Semantic Context Effects Research Articles

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.

The effect of semantic context on speech intelligibility in reverberant rooms.

Although it is well known that semantic context affects speech intelligibility and that different reverberant rooms affect speech intelligibility differentially, these effects have seldom been studied together. Revised SPIN sentences in a background of Gaussian noise in simulated rooms with reverberation time (T60) of 1 and 0.25 s were used. The carrier phrase and the target word of the speech stimuli were manipulated to be either in the same room or in different rooms. As expected, intelligibility of predictable sentences was higher compared to unpredictable sentences-the context effect. The context effect was higher in the low-reverberant room as compared to the high-reverberant room. When the carrier phrase and target words were in different rooms, the context effect was higher when the carrier phrase was in the low-reverberant room and target word in the high-reverberant room. For predictable sentences, changing the target word from high-reverberation to low reverberation with a high reverberant carrier increased intelligibility. However, with a low-reverberant carrier and different rooms for the target word, there was no change in intelligibility. Overall, it could be concluded that there is an interaction between semantic context and room acoustics for speech intelligibility.

Visual word recognition: Evidence for global and local control over semantic feedback.

Two lexical decision experiments examined the joint effects of stimulus quality, semantic context, and cue-target associative strength when all factors were intermixed in a block of trials. Both experiments found a three-way interaction. Semantic context and stimulus quality interacted when associative strength between cue-target pairs was strong, and the interaction was eliminated when the strength was weak. These results support a role for a local mechanism that relies on trial specific information, in addition to a mechanism that makes use of global information available across a block of trials. The absence of an interaction between the joint effects of semantic context and stimulus quality is attributed to blocking the feedback from the semantic system to the orthographic system, functionally separating the orthographic and semantic modules.

Semantic context effects when naming Japanese kanji, but not Chinese hànzì

The process of reading aloud bare nouns in alphabetic languages is immune to semantic context effects from pictures. This is accounted for by assuming that words in alphabetic languages can be read aloud relatively fast through a sub-lexical grapheme–phoneme conversion (GPC) route or by a direct route from orthography to word form. We examined semantic context effects in a word-naming task in two languages with logographic scripts for which GPC cannot be applied: Japanese kanji and Chinese hànzì. We showed that reading aloud bare nouns is sensitive to semantically related context pictures in Japanese, but not in Chinese. The difference between these two languages is attributed to processing costs caused by multiple pronunciations for Japanese kanji.

Effects of semantic context and feedback on perceptual learning of speech processed through an acoustic simulation of a cochlear implant.

The effect of feedback and materials on perceptual learning was examined in listeners with normal hearing who were exposed to cochlear implant simulations. Generalization was most robust when feedback paired the spectrally degraded sentences with their written transcriptions, promoting mapping between the degraded signal and its acoustic-phonetic representation. Transfer-appropriate processing theory suggests that such feedback was most successful because the original learning conditions were reinstated at testing: Performance was facilitated when both training and testing contained degraded stimuli. In addition, the effect of semantic context on generalization was assessed by training listeners on meaningful or anomalous sentences. Training with anomalous sentences was as effective as that with meaningful sentences, suggesting that listeners were encouraged to use acoustic-phonetic information to identify speech than to make predictions from semantic context.

Functional neural networks underlying semantic encoding of associative memories

Evidence suggests that theta oscillations recruit distributed cortical representations to improve associative encoding under semantically congruent conditions. Here we show that positive effects of semantic context on encoding and retrieval of associations are mediated by changes in the coupling pattern between EEG theta sources. During successful encoding of semantically congruent face-location associations, the right superior parietal lobe showed enhanced theta phase synchronization with other regions within the lateral posterior parietal lobe (PPL) and left medial temporal lobe (MTL). However, functional coordination involving the inferior parietal lobe was higher in the incongruent condition. These results suggest a differential engagement of top-down and bottom-up mechanisms during encoding of semantically congruent and incongruent episodic associations, respectively. Although retrieval processes operated on a similar neural network, the main difference with the study phase was the larger amount of functional links shown by the lateral prefrontal cortex with regions of the MTL and PPL. All together, these results suggest that theta oscillations mediate, at least partially, the positive effect of semantic congruence on associative memory by (i) optimizing top-down attentional mechanisms through enhanced theta phase synchronization between dorsal regions of the PPL and MTL and (ii) by adjusting the control of automatic attention to sensory and contextual information reactivated in the MTL through functional connections with the inferior parietal lobe during both encoding and retrieval processes.

