N400-like Effect Research Articles

Neurodevelopment for syntactic processing distinguishes childhood stuttering recovery versus persistence.

BackgroundCharacterized by the presence of involuntary speech disfluencies, developmental stuttering is a neurodevelopmental disorder of atypical speech-motor coordination. Although the etiology of stuttering is multifactorial, language development during early childhood may influence both the onset of the disorder and the likelihood of recovery. The purpose of this study was to determine whether differences in neural indices mediating language processing are associated with persistence or recovery in school-age children who stutter.MethodsEvent-related brain potentials (ERPs) were obtained from 31 6–7-year-olds, including nine children who do not stutter (CWNS), 11 children who had recovered from stuttering (CWS-Rec), and 11 children who persisted in stuttering (CWS-Per), matched for age, and all with similar socioeconomic status, nonverbal intelligence, and language ability. We examined ERPs elicited by semantic and syntactic (phrase structure) violations within an auditory narrative consisting of English and Jabberwocky sentences. In Jabberwocky sentences, content words were replaced with pseudowords to limit semantic context. A mixed effects repeated measures analysis of variance (ANOVA) was computed for ERP components with four within-subject factors, including condition, hemisphere, anterior/posterior distribution, and laterality.ResultsDuring the comprehension of English sentences, ERP activity mediating semantic and syntactic (phrase structure) processing did not distinguish CWS-Per, CWS-Rec, and CWNS. Semantic violations elicited a qualitatively similar N400 component across groups. Phrase structure violations within English sentences also elicited a similar P600 component in all groups. However, identical phrase structure violations within Jabberwocky sentences elicited a P600 in CWNS and CWS-Rec, but an N400-like effect in CWS-Per.ConclusionsThe distinguishing neural patterns mediating syntactic, but not semantic, processing provide evidence that specific brain functions for some aspects of language processing may be associated with stuttering persistence. Unlike CWS-Rec and CWNS, the lack of semantic context in Jabberwocky sentences seemed to affect the syntactic processing strategies of CWS-Per, resulting in the elicitation of semantically based N400-like activity during syntactic (phrase structure) violations. This vulnerability suggests neural mechanisms associated with the processing of syntactic structure may be less mature in 6–7-year-old children whose stuttering persisted compared to their fluent or recovered peers.

Brain mechanisms for processing co-speech gesture: A cross-language study of spatial demonstratives

Abstract This electrophysiological study investigated the relationship between language and nonverbal socio-spatial context for demonstrative use in speech communication. Adult participants from an English language group and a Japanese language group were asked to make congruency judgment for simultaneous presentation of an audio demonstrative phrase in their native language and a picture that included two human figures as speaker and hearer, as well as a referent object in different spatial arrangements. The demonstratives (“this” and “that” in English, and “ko,” “so,” and “a” in Japanese) were varied for the visual scenes to produce expected and unexpected combinations to refer to an object based on its relative spatial distances to the speaker and hearer. Half of the trials included an accompanying pointing gesture in the picture, and the other half did not. Behavioral data showed robust congruency effects with longer reaction time for the incongruent trials in both subject groups irrespective of the presence or absence of the pointing gesture. Both subject groups also showed a significant N400-like congruency effect in the event-related potential responses for the gesture trials, a finding predicted from previous work (Stevens & Zhang, 2013). In the no-gesture trials, the English data alone showed a P600 congruency effect preceded by a negative deflection. These results provide evidence for shared brain mechanisms for processing demonstrative expression congruency, as well as language-specific neural sensitivity to encoding the co-expressivity of gesture and speech.

N400 Effect When a Semantic Anomaly is Detected in Action Representation. A Source Localization Analysis

The strength relationship between action and language was largely discussed. In the present research, we explored this link by considering the cortical response (N400 event-related potential effect) to the semantic incongruence induced by a final anomalous object-related action within an actions' sequence. Seventeen participants performed an explicit task to distinguish congruous from incongruous final target action. Event-related potentials analysis showed a significant N400-like effect more frontally (dorsolateral prefrontal cortex) and temporoparietal (mainly left supramarginal gyrus) distribution in response to incongruous condition. It can be argued that the N400-like effect is similar in nature to the N400, which is generally evoked by linguistic stimuli. Nevertheless, the cortical source analysis (low-resolution electromagnetic tomography) showed significant differences for the cortical generators induced by an action processing. This fact may be explained by assuming that object-related action representation activates a specific cortical network, more directly related to congruous/incongruous object use comprehension in relationship with a specific context.

