Asymmetric aging effects on semantic and phonological processes: naming in the picture-word interference task

In 2 experiments, participants named pictures while ignoring auditory word distractors. For pictures with homophone names (e.g., ball), distractors semantically related to the nondepicted meaning (e.g., prom) facilitated naming by top-down phonological connections for young but not for older adults. Slowing from unrelated distractors and facilitation from phonologically related distractors were age invariant except in distractors that were both semantically and phonologically related. Only distractors semantically related to the picture interfered more for older than younger adults. These results ar einconsistent with age-linked deficits in inhibition of irrelevant information from either internal or external sources. Rather, aging affects priming transmission in a connectionist network with asymmetric effects on semantic and phonological connections involved in comprehension and production, respectively.     

Challenging the widespread assumption that connectionism and distributed representations go hand-in-hand

One of the central claims associated with the parallel distributed processing approach popularized by D.E. Rumelhart, J.L. McClelland and the PDP Research Group is that knowledge is coded in a distributed fashion. Localist representations within this perspective are widely rejected. It is important to note, however, that connectionist networks can learn localist representations and many connectionist models depend on localist coding for their functioning. Accordingly, a commitment to distributed representations should be considered a specific theoretical claim regarding the structure of knowledge rather than a core principle, as often assumed. In this paper, it is argued that there are fundamental computational and empirical challenges that have not yet been addressed by distributed connectionist theories that are readily accommodated within localist approaches. This is highlighted in the context of modeling word and nonword naming, the domain in which some of the strongest claims have been made. It is shown that current PDP models provide a poor account of naming monosyllable items, and that distributed representations make it difficult for these models to scale up to more complex language phenomena. At the same time, models that learn localist representations are shown to hold promise in supporting many of the core reading and language functions on which PDP models fail. It is concluded that the common rejection of localist coding schemes within connectionist architectures is premature.     

Lexical selection is not by competition: a reinterpretation of semantic interference and facilitation effects in the picture-word interference paradigm

The dominant view in the field of lexical access in speech production maintains that selection of a word becomes more difficult as the levels of activation of nontarget words increase--selection by competition. The authors tested this prediction in two sets of experiments. First, the authors show that participants are faster to name pictures of objects (e.g., "bed") in the context of semantically related verb distractors (e.g., sleep) compared with unrelated verb distractors (e.g., shoot). In the second set of experiments, the authors show that target naming latencies (e.g., "horse") are, if anything, faster for within--category semantically close distractor words (e.g., zebra) than for within--category semantically far distractor words (e.g., whale). In the context of previous research, these data ground a new empirical generalization: As distractor words become semantically closer to the target concepts--all else being equal--target naming is facilitated. This fact means that lexical selection does not involve competition, and consequently, that the semantic interference effect does not reflect a lexical level process. This conclusion has important implications for models of lexical access and interpretations of Stroop-like interference effects.     

Tracing attention and the activation flow of spoken word planning using eye movements

The flow of activation from concepts to phonological forms within the word production system was examined in 3 experiments. In Experiment 1, participants named pictures while ignoring superimposed distractor pictures that were semantically related, phonologically related, or unrelated. Eye movements and naming latencies were recorded. The distractor pictures affected the latencies of gaze shifting and vocal naming. The magnitude of the phonological effects increased linearly with latency, excluding lapses of attention as the cause of the effects. In Experiment 2, no distractor effects were obtained when both pictures were named. When pictures with superimposed distractor words were named or the words were read in Experiment 3, the words influenced the latencies of gaze shifting and picture naming, but the pictures yielded no such latency effects in word reading. The picture-word asymmetry was obtained even with equivalent reading and naming latencies. The picture-picture effects suggest that activation spreads continuously from concepts to phonological forms, whereas the picture-word asymmetry indicates that the amount of activation is limited and task dependent.     

The Distractor Picture Paradox in Speech Production: Evidence from the Word Translation Task

Several naming studies show that distractor pictures, even when intentionally ignored by the speaker, are still capable of activating their respective phonological representations. However results from word translation studies suggest that distractor pictures are only conceptually activated. Here we tested the reliability of the word translation results. In four experiments, bilingual participants translated words from one language to the other one while ignoring the presentation of pictures. In Experiment 1a phonological related pictures sped up translation latencies. However, the effect disappeared when the percentage of related trials was reduced (Experiment 1b). In Experiment 2a translation latencies were faster when the words were accompanied by semantically related pictures than by unrelated pictures. Importantly, the effect was still reliable when the proportion of related trials was reduced and the total number of semantic categories was increased (Experiment 2b). Theoretical implications of the influence of distractor pictures during speech production are discussed.     

