Lexical stress encoding in single word production estimated by event-related brain potentials

A mapping-knowledge-domain analysis of ERP research on language processing

The event-related potentials (ERPs) technique represents a newly developed methodology in cognitive neuroscience and has significantly extended the scope of linguistic studies, offering valuable insights into cognitive processes related to language. While extant literature reviews have addressed specific facets of ERP research on language processing, a comprehensive overview of this domain remains notably absent. This study aims to fill this gap by pioneering a mapping-knowledge-domain analysis of ERP research on language processing using Citespace, a visualized bibliometric software. The current study conducted a meticulous survey and evaluation of relevant literature extracted from the Web of Science core collection. Initially, this study outlines the spatial-temporal distribution within this domain. Subsequently, employing document co-citation analysis, keyword co-occurrence analysis, cluster analysis, and burst detection analysis, this study delved deeper into the research landscape. Findings reveal that key areas in ERP research on language processing predominantly focus on sentence comprehension, reading comprehension, and mismatch negativity, with notable emphasis on topics such as speech perception, temporal dynamics, and working memory. The current study advocates for future investigations to concentrate on larger linguistic units, explore the integration of ERP components and their functional significance, and scrutinize individual differences among participants. These directions are imperative for advancing the understanding of language processing mechanisms.

Noun-phrase production as a window to language selection: An ERP study

Characterising the time course of non-native language production is critical in understanding the mechanisms behind successful communication. Yet, little is known about the modulating role of cross-linguistic influence (CLI) on the temporal unfolding of non-native production and the locus of target language selection. In this study, we explored CLI effects on non-native noun phrase production with behavioural and neural methods. We were particularly interested in the modulation of the P300 as an index for inhibitory control, and the N400 as an index for co-activation and CLI. German late learners of Spanish overtly named pictures while their EEG was monitored. Our results indicate traceable CLI effects at the behavioural and neural level in both early and late production stages. This suggests that speakers faced competition between the target and non-target language until advanced production stages. Our findings add important behavioural and neural evidence to the underpinnings of non-native production processes, in particular for late learners.

Prosody perception and production by children with cochlear implants

The perception and production of emotional and linguistic (focus) prosody were compared in children with cochlear implants (CI) and normally hearing (NH) peers. Thirteen CI and thirteen hearing-age-matched school-aged NH children were tested, as baseline, on non-verbal emotion understanding, non-word repetition, and stimulus identification and naming. Main tests were verbal emotion discrimination, verbal focus position discrimination, acted emotion production, and focus production. Productions were evaluated by NH adult Dutch listeners. All scores between groups were comparable, except a lower score for the CI group for non-word repetition. Emotional prosody perception and production scores correlated weakly for CI children but were uncorrelated for NH children. In general, hearing age weakly predicted emotion production but not perception. Non-verbal emotional (but not linguistic) understanding predicted CI children's (but not controls') emotion perception and production. In conclusion, increasing time in sound might facilitate vocal emotional expression, possibly requiring independently maturing emotion perception skills.

Morphological encoding beyond slots and fillers: An ERP study of comparative formation in English

One important organizational property of morphology is competition. Different means of expression are in conflict with each other for encoding the same grammatical function. In the current study, we examined the nature of this control mechanism by testing the formation of comparative adjectives in English during language production. Event-related brain potentials (ERPs) were recorded during cued silent production, the first study of this kind for comparative adjective formation. We specifically examined the ERP correlates of producing synthetic relative to analytic comparatives, e.g. angrier vs. more angry. A frontal, bilaterally distributed, enhanced negative-going waveform for analytic comparatives (vis-a-vis synthetic ones) emerged approximately 300ms after the (silent) production cue. We argue that this ERP effect reflects a control mechanism that constrains grammatically-based computational processes (viz. more comparative formation). We also address the possibility that this particular ERP effect may belong to a family of previously observed negativities reflecting cognitive control monitoring, rather than morphological encoding processes per se.

Lexical stress contrast marking in fluent and non-fluent aphasia in Spanish: The relationship between acoustic cues and compensatory strategies

This study sought to investigate stress production in Spanish by patients with Broca's (BA) and conduction aphasia (CA) as compared to controls. Our objectives were to assess whether: a) there were many abnormal acoustic correlates of stress as produced by patients, b) these abnormalities had a phonetic component and c) ability for articulatory compensation for stress marking was preserved. The results showed abnormal acoustic values in both BA and CA's productions, affecting not only duration but also F0 and intensity cues, and an interaction effect of stress pattern and duration on intensity cubes in BA, but not in CA or controls. The results are interpreted as deriving from two different underlying phenomena: in BA, a compensatory use of intensity as a stress cue in order to avoid 'equal stress'; in CA, related to either a 'subtle phonetic deficit' involving abnormal stress acoustic cue-processing or to 'clear-speech' effects.

