Contextual modulation of N400 amplitude to lexically ambiguous words

Though much is known about the N400 component, an event-related EEG potential that is sensitive to semantic manipulations, it is unclear whether modulations of N400 amplitude reflect automatic processing, controlled processing, or both. We examined this issue using a semantic judgment task that manipulated local and global contextual cues. Word triplets (prime-noun-target, e.g., finance-bank-money) were sequentially presented on a computer screen (500 ms duration, 1000 ms stimulus onset asynchrony), in which the second word was a homograph. The first word (prime) created a neutral-, dominant-meaning- or subordinate-meaning-biased "global context," and the third word (target) created a dominant- or subordinate-biased "local context" that was either congruent or incongruent with the "global context" established by the first prime word. Participants were instructed to read all three words but to decide only whether the second and third words were semantically related. Event-related potentials (ERPs), specifically the N400, were recorded to the third terminal word. N400 amplitudes evoked by dominant meaning-related third words incongruent with the globally biased subordinate context (e.g., river-bridge-money) were significantly more negative than dominant endings in neutral contexts (e.g., taxi-bank-money), but not different from unrelated filler triplets. In addition, there was some indication that left hemisphere, temporal-parietal electrode sites were associated with greater N400 negativity for dominant targets in conflicting subordinate global contexts than homologous right hemisphere electrode sites, the latter of which showed significant activation to subordinate meanings in cooperating contexts. Thus, N400 amplitude was more affected by global than local context suggesting that controlled processes may take priority over automatic processes in modulating N400 amplitude, especially for left hemisphere electrode sites.     

Influence of context on the activation and selection of ambiguous word senses

The activation of ambiguous word senses was investigated by measuring the amount of interference in naming the ink color of a word that was either related or unrelated to one of the meanings of a preceding ambiguous word. In agreement with previous results obtained using this procedure (Conrad, 1974), evidence was obtained that both meanings of the ambiguous words are activated even in the presence of biasing context. However, contrary to previous findings, the degree of activation of each word sense depended on its degree of compatibility with the context. These results are consistent with a language processing system in which all interpretations of an ambiguity are accessed and then processed until an accurate determination has been made of which interpretation best satisfies the syntactic and semantic constraints that govern it.     

Semantic information is used by a deep dyslexic to parse compounds

We report a case study of a 48 year-old patient, J.O., who was tested 20 years after the removal of a tumor in the left temporal-parietal region. This surgery and subsequent radiation resulted in right side paralysis and numerous language problems. Tests of J.O.'s single word reading abilities indicate that she could be classified as a deep dyslexic with over 16% of her errors in word naming having a clear semantic relationship with the target word (Coltheart, 1980). We examined her ability to read compound words aloud and following Libben (1993) we provide evidence that J.O. is a second case in which there is obligatory access of morphological constituents of compound words. These data are discussed within the context of Libben's (1998) compound word processing model.     

Time course of priming for associate and inference words in a discourse context

The construction of word meanings in a discourse context was conceptualized as a process of sense activation, sense selection, and sense elaboration. In three experiments, subjects read texts presented by a rapid serial visual procedure and performed a lexical decision on visually presented targets that followed ambiguous prime words. When the target was a word, it was either an associate of the prime word, a probable inference suggested by the discourse, or an unrelated word. For associates, lexical decisions that related to either the appropriate or the inappropriate sense of the ambiguous word were generally facilitated at short (200-400 msec) prime-target stimulus onset asynchronies (SOAs). At longer SOAs, responses were faster to appropriate than to inappropriate associates. For the thematic inferences, there was no difference between these (appropriate) inferences and (inappropriate) control words at short SOAs. At long SOAs (1,000 and 1,500 msec), however, inference words were facilitated. The results are interpreted as consistent with a model of lexical processing in which sense activation functions independently of context. Discourse context effects, whether on sense selection (suppression of inappropriate associates) or on sense elaboration (creation of inferences), are seen as postlexical.     

Imageability and word recognition in the left and right visual fields: a signal detection analysis

Identifying the information processing constraints that determine whether or not imagery moderates visual field asymmetries is essential for constructing a dynamic model of hemispheric interaction during language processing. In this investigation, we manipulated the global experimental context in which imageable and nonimageable words were presented by contrasting mixed and blocked word lists using a lateralized lexical decision task. Signal detection analyses were employed to assess whether global stimulus context and imageability differentially affect word discriminability (d prime) and response bias (log beta) across visual fields. Both discriminability and response bias varied with imageability and stimulus context, but to a comparable extent across visual fields. This suggests that both hemispheres are sensitive to the global context in which words are presented, and can adjust processing based not only on semantic characteristics of the words themselves, but also on the variability of items in the stimulus environment.     

