Lexical Inhibition Research Articles

Lexical inhibition after semantic violations recruits a domain-general inhibitory control mechanism.

Language processing is incremental. As language signals-for example, words in a sentence-unfold, humans predict and activate likely upcoming input to facilitate comprehension. Prediction not only accelerates understanding but also prompts reassessment in the case of prediction error, fostering learning and refining comprehension skills. Therefore, it is paramount to understand what happens when linguistic predictions are violated-for example, when a sentence ends in an unpredicted word. One theory, which we test here, is that the originally predicted word is actively inhibited after semantic violations. Furthermore, we tested whether this purported lexical inhibition process is achieved by a domain-general mechanism-that is, one that also inhibits other processes (e.g., movement). We combined a semantic violation task, in which highly constrained sentences primed specific words but sometimes continued otherwise, with a motoric stop-signal task. Across two experiments, semantic violations significantly impaired simultaneous action-stopping. This implies that lexical and motor inhibition share the same process. In support of this view, multivariate decoding of electroencephalographic recordings showed early overlap in neural processing between action-stopping (motor inhibition) and semantic violations (lexical inhibition). Moreover, a known signature of motor inhibition (the stop-signal P3) was reduced after this initial overlap period, further suggesting the presence of a bottleneck due to shared processing. These findings show that semantic violations trigger inhibitory processing and suggest that this lexical inhibition recruits a domain-general inhibitory control mechanism. This provides a new perspective on long-standing debates in psycholinguistics, extends the range of a well-characterized cognitive control mechanism into the linguistic domain, and offers support for recent neurobiological models of domain-general inhibitory control. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Supplemental Material for Lexical Inhibition After Semantic Violations Recruits a Domain-General Inhibitory Control Mechanism

Supplemental Material for Lexical Inhibition After Semantic Violations Recruits a Domain-General Inhibitory Control Mechanism

The development of lexical inhibition in spoken word recognition.

As a spoken word unfolds over time, similar sounding words (cap and cat) compete until one word "wins". Lexical competition becomes more efficient from infancy through adolescence. We examined one potential mechanism underlying this development: lexical inhibition, by which activated candidates suppress competitors. In Experiment 1, younger (7-8 years) and older (12-13 years) children heard words (cap) in which the onset was manipulated to briefly boost competition from a cohort competitor (cat). This was compared to a condition with a nonword (cack) onset that would not inhibit the target. Words were presented in a visual world task during which eye movements were recorded. Both groups showed less looking to the target when perceiving the competitor-splice relative to the nonword-splice, showing engagement of lexical inhibition. Exploratory analyses of linguistic adaptation across the experiment revealed that older children demonstrated consistent lexical inhibition across the experiment and younger children did not, initially showing no effect in the first half of trials and then a robust effect in the latter half. In Experiment 2, adults also displayed consistent lexical inhibition in the same task. These findings suggest that younger children do not consistently engage lexical inhibition in typical listening but can quickly bring it online in response to certain linguistic experiences. Computational modeling showed that age-related differences are best explained by increased engagement of inhibition rather than growth in activation. These findings suggest that continued development of lexical inhibition in later childhood may underlie increases in efficiency of spoken word recognition. (PsycInfo Database Record (c) 2023 APA, all rights reserved).

Supplemental Material for The Development of Lexical Inhibition in Spoken Word Recognition

Supplemental Material for The Development of Lexical Inhibition in Spoken Word Recognition

Idiosyncratic use of bottom-up and top-down information leads to differences in speech perception flexibility: Converging evidence from ERPs and eye-tracking

Listeners generally categorize speech sounds in a gradient manner. However, recent work, using a visual analogue scaling (VAS) task, suggests that some listeners show more categorical performance, leading to less flexible cue integration and poorer recovery from misperceptions (Kapnoula et al., 2017, 2021). We asked how individual differences in speech gradiency can be reconciled with the well-established gradiency in the modal listener, showing how VAS performance relates to both Visual World Paradigm and EEG measures of gradiency. We also investigated three potential sources of these individual differences: inhibitory control; lexical inhibition; and early cue encoding. We used the N1 ERP component to track pre-categorical encoding of Voice Onset Time (VOT). The N1 linearly tracked VOT, reflecting a fundamentally gradient speech perception; however, for less gradient listeners, this linearity was disrupted near the boundary. Thus, while all listeners are gradient, they may show idiosyncratic encoding of specific cues, affecting downstream processing.

