Time Course Of Lexical Access Research Articles

Do subsyllabic units play a role in Mandarin spoken word recognition? Evidence from phonotactic processing

This study investigates the roles of Mandarin subsyllabic units in spoken word recognition by examining the neural processing of two phonotactic anomalies: (1) segmental gaps, which contain a non-existing combination of segments (e.g., *[ki1]); and (2) tonal gaps, which refer to a nonword comprised of possible segment combinations with an incongruous tone (e.g., *[tau2]; cf. [tau1] “knife”). Event-related potentials were recorded while participants performed an auditory lexical decision task. The response to segmental gaps differed from the other stimuli types in the amplitudes and scalp distributions of several components, including the P350, the N400, and the late positive complex. The P350 effect occurred around 370 ms before the entire syllable was revealed, indicating that lexical processing is not based solely on syllable representations. Furthermore, the overall differences between segmental and tonal gaps suggest that tones and vowels are dissociable. These results thus provide converging evidence for the view that Mandarin syllables are processed incrementally through phonemes. • The phonotactic effect on the ERP appears before the syllable ends. • Tone- and segment-induced phonotactic anomalies evoke different neural responses. • Monosyllabic words are processed incrementally through subsyllabic units. • Vowels and tones are dissociable in the later time course of lexical access.

Cross-modal and cross-language activation in bilinguals reveals lexical competition even when words or signs are unheard or unseen

We exploit the phenomenon of cross-modal, cross-language activation to examine the dynamics of language processing. Previous within-language work showed that seeing a sign coactivates phonologically related signs, just as hearing a spoken word coactivates phonologically related words. In this study, we conducted a series of eye-tracking experiments using the visual world paradigm to investigate the time course of cross-language coactivation in hearing bimodal bilinguals (Spanish-Spanish Sign Language) and unimodal bilinguals (Spanish/Basque). The aim was to gauge whether (and how) seeing a sign could coactivate words and, conversely, how hearing a word could coactivate signs and how such cross-language coactivation patterns differ from within-language coactivation. The results revealed cross-language, cross-modal activation in both directions. Furthermore, comparison with previous findings of within-language lexical coactivation for spoken and signed language showed how the impact of temporal structure changes in different modalities. Spoken word activation follows the temporal structure of that word only when the word itself is heard; for signs, the temporal structure of the sign does not govern the time course of lexical access (location coactivation precedes handshape coactivation)-even when the sign is seen. We provide evidence that, instead, this pattern of activation is motivated by how common in the lexicon the sublexical units of the signs are. These results reveal the interaction between the perceptual properties of the explicit signal and structural linguistic properties. Examining languages across modalities illustrates how this interaction impacts language processing.

The impact of visual cues during visual word recognition in deaf readers: An ERP study

Although evidence is still scarce, recent research suggests key differences in how deaf and hearing readers use visual information during visual word recognition. Here we compared the time course of lexical access in deaf and hearing readers of similar reading ability. We also investigated whether one visual property of words, the outline-shape, modulates visual word recognition differently in both groups. We recorded the EEG signal of twenty deaf and twenty hearing readers while they performed a lexical decision task. In addition to the effect of lexicality, we assessed the impact of outline-shape by contrasting responses to pseudowords with an outline-shape that was consistent (e.g., mofor) or inconsistent (e.g., mosor) with their baseword (motor). Despite hearing readers having higher phonological abilities, results showed a remarkably similar time course of the lexicality effect in deaf and hearing readers. We also found that only for deaf readers, inconsistent-shape pseudowords (e.g., mosor) elicited larger amplitude ERPs than consistent-shape pseudowords (e.g., mofor) from 150 ms after stimulus onset and extending into the N400 time window. This latter finding supports the view that deaf readers rely more on visual characteristics than typical hearing readers during visual word recognition. Altogether, our results suggest different mechanisms underlying effective word recognition in deaf and hearing readers.

Interference Resolution in Nonfluent Variant Primary Progressive Aphasia: Evidence From a Picture-Word Interference Task.