Testing theories of irony processing using eye-tracking and ERPs.

Not much is known about how people comprehend ironic utterances, and to date, most studies have simply compared processing of ironic versus non-ironic statements. A key aspect of the graded salience hypothesis, distinguishing it from other accounts (such as the standard pragmatic view and direct access view), is that it predicts differences between processing of familiar and unfamiliar ironies. Specifically, if an ironic utterance is familiar, then the ironic interpretation should be available without the need for extra inferential processes, whereas for unfamiliar ironies, the literal interpretation would be computed first, and a mismatch with context would lead to a re-interpretation of the statement as being ironic. We recorded participants' eye movements while they were reading (Experiment 1), and electrical brain activity while they were listening to (Experiment 2), familiar and unfamiliar ironies compared to non-ironic controls. Results show disruption to eye movements and an N400-like effect for unfamiliar ironies only, supporting the predictions of the graded salience hypothesis. In addition, in Experiment 2, a late positivity was found for both familiar and unfamiliar ironic materials, compared to non-ironic controls. We interpret this positivity as reflecting ongoing conflict between the literal and ironic interpretations of the utterance.

Long-term information and distributed neural activation are relevant for the “internal features advantage” in face processing: Electrophysiological and source reconstruction evidence

In face processing tasks, prior presentation of internal facial features, when compared with external ones, facilitates the recognition of subsequently displayed familiar faces. In a previous ERP study (Olivares & Iglesias, 2010) we found a visibly larger N400-like effect when identity mismatch familiar faces were preceded by internal features, as compared to prior presentation of external ones. In the present study we contrasted the processing of familiar and unfamiliar faces in the face-feature matching task to assess whether the so-called “internal features advantage” relies mainly on the use of stored face-identity-related information or if it might operate independently from stimulus familiarity. Our participants (N = 24) achieved better performance with internal features as primes and, significantly, with familiar faces. Importantly, ERPs elicited by identity mismatch complete faces displayed a negativity around 300–600 msec which was clearly enhanced for familiar faces primed by internal features when compared with the other experimental conditions. Source reconstruction showed incremented activity elicited by familiar stimuli in both posterior (ventral occipitotemporal) and more anterior (parahippocampal (ParaHIP) and orbitofrontal) brain regions. The activity elicited by unfamiliar stimuli was, in general, located in more posterior regions. Our findings suggest that the activation of multiple neural codes is required for optimal individuation in face-feature matching and that a cortical network related to long-term information for face-identity processing seems to support the internal feature effect.

Is it over-respectful or disrespectful? Differential patterns of brain activity in perceiving pragmatic violation of social status information during utterance comprehension

A critical issue in the study of language communication is how extra-linguistic information, such as the social status of the communicators, is taken into account by the online comprehension system. In Mandarin Chinese, the second-person pronoun (you/your) can be in a respectful form (nin/nin-de) when the addressee is of higher status than the speaker or in a less respectful form (ni/ni-de) when the addressee is of equal or lower status. We conducted an event-related potential (ERP) study to investigate how social status information affects pronoun resolution during utterance comprehension. Participants read simple conversational scenarios for comprehension, with each scenario including a context describing a speaker and an addressee and a directly-quoted utterance beginning with the second-person pronoun. The relative status between the speaker and the addressee was varied, creating conditions in which the second-person pronoun was either consistent or inconsistent with the relationship between conversants, or in which the two conversants were of equal status. ERP results showed that, compared with the status-consistent and status-equal conditions, the status-inconsistent condition elicited an anterior N400-like effect on nin-de (over-respectful) and a broadly distributed N400 on ni-de (disrespectful). In a later time window, both the status-reversed and the status-equal conditions elicited a sustained positivity effect on nin-de and a sustained negativity effect on ni-de. These findings suggest that the comprehender builds up expectance towards the upcoming pronoun based on the perceived social status of conversants. While the inconsistent pronoun causes semantic integration difficulty in an earlier stage of processing, the strategy to resolve the inconsistency and the corresponding brain activity vary according to the pragmatic implications of the pronoun.

