A transfer analysis of the repetition effect in the lexical and ambiguity decision tasks

Two experiments were performed in an attempt to evaluate explanations of repetition priming-the facilitation observed when the same word is processed a second time in the same task. One task employed was lexical decision (word/nonword) and the other was ambiguity decision (ambiguous/ unambiguous). In the first experiment, transfer on a lexical decision task was measured following either a lexical decision or an ambiguity decision. When the identical lists were processed in the first phase for lexical and ambiguity decision, equal repetition effects were obtained on lexical decision. However, when the ambiguity task was presented without nonwords, no repetition priming occurred. In a second experiment, the within-task repetition effect was large for the ambiguity decision, whereas no transfer was obtained from lexical decision to ambiguity decision. The results were interpreted as being consistent with a transfer-appropriate processing account of repetition priming.     

Linguistic humor comprehension in children with articulation impairments

This study investigated the ability of children with articulation disorders to comprehend linguistic humor. It was hypothesized that children with articulation disorders would have more difficulty understanding humor based on phonological differences than humor based on lexical differences. A second hypothesis predicted that children with articulation disorders would have more difficulty understanding riddles in which the phoneme they misarticulated, either /s/ or /r/, was the source of ambiguity than riddles in which the source of ambiguity did not involve the phoneme they misarticulated. Results did not confirm the first hypothesis as there were no statistically significant differences between groups with regard to the children's ability to understand phonological vs lexical humor. The second hypothesis was supported. Children had significantly more difficulty understanding riddles in which the source of ambiguity related to the phoneme they misarticulated, either /s/ or /r/ than they did understanding phonological humor involving nonerror phonemes.     

Semantic Ambiguity Effects in L2 Word Recognition

The present study examined the ambiguity effects in second language (L2) word recognition. Previous studies on first language (L1) lexical processing have observed that ambiguous words are recognized faster and more accurately than unambiguous words on lexical decision tasks. In this research, L1 and L2 speakers of English were asked whether a letter string on a computer screen was an English word or not. An ambiguity advantage was found for both groups and greater ambiguity effects were found for the non-native speaker group when compared to the native speaker group. The findings imply that the larger ambiguity advantage for L2 processing is due to their slower response time in producing adequate feedback activation from the semantic level to the orthographic level.     

Ambiguity Advantage Revisited: Two Meanings are Better than One When Accessing Chinese Nouns

This paper revisits the effect of lexical ambiguity in word recognition, which has been controversial as previous research reported advantage, disadvantage, and null effects. We discuss factors that were not consistently treated in previous research (e.g., the level of lexical ambiguity investigated, parts of speech of the experimental stimuli, and the choice of non-words) and report on a lexical decision experiment with Chinese nouns in which ambiguous nouns with homonymic and/or metaphorical meanings were contrasted with unambiguous nouns. An ambiguity advantage effect was obtained—Chinese nouns with multiple meanings were recognized faster than those with only one meaning. The results suggested that both homonymic and metaphorical meanings are psychologically salient semantic levels actively represented in the mental lexicon. The results supported a probability-based model of random lexical access with multiple meanings represented by separate semantic nodes. We further discuss these results in terms of lexical semantic representation and how different experimental paradigms result in different ambiguity effects in lexical access.     

Ambiguity and synonymy effects in lexical decision,naming, and semantic categorization tasks: interactions between orthography,phonology, and semantics

In this article, ambiguity and synonymy effects were examined in lexical decision, naming, and semantic categorization tasks. Whereas the typical ambiguity advantage was observed in lexical decision and naming, an ambiguity disadvantage was observed in semantic categorization. In addition, a synonymy effect (slower latencies for words with many synonyms than for words with few synonyms) was observed in lexical decision and naming but not in semantic categorization. These results suggest that (a) an ambiguity disadvantage arises only when a task requires semantic processing, (b) the ambiguity advantage and the synonymy disadvantage in lexical decision and naming are due to semantic feedback, and (c) these effects are determined by the nature of the feedback relationships from semantics to orthography and phonology.     

The influence of the lexicon on phonetic categorization: stimulus quality in word-final ambiguity.

The categorization of word-final phonemes provides a test to distinguish between an interactive and an autonomous model of speech recognition. Word-final lexical effects ought to be stronger than word-initial lexical effects, and the models make different reaction time (RT) predictions only for word-final decisions. A first experiment found no lexical shifts between the categorization functions of word-final fricatives in pairs such as fish-fiss and kish-kiss. In a second experiment, with stimuli degraded by low-pass filtering, reliable lexical shifts did emerge. Both models need revision to account for this stimulus-quality effect. Stimulus quality rather than stimulus ambiguity per se determines the extent of lexical involvement in phonetic categorization. Furthermore, the lexical shifts were limited to fast RT ranges, contrary to the interactive model's predictions. These data therefore favor an autonomous bottom-up model of speech recognition.     