颜色词素在词义不透明双字词中的语义激活

多词素词的心理表征和和词义激活已成为心理语言学领域的研究热点。目前主要有三种理论:词素分解储存模型、整词储存模型和混合表征模型。针对词义不透明词中词素与整词的关系,利用语义启动和色词干扰的实验范式,对颜色词素在词义不透明双字词中的语义激活进行了研究。结果表明,词义不透明双字词的词素与整词之间存在着心理资源竞争,表现出相互抑制的关系,它们的力量对比随时间变化而改变,出现此消彼长的趋势。研究还表明,多词素词中的词素加工,不仅受词素结构影响,也受词素本身性质影响。由于颜色词素的加工既涉及语义系统,也涉及知觉系统,所以虽然在多词素词中处于附加词素的地位,也具有加工上的优势。     

Phonetic-semantic mediated false recognition: does activation fail to spread?

Spoken word recognition involves brief activation of candidate words. Six experiments examined whether words semantically related to phonologically activated words would be falsely recognized. Experiments 1 and 2 involved homophones as test words; Experiment 3 used strong associates for the semantic mediation link. Experiment 4 approximated lists of "strong" converging associates. Experiment 5 expanded the real time needed for word identification by using a gating procedure during study. In Experiment 6, the goal was to create a more sensitive test by requiring participants to indicate which of two lures (mediated or control) was "most likely" to be new. Recognition errors were sensitive to separate phonetic and semantic stages in the mediated chain; however, there was little evidence of mediated false recognition, despite expectations derived from common models of spreading activation.     

Neural responses to morphological, syntactic, and semantic properties of single words: an fMRI study

Dissociations in the recognition of specific classes of words have been documented in brain-injured populations. These include deficits in the recognition and production of morphologically complex words as well as impairments specific to particular syntactic classes such as verbs. However, functional imaging evidence for distinctions among the neural systems underlying these dissociations has been inconclusive. We explored the neural systems involved in processing different word classes in a functional Magnetic Resonance Imaging study, contrasting four groups of words co-varying morphological complexity (simple, monomorphemic words vs complex derived or inflected words) and syntactic class (verbs vs nouns/adjectives). Subtraction of word from letter string processing showed activation in left frontal and temporal lobe regions consistent with prior studies of visual word processing. No differences were observed for morphologically complex and simple words, despite adequate power to detect stimulus specific effects. A region of posterior left middle temporal gyrus showed significantly increased activation for verbs. Post hoc analyses showed that this elevated activation could also be related to semantic properties of the stimulus items (verbs have stronger action associations than nouns, and action association is correlated with activation). Results suggest that semantic as well as syntactic factors should be considered when assessing the neural systems involved in single word comprehension.     

Dual vs. single encoding in recognition memory as a function of lag,delay, and availability of semantic information

One objective of the study was to assess the view of Winograd and Raines (1972) that the absence of a difference between dual as opposed to single encodings of a word at long lags may be due to the fact that subjects can establish two independent temporal tags when a to-be-remembered (TBRI word is presented at long lags. Winograd and Raines' argument that the effectiveness of any such temporal tags should diminish over time was examined. A second objective was to determine whether providing information about the semantic senses used during encoding operations would facilitate recognition, as "sense tagging" theories require. Words were presented twice in either the same low-frequency context or the same high-frequency context, or once in both a high- and low-frequency context at Lags 0 and 15. A recognition test was given immediately, or after a 1-week delay. The test was either context free or each word was accompanied by phrases which, in the case of TBR words, cued subjects with respect to the semantic senses of the word used in initial encoding. All manipulations influenced performance, but not in accordance with theoretical expectations.     

The distinctiveness of emotion concepts: a comparison between emotion, abstract, and concrete words

Are the concepts represented by emotion words different from abstract words in memory? We examined the distinct characteristics of emotion concepts in 3 separate experiments. The first demonstrated that emotion words are better recalled than both concrete and abstract words in a free recall task. In the second experiment, ratings of abstract, concrete, and emotion words were compared on concreteness, imageability, and context availability scales. Results revealed a difference between all 3 word types on each of the 3 scales. The third experiment investigated priming in a lexical decision task for homogeneous (abstract-abstract and emotion-emotion) and heterogeneous (abstract-emotion and emotion-abstract) associated word pairs. Priming occurred only for the homogeneous and heterogeneous abstract-emotion word pair conditions. Possible explanations for these findings are discussed in terms of the circumplex, hierarchical, and semantic activation models. The results are most consistent with the predictions of the semantic activation model.     

