Lexical decision in sentences: Effects of syntactic structure

A lexical decision paradigm was used to examine syntactic influence on word recognition in sentences. Initial fragments of sentences were presented visually (CRT display) one word at a time (at reading speeds), from left to right. The string terminated with the appearance of a lexical decision target. The grammatical structure of the incomplete sentence affected lexical decision reaction time (RT). In Experiment 1, modal verb contexts followed by main verb targets and preposition contexts followed by noun targets produced lower RTs than did the opposite pairings (i.e., modal/noun and preposition/verb). In Experiment 2, transitive verb contexts followed by noun targets and subject noun phrase contexts followed by verb targets yielded lower RTs than did the opposite pairings. Similar contrasts for adjective targets did not yield comparable effects in Experiment 2, but did when the adjective was the head of a predictable phrase (Experiment 4). In Experiment 3, noun targets yielded lower RTs than did verb targets after contexts of a transitive verb followed by a prepositional phrase. An account of these effects is offered in terms of parsing constraints on phrasal categories.     

Grammatical priming of inflected nouns

In normal linguistic usage, the inflected nouns of Sorbo-Croatian are usually preceded by prepositions that help to specify which particular grammatical case is intended and to stress the noun’s function in the sentence. In a lexical decision task, it was demonstrated that lexical decision times to nouns in a grammatical case that demands a preposition were faster when the preposition was appropriate to the case than when it was either inappropriate to the case or a nonsense syllable. This result lends support to the intuition that priming can occur among sentential components.     

Competition in lexical processing of Italian noun/verb homographs

The study investigates the lexical representation of Italian noun/verb homographs, introducing a factor which has been analysed in production studies: the specific-word frequency (SWF). The SWF parameter allows to understand whether the grammatical class information is specified within the lexical knowledge or it is selected during post-lexical stages. We ran six lexical decision tasks employing the priming paradigm and a grammatical decision task to investigate the lexical representation of noun/verb homographs. In addition, we sought to determine the role played by the frequency of representations and the temporal activation of the grammatical class information. Our findings support the claim that these forms have independent representations for each syntactic role they can play. We interpreted these findings in the light of what we call the “Nominal Dominance” effect, which affects the lexical access of noun/verb homographs. We also discuss the relation between nominal dominance and lexical frequency.     

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 role of verb argument structure in sentence processing: Distinguishing between syntactic and semantic effects

This paper describes an ongoing research program designed to investigate how syntactic and semantic aspects of lexical information become available to the sentence processing system. The two experiments described here distinguished between syntactic and semantic representations by using cross-modal naming and lexical decision in a new way. The relationship between the main verb and the probe word was varied such that the probe word met either the syntactic criteria to be an argument, the semantic criteria, neither, or both the syntactic and semantic criteria. Lexical decision times were sensitive to both syntactic and semantic congruity, while naming times were sensitive only to syntactic congruity. The two tasks were then used to investigate syntactic and semantic representations when verb argument structure was ambiguous. Subcategorized structures were constructed without regard for biasing context, but the contextually inappropriate thematic frame was ruled out while the inappropriate syntactic frame was still available.     

The return of “visiting relatives”: Pragmatic effects in sentence processing

Two experiments were performed to investigate the role of syntactic and pragmatic cues on the disambiguation of noun phrases of the form VERB+ing NOUN+s, like visiting relatives, that can be interpreted as either singular or plural noun phrases. Both experiments used a self-paced reading task in which reading times were measured for two words, a verb and an adverb, immediately following the potentially ambiguous noun phrase. The interpretation of the noun phrase as singular or plural was biased by pragmatic cues in the first experiment and by syntactic cues in the second experiment. In both experiments, subjects were faster to read the adverb following the verb when the interpretation biased by the cues agreed in number with the verb that immediately followed the target noun phrase than when it did not agree with the verb. These results suggest that pragmatic cues, like syntactic cues, can be utilized rapidly in sentence processing.     

Establishing the loci of serial and parallel effects in syntactic processing

Recent experimental work has demonstrated a robust effect of syntactic context on lexical decision times. Wright and Garrett (1984) report that targets belonging to syntactic categories required by the context produce faster RTs than either ungrammatical or optional continuations of the context string. The present study reports that structurally ambiguous contexts produced faster recognition times for syntactic categories required by only the putative nonpreferred reading of the ambiguities tested. These findings are argued to favor a parallel processing model in which syntactic representations are ranked according to structural criteria and shunted in a serial fashion to subsequent processors.     

