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.     

Perception Abilities of L1 Cypriot Greek Listeners - Types of Errors Involving Plosive Consonants in L2 English

This paper investigates the difficulties adult second language (L2) users of English encounter with plosive consonants in the L2. It presents the results of a task examining the acquisition of plosive voicing contrasts by college students with Cypriot Greek (CG) linguistic background. The task focused on the types of errors involving plosive consonants indicating that performance was significantly better in the voiceless plosive category. Participants were able to perceive voiced plosives but they treated such instances as a /nasal + voiced plosive/ sequence. Therefore, the question raised concerns different phonological contrasts realised through similar phonetic cues. The patterns observed suggested that this gap between phonetic cues and phonological contrast might explain why CG users have difficulties perceiving voiced English plosives. In this context, voice onset time (VOT) differences between the L1 and L2 are of crucial importance. In English, voiced plosives are characterised by short lag VOT while their voiceless counterparts fall within the long lag VOT continuum. The same phonetic contrast is used in CG to differentiate between single and geminate voiceless plosives. The results are discussed in relation to the frameworks of second language phonology and speech perception suggesting that the difficulties faced by the L2 listeners support the operation of a phonetic-phonological challenge.     

Exploring the role of lexical stress in lexical recognition

Three cross-modal priming experiments examined the role of suprasegmental information in the processing of spoken words. All primes consisted of truncated spoken Dutch words. Recognition of visually presented word targets was facilitated by prior auditory presentation of the first two syllables of the same words as primes, but only if they were appropriately stressed (e.g., OKTOBER preceded by okTO-); inappropriate stress, compatible with another word (e.g., OKTOBER preceded by OCto-, the beginning of octopus), produced inhibition. Monosyllabic fragments (e.g., OC-) also produced facilitation when appropriately stressed; if inappropriately stressed, they produced neither facilitation nor inhibition. The bisyllabic fragments that were compatible with only one word produced facilitation to semantically associated words, but inappropriate stress caused no inhibition of associates. The results are explained within a model of spoken-word recognition involving competition between simultaneously activated phonological representations followed by activation of separate conceptual representations for strongly supported lexical candidates; at the level of the phonological representations, activation is modulated by both segmental and suprasegmental information.     

Bias effects in facilitatory phonological priming

In four experiments, we examined the facilitation that occurs when spoken-word targets rhyme with preceding spoken primes. In Experiment 1, listeners' lexical decisions were faster to words following rhyming words (e.g., ramp-LAMP) than to words following unrelated primes (e.g., pink-LAMP). No facilitation was observed for nonword targets. Targets that almost rhymed with their primes (foils; e.g., bulk-SULSH) were included in Experiment 2; facilitation for rhyming targets was severely attenuated. Experiments 3 and 4 were single-word shadowing variants of the earlier experiments. There was facilitation for both rhyming words and nonwords; the presence of foils had no significant influence on the priming effect. A major component of the facilitation in lexical decision appears to be strategic: listeners are biased to say "yes" to targets that rhyme with their primes, unless foils discourage this strategy. The nonstrategic component of phonological facilitation may reflect speech perception processes that operate prior to lexical access.     

Linguistic relativism and selective adaptation for speech: A comparative study of English and Thai

The effect of repeated exposure to prevoiced and voiced stimuli on the voiced/voiceless category boundary was compared for monolingual native English speakers and bilingual native speakers of Thai. The English speakers, for whom the two adaptors were members of the same phoneme class, showed equivalent shifts towards the adapting stimulus under both conditions. The Thai subjects, who perceived the two adaptors as belonging to two distinct phoneme classes, showed a shift of the voiced/voiceless boundary only for the voiced adaptation condition; exposure to the prevoiced adaptor had no effect.     