汉语口语词汇产生中的多重音韵激活：单词翻译任务的ERP研究

口语词汇产生过程中, 非目标词是否会产生音韵激活是独立两阶段模型和交互激活模型的争论焦点之一。研究运用事件相关电位技术, 考察了被试在翻译命名任务中是否受到背景图片音韵或语义干扰词的影响。行为反应时中未发现显著的音韵效应, 而语义效应显著, 表明非目标词不会产生音韵激活。事件相关电位的结果显示在目标单词呈现后的400~600 ms时间窗口中出现了显著的语义效应, 在600~700 ms时间窗口内出现了边缘显著的语义效应和音韵效应, 均表现为相关条件比无关条件波幅更正。上述结果表明在将英语翻译成汉语的过程中, 尽管在脑电上呈现出可能存在微弱的多重音韵激活, 但行为结果并不会显示出非目标项的音韵激活。研究结果支持了汉语口语词汇产生遵循独立两阶段模式的观点。     

情绪名词的具体性效应：来自ERP的证据

词汇的具体性和情绪性是影响词汇加工的不同因素, 高具体性和情绪性都能够促进词汇的加工。本研究同时操纵词汇的具体性和情绪性, 使用词汇判定任务和愉悦度判断任务, 探讨了情绪名词的具体性效应及其具体性效应是否受词汇情绪信息的影响。结果发现：情绪名词的具体性效应受内隐或外显情绪条件的影响, 具体的情绪词比抽象的情绪词反应时间更短、正确率更高, 诱发了更大的N400和减小的LPC, 但LPC的具体性效应只表现在内隐情绪任务中。词汇的具体性和情绪性的相互影响发生在内隐情绪任务中的语义加工阶段, 正性、负性的具体词和抽象词的加工在N400成分上差异不显著, 而中性具体词和抽象词在N400成分上差异显著, 说明词汇的情绪信息为抽象词的加工提供了充分的语境, 因此消除了具体词的加工优势。     

Semantic similarity, predictability, and models of sentence processing

The effects of word predictability and shared semantic similarity between a target word and other words that could have taken its place in a sentence on language comprehension are investigated using data from a reading time study, a sentence completion study, and linear mixed-effects regression modeling. We find that processing is facilitated if the different possible words that could occur in a given context are semantically similar to each other, meaning that processing is affected not only by the nature of the words that do occur, but also the relationships between the words that do occur and those that could have occurred. We discuss possible causes of the semantic similarity effect and point to possible limitations of using probability as a model of cognitive effort.     

The neurobiology of adaptive learning in reading: A contrast of different training conditions

fMRI was used to investigate the separate influences of orthographic, phonological, and semantic processing on the ability to learn new words and the cortical circuitry recruited to subsequently read those words. In a behavioral session, subjects acquired familiarity for three sets of pseudowords, attending to orthographic, phonological, or (learned) semantic features. Transfer effects were measured in an event-related fMRI session as the subjects named trained pseudowords, untrained pseudowords, and real words. Behaviorally, phonological and semantic training resulted in better learning than did orthographic training. Neurobiologically, orthographic training did not modulate activation in the main reading regions. Phonological and semantic training yielded equivalent behavioral facilitation but distinct functional activation patterns, suggesting that the learning resulting from these two training conditions was driven by different underlying processes. The findings indicate that the putative ventral visual word form area is sensitive to the phonological structure of words, with phonologically analytic processing contributing to the specialization of this region.     

Foreign accents reduce false recognition rates in the DRM paradigm

ABSTRACT

More cognitive resources are required to comprehend foreign-accented than native speech. Focusing these cognitive resources on resolving the acoustic mismatch between the foreign-accented input and listeners’ stored representations of spoken words can affect other cognitive processes. Across two studies, we explored whether processing foreign-accented speech reduces the activation of semantic information. This was achieved using the DRM paradigm, in which participants study word lists and typically falsely remember non-studied words (i.e. critical lures) semantically associated with the studied words. In two experiments, participants were presented with word lists spoken both by a native and a foreign-accented speaker. In both experiments we observed lower false recognition rates for the critical lures associated with word lists presented in a foreign accent, compared to native speech. In addition, participants freely recalled more studied words when they had been presented in a native, compared to a foreign, accent, although this difference only emerged in Experiment 2, where the foreign speaker had a very strong accent. These observations suggest that processing foreign-accented speech modulates the activation of semantic information.

