Semantic context effects in the comprehension of reduced pronunciation variants

Listeners require context to understand the highly reduced words that occur in casual speech. The present study reports four auditory lexical decision experiments in which the role of semantic context in the comprehension of reduced versus unreduced speech was investigated. Experiments 1 and 2 showed semantic priming for combinations of unreduced, but not reduced, primes and low-frequency targets. In Experiment 3, we crossed the reduction of the prime with the reduction of the target. Results showed no semantic priming from reduced primes, regardless of the reduction of the targets. Finally, Experiment 4 showed that reduced and unreduced primes facilitate upcoming low-frequency related words equally if the interstimulus interval is extended. These results suggest that semantically related words need more time to be recognized after reduced primes, but once reduced primes have been fully (semantically) processed, these primes can facilitate the recognition of upcoming words as well as do unreduced primes.     

Semantic priming and identification of near threshold primes in a lexical decision task

Three experiments examined both the impact of semantic analysis of 50-msec, masked visual primes on a target response and the impact of semantic analysis of the target on a prime response. The first two experiments used a prime-target interval of 1000 msec. In Experiment 1, subjects reported the identity of each prime: (a) after a lexical decision about the target, (b) both before and after a lexical decision, or (c) after a target detection response. Prime report after both types of target response showed retroactive priming in which report was facilitated by related targets and inhibited by unrelated targets. Analyses of lexical decision latency and accuracy conditionalized on prime report showed that semantic priming was restricted to reported related primes. In Experiment 2, subjects made no overt response to the primes. Priming was conditionalized on recognition of the primes on a subsequent test. The pattern was the same as Experiment 1: There was priming only for recognized primes; recognition memory showed a pattern consistent with retroactive priming. Experiment 3 also conditionalized priming on recognition performance but used a prime-target interval of only 250 msec. Again, semantic priming was found only for recognized primes, and recognition memory revealed retroactive priming. Retroactive priming indicates an interdependency between prime and target processing that needs to be incorporated into models of semantic priming.     

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。     

Semantic word priming in the absence of eye fixations: Relative contributions of overt and covert attention

In the present study, we investigated the role of covert and overt attention in word identification. In repetition and semantic priming paradigms, prime words were followed by a probe for lexical decision. To make the primes available only to covert attention, we presented them for 150 msec, parafoveally (2.2° away from fixation), and under gaze-contingent foveal masking. To make the primes available to overt attention, we presented them for 150 msec, at fixation, with no masking. Results showed both repetition and semantic priming in the absence of eye fixations on the primes: There was facilitation for identical and semantically related probe words, relative to an unrelated prime-probe condition. This revealed that both word form and meaning can be processed by covert attention alone. The pattern of relative contributions of covert (∼~25%) and overt (∼~75%) attention was similar for repetition and semantic priming.     

Phonological processing and lexical access in aphasia

This study explored the relationship between on-line processing of phonological information and lexical access in aphasic patients. A lexical decision paradigm was used in which subjects were presented auditorily with pairs of words or word-like stimuli and were asked to make a lexical decision about the second stimulus in the pair. The initial phonemes of the first word primes, which were semantically related to the real word targets, were systematically changed by one or more than one phonetic feature, e.g., cat-dog, gat-dog, wat-dog. Each of these priming conditions was compared to an unrelated word baseline condition, e.g., nurse-dog. Previous work with normals showed that even a nonword stimulus receives a lexical interpretation if it shares a sufficient number of phonetic features with an actual word in the listener's lexicon. Results indicated a monotonically decreasing degree of facilitation as a function of phonological distortion. In contrast, fluent aphasics showed priming in all phonological distortion conditions relative to the unrelated word baseline. Nonfluent aphasics showed priming only in the undistorted, related word condition relative to the unrelated word baseline. Nevertheless, in a secondary task requiring patients to make a lexical decision on the nonword primes presented singly, all aphasics showed phonological feature sensitivity. These results suggest deficits for aphasic patients in the various processes contributing to lexical access, rather than impairments at the level of lexical organization or phonological organization.     