Phonological priming in spoken word recognition: Task effects

In two experiments, we examined the role of phonological relatedness between spoken items using both the lexical decision task and the shadowing task. In Experiment 1, words were used as primes and overlaps of zero (control), one, two, or all four or five (repetition) phonemes were compared. Except for the repetition conditions, in which facilitation was found, phonological overlap resulted in interference on word responses. These effects occurred in both tasks but were larger in lexical decision than in shadowing. The effects that were evident in shadowing can be attributed to an attentional mechanism linked to the subjects' expectancies of repetitions. The extra effects obtained in lexical decision can be interpreted by taking into account both activation of the response corresponding to the prime's lexical status and postlexical processes that check for phonological congruency between prime and target. In Experiment 2, some modifications were introduced to prevent the involvement of strategic factors, and pseudowords were used as primes. No effect at all was observed in shadowing, whereas in lexical decision interference effects occurred, which is consistent with the hypothesis that lexical decision may be negatively affected by finding a phonological discrepancy at the same time as the primed response is reactivated. Neither experiment provided evidence for the occurrence of phonological priming in the perceptual processing of words.     

Contextual influences on the internal structure of phonetic categories: A distinction between lexical status and speaking rate

Previous research has shown that phonetic categories have a graded internal structure that is highly dependent on acoustic-phonetic contextual factors, such as speaking rate; these factors alter not only the location of phonetic category boundaries, but also the location of a category’s best exemplars. The purpose of the present investigation, which focused on the voiceless category as specified by voice onset time (VOT), was to determine whether a higher order linguistic contextual factor, lexical status, which is known to alter the location of the voiced—voiceless phonetic category boundary, also alters the location of the best exemplars of the voiceless category. The results indicated that lexical status has a more limited and qualitatively different effect on the category’s best exemplars than does the acousticphonetic factor of speaking rate. This dissociation is discussed in terms of a production-based account in which perceived best exemplars of a category track contextual variation in speech production.     

The processing of pseudohomophones by adults with a history of developmental language disabilities

Psuedohomophones are nonwords that sound like real words (e.g., BRANE). These items were used to gauge phonological access in adults who have experienced developmental language processing deficits (DLD). The standard effect for these items in lexical decision is an increase in response times over nonpseudohomophone nonwords. This disadvantage reflects phonological processing. In our first experiment the DLD group did not produce this pseudohomophone effect whereas in a second experiment they showed semantic priming effects when pseudohomophones were used as primes in lexical decision. The results therefore indicate that phonological processing of nonwords by adults with DLD can be uncovered under certain carefully controlled experimental conditions.     

Semantic Processing of Foveally and Parafoveally Presented Words in a Lexical Decision Task

Using a lexical decision task in which two primes appeared simultaneously in the visual field for 150 msec followed by a target word, two experiments examined semantic priming from attended and unattended primes as a function of both the separation between the primes in the visual field and the prime-target stimulus-onset asynchrony (SOA). In the first experiment significant priming effects were found for both the attended and unattended prime words, though the effect was much greater for the attended words. In addition, and also for both attention conditions, priming showed a tendency to increase with increasing eccentricity (2.3°, 3.3°, and 4.3°) between the prime words in the visual field at the long (550 and 850 msec) but not at the short (250 msec) prime-target SOA. In the second experiment the prime stimuli were either two words (W-W) or one word and five Xs (W-X). We manipulated the degree of eccentricity (2° and 3.6°) between the prime stimuli and used a prime-target SOA of 850 msec. Again significant priming was found for both the attended and unattended words but only the W-W condition showed a decrement in priming as a function of the separation between the primes; this decrement came to produce negative priming for the unattended word at the narrow (2°) separation. These results are discussed in relation to the semantic processing of parafoveal words and the inhibitory effects of focused attention.     