Picture-word interference tasks have been used to investigate (a) the time course of lexical access in individuals with primary progressive aphasia (PPA) and (b) how these individuals resolve competition during lexical selection. To investigate the time course of Greek-speaking individuals with PPA to produce grammatical gender-marked determiner phrases by examining their picture-naming latencies in the context of distractor words. Eight individuals with nonfluent variant PPA (nfv-PPA; M age = 62.8 years) and eight cognitively intact controls (M age = 61.1 years) participated in our study. In a picture-word interference task, the study participants named depicted objects by producing determiner + noun sequences. Interference was generated by manipulating the grammatical gender of the depicted objects and distractor words. Two stimulus onset asynchronies were used: +200 ms and +400 ms. The individuals with nfv-PPA exhibited longer picture-naming latencies than the controls (P = 0.003). The controls exhibited interference from incongruent distractors at both asynchronies (P < 0.001); the individuals with PPA exhibited interference from incongruent distractors only at the +400-ms interval (P = 0.002). The gender-congruency effect was stronger for the individuals with PPA than for the controls at the +400-ms interval (P = 0.05); the opposite pattern was observed at the +200-ms interval (P = 0.024). Gender interference resolution was abnormal in the individuals with nfv-PPA. The results point to deficits in lexicosyntactic networks that compromised the time course of picture-naming production.

A novel eye tracking paradigm for assessing semantic and phonologic activation in aphasia

A novel eye tracking paradigm for assessing semantic and phonologic activation in aphasia

Tracking the time course of lexical access in orthographic production: An event-related potential study of word frequency effects in written picture naming

Previous studies of spoken picture naming using event-related potentials (ERPs) have shown that speakers initiate lexical access within 200ms after stimulus onset. In the present study, we investigated the time course of lexical access in written, rather than spoken, word production. Chinese participants wrote target object names which varied in word frequency, and written naming times and ERPs were measured. Writing latencies exhibited a classical frequency effect (faster responses for high- than for low-frequency names). More importantly, ERP results revealed that electrophysiological activity elicited by high- and low frequency target names started to diverge as early as 168ms post picture onset. We conclude that lexical access during written word production is initiated within 200ms after picture onset. This estimate is compatible with previous studies on spoken production which likewise showed a rapid onset of lexical access (i.e., within 200ms after stimuli onset). We suggest that written and spoken word production share the lexicalization stage.

Electrophysiological assessment of the time course of bilingual visual word recognition: Early access to language membership

Previous research examining the time course of lexical access during word recognition suggests that phonological processing precedes access to semantic information, which in turn precedes access to syntactic information. Bilingual word recognition likely requires an additional level: knowledge of which language a specific word belongs to. Using the recording of event-related potentials, we investigated the time course of access to language membership information relative to semantic (Experiment 1) and syntactic (Experiment 2) encoding during visual word recognition. In Experiment 1, Spanish–English bilinguals viewed a series of printed words while making dual-choice go/nogo and left/right hand decisions based on semantic (whether the word referred to an animal or an object) and language membership information (whether the word was in English or in Spanish). Experiment 2 used a similar paradigm but with syntactic information (whether the word was a noun or a verb) as one of the response contingencies. The onset and peak latency of the N200, a component related to response inhibition, indicated that language information is accessed earlier than semantic information. Similarly, language information was also accessed earlier than syntactic information (but only based on peak latency). We discuss these findings with respect to models of bilingual word recognition and language comprehension in general.

Processing lexical ambiguity in sentential context: Eye-tracking data from brain-damaged and non-brain-damaged individuals

The purpose of the present study was to identify general and syndrome-specific deficits in the lexical processing of individuals with non-fluent and fluent aphasia compared to individuals without cognitive, neurological or language impairments. The time course of lexical access, as well as lexical selection and integration was studied using a visual-world paradigm in three groups of Russian speakers: 36 individuals in the control group, 15 individuals with non-fluent aphasia and eight individuals with fluent aphasia. Participants listened to temporarily ambiguous sentences wherein the context biased the interpretation of an ambiguous word toward one of its two meanings. In half of the experimental sentences, a reanalysis was needed upon encountering the disambiguating phrase. The effect of the length of the intervening material between the ambiguous word and the disambiguation point was additionally monitored. All groups of participants showed intact lexical access under slowed speech rate, but non-fluent participants experienced difficulties with timely activation of multiple referents. At later stages of lexical processing, they additionally demonstrated a specific impairment of reanalysis. The deficit in participants with fluent aphasia was not focalized at any specific stage of lexical processing. Rather, the breakdown of lexical processes in fluent aphasia was likely related to difficulties with the inhibition of irrelevant lexical activation, which is further supported by the finding that increased phonological distance between the ambiguous word and ambiguity resolution was influential to the offline performance in this group.

The influence of frequency across the time course of morphological processing: Evidence from the transposed-letter effect

The role that morphology plays in lexical access has been the subject of much debate, as has the influence of word frequency on morphological processing. The effect of frequency on morphological processing across the time course of lexical access was investigated using the transposed-letter effect. The results of two experiments (one masked-priming experiment and one eye-tracking experiment) outline a process in which morphological structure can be detected quickly and independently of frequency. The present study is also the first to show that transpositions that cross morpheme boundaries can be as disruptive as letter substitutions in inflected words, replicating earlier results with derived and compound words.