On the time course of lexical stress priming in speech production: Behavioral and ERPs evidence from a free-stress language

The goal of the present research was to study the time course of lexical stress encoding in a free-stress language with unpredictable stress. To this aim we measured event-related brain potentials (ERPs) during lexical priming. Participants named pictures bearing either the dominant or non-dominant stress pattern, and preceded by either a congruent or an incongruent word prime (e.g., CInema-FRAgola'cinema-strawberry' vs. benZIna-FRAgola'petrol-strawberry'). Behavioral results show that participants were slower in naming targets that had the same stress pattern as the prime, and were also faster in producing words with the dominant stress pattern in the language. The electrophysiological results show that both the effects are compatible with the time course of phonological encoding in speech production. Surprisingly, a dominant stress effect occurred in the ERPs elicited by the primes, with a larger positivity for non-dominant stress words in a 150-250ms time-window. The pattern of results indicates that during speech production: a) the system is sensitive to the stress patterns distribution; b) the automatic pre-activation of a metrical frame may interfere with the phonological encoding of a to-be-uttered word.

The Contributions of Segmental and Suprasegmental Information in Reading Chinese Characters Aloud

The Chinese writing system provides an excellent case for testing the contribution of segmental and suprasegmental information in reading words aloud within the same language. In logographic Chinese characters, neither segmental nor tonal information is explicitly represented, whereas in Pinyin, an alphabetic transcription of the character, both are explicitly represented. Two primed naming experiments were conducted in which the targets were always written characters. When logographic characters served as the primes (Experiment 1), syllable segmental and tonal information appeared to be represented and encoded as an integral unit which in turn facilitated target character naming. When Pinyin served as the primes (Experiment 2), the explicit phonetic representation facilitated encoding of both segmental and suprasegmental information, but with later access to suprasegmental information. In addition, Chinese speakers were faster to name characters than Pinyin in a simple naming task (Experiment 3), suggesting that Pinyin may be read via a phonological assembly route, whereas characters may be read via a lexical route. Taken together, our findings point to the need to consider the contributions of both segmental and suprasegmental information and the time course in the well-established models for reading aloud, as well as the cognitive mechanisms underlying the reading aloud of logographic characters versus alphabetic Pinyin script.

Temporospatial identification of language-related cortical function by a combination of transcranial magnetic stimulation and magnetoencephalography

INTRODUCTION

Identification of language-related cortical functions can be carried out noninvasively by transcranial magnetic stimulation (TMS) and magnetoencephalography (MEG), which allow for lesion-based interrogation and global temporospatial investigation of cortices, respectively. Combining these two modalities can improve the accuracy of the identification, but the relationships between them remain unclear. We compared TMS and MEG responses during the same language task to elucidate their temporospatial relationships and used the results to develop a novel method to identify language-related cortical functions.

METHODS

Twelve healthy right-handed volunteers performed a picture-naming task during TMS and MEG. TMS was applied on the right or left inferior frontal gyrus (IFG) at five time points, and the reaction times (RTs) for naming the pictures were measured. The temporospatial oscillatory changes measured by MEG during the same task were then compared with the TMS results.

RESULTS

Transcranial magnetic stimulation of the left IFG significantly lengthened RTs at 300 and 375 msec after picture presentation, whereas TMS of the right IFG did not change RTs significantly. Interestingly, the stimulus time point at which RTs increased significantly for each individual was correlated with when the low gamma event-related desynchronizations (ERDs) peaked in the left IFG. Moreover, combining the results of TMS and MEG improved the detection rate for identifying the laterality of language function.

CONCLUSIONS

These results suggest that the low gamma ERDs measured by MEG strongly relate to the language function of picture naming in the left IFG. Finally, we propose a novel method to identify language-related cortical functions by combining TMS and MEG.

