e., identity priming) for analyzing, whether this effect reflects center-surround or spreading inhibition. If the repeated masked technique reflects spreading inhibition, a negative effect should also appear for identity priming. In contrast, a center-surround approach would predict a positive effect. In accordance with the latter hypothesis, we found a significant positive effect in identity priming (Experiment 1a) and significant difference to the negatively signed semantic priming effect when primes were category labels (Experiment 1b). This is indicative of the repeated masked semantic priming effect being a negatively signed semantic priming effect due to a center-surround mechanism.     

Semantic priming of person recognition: Categorial priming may be a weaker form of the associative priming effect

An interactive activation and competition account (Burton, Bruce, & Johnston, 1990) of the semantic priming effect in person recognition studies relies on the fact that primes and targets (people) have semantic information in common. However, recent investigations into the type of relationship needed to mediate the semantic priming effect have suggested that the prime and target must be close associates (e.g., Barry, Johnston, & Scanlan, 1998; Young, Flude, Hellawell, & Ellis, 1994). A review of these and similar papers suggests the possibility of a small but non-reliable effect based purely on categorial relationships. Experiment 1 provided evidence that when participants were asked to make a name familiarity decision it was possible to boost this small categorial effect when multiple (four) primes were presented prior to the target name. Results from Experiment 2 indicated that the categorial effect was not due to the particular presentation times of the primes. This boosted categorial effect was shown to cross domains (names to faces) in Experiment 3 and persist in Experiment 4 when the task involved naming the target face. The similarity of the pattern of results produced by the associative priming effect and this boosted categorial effect suggests that the two may be due to the same underlying mechanism in semantic memory.     

Masked form priming is moderated by the size of the letter-order-free orthographic neighbourhood

University students made lexical decisions to targets preceded by masked primes. In Experiment 1, transposed-letter primes were used also in the sandwich priming paradigm, in which the target is briefly pre-presented prior to the prime. The priming effects in the masked paradigm, but not in the sandwich paradigm, were moderated by the density of the letter-order-free neighbourhood of the target. In Experiment 2, letter-order-free neighbour prime words produced a priming cost in masked priming. These results are consistent with the idea that sandwich priming attenuates letter-order-free neighbour competition in target identification. Unexpectedly, no priming cost was produced by conventional (letter-position-preserving) word neighbour primes. Order-free neighbours may produce facilitation of target processing less, and more variably, than conventional neighbours.     

Inhibition from semantically related primes: Evidence of a category-specific inhibition

The phenomenon of inhibition from generating successive items within a category, reported by A. S. Brown (1981), was examined in two experiments. Subjects responded on target trials by either generating targets (e.g., generating BASS to B when it followed the category name FISH, Experiment 1) or reading them (reading BASS when it followed the category name FISH, Experiment 2). Prior to target trials, all subjects received priming trials consisting of either one or four exemplars from a single semantic category, which could be either the same category as the target’s category (related priming condition) or an unrelated category (unrelated priming condition). In both experiments, different groups of subjects either read or generated primes. When primes were read, target response times (RTs) were always facilitated in the related priming condition compared with in the unrelated priming condition. However, when primes were generated, this facilitation from related primes was eliminated, except in the one-prime condition, when targets were also generated. When primes and targets were both generated, RTs in the related priming condition were slower following four primes than following one prime. Thus, category-specific inhibition from multiple related primes is greatest when both primes and targets must be actively retrieved.