Nfluences of Linguistic and Non-Linguistic Factors in the Processing of American Sign Language: Evidence from Handshape Monitoring

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Interaction of top-down and bottom-up processing on categorical perception.

To investigate the processing of acoustic and semantic information on phonemic categorical perception, two nine-step continua consisting of natural and synthetic consonant-vowel (CV) syllables were presented in four different contexts. For both natural and synthetic speech, /ti/-/pi/ continua varying in spectral tilt were constructed. The four contexts included the isolated CV syllable, a neutral context sentence with the CV at the end, and two additional sentences with varying semantic load. One semantically favored a /p/ response and one a /t/ response. Eleven adults with normal hearing (2 males, 9 females, 21 45 years old, mean age=27) labeled the consonant in the CV syllable. Results showed a pattern of statistically-significant differences between the isolated and neutral context versus the semantically-loaded sentences for both natural and synthetic stimuli, suggesting an effect of semantic context. The differences appeared in the vicinity of the boundaries of the psychometric functions, suggesting an interaction between top-down and bottom-up processing. Strictly bottom-up processing would have shown overlaid response functions, and strictly top-down processing would have shown differences at the endpoints. The pattern of results suggests interactive, parallel rather than hierarchical processing.

Wave-ering: An ERP study of syntactic and semantic context effects on ambiguity resolution for noun/verb homographs

Two event-related potential experiments investigated the effects of syntactic and semantic context information on the processing of noun/verb (NV) homographs (e.g., park). Experiment 1 embedded NV-homographs and matched unambiguous words in contexts that provided only syntactic cues or both syntactic and semantic constraints. Replicating prior work, when only syntactic information was available NV-homographs elicited sustained frontal negativity relative to unambiguous words. Semantic constraints eliminated this frontal ambiguity effect. Semantic constraints also reduced N400 amplitudes, but less so for homographs than unambiguous words. Experiment 2 showed that this reduced N400 facilitation was limited to cases in which the semantic context picks out a non-dominant meaning, likely reflecting the semantic mismatch between the context and residual, automatic activation of the contextually-inappropriate dominant sense. Overall, the findings suggest that ambiguity resolution in context involves the interplay between multiple neural networks, some involving more automatic semantic processing mechanisms and others involving top-down control mechanisms.

Semantic Context and Visual Feature Effects in Object Naming: An fMRI Study using Arterial Spin Labeling

Previous behavioral studies reported a robust effect of increased naming latencies when objects to be named were blocked within semantic category, compared to items blocked between category. This semantic context effect has been attributed to various mechanisms including inhibition or excitation of lexico-semantic representations and incremental learning of associations between semantic features and names, and is hypothesized to increase demands on verbal self-monitoring during speech production. Objects within categories also share many visual structural features, introducing a potential confound when interpreting the level at which the context effect might occur. Consistent with previous findings, we report a significant increase in response latencies when naming categorically related objects within blocks, an effect associated with increased perfusion fMRI signal bilaterally in the hippocampus and in the left middle to posterior superior temporal cortex. No perfusion changes were observed in the middle section of the left middle temporal cortex, a region associated with retrieval of lexical-semantic information in previous object naming studies. Although a manipulation of visual feature similarity did not influence naming latencies, we observed perfusion increases in the perirhinal cortex for naming objects with similar visual features that interacted with the semantic context in which objects were named. These results provide support for the view that the semantic context effect in object naming occurs due to an incremental learning mechanism, and involves increased demands on verbal self-monitoring.

Semantic context effects in language production: A swinging lexical network proposal and a review

The investigation of semantic context effects has served as a valuable tool in investigating mechanisms of language production. Classic semantic interference effects have provided influential support for and interest in a competitive lexical selection mechanism. However, recent interest in semantic facilitation effects has stimulated a discussion on whether context effects reflect competition during lexical selection. In this review we propose a framework of lexical selection by competition that is sensitive to the activation of lexical cohorts. We outline our proposal and then present a selective review of the empirical evidence, much of which has been central to the development of alternative non-competitive models. We suggest that by adopting the assumptions of our proposal we can parsimoniously account for a majority of the discussed semantic facilitation and interference effects.

Effects of semantic context and regional dialect variation on speech intelligibility in noise.