Developmental trajectory for production of prosody: lexical stress contrastivity in children ages 3 to 7 years and in adults

PURPOSE

Accurate production of lexical stress within English polysyllabic words is critical for intelligibility and is affected in many speech-language disorders. However, models of speech production remain underspecified with regard to lexical stress. In this study, the authors report a large-scale acoustic investigation of lexical stress production in typically developing Australian English-speaking children ages 3-7 years ( n = 73) compared with young adults ( n = 24).

METHOD

Participants named pictures of highly familiar strong-weak and weak-strong polysyllabic words. Of 388 productions, 325 met criteria for acoustic measurement. Relative vowel duration, peak intensity, and peak f (0) over the first two syllables were measured. Result Lexical stress was marked consistently by duration and intensity but not f (0). Lexical stress on strong-weak words was adultlike by 3 years. All 3 measures showed significant differences between adults and children for weak-strong words still present at 7 years.

CONCLUSION

Our findings suggest that protracted development of weak-strong stress production reflects physiological constraints on producing short articulatory durations and rising intensity contours. Findings validate treatment that is centered on strong-weak stress production for children ≥ 3 years with dysprosody. Although intervention for the production of weak-strong words may be initiated before age 7 years, reference to normative acoustic data is preferable to relying on perceptual judgments of accuracy.

A funny thing happened on the way to articulation: N400 attenuation despite behavioral interference in picture naming

We measured Event-Related Potentials (ERPs) and naming times to picture targets preceded by masked words (stimulus onset asynchrony: 80 ms) that shared one of three different types of relationship with the names of the pictures: (1) Identity related, in which the prime was the name of the picture ("socks" - <picture of socks>), (2) Phonemic Onset related, in which the initial segment of the prime was the same as the name of the picture ("log" - <picture of a leaf>), and (3) Semantically related in which the prime was a co-category exemplar and associated with the name of the picture ("cake" - <picture of a pie>). Each type of related picture target was contrasted with an Unrelated picture target, resulting in a 3×2 design that crossed Relationship Type between the word and the target picture (Identity, Phonemic Onset and Semantic) with Relatedness (Related and Unrelated). Modulation of the N400 component to related (versus unrelated) pictures was taken to reflect semantic processing at the interface between the picture's conceptual features and its lemma, while naming times reflected the end product of all stages of processing. Both attenuation of the N400 and shorter naming times were observed to pictures preceded by Identity related (versus Unrelated) words. No ERP effects within 600 ms, but shorter naming times, were observed to pictures preceded by Phonemic Onset related (versus Unrelated) words. An attenuated N400 (electrophysiological semantic priming) but longer naming times (behavioral semantic interference) were observed to pictures preceded by Semantically related (versus Unrelated) words. These dissociations between ERP modulation and naming times suggest that (a) phonemic onset priming occurred late, during encoding of the articulatory response, and (b) semantic behavioral interference was not driven by competition at the lemma level of representation, but rather occurred at a later stage of production.

The spatial and temporal signatures of word production components: a critical update

In the first decade of neurocognitive word production research the predominant approach was brain mapping, i.e., investigating the regional cerebral brain activation patterns correlated with word production tasks, such as picture naming and word generation. Indefrey and Levelt (2004) conducted a comprehensive meta-analysis of word production studies that used this approach and combined the resulting spatial information on neural correlates of component processes of word production with information on the time course of word production provided by behavioral and electromagnetic studies. In recent years, neurocognitive word production research has seen a major change toward a hypothesis-testing approach. This approach is characterized by the design of experimental variables modulating single component processes of word production and testing for predicted effects on spatial or temporal neurocognitive signatures of these components. This change was accompanied by the development of a broader spectrum of measurement and analysis techniques. The article reviews the findings of recent studies using the new approach. The time course assumptions of Indefrey and Levelt (2004) have largely been confirmed requiring only minor adaptations. Adaptations of the brain structure/function relationships proposed by Indefrey and Levelt (2004) include the precise role of subregions of the left inferior frontal gyrus as well as a probable, yet to date unclear role of the inferior parietal cortex in word production.

The time course of segment and tone encoding in Chinese spoken production: an event-related potential study

The present study investigated the time course of segment and tone encoding in Chinese spoken production with an event-related brain potentials (ERPs) experiment. Native Chinese speakers viewed a series of pictures and made Go/noGo decisions along dimensions of segmental onset or tone information of picture names. Behavioral data and onset latency of the N200 effect indicated that segmental information became available prior to tonal information. Moreover, the results of scalp distributions and onset latency patterns of the N200 effect on segmental and tonal decisions suggest that segmental and metrical encoding is relatively disassociated in Chinese spoken production. Our findings provide additional evidence from Chinese as a kind of non-alphabetic language concerning theories of phonological encoding based on alphabetic languages.