Oral stereognosis: Effect of varying form set,answer type,and retention time

The oral stereognosis abilities of 40 young adults were investigated as a function of oral stereognosis form sets (four sets), retention time (unlimited and 5 sec), and response type (oral discrimination and visual recognition). Results showed that the Penn State forms were the easiest for the subjects under all conditions and that the Ringel form set was the most difficult under all conditions. A significant interaction between oral form sets and answer type indicated that the visual recognition task, rather than the discrimination task, was primarily responsible for the differences between the oral form sets. A three-way interaction revealed that the retention times had a significant effect on the two form sets of medium difficulty (NIDR-10 and NIDR-20) for the visual recognition condition. The results are discussed in view of their research and clinical implications.     

Effect of backward priming on word recognition in single-word and sentence contexts

Backward priming was investigated under conditions similar to those used in lexical ambiguity research. Subjects received prime-target word pairs that were associated either unidirectionally (BABY-STORK) or bidirectionally (BABY-CRY). In the first experiment, targets were presented 500 ms following the onset of visual primes, and subjects made naming or lexical decision responses to the targets. Forward priming was obtained in all conditions, while backward priming (i.e., priming for pairs in which there was a unidirectional target-to-prime association, as in BABY-STORK) occurred only with lexical decision. In the second experiment, primes were presented auditorily, either in isolation or in a sentence. Targets followed the offset of the primes either immediately or after 200 ms. Backward priming occurred with both response tasks, but only when the prime was an isolated word. In addition, backward priming decreased over time with the naming task, but not with lexical decision. These results suggest that the locus of the backward priming effect is different for the two response tasks. Further, the lack of a backward priming effect with sentence contexts suggests that backward priming cannot account for the demonstrations of multiple access in the lexical ambiguity literature. These results, therefore, support a context-independent view of lexical access.     

The cognitive processing of Japanese loanwords in katakana

Abstract: The present study examined two questions concerning the cognitive processing of Japanese loanwords borrowed from English and written in katakana. The first question was whether "interlexical activation" occurs between Japanese and English. Results from a lexical decision task showed that loanwords phonetically similar to the original English words were judged with the same speed and accuracy as those being phonetically dissimilar to their original English words. The study further examined the cognitive processing of unadopted loanwords (i.e., words unlisted in a Japanese loanword dictionary). Reaction times displayed the shortest mean for non-words, followed by pseudo-loanwords, and finally unadopted loanwords. Thus, the only time the lexical representation of an original English word was possibly activated was when native Japanese speakers had seldom seen the word in katakana. The second question was what creates the "lexical mental boundary" between adopted and unadopted loanwords. A questionnaire showed that native Japanese speakers are likely to use decision-making strategies for determining lexicality of loanwords in Japanese based on their daily experience of exposure to katakana words in print.     

Cognitive processes,school achievement,and comprehension of ambiguous sentences

Previous research has identified three distinct forms of linguistic ambiguity: lexical, surface structural, and deep structural. Cummins and Das (1978) studied these forms of ambiguity in the context of Das, Kirby and Jarman's (1979) model of simultaneous and successive processing, and demonstrated that comprehension of lexical ambiguity depended upon simultaneous processing, while that of surface and deep structural ambiguity depended upon successive processing. The present study investigated the relationship between these cognitive and linguistic processes in a group of older children. The subjects' level of English achievement was also considered. The results showed that comprehension of all three forms of ambiguity was strongly related to level of English achievement, though deep structure ambiguities best descriminated the English achievement groups. Results also showed that perception of all types of ambiguity was related to both simultaneous and successive processing. Subjects with high successive processing scores had an additional advantage in perceiving deep structure ambiguities. These results suggest the need for an elaboration of the Cummins and Das cognitive process model of liguistic processes, demonstrating that a variety of task variables can alter the cognitive processes required in performance of linguistic tasks.This study was supported by an Australian Research Grants Committee grant to J. B. Biggs and the author.     