On the Locus of L2 Lexical Fuzziness: Insights From L1 Spoken Word Recognition and Novel Word Learning.

The examination of how words are learned can offer valuable insights into the nature of lexical representations. For example, a common assessment of novel word learning is based on its ability to interfere with other words; given that words are known to compete with each other (Luce and Pisoni, 1998; Dahan et al., 2001), we can use the capacity of a novel word to interfere with the activation of other lexical representations as a measure of the degree to which it is integrated into the mental lexicon (Leach and Samuel, 2007). This measure allows us to assess novel word learning in L1 or L2, but also the degree to which representations from the two lexica interact with each other (Marian and Spivey, 2003). Despite the somewhat independent lines of research on L1 and L2 word learning, common patterns emerge across the two literatures (Lindsay and Gaskell, 2010; Palma and Titone, 2020). In both cases, lexicalization appears to follow a similar trajectory. In L1, newly encoded words often fail at first to engage in competition with known words, but they do so later, after they have been better integrated into the mental lexicon (Gaskell and Dumay, 2003; Dumay and Gaskell, 2012; Bakker et al., 2014). Similarly, L2 words generally have a facilitatory effect, which can, however, become inhibitory in the case of more robust (high-frequency) lexical representations. Despite the similar pattern, L1 lexicalization is described in terms of inter-lexical connections (Leach and Samuel, 2007), leading to more automatic processing (McMurray et al., 2016); whereas in L2 word learning, lack of lexical inhibition is attributed to less robust (i.e., fuzzy) L2 lexical representations. Here, I point to these similarities and I use them to argue that a common mechanism may underlie similar patterns across the two literatures.

Word stress processing integrates phonological abstraction with lexical access – An ERP study

It is unclear whether word stress in a language is stored as part of the word or whether it is generated by a rule. We test the generativist hypothesis of lexical storage stating that only unpredictable stress is stored in long-term memory against the contrasting usage-based approach assuming that all phonetic information regardless of its (un)predictability is stored in the mental lexicon together with the word. In a correctness judgment task involving correctly and incorrectly stressed penults and antepenults, we found that incorrectly stressed penults do not evoke an N400 effect, whereas incorrectly stressed antepenults do: there is increased negativity with a peak latency around 350–600 ms from word onset. Only changes to words with exceptional stress cause lexical inhibition, hence exceptional but not default stress markers are stored in the lexicon. Additionally, differences in processing patterns between the N400 and the late positivity component window point to an integration of two stages of word processing: pre-lexical stress recognition and stress-to-meaning matching. The results of the study support the view that stress should be understood as abstract phonological information. • Changes to the original stress in exceptions, but not words with default stress cause lexical inhibition in Spanish. • Following the generative phonology framework, predictable stress information is not stored in the lexicon. • Combined N400 and positivity effects show integration of pre-lexical stress recognition and stress-to-meaning matching. • Electrophysiological data confirm that stress is an abstract phonological category.

A real-time mechanism underlying lexical deficits in developmental language disorder: Between-word inhibition

Eight to 11% of children have a clinical disorder in oral language (Developmental Language Disorder, DLD). Language deficits in DLD can affect all levels of language and persist through adulthood. Word-level processing may be critical as words link phonology, orthography, syntax and semantics. Thus, a lexical deficit could cascade throughout language. Cognitively, word recognition is a competition process: as the input (e.g., lizard) unfolds, multiple candidates (liver, wizard) compete for recognition. Children with DLD do not fully resolve this competition, but it is unclear what cognitive mechanisms underlie this. We examined lexical inhibition—the ability of more active words to suppress competitors—in 79 adolescents with and without DLD. Participants heard words (e.g. net) in which the onset was manipulated to briefly favor a competitor (neck). This was predicted to inhibit the target, slowing recognition. Word recognition was measured using a task in which participants heard the stimulus, and clicked on a picture of the item from an array of competitors, while eye-movements were monitored as a measure of how strongly the participant was committed to that interpretation over time. TD listeners showed evidence of inhibition with greater interference for stimuli that briefly activated a competitor word. DLD listeners did not. This suggests deficits in DLD may stem from a failure to engage lexical inhibition. This in turn could have ripple effects throughout the language system. This supports theoretical approaches to DLD that emphasize lexical-level deficits, and deficits in real-time processing.