句子语境中语义联系启动作用的研究

通过对比研究正序和乱序两种句子语境对目标词加工的不同影响,来探讨句子语境中语义联系启动作用及作用点问题。实验一采用词汇命名任务研究发现,句法成分影响命名任务,句法违反对命名任务产生较大的抑制作用。语义违反则对命名任务没有产生显著的抑制作用。实验二利用词汇决定任务发现,词序影响决定任务,乱序对词汇决定产生很大的抑制作用。语义违反对决定任务地产生较大的抑制作用。结果表,中义联系启动是短暂的,它的保持和传递需要句法成分的支持。     

Pre- and postlexical loci of contextual effects on word recognition

The context in which a word occurs could influence either the actual decoding of the word or a postrecognition judgment of the relatedness of word and context. In this research, we investigated the loci of contextual effects that occur in lexical priming, when prime and target words are related along different dimensions. Both lexical decision and naming tasks were used because previous research had suggested that they are differentially sensitive to postlexical processing. Semantic and associative priming occurred with both tasks. Other facilitative contextual effects, due to syntactic relations between words, backward associations, or changes in the proportion of related items, occurred only with the lexical decision task. The results indicate that only associative and semantic priming facilitate the decoding of a target; the other effects are postlexical. The results are related to the different demands of the naming and lexical decision tasks, and to current models of word recognition.     

Effect of Representational Distance Between Meanings on Recognition of Ambiguous Spoken Words

Previous research indicates that mental representations of word meanings are distributed along both semantic and syntactic dimensions such that nouns and verbs are relatively distinct from one another. Two experiments examined the effect of representational distance between meanings on recognition of ambiguous spoken words by comparing recognition of unambiguous words, noun–verb homonyms, and noun–noun homonyms. In Experiment 1, auditory lexical decision was fastest for unambiguous words, slower for noun–verb homonyms, and slowest for noun–noun homonyms. In Experiment 2, response times for matching spoken words to pictures followed the same pattern and eye fixation time courses revealed converging, gradual time course differences between conditions. These results indicate greater competition between meanings of ambiguous words when the meanings are from the same grammatical class (noun–noun homonyms) than when they are from different grammatical classes (noun–verb homonyms).     

句子语境中语义联系效应和句法效应的研究

通过对比研究句子语境中句法成分和语义联系对目标词加工的不同影响,来探讨句子语境的作用机制和作用点问题。实验一采用词汇命名任务研究发现,句法违反对词汇命名会产生抑制作用,而语义违反对词汇命名却没有发现抑制作用。实验二利用词汇决定任务发现,句法和语义成分影响词汇决定任务,句法违反和语义违反对词汇决定任务均会产生抑制作用。结果表明,句子语境加工中,对内容词语义整合过程中存在一个句法成分的独立加工水平。     

Being forward not backward: lexical limits to masked priming

This study investigated whether masked priming is mediated by existing memory representations by determining whether nonwords targets would show repetition priming. To avoid the potential confound that nonword repetition priming would be obscured by a familiarity response bias, the standard lexical decision and naming tasks were modified to make targets unfamiliar. Participants were required to read a target string from right to left (i.e., "ECAF" should be read as "FACE") and then make a response. To examine if priming was based on lexical representations, repetition primes consisted of words when read forwards or backwards (e.g., "face", "ecaf") and nonwords (e.g., "pame", "emap"). Forward and backward primes were used to test if task instruction affected prime encoding. The lexical decision and naming tasks showed the same pattern of results: priming only occurred for forward primes with word targets (e.g., "face-ECAF"). Additional experiments to test if response priming affected the LDT indicated that the lexical status of the prime per se did not affect target responses. These results showed that the encoding of masked primes was unaffected by the novel task instruction and support the view that masked priming is due to the automatic triggering of pre-established computational processes based on stored information.     