Identification reaction times of voiced/voiceless continua: a right-ear advantage for VOT values near the phonetic boundary

We explored the degree to which the duration of acoustic cues contributes to the respective involvement of the two hemispheres in the perception of speech. To this end, we recorded the reaction time needed to identify monaurally presented natural French plosives with varying VOT values. The results show that a right-ear advantage is significant only when the phonetic boundary is close to the release burst, i.e., when the identification of the two successive acoustical events (the onset of voicing and the release from closure) needed to perceive a phoneme as voiced or voiceless requires rapid information processing. These results are consistent with the recent hypothesis that the left hemisphere is superior in the processing of rapidly changing acoustical information.     

Lexical and Metrical Stress in Word Recognition: Lexical or Pre-lexical Influences?

The influence of lexical stress and/or metrical stress on spoken word recognition was examined. Two experiments were designed to determine whether response times in lexical decision or shadowing tasks are influenced when primes and targets share lexical stress patterns (JUVenile–BIBlical [Syllables printed in capital letters indicate those syllables receiving primary lexical stress.]). The results did not support an effect of lexical stress on the organization of lexical memory. In Experiment 3 primes and targets whose first syllables shared lexical stress only (MUDdy–PASta), metrical stress only (alTHOUGH–PASta), both cues (LECtern–PASta), or neither cue (conTROL–PASta) revealed no priming effect. However, targets whose first syllables were strong were responded to faster than targets whose first syllables were weak. Experiment 4 manipulated the metrical stress patterns of bi-syllabic primes and targets. Targets with strong–weak metrical stress patterns were responded to more quickly than those with strong–strong or weak–strong patterns. Although the priming paradigm did not reveal an influence of lexical and metrical stress on the organization of lexical memory, the data do support an influence of strong syllables on the processing of auditorily presented words.     

Mapping from Sound to Meaning: Reduced Lexical Activation in Broca''s Aphasics

Recent studies of lexical access in Broca's aphasics suggest that lexical activation levels are reduced in these patients. The present study compared the performance of Broca's aphasics with that of normal subjects in an auditory semantic priming paradigm. Lexical decision times were measured in response to word targets preceded by an intact semantically related prime word ("cat"-"dog"), by a related prime in which one segment was acoustically altered to produce a poorer phonetic exemplar ("c*at"-"dog"), and by a semantically unrelated prime ("ring"-"dog"). The effects of the locus of the acoustic distortion within the prime word (initial or final position) and the presence of potential lexical competitors ("cat" --> /gaet/versus "coat" --> "goat") were examined. In normal subjects, the acoustic manipulations produce a small, short-lived reduction in semantic facilitation irrespective of the position of the distortion in the prime word or the presence of a voiced lexical competitor. In contrast, Broca's aphasics showed a large and lasting reduction in priming in response to word-initial acoustic distortions, but only a weak effect of word-final distortions on priming. In both phonetic positions, the effect of distortion was greater for prime words with a lexical competitor. These findings are compatible with the claim that Broca's aphasics have reduced lexical activation levels, which may result in a disruption of the bottom-up access of words on the basis of acoustic input as well as increased vulnerability to competition between acoustically similar lexical items.     

Semantic transparency and masked morphological priming: The case of prefixed words

In four lexical decision experiments, we investigated masked morphological priming with Dutch prefixed words. Reliable effects of morphological relatedness were obtained with visual primes and visual targets in the absence of effects due to pure form overlap. In certain conditions, priming effects were significantly greater with semantically transparent prefixed primes (e.g., rename-name) relative to the priming effects obtained with semantically opaque prefixed words (e.g., relate-late), even with very brief (40-msec) prime durations. With visual primes and auditory targets (cross-modal priming), significant facilitation was found in all related prime conditions, independent of whether or not primes were morphologically related to targets. The results are interpreted within a bimodal hierarchical model of word recognition in which morphological effects arise through the interplay of sublexical (morpho-orthographic) and supralexical (morpho-semantic) representations. The word stimuli from this study may be downloaded as supplemental materials from http://mc.psychonomic-journals .org/content/supplemental.     