Language control and lexical access in diglossic speech production: Evidence from variety switching in speakers of Swiss German

Diglossic speakers of two varieties of a language switch between their language varieties as bilinguals do between their languages, instead of having the otherwise typical probabilistic distributions of variants across varieties. To investigate the mechanisms involved in diglossic language control and lexical access, we conducted two switching experiments, in which participants who were highly proficient in the two varieties, or languages, named pictures in Swiss German or Standard German (Experiment 1), or in Swiss German or Tamil (Experiment 2), with pictures having cognate or non-cognate names in Swiss German and Standard German. The overall magnitude of switch costs in diglossic switching was comparable to switch costs in bilingual switching. Switch costs were asymmetric, favouring switching into the sociolinguistically preferred variety (Swiss German) in Experiment 1 and the slightly less dominant language (Tamil) in Experiment 2. Cognate gains were higher for Swiss German than Standard German and occurred even for Tamil responses. These results are compatible with a model that assumes that diglossic switching is influenced by similar mechanisms of language control as bilingual switching, that inhibitory processes are involved, that the amount of lexical inhibition depends on the relative strengths of lexical representations and on top-down control, and that diglossic cognates have integrated lexical representations.

Lexical inhibition due to failed prediction: Behavioral evidence and ERP correlates.

During sentence processing, comprehenders form expectations regarding upcoming material, and may even predict a specific word. Previous event-related potential (ERP) studies have shown that disconfirmed predictions elicit a post-N400-positivity (PNP) with two distinct distributions. A frontal-PNP (f-PNP) is elicited when an unexpected but congruent word appears instead of a highly predictable word, whereas an anomalous word elicits a posterior-PNP. The current study tested the hypothesis that during the processing of a sentence, the predicted word is inhibited to enable the integration of unexpected but congruent material, and that this inhibitory process is reflected in the f-PNP component. In contrast, anomalous continuations, which are not compatible with the preceding context, do not induce inhibition. Experiment 1 used cross-modal lexical priming to test inhibition patterns of predicted words, demonstrating inhibition when integration of a congruent-unexpected word was needed, but not when an anomaly was encountered. Experiment 2 showed that the inhibition observed in Experiment 1 is specific to the predicted word and does not stem from competition between two congruent continuations. In Experiment 3 we recorded ERPs using the same materials, and found that the f-PNP component is elicited under the same conditions giving rise to behavioral inhibition, and that the two are correlated, thus providing preliminary support for the hypothesis that this component reflects an inhibitory process. (PsycINFO Database Record

Modality effects in language switching: Evidence for a bimodal advantage

In language switching, it is assumed that in order to produce a response in one language, the other language must be inhibited. In unimodal (spoken-spoken) language switching, the fact that the languages share the same primary output channel (the mouth) means that only one language can be produced at a time. In bimodal (spoken-signed) language switching, however, it is possible to produce both languages simultaneously. In our study, we examined modality effects in language switching using multilingual subjects (speaking German, English, and German Sign Language). Focusing on German vocal responses, since they are directly compatible across conditions, we found shorter reaction times, lower error rates, and smaller switch costs in bimodal vs. unimodal switching. This result suggests that there are different inhibitory mechanisms at work in unimodal and bimodal language switching. We propose that lexical inhibition is involved in unimodal switching, whereas output channel inhibition is involved in bimodal switching.