Ambiguity,Competition, and Blending in Spoken Word Recognition

A critical property of the perception of spoken words is the transient ambiguity of the speech signal. In localist models of speech perception this ambiguity is captured by allowing the parallel activation of multiple lexical representations. This paper examines how a distributed model of speech perception can accommodate this property. Statistical analyses of vector spaces show that coactivation of multiple distributed representations is inherently noisy, and depends on parameters such as sparseness and dimensionality. Furthermore, the characteristics of coactivation vary considerably, depending on the organization of distributed representations within the mental lexicon. This view of lexical access is supported by analyses of phonological and semantic word representations, which provide an explanation of a recent set of experiments on coactivation in speech perception (Gaskell & Marslen–Wilson, 1999).     

Auditory context effects in picture naming investigated with event-related fMRI

Naming an object entails a number of processing stages, including retrieval of a target lexical concept and encoding of its phonological word form. We investigated these stages using the picture-word interference task in an fMRI experiment. Participants named target pictures in the presence of auditorily presented semantically related, phonologically related, or unrelated distractor words or in isolation. We observed BOLD signal changes in left-hemisphere regions associated with lexical-conceptual and phonological processing, including the midto-posterior lateral temporal cortex. However, these BOLD responses manifested as signal reductions for all distractor conditions relative to naming alone. Compared with unrelated words, phonologically related distractors showed further signal reductions, whereas only the pars orbitalis of the left inferior frontal cortex showed a selective reduction in response in the semantic condition. We interpret these findings as indicating that the word forms of lexical competitors are phonologically encoded and that competition during lexical selection is reduced by phonologically related distractors. Since the extended nature of auditory presentation requires a large portion of a word to be presented before its meaning is accessed, we attribute the BOLD signal reductions observed for semantically related and unrelated words to lateral inhibition mechanisms engaged after target name selection has occurred, as has been proposed in some production models.     

How lingering representations of abandoned context words affect speech production

Four experiments tested whether and how initially planned but then abandoned speech can influence the production of a subsequent resumption. Participants named initial pictures, which were sometimes suddenly replaced by target pictures that were related in meaning or word form or were unrelated. They then had to stop and resume with the name of the target picture. Target picture naming latencies were measured separately for trials in which the initial speech was skipped, interrupted, or completed. Semantically related initial pictures helped the production of the target word, although the effect dissipated once the utterance of the initial picture name had been completed. In contrast, phonologically related initial pictures hindered the production of the target word, but only for trials in which the name of the initial picture had at least partly been uttered. This semantic facilitation and phonological interference did not depend on the time interval between the initial and target picture, which was either varied between 200 ms and 400 ms (Experiments 1-2) or was kept constant at 300 ms (Experiments 3-4). We discuss the implications of these results for models of speech self-monitoring and for models of problem-free word production.     

Models of word production

Research on spoken word production has been approached from two angles. In one research tradition, the analysis of spontaneous or induced speech errors led to models that can account for speech error distributions. In another tradition, the measurement of picture naming latencies led to chronometric models accounting for distributions of reaction times in word production. Both kinds of models are, however, dealing with the same underlying processes: (1) the speaker’s selection of a word that is semantically and syntactically appropriate; (2) the retrieval of the word’s phonological properties; (3) the rapid syllabification of the word in context; and (4) the preparation of the corresponding articulatory gestures. Models of both traditions explain these processes in terms of activation spreading through a localist, symbolic network. By and large, they share the main levels of representation: conceptual/semantic, syntactic, phonological and phonetic. They differ in various details, such as the amount of cascading and feedback in the network. These research traditions have begun to merge in recent years, leading to highly constructive experimentation. Currently, they are like two similar knives honing each other. A single pair of scissors is in the making.     