Syntactic priming effects in aphasia: an investigation of local syntactic dependencies

This study explored on-line processing of local syntactic dependencies in normal subjects and in Broca's and Wernicke's aphasics using a lexical decision paradigm. In addition, subjects performed a grammatically judgement task on the real word pairs used in the lexical decision tasks. Results of two experiments for normal subjects indicated different syntactic priming effects as a function of the type of local syntactic dependency. Word pairs that formed a single constituent phrase, i.e., a verb phrase, showed both facilitory and inhibitory effects, whereas word pairs that reflected local syntactic dependencies across a phrase boundary, i.e., pronoun verb, showed only inhibitory effects. Broca's aphasics failed to show facilitory effects when presented with word pairs forming a single constituent phrase but, similar to normals, did show inhibition when presented with word pairs that reflected local syntactic dependencies across a phrase boundary. In contrast, Wernicke's aphasics failed to show inhibitory effects in both experiments. The implications of these results for theories of language processing deficits in aphasia are considered.     

Priming and the effects of sentence and lexical contexts on naming time: Evidence for autonomous lexical processing

Models of language processing which stress the autonomy of processing at each level predict that the semantic properties of an incomplete sentence context should have no influence on lexical processing, either facilitatory or inhibitory. An experiment similar to those reported by Fischler and Bloom (1979) and Stanovich and West (1979, 1981) was conducted using naming time as an index of lexical access time. No facilitatory effects of context were observed for either highly predictable or semantically appropriate (but unpredictable) completions, whereas strong inhibitory effects were obtained for inappropriate completions. When lexical decision time was the dependent measure, the same results were obtained, except that predictable completions now produced strong facilitation. In a further experiment the inhibitory effects of context on lexical decision times for inappropriate targets were maintained, even though unfocussed contexts were used, in which no clear expectancy for a particular completion was involved. These results were interpreted in terms of a two-factor theory which attributes the facilitation observed with the lexical decision task to postaccess decision processes which are not involved in the naming task. The inhibitory effects were attributed to interference resulting from semantic integration. In contrast to the results for sentence contexts, lexical contexts of the doctor-nurse variety produced clear facilitation effects on naming time (but no inhibitory effects). It was also shown that relatively minor variations in the type of neutral context could completely alter the relative importance of facilitation and inhibition.     

Building Syntactic Structure in Speaking

We investigated how people produce simple and complex phrases in speaking using a newly developed immediate recall task. People read and tried to memorize a target sentence, then read a prime sentence, then did a distractor task involving the prime sentence. Despite the delay and activity between memory and recall, people could still recall the target sentence although the syntactic form of the recalled sentence was influenced by the syntactic form of the prime sentence. This result replicates the syntactic priming effect found with other experimental paradigms. Using this task, we tested how people used abstract syntactic plans to produce simple and complex noun phrases. We found syntactic priming both when targets and prime sentences matched in complexity and when they did not match, suggesting that simple and complex noun phrases are built by the same syntactic routines during speech production.     

The syntactic priming effect: Evoked response evidence for a prelexical locus

Twenty subjects made lexical decisions in a syntactic priming paradigm. Target stimuli (nouns, verbs, abiguous noun--verb words, and nonsense words) were immediately preceded on each trial by a function word syntactic prime, creating appropriate or inappropriate syntactic contexts for the real word targets. Evoked responses to the targets were recorded from left and right frontal, temporal, and temporoparietal sites. Principal components analysis revealed a component peaking at 140 msec which discriminated words in appropriate contexts from words in inappropriate contexts, independent of lexical syntactic class, with maximal discrimination at temporoparietal sites. Evidence for the identification of the syntactic class of target items was not observed in the evoked response until 80 msec after this syntactic priming effect occurred. These results suggest a prelexical locus for the syntactic priming effect. The implications of these results for current conceptions of the modularity of the mental lexicon are discussed.     