The time course of semantic and orthographic encoding in Chinese word production: an event-related potential study

Previous studies have shown that access to conceptual/semantic information precedes phonological access in alphabetic language production such as English or Dutch. The present study investigated the time course of semantic and orthographic encoding in Chinese (a non-alphabetic language) spoken word production. Participants were shown pictures and carried out a dual-choice go/nogo task based on semantic information and orthographic information. The results of the N200 (related to response inhibition) and LRP (related to response preparation) indicated that semantic access preceded orthographic encoding by 176-202 ms. The different patterns of the two N200 effects suggest that they may tap into different processes. The N200 and LRP analyses also indicate that accessing the orthographic representation in speaking is likely optional and depends on specific task requirement.

Brain error-monitoring activity is affected by semantic relatedness: an event-related brain potentials study

Speakers continuously monitor what they say. Sometimes, self-monitoring malfunctions and errors pass undetected and uncorrected. In the field of action monitoring, an event-related brain potential, the error-related negativity (ERN), is associated with error processing. The present study relates the ERN to verbal self-monitoring and investigates how the ERN is affected by auditory distractors during verbal monitoring. We found that the ERN was largest following errors that occurred after semantically related distractors had been presented, as compared to semantically unrelated ones. This result demonstrates that the ERN is sensitive not only to response conflict resulting from the incompatibility of motor responses but also to more abstract lexical retrieval conflict resulting from activation of multiple lexical entries. This, in turn, suggests that the functioning of the verbal self-monitoring system during speaking is comparable to other performance monitoring, such as action monitoring.

Electrophysiological estimates of the time course of semantic and metrical encoding in Chinese speech production

Previous research has shown that conceptual/semantic information precedes segmental information in stress language production (such as English or Dutch). The present study investigated the relative time course of semantic and metrical encoding during Chinese (a tone language) production. Participants were shown pictures and carried out a dual-choice go/nogo decision based on semantic information (whether the depicted item was of a living or non-living object) and metrical information (whether the tone of picture's name was one type, tone 1 or tone 2, or the other type, tone 3 or tone 4). The behavior data, the N200 (related to response inhibition) and the lateralized readiness potentials (LRP, related to response preparation) indicated that semantic encoding was prior to metrical encoding. It provided evidence for early semantic encoding and later metrical encoding of speech production, and supported the serial model or the cascading model, rather than the parallel model of language production. This conclusion relating to the time course of semantic versus segmental encoding in stress languages might be generalized to semantic versus metrical encoding in tone languages such as Chinese.

Bilingual language control: An event-related brain potential study

This study addressed how bilingual speakers switch between their first and second language when speaking. Event-related brain potentials (ERPs) and naming latencies were measured while unbalanced German (L1)-Dutch (L2) speakers performed a picture-naming task. Participants named pictures either in their L1 or in their L2 (blocked language conditions), or participants switched between their first and second language unpredictably (mixed language condition). Furthermore, form similarity between translation equivalents (cognate status) was manipulated. A cognate facilitation effect was found for L1 and L2 indicating phonological activation of the non-response language in blocked and mixed language conditions. The ERP data also revealed small but reliable effects of cognate status. Language switching resulted in equal switching costs for both languages and was associated with a modulation in the ERP waveforms (time windows 275-375 ms and 375-475 ms). Mixed language context affected especially the L1, both in ERPs and in latencies, which became slower in L1 than L2. It is suggested that sustained and transient components of language control should be distinguished. Results are discussed in relation to current theories of bilingual language processing.

Effects of time pressure on verbal self-monitoring: An ERP study

The Error-Related Negativity (ERN) is a component of the event-related brain potential (ERP) that is associated with action monitoring and error detection. The present study addressed the question whether or not an ERN occurs after verbal error detection, e.g., during phoneme monitoring. We obtained an ERN following verbal errors which showed a typical decrease in amplitude under severe time pressure. This result demonstrates that the functioning of the verbal self-monitoring system is comparable to other performance monitoring, such as action monitoring. Furthermore, we found that participants made more errors in phoneme monitoring under time pressure than in a control condition. This may suggest that time pressure decreases the amount of resources available to a capacity-limited self-monitor thereby leading to more errors.