Speech recognition in adverse conditions: A review

This article presents a review of the effects of adverse conditions (ACs) on the perceptual, linguistic, cognitive, and neurophysiological mechanisms underlying speech recognition. The review starts with a classification of ACs based on their origin: Degradation at the source (production of a noncanonical signal), degradation during signal transmission (interfering signal or medium-induced impoverishment of the target signal), receiver limitations (peripheral, linguistic, cognitive). This is followed by a parallel, yet orthogonal classification of ACs based on the locus of their effect: Perceptual processes, mental representations, attention, and memory functions. We then review the added value that ACs provide for theories of speech recognition, with a focus on fundamental themes in psycholinguistics: Content and format of lexical representations, time-course of lexical access, word segmentation, feed-back in speech perception and recognition, lexical-semantic integration, interface between the speech system and general cognition, neuroanatomical organisation of speech processing. We conclude by advocating an approach to speech recognition that includes rather than neutralises complex listening environments and individual differences.

The time course of lexical access in morphologically complex words

Compounding, the concatenation of words (e.g. dishwasher), is an important mechanism across many languages. This study investigated whether access of initial compound constituents occurs immediately or, alternatively, whether it is delayed until the last constituent (i.e. the head). Electroencephalogram was measured as participants listened to German two-constituent compounds. Both the initial as well as the following head constituent could consist of either a word or nonword, resulting in four experimental conditions. Results showed a larger N400 for initial nonword constituents, suggesting that lexical access was attempted before the head. Thus, this study provides direct evidence that lexical access of transparent compound constituents in German occurs immediately, and is not delayed until the compound head is encountered.

The time course of word retrieval revealed by event-related brain potentials during overt speech

Speech production is one of the most fundamental activities of humans. A core cognitive operation involved in this skill is the retrieval of words from long-term memory, that is, from the mental lexicon. In this article, we establish the time course of lexical access by recording the brain electrical activity of participants while they named pictures aloud. By manipulating the ordinal position of pictures belonging to the same semantic categories, the cumulative semantic interference effect, we were able to measure the exact time at which lexical access takes place. We found significant correlations between naming latencies, ordinal position of pictures, and event-related potential mean amplitudes starting 200 ms after picture presentation and lasting for 180 ms. The study reveals that the brain engages extremely fast in the retrieval of words one wishes to utter and offers a clear time frame of how long it takes for the competitive process of activating and selecting words in the course of speech to be resolved.

Semantic and phonological influences on picture naming by children and teenagers

We investigated the stages of picture naming with a new children's picture–word task. In Experiment 1, 24 normal children between 5 and 7 years named pictures while attempting to ignore auditory distractors. The relation between the onsets of the distractors and the pictures varied. Naming performance for semantic distractors showed interference when the distractor's onset was before the picture's onset. Naming performance for phonological nonsense-syllable distractors showed facilitation (congruent distractors) or interference (conflicting distractors) at all onset asymmetries. Overall results resembled findings in teenagers (Experiment 2) and previous findings in adults. The nature of linguistic knowledge and the time course of lexical access, as indexed by performance on a picture–word task, is remarkably similar in children, teenagers, and adults.

Frequency effects in noun phrase production: Implications for models of lexical access

We investigated the processes of lexical retrieval during the production of adjectival noun phrases (NPs) such as "the blue kite". We used various current assumptions about the scope of grammatical and phonological encoding and about the locus of the classic frequency effect to derive predictions about possible frequency effects in the NP naming task. The predictions were tested in two picture-naming experiments where we manipulated orthogonally the frequencies of the adjective and of the noun that composed the NPs. We consistently found frequency effects for both adjectives and nouns. Moreover the effects were additive. We argue that the existence of a frequency effect for the noun during noun phrase production restricts the various combinations of assumptions that speech production models can hold simultaneously. Possible implications of the additivity of the effects for the time course of lexical access are also discussed.

Regularity Revisited: Evidence from Lexical Access of Verbs and Nouns in Greek

The present study investigates the relationship between morphological regularity and form during lexical processing using a visual priming paradigm varying the prime duration. We addressed the effect of regularity on morphological facilitation in nouns and verbs by exploiting particular characteristics of a highly inflected language, Greek, in which it is possible to manipulate morphological regularity while controlling the degree of orthographic overlap between morphological relatives. The effects of morphological regularity were found to crucially depend on the time course of lexical access. Moreover, morphological regularity was found to affect nouns and verbs differentially. We interpret these findings with respect to the distinction between affix processing and allomorph retrieval and discuss the issues of form overlap and orthographic boundaries in morphological processing.