Bimodal language switching: New insights from signing and typing

Abstract Language switching typically refers to unimodal switching between two spoken languages. In bimodal language switching, one language is produced vocally and the other language is produced manually (e.g., a sign language). We compared unimodal language switching with two different kinds of bimodal language switching for non-signers. In Experiment 1a and 1b participants switched between speaking and newly learned signs. Participants of Experiment 2 switched between two originally spoken languages in a bimodal way: One language was produced vocally and the other language was produced manually (by typing). Interestingly, switch costs were reduced for bimodal compared to unimodal switching in Experiment 1a and 1b but not in Experiment 2. This speaks for different language control mechanisms. We assume less costly output channel inhibition for switching between speaking and signing (Experiment 1a and 1b) and more costly lexical inhibition for switching between speaking and typing (Experiment 2).

Training alters the resolution of lexical interference: Evidence for plasticity of competition and inhibition.

Language learning is generally described as a problem of acquiring new information (e.g., new words). However, equally important are changes in how the system processes known information. For example, a wealth of studies has suggested dramatic changes over development in how efficiently children recognize familiar words, but it is unknown what kind of experience-dependent mechanisms of plasticity give rise to such changes in real-time processing. We examined the plasticity of the language processing system by testing whether a fundamental aspect of spoken word recognition, lexical interference, can be altered by experience. Adult participants were trained on a set of familiar words over a series of 4 tasks. In the high-competition (HC) condition, tasks were designed to encourage coactivation of similar words (e.g., net and neck) and to require listeners to resolve this competition. Tasks were similar in the low-competition (LC) condition, but did not enhance this competition. Immediately after training, interlexical interference was tested using a visual world paradigm task. Participants in the HC group resolved interference to a fuller degree than those in the LC group, demonstrating that experience can shape the way competition between words is resolved. TRACE simulations showed that the observed late differences in the pattern of interference resolution can be attributed to differences in the strength of lexical inhibition. These findings inform cognitive models in many domains that involve competition/interference processes, and suggest an experience-dependent mechanism of plasticity that may underlie longer term changes in processing efficiency associated with both typical and atypical development.

Eyes wide open: Pupil size as a proxy for inhibition in the masked-priming paradigm.

A core assumption underlying competitive-network models of word recognition is that in order for a word to be recognized, the representations of competing orthographically similar words must be inhibited. This inhibitory mechanism is revealed in the masked-priming lexical-decision task (LDT) when responses to orthographically similar word prime-target pairs are slower than orthographically different word prime-target pairs (i.e., inhibitory priming). In English, however, behavioral evidence for inhibitory priming has been mixed. In the present study, we utilized a physiological correlate of cognitive effort never before used in the masked-priming LDT, pupil size, to replicate and extend behavioral demonstrations of inhibitory effects (i.e., Nakayama, Sears, & Lupker, Journal of Experimental Psychology: Human Perception and Performance, 34, 1236-1260, 2008, Exp. 1). Previous research had suggested that pupil size is a reliable indicator of cognitive load, making it a promising index of lexical inhibition. Our pupillometric data replicated and extended previous behavioral findings, in that inhibition was obtained for orthographically similar word prime-target pairs. However, our response time data provided only a partial replication of Nakayama et al. Journal of Experimental Psychology: Human Perception and Performance, 34, 1236-1260, 2008. These results provide converging lines of evidence that inhibition operates in word recognition and that pupillometry is a useful addition to word recognition researchers' toolbox.

The lexical inhibition of the phonological information in Korean visual word recognition

Two Experiments using a primed lexical decision task investigated what types of linguistic information elicits lexical inhibition during visual word recognition of Korean. We measured participants’ reaction times for this task and three prime-target conditions were used: 1) orthographically related 2) phonologically related and 3) control condition. We attempted to examine how lexical competition occurs when prime words had phonological change and whether the inhibition is modulated by word frequency of prime words (Experiment 1), and investigate whether the lexical competition is modulated by lexical status of the prime stimuli (Experiment 2). In Experiment 1, we showed that the reaction times were slower in the phonologically related condition as compared to the control condition, whereas they were faster in the orthographically related condition relative to the control condition. Moreover, this tendency was more noticeable in the low frequency prime condition relative to the high frequency prime condition. However, neither the inhibitory effect by the phonologically related prime nor the facilitative effect of the orthographically related prime were observed in Experiment 2 in which nonword primes were used, suggesting that the inhibitory priming effect is generated due to lexical competition between the prime and the target within a lexical level, not via a pre-lexical level in Korean visual word recognition.