Semantic component of a cross-modal Stroop-like task

Three experiments showed that the pattern of interference of single-modality Stroop tests also exists cross-modally. Distractors and targets were either pictures or auditory words. In a naming task (Experiment 1), word distractors from the same semantic category as picture targets interfered with picture naming more than did semantically unrelated distractors; the semantic category of picture distractors did not differentially affect word naming. In a categorization task (Experiment 2), this Stroop-like effect was reversed: Picture distractors from the same semantic category as word targets interfered less with word categorization than picture distractors that were semantically unrelated; the semantic category of word distractors did not differentially affect picture categorization. Experiment 3 replicated these effects when each subject performed both tasks; the task, naming or categorizing, determined the pattern of interference between pictures and auditory words. The results thus support the existence of a semantic component of a cross-modal Stroop-like effect.     

Homophonic context effects when naming Japanese kanji: evidence for processing costs?

The current study investigated the effects of phonologically related context pictures on the naming latencies of target words in Japanese and Chinese. Reading bare words in alphabetic languages has been shown to be rather immune to effects of context stimuli, even when these stimuli are presented in advance of the target word (e.g., Glaser & Düngelhoff, 1984 ; Roelofs, 2003 ). However, recently, semantic context effects of distractor pictures on the naming latencies of Japanese kanji (but not Chinese hànzì) words have been observed (Verdonschot, La Heij, & Schiller, 2010 ). In the present study, we further investigated this issue using phonologically related (i.e., homophonic) context pictures when naming target words in either Chinese or Japanese. We found that pronouncing bare nouns in Japanese is sensitive to phonologically related context pictures, whereas this is not the case in Chinese. The difference between these two languages is attributed to processing costs caused by multiple pronunciations for Japanese kanji.     

Writing words from pictures: What representations are activated, and when?

In three experiments, the nature of the representations involved in written picture naming and the time course of their activation were investigated. French participants had to produce picture names while hearing distractors. In Experiment 1, distractors semantically related to the picture names yielded a semantic interference effect when a stimulus onset asynchrony (SOA) of--150 msec, but not when a SOA of 0 msec, was used, in both spoken and written picture naming. Experiment 2 showed that the semantic interference effect was not located at the conceptual level. In Experiment 3, participants wrote down picture names while hearing semantically related, phonologically related, both semantically and phonologically related, or unrelated distractors, presented at both SOAs. A semantic interference effect was obtained with phonologically unrelated distractors but was eliminated with phonologically related distractors. Facilitatory effects of phonologically related distractors were found at both SOAs. The implications of the findings for written picture naming are discussed.     

汉语词汇产生中音、形、义三种信息激活的时间进程

采用图-词干扰范式和图片命名方法,探讨语音、语义、字形在汉语词汇产生中激活的时间进程与特点。选择与目标图片名称(如“羊”)具有同音(“阳”)、语义相联(“牛”)、字形相似(“丰”)或无关控制(“冷”)等四种关系的干扰字,依SOA条件呈现在将要被命名的图片上,发现图片命名时间受干扰字的影响：语义干扰效应存在于较早期的SOA(0ms)条件中,在较晚期SOA(150ms)时有很大的减弱;语音促进效应和字形促进效应同时强烈地存在于早期和晚期SOA。实验发现了词条选择(语义激活)和音位编码(语音提取)在激活时间上的重叠现象,与传统的独立两阶段模型的预期存在明显矛盾,倾向于支持交互作用理论的观点。     

Naming and categorizing objects: Task differences modulate the polarity of semantic effects in the picture–word interference paradigm

The picture-word interference paradigm is a prominent tool for studying lexical retrieval during speech production. When participants name the pictures, interference from semantically related distractor words has regularly been shown. By contrast, when participants categorize the pictures, facilitation from semantically related distractors has typically been found. In the extant studies, however, differences in the task instructions (naming vs. categorizing) were confounded with the response level: While responses in naming were typically located at the basic level (e.g., "dog"), responses were located at the superordinate level in categorization (e.g., "animal"). The present study avoided this confound by having participants respond at the basic level in both naming and categorization, using the same pictures, distractors, and verbal responses. Our findings confirm the polarity reversal of the semantic effects--that is, semantic interference in naming, and semantic facilitation in categorization. These findings show that the polarity reversal of the semantic effect is indeed due to the different tasks and is not an artifact of the different response levels used in previous studies. Implications for current models of language production are discussed.     