Subcategorical mismatches and the time course of lexical access: Evidence for lexical competition

Participants' eye movements were monitored as they followed spoken instructions to click on a pictured object with a computer mouse (e.g., ''click on the net''). Participants were slower to fixate the target picture when the onset of the target word came from a competitor word (e.g., ne(ck)t) than from a nonword (e.g., ne(p)t), as predicted by models of spoken-word recognition that incorporate lexical competition. This was found whether the picture of the competitor word (e.g., the picture of a neck) was present on the display or not. Simulations with the TRACE model captured the major trends of fixations to the target and its competitor over time. We argue that eye movements provide a fine-grained measure of lexical activation over time, and thus reveal effects of lexical competition that are masked by response measures such as lexical decisions.

Lexical access in the production of pronouns

Speakers can use pronouns when their conceptual referents are accessible from the preceding discourse, as in ` The flower is red. It turns blue'. Theories of language production agree that in order to produce a noun semantic, syntactic, and phonological information must be accessed. However, little is known about lexical access to pronouns. In this paper, we propose a model of pronoun access in German. Since the forms of German pronouns depend on the grammatical gender of the nouns they replace, the model claims that speakers must access the syntactic representation of the replaced noun (its lemma) to select a pronoun. In two experiments using the lexical decision during naming paradigm [Levelt, W.J.M., Schriefers, H., Vorberg, D., Meyer, A.S., Pechmann, T., Havinga, J., 1991a. The time course of lexical access in speech production: a study of picture naming. Psychological Review 98, 122–142], we investigated whether lemma access automatically entails the activation of the corresponding word form or whether a word form is only activated when the noun itself is produced, but not when it is replaced by a pronoun. Experiment 1 showed that during pronoun production the phonological form of the replaced noun is activated. Experiment 2 demonstrated that this phonological activation was not a residual of the use of the noun in the preceding sentence. Thus, when a pronoun is produced, the lemma and the phonological form of the replaced noun become reactivated.

Effects of affective tone of voice on spoken word recognition

Traditionally, the study of emotional tone of voice has been considered separately from the study of formal linguistic aspects of spoken language. Research has typically focused either on how listeners detect emotion in an individual’s voice, or on how listeners extract abstract linguistic content. The present study was designed to investigate how these two sources of information interact. In two experiments, listeners were presented with homophones that had one affective (happy or sad) and one neutral meaning and with nonhomophones that had either a happy, sad, or neutral meaning. Within each experiment, words were spoken in a tone of voice that was either congruent, incongruent, or neutral with respect to affective meaning. In the first experiment, naming latencies were collected to determine if tone of voice affects the speed of lexical processing. In the second experiment, transcription accuracy was assessed to determine if tone of voice affects the selection of word meaning. The results suggest that emotional tone of voice was used to resolve lexical ambiguity, but did not appear to affect specifically the time course of lexical access. The implications of these results for current theories of spoken word recognition will be discussed. [Work supported by NIH.]

Integrating Form and Meaning: A Distributed Model of Speech Perception

We present a new distributed connectionist model of the perception of spoken words. The model employs a representation of speech that combines lexical information with abstract phonological information, with lexical access modelled as a direct mapping onto this single distributed representation. We first examine the integration of partial cues to phonological identity, showing that the model provides a sound basis for simulating phonetic and lexical decision data from Marslen-Wilson and Warren (1994). We then investigate the time course of lexical access, and argue that the process of competition between word candidates during lexical access can be interpreted in terms of interference between distributed lexical representations. The relation between our model and other models of spoken word recognition is discussed.

A listener's investigation of printed word processing.

The present study examines the time course of lexical access in written-word recognition by comparing words with early and late uniqueness points (UPs). Three experiments, which used a normal (simultaneous) presentation of the letters under 3 different tasks (gender classification, naming, and semantic classification) provided no evidence for sequential processing. Rather, a small advantage in favor of words with late UP was found, which may be interpreted in terms of the lower n-gram frequencies of early-UP words. Experiment 4 supported this interpretation and discussed an alternative interpretation in terms of parafoveal preview of the initial letters. A last experiment, which used an incremental presentation of the word letters, gave rise to a UP effect comparable in size to that obtained in an auditory study, suggesting that a temporal distribution of the signal is a sufficient condition for directional processing.