Does jugde activate COURT? Transposed-letter similarity effects in masked associative priming

Transposed-letter (TL) nonwords (e.g., jugde) can be easily misperceived as words, a fact that is somewhat inconsistent with the letter-position-coding schemes employed by most current models of visual word recognition. To examine this issue further, we conducted four masked semantic/associative priming experiments, using a lexical decision task. In Experiment 1, the related primes could be words, TL-internal nonwords, or replacement-letter (RL) nonwords (e.g., judge, jugde, or judpe, respectively; the target would be COURT). Relative to an unrelated condition, masked TL-internal primes produced a significant semantic/associative priming effect, an effect that was only slightly smaller than the priming effect for word primes. No effect, however, was observed for RL-nonword primes. In Experiment 2, the TL-nonword primes were created by switching the two final letters of the primes (e.g., judeg). The results again showed a semantic/associative priming effect for word primes, but not for TL-final nonword primes or for RL-nonword primes. Experiment 3 replicated the associative/semantic priming effect for TL-internal nonword primes, with, again, no effect for TL-final nonword primes. Finally, Experiment 4 again failed to yield a priming effect for TL-final nonword primes. The implications of these results for the choice of a letter-position-coding scheme in visual word recognition models are discussed.     

Lexical viability constraints on speech segmentation by infants

The Possible Word Constraint limits the number of lexical candidates considered in speech recognition by stipulating that input should be parsed into a string of lexically viable chunks. For instance, an isolated single consonant is not a feasible word candidate. Any segmentation containing such a chunk is disfavored. Five experiments using the head-turn preference procedure investigated whether, like adults, 12-month-olds observe this constraint in word recognition. In Experiments 1 and 2, infants were familiarized with target words (e.g., rush), then tested on lists of nonsense items containing these words in "possible" (e.g., "niprush" [nip+rush]) or "impossible" positions (e.g., "prush" [p+rush]). The infants listened significantly longer to targets in "possible" versus "impossible" contexts when targets occurred at the end of nonsense items (rush in "prush"), but not when they occurred at the beginning (tan in "tance"). In Experiments 3 and 4, 12-month-olds were similarly familiarized with target words, but test items were real words in sentential contexts (win in "wind" versus "window"). The infants listened significantly longer to words in the "possible" condition regardless of target location. Experiment 5 with targets at the beginning of isolated real words (e.g., win in "wind") replicated Experiment 2 in showing no evidence of viability effects in beginning position. Taken together, the findings suggest that, in situations in which 12-month-olds are required to rely on their word segmentation abilities, they give evidence of observing lexical viability constraints in the way that they parse fluent speech.     

Pseudohomophone priming in lexical decision is not fragile in a sparse lexical neighborhood

In lexical decision, to date few studies in English have found a reliable pseudohomophone priming advantage with orthographically similar primes (the klip-plip effect; Frost, Ahissar, Gotesman, & Tayeb, 2003; see Rastle & Brysbaert, 2006, for a review). On the basis of the Bayseian reader model of lexical decision (Norris, 2006, 2009), we hypothesized that this was because in previous studies, lexical decisions could have been made without finding a match between the input and a unique lexical representation. Consistent with our hypothesis, we found that words from dense neighborhoods showed neither an orthographic form priming effect nor a pseudohomophone priming advantage; in contrast, with words from a sparse lexical neighborhood, a sizeable orthographic form priming effect was found, and a robust pseudohomophone priming advantage, which was not limited to the overlap of onset phoneme, was also observed. Identity primes produced greater facilitation than pseudohomophone primes. We consider the implication of these findings for the role of assembled phonology in lexical access.     