Lexical inhibition of neighbors during visual word recognition: An unmasked priming investigation

Two experiments investigated the lexical inhibitory effect of orthographic neighbors relative to identity priming effects in an unmasked priming paradigm combined with a lexical decision task on word targets. Targets were preceded either by the same word, by a lower frequency orthographic word neighbor, by an orthographic pseudoword neighbor or by an unrelated prime. Experiment 1 showed a standard facilitatory effect from identity primes, whereas inhibitory priming effects were observed for both types of neighbor primes. Experiment 2 examined the time-course of these effects by using event-related potential recordings. A generalized relatedness effect was found in the 200–400ms time-window, with smaller negativities generated by related primes than unrelated primes regardless of prime type. In contrast, at 400ms, while identity primes were associated with smaller negativities than unrelated primes, word neighbor primes were associated with greater negativities than unrelated primes. Additionally, pseudoword neighbor primes produce null effects as compared to unrelated primes. These results are discussed in terms of competition between activated lexical representations and revealed that such a mechanism is modulated by the lexical status of the prime.

Code-switching in multilingual aphasia

Code-switching in multilingual aphasia

Phoneme categorization and discrimination in younger and older adults: A comparative analysis of perceptual, lexical, and attentional factors.

This study investigates the extent to which age-related language processing difficulties are due to a decline in sensory processes or to a deterioration of cognitive factors, specifically, attentional control. Two facets of attentional control were examined: inhibition of irrelevant information and divided attention. Younger and older adults were asked to categorize the initial phoneme of spoken syllables ("Was it m or n?"), trying to ignore the lexical status of the syllables. The phonemes were manipulated to range in eight steps from m to n. Participants also did a discrimination task on syllable pairs ("Were the initial sounds the same or different?"). Categorization and discrimination were performed under either divided attention (concurrent visual-search task) or focused attention (no visual task). The results showed that even when the younger and older adults were matched on their discrimination scores: (1) the older adults had more difficulty inhibiting lexical knowledge than did younger adults, (2) divided attention weakened lexical inhibition in both younger and older adults, and (3) divided attention impaired sound discrimination more in older than younger listeners. The results confirm the independent and combined contribution of sensory decline and deficit in attentional control to language processing difficulties associated with aging. The relative weight of these variables and their mechanisms of action are discussed in the context of theories of aging and language.

Syllable priming with pseudowords in the lexical decision task.

This study investigated the processes underlying the effect of masked syllable priming in French with pseudoword primes and word targets. Two lexical-decision task (LDT) experiments examined whether the syllable priming effect depends on syllable frequency and might rely on a general abstract structure. The results of Experiment 1 revealed an inhibitory priming effect, with pseudoword primes and word targets sharing a high-frequency first syllable, which was not due to the abstract syllable structure. In contrast, no inhibition was observed with a low-frequency first syllable in Experiment 2. Syllable frequency appears to be an important factor determining the speed of target processing in masked priming. This is attributed to variations in the respective contributions of sublexical activation and lexical inhibition processes.

A bilingual child's language profile: Impaired English but intact Vietnamese

The literature asserts that language impairment always manifests in both languages of a bilingual child. The case reported describes a boy, aged 8 years whose first language (L1, Vietnamese) is intact while his acquisition of English (L2, learned from 4 years) is significantly impaired. Culturally appropriate language assessments included dynamic assessment, composite scoring, and peer–child comparison. Analysis revealed poor L2 lexical development, with underspecified lexical templates and inhibited access to lexical knowledge in English. No such difficulties were evident in L1. Peter's profile allows evaluation of current models of bilingual language development. A specific deficit in lexical inhibition of L1 might plausibly account for impairment only in L2.