Deficits in thematic integration processes in Broca's and Wernicke's aphasia

This study investigated how normal subjects and Broca's and Wernicke's aphasics integrate thematic information incrementally using syntax, lexical-semantics, and pragmatics in a simple active declarative sentence. Three priming experiments were conducted using an auditory lexical decision task in which subjects made a lexical decision on a 'target' (the last word of each sentence) preceded by a 'prime' (a subject noun phrase and verb). The presence and magnitude of priming was compared to a baseline condition in which non-words systematically replaced real word primes. Normal subjects showed evidence for combinatorial thematics by exhibiting significant and larger amounts of thematic priming in the condition where two real words were present in the prime than in the conditions in which only one real word was present in the prime. Additionally, normal subjects showed sensitivity to both syntactic structures and pragmatics. In contrast, Broca's patients did not show significant priming for any condition nor did they show a difference in the magnitude of priming among the conditions. Nonetheless, they showed sensitivity to pragmatics. Wernicke's patients showed significant priming for all conditions, but did not show differences in the magnitude of priming among the conditions. However, they showed sensitivity to sentence grammaticality and pragmatics. The distinct patterns of performance of Broca's and Wernicke's aphasics are discussed in terms of the nature of their impairments in the processes of combinatorial thematics.     

Context effects in visual word recognition: Lexical relatedness and syntactic context

In three experiments, we investigated how associative word-word priming effects in German depend on different types of syntactic context in which the related words are embedded. The associative relation always concerned a verb as prime and a noun as target. Prime word and target word were embedded in visually presented strings of words that formed either a correct sentence, a scrambled list of words, or a sentence in which the target noun and the preceding definite article disagreed in syntactic gender. In contrast to previous studies (O’Seaghdha, 1989; Simpson, Peterson, Casteel, & Burgess, 1989), associative priming effects were not only obtained in correct sentences but also in scrambled word lists. Associative priming, however, was not obtained when the definite article and the target noun disagreed in syntactic gender. The latter finding suggests that a rather local violation of syntactic coherence reduces or eliminates word-word priming effects. The results are discussed in the context of related work on the effect of gender dis-/agreement between a syntactic context and a target noun.     

The noun-verb problem in Chinese aphasia.

Previous studies have shown that Broca's aphasics experience a selective difficulty with action naming inside or outside of a sentence context. Conversely, it has been suggested that Wernicke's aphasics are particularly impaired in object naming. A number of explanations have been offered to account for this double dissociation, including grammatical accounts according to which the main verb problem in agrammatic Broca's aphasics is viewed as a by-product of their syntactic and/or morphological impairment, due perhaps to the greater morphological load carried by verbs (compared with nouns). In the Chinese language, there are no verb conjugations and no declensions. Hence there is no reason to expect a relationship between morphological impairment and deficits in action naming. We examined comprehension and production of object and action names, outside of a sentence context, in a sample of Chinese-speaking Broca's and Wernicke's aphasics. There was an interaction between patient group and object/action naming, but no corresponding interaction on the comprehension task. We conclude that action-naming deficits in Broca's aphasia (and/or the corresponding sparing of action names in Wernicke's aphasia) cannot be attributed to morphological differences between nouns and verbs. We also found a sublexical variant of the noun/verb dissociation applied to the internal structure of compound words made up of a verbal and a nominal element: Broca's aphasics tended to lexicalize the verbal portion of these words more often than the nominal compound, while Wernicke's showed the opposite pattern. These sublexical effects are difficult to explain in syntactic terms nor do they fit the standard lexical view. A modified lexical account is proposed, emphasizing semantic/conceptual effects in a distributed lexicon.     

Phonemic priming with words and pseudowords

Abstract

The bi-alphabetic nature of the Serbo-Croatian writing system allows unequivocal examination of phonemic similarity unconfounded with graphemic similarity. The Roman and Cyrillic alphabets are largely independent but map onto the same sounds. A lower-case context written in one alphabet bears no visual similarity to an uppercase target written in the other alphabet. One naming experiment and one lexical decision experiment investigated phonemic priming of high-frequency words and pseudowords with word and pseudoword contexts. For naming, targets that were phone-mically similar to the preceding context were named significantly faster than were phonemically dissimilar targets. This result was indifferent to the lexicality of the contexts and targets. For lexical decision, in contrast, phonemically similar word-word pairs showed inhibition, whereas phonemically similar pseudoword-word pairs showed facilitation relative to their phonemically dissimilar counterparts. These results were discussed in terms of (1) a model of visual word processing that posits a layer of phoneme units between letter units and word units, and (2) the idea that active word units inhibit one another in proportion to each one's frequency. In this account, phonemic similarity effects in naming are based on the states of the phoneme units, while phonemic similarity effects in lexical decision are based on the states of the word units. These results lend further support to the claim that, for readers of Serbo-Croatian, the visual computation of phonology is automatic and prelexical.