Highlights

• The DRM paradigm was used to explore whether semantic activation is reduced when processing foreign-accented speech.

• Across two experiments, false recognition of non-studied semantic associates was lower when word lists were presented in a foreign accent, compared to native speech.

• The above results suggest semantic activation may be reduced when processing foreign-accented speech.

• Additionally, it was found that when the foreign speaker had a mild accent, correct recall of studied words was uninfluenced. If the foreign speaker had a strong accent, however, correct recall of studied words was reduced.

     

Polysemy and the subjective lexicon: Semantic relatedness and the salience of intraword senses

Subjective perceptions of the senses of polysemous English words are collected in questionnaire studies and the effects of variability in semantic distances among these senses are examined in an experiment. In the first of two questionnaire studies, native speakers produce meanings for 175 polysemous words; from their responses, the most frequently produced meaning for each word is identified as its dominant sense. In a second questionnaire, independent subjects rate the semantic relatedness between the dominant meaning and the other senses generated for each word in the first study. Relatedness measures vary, raising the possibility that polysemous words vary in terms of the salience of their different senses in different contexts. This is confirmed in an experiment showing that salience ratings are influenced by the interacting factors of sentential context, extent of relatedness of the senses, and the dominance status of the senses.This research was supported by a grant from the Special Research Fund, University of Western Australia, to Kevin Durkin.     

语境情绪韵律对新异词汇学习过程的影响

模拟自然学习语境,探讨情绪韵律对具体和抽象词学习的调节作用及其产生原因。被试在高兴、愤怒、中性语境情绪韵律条件下学习抽象和具体词,记录学习过程及测试过程中的行为与脑电反应。结果发现在愤怒韵律背景下学习的抽象词加工的正确率更低、反应时更长;并且诱发了更为显著的脑电成分。表明愤怒韵律对词汇学习尤其是抽象词学习有显著的消极作用。此外,情绪韵律对词汇学习的调节作用是在学习过程中对词汇语义提取及晚期语义整合产生影响而形成的。     

Word identification: Imageability, semantics, and the content-functor distinction

It has often been suggested that different special-purpose mechanisms underlie the processing of content words and function words. The received view is that processing differences in various tasks arise because of differences between these word classes in terms of their semantic/syntactic function, despite the fact that these tasks often involve word processing in the absence of any sentence context. It is also well known that the ease with which a word arouses a sensory impression is often a good predictor of word-processing performance, yet the literature largely ignores the fact that, typically, imageability and word class are confounded factors. A series of three experiments shows that in the context of a Stroop task, the typical content-function word difference can be obtained, but that this word class difference disappears completely when the items are matched on the dimension of imageability. It is suggested that the processing of decontextualized content and function words does not necessarily engage distinct special purpose processing mechanisms. Implications for understanding previously published work on word class effects in other paradigms are briefly noted.     

The Effect of Non-sentential Context Prosody on Homographs’ Lexical Activation in Persian

This study examines the effect of non-sentential context prosody pattern on lexical activation in Persian. For this purpose a questionnaire including target and non-target words is used. The target words are homographs with two possible stress patterns belonging to different syntactic categories. Participants are asked to read out the words aloud and note the first word that comes to their mind. The results show that by reading the target words, both meanings of the target words are activated in mind and the prosodic pattern of the non-sentential preceding context does not affect the activation of the other stress pattern meaning. This result suggests that the metrical prosodic pattern of non-sentential context is not a strong constraint to determine which meaning of the target word must be activated. The experiment also illustrates that the stress pattern used to read the target words does not necessarily matches the stress pattern of the target word which relates to the written word. These findings confirm Swinney (Verb Learn Verb Behav 18:645–665, 1979) and Elston-Güttler and Friederici’s (J Mem Lang 52(2):256–283, 2005) finding that both meanings of an ambiguous word are accessed at the first stage. This study shows that in lack of semantic context, Persian natives behave homographs as ambiguous words and there is no bias towards preferring one meaning over another.