Phonological, Semantic, and Mediated Priming in Aphasia

An auditory lexical decision task was conducted to examine rhyme, semantic, and mediated priming in nonfluent and fluent aphasic patients and normal controls. Overall, monosyllabic word targets were responded to faster when preceded by rhyming word and nonword primes than unrelated primes. Similarly, semantically related primes facilitated lexical decisions to word targets. No evidence of mediated priming emerged. Results for individual subjects suggest differences in patterns across the subject groups. Implications of the findings for the integrity of lexical access in aphasic patients are considered.     

The influence of context on lexical decision times for emotionally aversive words

Forty-eight undergraduates made lexical decisions about emotionally aversive and nonemotional words. Emotionally aversive target words were preceded either by an emotionally aversive prime word, a nonemotional but semantically related prime or a nonemotional and semantically unrelated prime. Nonemotional targets were preceded by nonemotional primes which were either semantically related to targets, unrelated, or neutral (strings of Xs). Primes were presented for 50 ms to one group of 16 participants, 500 ms to a second group and 1250 ms to a third group. Measurement of lexical decision time showed significant semantic primary effects for nonemotional targets, and these were not influenced by prime duration. Priming effects for emotionally aversive targets due both to emotional and nonemotional relatedness of primes and targets were also found and these effects were not influenced by prime duration. The results are considered to be consistent with Bower’s (1981) associative network theory of memory, and possible clinical implications for explaining spontaneous panic attacks and the incubation of anxiety are discussed.     

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.     

Masked inhibitory priming in english: evidence for lexical inhibition

Predictions derived from the interactive activation (IA) model were tested in 3 experiments using the masked priming technique in the lexical decision task. Experiment 1 showed a strong effect of prime lexicality: Classifications of target words were facilitated by orthographically related nonword primes (relative to unrelated nonword primes) but were inhibited by orthographically related word primes (relative to unrelated word primes). Experiment 2 confirmed IA's prediction that inhibitory priming effects are greater when the prime and target share a neighbor. Experiment 3 showed a minimal effect of target word neighborhood size (N) on inhibitory priming but a trend toward greater inhibition when nonword foils were high-N than when they were low-N. Simulations of 3 different versions of the IA model showed that the best fit to the data is produced when lexical inhibition is selective and when masking leads to reset of letter activities.     

Event-related potential and reaction time evidence for inhibition between alternative meanings of ambiguous words

We investigated the effects of two primes that converged onto the same semantic target representation (e.g., LION-STRIPES-TIGER) or diverged onto different semantic target representations (e.g., KIDNEY-PIANO-ORGAN). Balota and Paul (1996) showed that the RT effects of two related primes in naming and lexical decision are additive, both for unambiguous and ambiguous words. Only in a relatedness judgment task ambiguous words showed underadditivity, whereas unambiguous words again showed additivity. This underadditivity was interpreted to reflect inhibition of alternative meanings of ambiguous words. In this article we tested whether inhibition occurs for N400, assumed to index postlexical integration. In lexical decision, we found additive N400 and RT effects for unambiguous and for ambiguous words. In a relatedness judgment task we observed differences between measures: (1) for unambiguous words overadditivity for N400 vs. additivity for RT; (2) although, for ambiguous words underadditivity occurred for N400 and RT, the effects were different. For RT, the alternative meaning was only less available, whereas for N400 the alternative meaning appeared completely unavailable. Our results have implications for our understanding of inhibitory processes in the processing of ambiguous words and for the functional significance of N400.     

Semantic priming of different affective categories

The authors investigated affective semantic priming using a lexical decision task with 4 affective categories of related word pairs: neutral, happy, fearful, and sad. Results demonstrated a striking and reliable effect of affective category on semantic priming. Neutral and happy prime-targets yielded significant semantic priming. Fearful pairs showed no or modest priming facilitation, and sad primes slowed reactions to sad targets. A further experiment established that affective primes do not have generalized facilitatory-inhibitory effects. The results are interpreted as showing that the associative mechanisms that support semantic priming for neutral words are also shared by happy valence words but not for negative valence words. This may reflect increased vigilance necessary in adverse contexts or suggest that the associative mechanisms that bind negative valence words are distinct.     