Phonological and conceptual activation in speech comprehension

We propose that speech comprehension involves the activation of token representations of the phonological forms of current lexical hypotheses, separately from the ongoing construction of a conceptual interpretation of the current utterance. In a series of cross-modal priming experiments, facilitation of lexical decision responses to visual target words (e.g., time) was found for targets that were semantic associates of auditory prime words (e.g., date) when the primes were isolated words, but not when the same primes appeared in sentence contexts. Identity priming (e.g., faster lexical decisions to visual date after spoken date than after an unrelated prime) appeared, however, both with isolated primes and with primes in prosodically neutral sentences. Associative priming in sentence contexts only emerged when sentence prosody involved contrastive accents, or when sentences were terminated immediately after the prime. Associative priming is therefore not an automatic consequence of speech processing. In no experiment was there associative priming from embedded words (e.g., sedate-time), but there was inhibitory identity priming (e.g., sedate-date) from embedded primes in sentence contexts. Speech comprehension therefore appears to involve separate distinct activation both of token phonological word representations and of conceptual word representations. Furthermore, both of these types of representation are distinct from the long-term memory representations of word form and meaning.     

Repetition priming in an auditory lexical decision task: Effects of lexical status

The effect of lexical status on the time course of repetition priming was examined in an auditory lexical decision task. Words and nonwords were repeated at lags of 0, 1, 4, and 8 items (Experiment 1A) and 0, 2, 4, and 8 items (Experiment 1B). The pattern of repetition effects differed for words and nonwords in that repetition priming for nonwords at lag 0 was significantly greater than for words. The magnitude of this effect decreased when one or more items intervened. A second experiment, replicating Experiment 1A with visual presentation, clarified that the greater magnitude of repetition priming for nonwords at lag 0 is unique to the auditory modality. This finding suggests that in the course of forming a stable perceptual representation, the details of the acoustic/phonological information of an auditory stimulus are more readily available for nonwords than for words. The capacity to carry this phonological information is limited, however, and can only be maintained until another stimulus is encountered.     

汉语听觉词汇加工中声调信息对语义激活的制约作用

进行了三个跨通道启动词汇判断实验,探讨汉语听觉词汇加工中声调信息对语义激活的制约作用。实验一和二使用具有相同音段信息、但不同声调信息的双音节合成词（如“条约”和“跳跃”）作为听觉启动词,与其中一个词有语义关系的双字词作为视觉探测词。语义启动词与其配对的声调不匹配词在第一音节的声调、第二音节的声调、或两个声调上有所不同。实验三改变语义启动词的第一或第二音节的声调,以产生声调不匹配的假词启动项;实验三还同时变化了原来的声调与产生的声调之间的相似性。实验结果表明,声调不匹配的启动项目是否产生显著的启动效应取决于词汇竞争的环境、声调输入与深层声调表征之间匹配的程度,以及不匹配的声调所在的位置。文章从语音输入中的声调信息如何激活词汇表征、声调信息如何存储在心理词典中、声调对语义激活的制约作用如何受竞争环境的影响这三个方面讨论了研究的发现。     

Phonological priming in auditory word recognition

Cohort theory, developed by Marslen-Wilson and Welsh (1978), proposes that a "cohort" of all the words beginning with a particular sound sequence will be activated during the initial stage of the word recognition process. We used a priming technique to test specific predictions regarding cohort activation in three experiments. In each experiment, subjects identified target words embedded in noise at different signal-to-noise ratios. The target words were either presented in isolation or preceded by a prime item that shared phonological information with the target. In Experiment 1, primes and targets were English words that shared zero, one, two, three, or all phonemes from the beginning of the word. In Experiment 2, nonword primes preceded word targets and shared initial phonemes. In Experiment 3, word primes and word targets shared phonemes from the end of a word. Evidence of reliable phonological priming was observed in all three experiments. The results of the first two experiments support the assumption of activation of lexical candidates based on word-initial information, as proposed in cohort theory. However, the results of the third experiment, which showed increased probability of correctly identifying targets that shared phonemes from the end of words, did not support the predictions derived from the theory. The findings are discussed in terms of current models of auditory word recognition and recent approaches to spoken-language understanding.