Speech intelligibility in noise is affected by the semantic content of the utterance; semantically predictable utterances are more intelligible than semantically unpredictable or anomalous utterances. However, dialect variation interacts with semantic predictability in production; talkers produce more dialect‐specific variants in semantically predictable contexts and more standard variants in semantically unpredictable contexts. The goal of the current study was to explore the interaction between dialect variation and semantic context in perception. Participants were asked to transcribe the final word of semantically predictable, unpredictable, and anomalous sentences produced by talkers from four regional dialects of American English and mixed with speech‐shaped noise. The listeners exhibited an intelligibility benefit in the predictable context relative to the other two semantic contexts, regardless of talker dialect. However, differences in intelligibility between the dialects were reduced in the unpredictable and anomalous contexts relative to the predictable context, suggesting greater online adaptation to dialect variation in the unpredictable and anomalous contexts than the predictable context. These results are consistent with the finding that dialect differences may be attenuated in production in low predictability contexts, and suggest that perceptual dialect adaptation is affected by fine‐grained intratalker acoustic variation.

Exploring the time course of semantic interference and associative priming in the picture–word interference task

The picture-word interference (PWI) task is a widely used technique for exploring effects of semantic context on lexical access. In this task, printed words are superimposed over pictures to be named, with the timing of the interfering word relative to the picture systematically manipulated. Two experiments (N = 24 adults in each) explored the time course of effects of associates (e.g., CARROT superimposed on a picture of a rabbit) versus coordinates (e.g., CHIPMUNK superimposed on a picture of a rabbit) on naming latencies. Associates led to faster picture naming than did unrelated words, with facilitative effects occurring at stimulus onset asynchronies (SOAs, in ms) ranging from -450 to 0. Coordinates led to slower naming latencies, with the interference effect restricted to SOAs of -150 and 0. The overlapping time course of associative priming and coordinate interference provides important constraints on models of lexical access in speech production.

Reading aloud: Evidence for contextual control over lexical activation.

Can readers exert control (albeit unconsciously) over activation at particular loci in the reading system? The authors addressed this issue in 4 experiments in which participants read target words aloud and the factors of prime-target relation (semantic, repetition), context (related, unrelated), stimulus quality (bright, dim), and relatedness proportion (RP; high, low) were manipulated. In the high RP condition (RP = .5), an interaction between semantic context and stimulus quality was observed in which low stimulus quality slowed unrelated targets more than related ones, replicating previous work. In contrast, the low RP condition (RP = .25) yielded additive effects of semantic context and stimulus quality. However, when low RP was examined within the context of repetition priming, context and stimulus quality once again interacted. These results are discussed in the context of a widely endorsed framework with the addition of the central assumption that there is control over feedback between various levels.

Interaction between process and content in semantic memory: An fMRI study of noun feature knowledge

Effective semantic processing requires both stored conceptual knowledge and the ability to relate this information to our environment. In the current study we examined how neural processing of a concept’s features was modulated by the semantic context in which they were presented using two types of nouns: complex nouns, in which all features contribute in a variable manner to an object’s meaning (apples are usually red, but not always), and nominal kinds, for which a single feature plays a diagnostic role (an uncle must be the brother of a parent). We used fMRI to monitor neural activity while participants viewed a list of features and decided whether the list accurately described a target concept. We focused on the effect of semantic context on processing of features critical to a concept’s representation. Task demands were manipulated by giving participants instructions that encouraged rule-based or similarity-based judgments. Activation patterns for feature processing were found to depend on the type of noun being evaluated and whether or not critical features were consistent with surrounding information: When processing critical features that contradicted other information, complex nouns resulted in additional recruitment in frontal and temporal cortex compared to nominal kinds. We observed modest effects of instruction condition, with rule-based instructions resulting in increased frontal processing and similarity-based instructions recruiting more temporal and parietal regions. Together, these results support the hypothesis that various classes of nouns are represented differently in semantic memory, and emphasize the dynamic interaction of process and content in semantic memory.

Effects of working memory load on lexical-semantic encoding in language production

Some models of lexical access in language production postulate that lexical-semantic encoding is driven bottom-up, by the conceptual input, and top-down, by a representation of the task. In the cyclic semantic blocking paradigm, participants repeatedly name sets of objects that are either semantically related or unrelated. Whereas the manipulation of semantic relatedness affects lexical-semantic encoding in a bottom-up fashion, the cyclic presentation of small object sets allows participants to bias the corresponding lexical-semantic representations top-down for selection. The role of working memory (WM) in this top-down modulation was investigated by crossing the cyclic semantic blocking paradigm with a manipulation of WM load. Participants' naming latencies displayed significant effects of semantic context, WM load, and their interaction. A word-naming task using the same materials yielded a main effect of WM load but no significant effects of semantic context or of its interaction with WM load. These and related results are discussed with regard to their implications for models of language production.