Exploring the additive effects of stimulus quality and word frequency: The influence of local and list-wide prime relatedness

Stimulus quality and word frequency produce additive effects in lexical decision performance, whereas the semantic priming effect interacts with both stimulus quality and word frequency effects. This pattern places important constraints on models of visual word recognition. In Experiment 1, all three variables were investigated within a single speeded pronunciation study. The results indicated that the joint effects of stimulus quality and word frequency were dependent upon prime relatedness. In particular, an additive effect of stimulus quality and word frequency was found after related primes, and an interactive effect was found after unrelated primes. It was hypothesized that this pattern reflects an adaptive reliance on related prime information within the experimental context. In Experiment 2, related primes were eliminated from the list, and the interactive effects of stimulus quality and word frequency found following unrelated primes in Experiment 1 reverted to additive effects for the same unrelated prime conditions. The results are supportive of a flexible lexical processor that adapts to both local prime information and global list-wide context.     

词素效应到底是什么？——来自维吾尔语的证据

利用维吾尔语的一些特点,采用视觉－视觉启动、听觉－视觉跨通道启动、和延迟重复启动等三种启动技术,改变目标词和启动词之间在词素、词形以及语义上的多种关系,通过比较启动效应的异同,来考察词素效应是否可以还原为词形启动效应、语义效应,是否可以看成是词形和语义在实时加工中相互作用的后果,从而探讨词汇加工中词素效应的实质。实验一发现,在明确配对的视觉－视觉和跨通道启动中,启动词和目标词之间只有在具有词素加语义关系（＋m＋o＋s / D,＋m＋o＋s / R;其中,m 代表词素,o 代表词形,s 代表语义,D 代表目标词为派生词,R代表目标词为自由词根;＋ 表示启动词和目标词之间在某个维度上相关,－表示启动词和目标词之间在某个维度上无关）时或者仅仅具有语义关系（－m－o＋s / D）时,才有显著的启动效应。如果启动词与目标词之间仅仅具有词素（词形）关系,而没有语义关系（＋m＋o－s / D）,或者仅仅具有词形关系（－m＋o－s / R）,它们之间的启动效应微乎其微。实验二通过使用维吾尔语中的借词和延迟启动技术,比较了词素加语义加词形（＋m＋o＋s / D）的启动和语义加词形启动（－m＋o＋s / D）以及语义启动（－m＋o＋s / D）,发现词素启动效应并没有不同于其他启动条件下的效应。两个实验都表明,语义关系是产生启动效应的关键,没有语义相关,就不可能产生词素启动,词素效应依赖于语义效应。有了语义关系,词素关系和词形关系产生的作用很小。因此,词汇加工的词素效应是词形和语义统计学规律的反应,是词形和语义加工相互作用的后果,心理词典中并不需要明确地表征词汇结构。     

Inhibition of associates and activation of synonyms in the rare-word paradigm: Further evidence for a center-surround mechanism

Two experiments investigated semantic priming effects in a modified version of the Dagenbach, Carr, and Barnhardt (1990) rare-word paradigm. After learning a list of rare words to a criterion of 50% recall, subjects participated in a lexical decision task in which the rare words served as primes. When the targets were associatively related to the primes, lexical decision responses were facilitated following recalled definitions and inhibited following unrecalled definitions. When the targets were synonyms of the rare words, facilitation occurred following both recalled and unrecalled definitions. The results were interpreted as supporting a center-surround model of attentional retrieval that may serve an adaptive role in new learning.     

Novel word integration in the mental lexicon: Evidence from unmasked and masked semantic priming

We sought to establish whether novel words can become integrated into existing semantic networks by teaching participants new meaningful words and then using these new words as primes in two semantic priming experiments, in which participants carried out a lexical decision task to familiar words. Importantly, at no point in training did the novel words co-occur with the familiar words that served as targets in the primed lexical decision task, allowing us to evaluate semantic priming in the absence of direct association. We found that familiar words were primed by the newly related novel words, both when the novel word prime was unmasked (Experiment 1) and when it was masked (Experiment 2), suggesting that the new words had been integrated into semantic memory. Furthermore, this integration was strongest after a 1-week delay and was independent of explicit recall of the novel word meanings: Forgetting of meanings did not attenuate priming. We argue that even after brief training, newly learned words become an integrated part of the adult mental lexicon rather than being episodically represented separately from the lexicon.     