On the role of regular phonological variation in lexical access: evidence from voice assimilation in French

The present study investigated whether lexical access is affected by a regular phonological variation in connected speech: voice assimilation in French. Two associative priming experiments were conducted to determine whether strongly assimilated, potentially ambiguous word forms activate the conceptual representation of the underlying word. Would the ambiguous word form [sud] (either assimilated soute 'hold' or soude 'soda') facilitate "bagage" 'luggage', which is semantically related to soute but not to soude? In Experiment 1, words in either canonical or strongly assimilated form were presented as primes. Both forms primed their related target to the same extent. Potential lexical ambiguity did not modulate priming effects. In Experiment 2, the primes such as assimilated soute pronounced [sud] used in Experiment 1 were replaced with primes such as soude canonically pronounced [sud]. No semantic priming effect was obtained with these primes. Therefore, the effect observed for assimilated forms in Experiment 1 cannot be due to overall phonological proximity between canonical and assimilated forms. We propose that listeners must recover the intended words behind the assimilated forms through the exploitation of the remaining traces of the underlying form, however subtle these traces may be.     

The contribution of morphology to word recognition

Summary Evidence of morphological processing was investigated in three word recognition tasks. In the first study, phonological ambiguity of the base morpheme in morphologically complex words of Serbo-Croatian was exploited in order to evaluate the claim that the base morpheme serves as the unit by which entries in the lexicon are accessed. An interaction of base morpheme ambiguity and affix characteristics was obtained and this outcome was interpreted as evidence that all morphological constituents of a word participate in lexical access. In the second study, facilitation due to morphological relatedness of prime and target was observed with Serbo-Croatian materials in the lexical decision and naming versions of the repetition priming task and results were interpreted as evidence of a morphological principle of organization among wholeword forms in the lexicon. In the third study, morphological affixes of both English and Serbo-Croatian words were segmented from a source word and affixed to a target word more rapidly than phonemically matched controls. Results suggest that the morphological constituents of complex words are available in some word recognition tasks and that morphological knowledge is represented in the speaker's lexicon.     

Strength of Discourse Context as a Determinant of the Subordinate Bias Effect

Two experiments examined the influence of strength of discourse bias on lexical ambiguity resolution. Short passages were constructed to bias polarized ambiguous words (homonyms) strongly or weakly toward the dominant or subordinate meanings. Using a self-paced reading task in Experiment 1, it was demonstrated that in strongly biased discourse, reading times for homonyms in dominant discourse did not differ from those in subordinate discourse. However, when the discourse was weakly biased, homonyms were read faster in dominant discourse than in subordinate discourse. Experiment 2 combined the reading paradigm with a naming task in order to provide an assessment of specific word-meaning activation. Reading times on ambiguous words replicated the results of Experiment 1. In addition, naming latencies for probe words revealed that only the contextually appropriate sense of a homonym was activated in strongly biased discourse. In contrast, both contextually appropriate and inappropriate senses were activated following a weakly biased subordinate discourse, whereas only the dominant sense was activated following weakly biased dominant discourse. The results demonstrate (1) an immediate influence of prior discourse information on lexical processing; and (2) that the strength of discourse constraints can play a governing role in lexical ambiguity resolution. The results were interpreted within the framework of a context-sensitive model of lexical ambiguity resolution.     

Accessing lexical ambiguities during sentence comprehension: Effects of frequency of meaning and contextual bias

Two hypotheses concerning the nature of lexical access, the exhaustive access and the terminating ordered search hypotheses, were examined in two separate studies using a crossmodal lexical priming task. In this task, subjects listened to sentences that were biased toward either the primary interpretation (a meaning occurring 75% or more of the time) or a secondary interpretation (a meaning occurring less than 25% of the time) of a lexical ambiguity that occurred in each sentence. Simultaneously, subjects made lexical decisions about visually presented words. Decisions to words related to both the primary and secondary meanings of the ambiguity were facilitated when presented immediately following occurrence of the ambiguity in the sentence. This effect held under each of the two biasing context conditions. However, when they were presented 1.5 sec following occurrence of the ambiguity, only visual words related to the contextually relevant meaning of the ambiguity were facilitated. These results support the exhaustive access hypothesis. It is argued that lexical access is an autonomous subsystem of the sentence comprehension routine in which all meanings of a word are momentarily accessed, regardless of the factors of contextual bias or bias associated with frequency of use.     