Semantic competition between hierarchically related words during speech planning

There is overwhelming evidence that during speech planning semantically related words become lexically activated and compete for selection with the to-be-produced target word. The vast majority of this evidence stems from studies using the picture-word task, in which a distractor word (e.g., bird) drawn from the same semantic category as the target (e.g., fish) was shown to inhibit the picture-naming response more strongly than did an unrelated distractor word. By contrast, corresponding evidence from distractor words (e.g., carp) bearing a hierarchical relation to the target (e.g., fish) is sparse and inconclusive. In the present study, we investigated effects of subordinate-level distractors during basic-level naming and effects of basic-level distractors during subordinate-level naming. Hierarchically related distractors were found to inhibit the naming response in both situations. This pattern of results did not depend on whether the pictures were preferably named at the basic level or at the subordinate level. The results suggest that hierarchically related name alternatives compete for selection.     

Lexical and conceptual factors in the naming of relations

Recent models of language production distinguish three main stages, the generation of a preverbal (or conceptual) message level representation, the stage of linguistic formulation processes (which access lexical items and generate the syntactic frames in which these items are inserted), and the stage of articulation. This means that at least two sources of difficulty in producing a lexical item must be distinguished. First, the difficulty can be due to properties of the message representation. So, for example, several concepts may compete for expression. Second, a given lexical item might be more difficult to access than another item because of differences in the complexity of the processes translating from conceptual to lexical representations. The present study presents evidence for these two sources of difficulty in producing lexical items for the domain of semantically unmarked versus marked dimensional adjectives (e.g., big versus small). The first set of experiments establishes an effect of semantic markedness in language production which is due to a difference in the difficulty of accessing unmarked versus marked lexical items. The second set of experiments shows that competition between concepts for expression can lead to incorrect selection of an (unintended) lexical item (as reflected in certain types of speech errors), or to a higher processing load for producing the correct (intended) lexical item. Together, these experiments support the distinction between a preverbal conceptual and a lexical level of representation in language production, and show that both levels contribute to the relative difficulty of producing lexical items.     

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。     

Dissociations in performance on novel versus irregular items: single-route demonstrations with input gain in localist and distributed models

Four pairs of connectionist simulations are presented in which quasi-regular mappings are computed using localist and distributed representations. In each simulation, a control parameter termed input gain was modulated over the only level of representation that mapped inputs to outputs. Input gain caused both localist and distributed models to shift between regularity-based and item-based modes of processing. Performance on irregular items was selectively impaired in the regularity-based modes, whereas performance on novel items was selectively impaired in the item-based modes. Thus, the models exhibited double dissociations without separable processing components. These results are discussed in the context of analogous dissociations found in language domains such as word reading and inflectional morphology.     

Listening back in time: Does attention to memory facilitate word-in-noise identification?

The ephemeral nature of spoken words creates a challenge for oral communications where incoming speech sounds must be processed in relation to representations of just-perceived sounds stored in short-term memory. This can be particularly taxing in noisy environments where perception of speech is often impaired or initially incorrect. Usage of prior contextual information (e.g., a semantically related word) has been shown to improve speech in noise identification. In three experiments, we demonstrate a comparable effect of a semantically related cue word placed after an energetically masked target word in improving accuracy of target-word identification. This effect persisted irrespective of cue modality (visual or auditory cue word) and, in the case of cues after the target, lasted even when the cue word was presented up to 4 seconds after the target. The results are framed in the context of an attention to memory model that seeks to explain the cognitive and neural mechanisms behind processing of items in auditory memory.     

口语产生中词频效应、音节频率效应和语音促进效应的认知年老化

采用图画-词汇干扰实验范式,考察了汉语口语产生过程中词频与音节频率效应、语音促进效应的认知年老化现象及其认知机制。结果发现,老年组的图画命名时间长于青年组,且老年组的词频效应和音节频率效应高于青年组,而语音相关效应低于青年组。老年组中词频和音节频率存在两因素交互作用,青年组则没有,这表明随着年龄增加,老年人的心理词典中不仅语义水平和音韵水平之间的联结强度变弱,而且信息之间的作用模式发生了变化。研究结果为激活不充分假设或传输不足假设提供了证据。