Integrative and semantic relations equally alleviate age-related associative memory deficits

Two experiments compared effects of integrative and semantic relations between pairs of words on lexical and memory processes in old age. Integrative relations occur when two dissimilar and unassociated words are linked together to form a coherent phrase (e.g., horse-doctor). In Experiment 1, older adults completed a lexical-decision task where prime and target words were related either integratively or semantically. The two types of relation both facilitated responses compared to a baseline condition, demonstrating that priming can occur in older adults with minimal preexisting associations between primes and targets. In Experiment 2, young and older adults completed a cued recall task with integrative, semantic, and unrelated word pairs. Both integrative and semantic pairs showed significantly smaller age differences in associative memory compared to unrelated pairs. Integrative relations facilitated older adults' memory to a similar extent as semantic relations despite having few preexisting associations in memory. Integratability of stimuli is therefore a new factor that reduces associative deficits in older adults, most likely by supporting encoding and retrieval mechanisms.     

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.     

On obtaining episodic priming in a lexical decision task following paired-associate learning

In four experiments, subjects made lexical (word-nonword) decisions to target letter strings after studying paired associates. In this lexical decision test, word targets previously studied as response terms in the paired associates were preceded at a 150-ms and/or 950-ms stimulus onset asynchrony (SOA) by one of various subsets of the following six types of primes: a neutral (XXX or ready) prime, a semantically unrelated word prime episodically related to the target through its having been previously studied in the same pair, a semantically related word prime previously studied in a pair with some other unrelated word, a semantically unrelated word prime previously studied in a pair with some other unrelated word, a nonstudied semantically related word prime, and a nonstudied semantically unrelated word prime. At the 950-ms SOA, facilitation of lexical decisions produced by the episodically related primes was greater in test lists in which there were no 150-ms SOA trials intermixed, no previously studied semantically related primes, and no studied nonword targets. At the 150-ms SOA, facilitation from episodic priming was greater in test lists in which there were no semantically related primes and all studied word targets and no studied nonword targets. Facilitation effects from semantically related primes were small in magnitude and occurred inconsistently. Discussion focused on the implications these results have for the episodic-semantic memory distinction and the automaticity of episodic and semantic priming effects.     

Priming word recognition with orthographic neighbors: effects of relative prime-target frequency

Four lexical decision experiments were performed with an orthographic priming paradigm in which test words were preceded by orthographically related or unrelated prime words. When prime words were presented for 350 ms without a mask, it was observed that primes that are lower frequency orthographic neighbors of the target interfered with target processing relative to an unrelated condition. When primes were higher frequency neighbors of the target, no interference or facilitation was observed. On the other hand, with briefly presented masked primes, interference was observed with higher frequency prime words. Finally, facilitatory effects in masked repetition priming were obtained with both high- and low-frequency prime-target pairs. The results are interpreted in terms of activation and selection processes operating in visual word recognition.     

Gradients versus dichotomies: How strength of semantic context influences event-related potentials and lexical decision times

In experiments devoted to word recognition and/or language comprehension, reaction time in the lexical decision task is perhaps the most commonly used behavioral dependent measure, and the amplitude of the N400 component of the event-related potential (ERP) is the most common neural measure. Both are sensitive to multiple factors, including frequency of usage, orthographic similarity to other words, concreteness of word meaning, and preceding semantic context. All of these factors vary continuously. Published results have shown that both lexical decision times and N400 amplitudes show graded responses to graded changes of word frequency and orthographic similarity, but a puzzling discrepancy in their responsivity to the strength of a semantic context has received little attention. In three experiments, we presented pairs of words varying in the strengths of their semantic relationships, as well as unrelated pairs. In all three experiments, N400 amplitudes showed a gradient from unrelated to weakly associated to strongly associated target words, whereas lexical decision times showed a binary division rather than a gradient across strengths of relationship. This pattern of results suggests that semantic context effects in lexical decision and ERP measures arise from fundamentally different processes.