The mental representation of lexical form: a phonological approach to the recognition lexicon

We propose a psycholinguistic model of lexical processing which incorporates both process and representation. The view of lexical access and selection that we advocate claims that these processes are conducted with respect to abstract underspecified phonological representations of lexical form. The abstract form of a given item in the recognition lexicon is an integrated segmental-featural representation, where all predictable and non-distinctive information is withheld. This means that listeners do not have available to them, as they process the speech input, a representation of the surface phonetic realisation of a given word-form. What determines performance is the abstract, underspecified representation with respect to which this surface string is being interpreted. These claims were tested by studying the interpretation of the same phonological feature, vowel nasality, in two languages, English and Bengali. The underlying status of this feature differs in the two languages; nasality is distinctive only in consonants in English, while both vowels and consonants contrast in nasality in Bengali. Both languages have an assimilation process which spreads nasality from a nasal consonant to the preceding vowel. A cross-linguistic gating study was conducted to investigate whether listeners would interpret nasal and oral vowels differently in two languages. The results show that surface phonetic nasality in the vowel in VN sequences is used by English listeners to anticipate the upcoming nasal consonant. In Bengali, however, nasality is initially interpreted as an underlying nasal vowel. Bengali listeners respond to CVN stimuli with words containing a nasal vowel, until they get information about the nasal consonant. In contrast, oral vowels in both languages are unspecified for nasality and are interpreted accordingly. Listeners in both languages respond with CVN words (which have phonetic nasality on the surface) as well as with CVC words while hearing an oral vowel. The results of this cross-linguistic study support, in detail, the hypothesis that the listener's interpretation of the speech input is in terms of an abstract underspecified representation of lexical form.     

The influence of global discourse on lexical ambiguity resolution

The influence of global discourse on the resolution of lexical ambiguity was examined in a series of naming experiments. Two-sentence passages were constructed to bias either the dominant or the subordinate meaning of a homonym that was embedded in a locally ambiguous sentence. The results provided evidence for the immediate (0-msec interstimulus interval) resolution of lexical ambiguity and were subsequently replicated in Experiment 2, in which an 80-msec stimulus onset asynchrony exposure duration was employed for the homonyms. Strong dominant and subordinate biased discourse contexts activated only the contextually appropriate sense of a homonym. In Experiment 3, each sentence of the discourse was presented in isolation. The pattern of activation obtained in Experiments 1 and 2 was found to be contingent on the integration of the two sentences to construct an overall global discourse representation of the text. The results support a context-sensitive model of lexical ambiguity resolution.     

A Connectionist Model of Phonological Representation in Speech Perception

A number of recent studies have examined the effects of phonological variation on the perception of speech. These studies show that both the lexical representations of words and the mechanisms of lexical access are organized so that natural, systematic variation is tolerated by the perceptual system, while a general intolerance of random deviation is maintained. Lexical abstraction distinguishes between phonetic features that form the invariant core of a word and those that are susceptible to variation. Phonological inference relies on the context of surface changes to retrieve the underlying phonological form. In this article we present a model of these processes in speech perception, based on connectionist learning techniques. A simple recurrent network was trained on the mapping from the variant surface form of speech to the underlying form. Once trained, the network exhibited features of both abstraction and inference in its processing of normal speech, and predicted that similar behavior will be found in the perception of nonsense words. This prediction was confirmed in subsequent research (Gaskell & Marslen-Wilson, 1994).     

The Interpretation of Sentence Ambiguity in Patients with Unilateral Focal Brain Surgery

Interpretations of ambiguous sentences were studied in patients with unilateral anterior temporal lobectomy or selective amygdalo-hippocampectomy. The sentences represented lexical and syntactic ambiguities. In both left- and right-sided groups, regardless of type of surgery, total mean score on the test was below normal. Left-sided cases, regardless of type of surgery, provided significantly fewer alternative interpretations than right-sided cases. The results suggest greater left than right hemisphere specialization in both lexical and syntactic processing, but also suggest right hemisphere involvement in resolution of lexical ambiguity.     

Effects of referential ambiguity,time constraints and addressee orientation on the production of morphologically complex words

In five experiments, participants were asked to describe unambiguously a target picture in a picture–picture paradigm. In the same-category condition, target (e.g., water bucket) and distractor picture (e.g., ice bucket) had identical names when their preferred, morphologically simple, name was used (e.g., bucket). The ensuing lexical ambiguity could be resolved by compound use (e.g., water bucket). Simple names sufficed as means of specification in other conditions, with distractors identical to the target, completely unrelated, or geometric figures. With standard timing parameters, participants produced mainly ambiguous answers in Experiment 1. An increase in available processing time hardly improved unambiguous responding (Experiment 2). A referential communication instruction (Experiment 3) increased the number of compound responses considerably, but morphologically simple answers still prevailed. Unambiguous responses outweighed ambiguous ones in Experiment 4, when timing parameters were further relaxed. Finally, the requirement to name both objects resulted in a nearly perfect ambiguity resolution (Experiment 5). Together, the results showed that speakers overcome lexical ambiguity only when time permits, when an addressee perspective is given and, most importantly, when their own speech overtly signals the ambiguity.