Single and multiple object naming in healthy ageing

We compared the performance of young (college-aged) and older (50+years) speakers in a single object and a multiple object naming task and assessed their susceptibility to semantic and phonological context effects when producing words amidst semantically or phonologically similar or dissimilar words. In single object naming, there were no performance differences between the age groups. In multiple object naming, we observed significant age-related slowing, expressed in longer gazes to the objects and slower speech. In addition, the direction of the phonological context effects differed for the two groups. The results of a supplementary experiment showed that young speakers, when adopting a slow speech rate, coordinated their eye movements and speech differently from the older speakers. Our results imply that age-related slowing in connected speech is not a direct consequence of a slowing of lexical retrieval processes. Instead, older speakers might allocate more processing capacity to speech monitoring processes, which would slow down their concurrent speech planning processes.

Semantic facilitation in category and action naming: Testing the message-congruency account

Basic-level picture naming is hampered by the presence of a semantically related context word (compared to an unrelated word), whereas picture categorization is facilitated by a semantically related context word. This reversal of the semantic context effect has been explained by assuming that in categorization tasks, basic-level distractor words (e.g., “dog”) do not compete with the selection of the correct category label (e.g., “animal”). In this article, we test an alternative account in terms of a congruency effect (“message-congruency”), which arises at the conceptual level when target (e.g., the picture of a cat) and context (e.g., the word “dog”) converge on the same to-be-verbalized concept (e.g., “animal”). In four experiments we observed a substantial message-congruency effect in categorization and action naming. Implications for models of spoken-word production are discussed.

N400, the reference electrode, and the semantic activation in prime-task experiments: A reply to Dombrowski and Heil (2006)

In two recent papers, Heil et al. [Heil, M., Rolke, B., Pecchinenda, A., 2004. Automatic semantic activation is no myth: semantic context effects on the N400 in the Letter-Search task in the absence of response time effects. Psychol. Sci., 15 (12), 852–857] and Marí-Beffa et al. [Marí-Beffa, P., Valdés, B., Cullen, D.J.D., Catena, A., Houghton, G., 2005. ERP analyses of task effects on semantic processing from words. Cogn. Brain Res., 23, 293–305] found opposite ERP effects of semantic priming following letter search (as measured by the N400). Dombrowski and Heil [Dombrowski, J.H., Heil, M., 2006. Semantic activation, letter search and N400: a reply to Marí-Beffa, Valdés, Cullen, Catena and Houghton (2005). Brain Res., 1073–1074, 440–443] have argued that the N400 modulation associated to semantic priming found by Marí-Beffa et al. [Marí-Beffa, P., Valdés, B., Cullen, D.J.D., Catena, A., Houghton, G., 2005. ERP analyses of task effects on semantic processing from words. Cogn. Brain Res., 23, 293–305] is due to the use of electrode Cz as reference, rather than to the task manipulation being studied (letter search vs. categorisation). In the current article we argue that the conclusions of Dombrowski and Heil are mistaken and are due in part on a misreading of Marí-Beffa et al. [Marí-Beffa, P., Valdés, B., Cullen, D.J.D., Catena, A., Houghton, G., 2005. ERP analyses of task effects on semantic processing from words. Cogn. Brain Res., 23, 293–305]. We argue instead that the differences between the results of Heil et al. [Heil, M., Rolke, B., Pecchinenda, A., 2004. Automatic semantic activation is no myth: semantic context effects on the N400 in the Letter-Search task in the absence of response time effects. Psychol. Sci., 15 (12), 852–857] and Marí-Beffa et al. [Marí-Beffa, P., Valdés, B., Cullen, D.J.D., Catena, A., Houghton, G., 2005. ERP analyses of task effects on semantic processing from words. Cogn. Brain Res., 23, 293–305] are largely due to differences in experimental method and procedure, rather than to the technique used for the ERP analysis.

When bees hamper the production of honey: Lexical interference from associates in speech production.

In this article, the authors explore semantic context effects in speaking. In particular, the authors investigate a marked discrepancy between categorically and associatively induced effects; only categorical relationships have been reported to cause interference in object naming. In Experiments 1 and 2, a variant of the semantic blocking paradigm was used to induce two different types of semantic context effects. Pictures were either named in the context of categorically related objects (e.g., animals: bee, cow, fish) or in the context of associatively related objects from different semantic categories (e.g., apiary: bee, honey, bee keeper). Semantic interference effects were observed in both conditions, relative to an unrelated context. Experiment 3 replicated the classic effects of categorical interference and associative facilitation in a picture-word interference paradigm with the material used in Experiment 2. These findings suggest that associates are active lexical competitors and that the microstructure of lexicalization is highly flexible and adjustable to the semantic context in which the utterance takes place.