The N2- and N400-like effects of radicals on complex Chinese characters

Participants were asked to complete a delayed character-matching task, while their event-related brain potentials (ERPs) elicited by Chinese character fragments were recorded. This task required participants to match probe characters with their preceding fragments, which were randomly assigned to be either radical or stroke-deleted. However, the same number of strokes was retained in either case. The stroke-deleted fragments, which contained fewer intact radicals, elicited larger N2- and N400-like components compared with the radical-deleted fragments. Stroke-deleted fragments displayed lower response accuracy than the radical-deleted fragments. These results indicate that simple radicals have an intermediate or sub-character function in Chinese character recognition. The processing of characters with more destroyed radicals is impeded within a multilayer interactive-activation model.

Development of lexical–semantic language system: N400 priming effect for spoken words in 18- and 24-month old children

Our aim was to investigate whether developing language system, as measured by a priming task for spoken words, is organized by semantic categories. Event-related potentials (ERPs) were recorded during a priming task for spoken words in 18- and 24-month-old monolingual French learning children. Spoken word pairs were either semantically related (e.g., train–bike) or unrelated (e.g., chicken–bike). The results showed that the N400-like priming effect occurred in 24-month-olds over the right parietal–occipital recording sites. In 18-month-olds the effect was observed similarly to 24-month-olds only in those children with higher word production ability. The results suggest that words are categorically organized in the mental lexicon of children at the age of 2years and even earlier in children with a high vocabulary.

The Electrophysiological Underpinnings of Processing Gender Stereotypes in Language

Despite the widely documented influence of gender stereotypes on social behaviour, little is known about the electrophysiological substrates engaged in the processing of such information when conveyed by language. Using event-related brain potentials (ERPs), we examined the brain response to third-person pronouns (lei “she” and lui “he”) that were implicitly primed by definitional (passeggera FEM “passenger”, pensionato MASC “pensioner”), or stereotypical antecedents (insegnante “teacher”, conducente “driver”). An N400-like effect on the pronoun emerged when it was preceded by a definitionally incongruent prime (passeggera FEM – lui; pensionato MASC – lei), and a stereotypically incongruent prime for masculine pronouns only (insegnante – lui). In addition, a P300-like effect was found when the pronoun was preceded by definitionally incongruent primes. However, this effect was observed for female, but not male participants. Overall, these results provide further evidence for on-line effects of stereotypical gender in language comprehension. Importantly, our results also suggest a gender stereotype asymmetry in that male and female stereotypes affected the processing of pronouns differently.

The Nature of Affective Priming in Music and Speech

The phenomenon of affective priming has caught scientific interest for over 30 years, yet the nature of the affective priming effect remains elusive. This study investigated the underlying mechanism of cross-modal affective priming and the influence of affective incongruence in music and speech on negativities in the N400 time-window. In Experiment 1, participants judged the valence of affective targets (affective categorization). We found that music and speech targets were evaluated faster when preceded by affectively congruent visual word primes, and vice versa. This affective priming effect was accompanied by a significantly larger N400-like effect following incongruent targets. In this experiment, both spreading of activation and response competition could underlie the affective priming effect. In Experiment 2, participants categorized the same affective targets based on nonaffective characteristics. However, as prime valence was irrelevant to the response dimension, affective priming effects could no longer be attributable to response competition. In Experiment 2, affective priming effects were observed neither at the behavioral nor electrophysiological level. The results of this study indicate that both affective music and speech prosody can prime the processing of visual words with emotional connotations, and vice versa. Affective incongruence seems to be associated with N400-like effects during evaluative categorization. The present data further suggest a role of response competition during the affective categorization of music, prosody, and words with emotional connotations.

Font effects of Chinese characters and pseudo-characters on the N400: Evidence for an orthographic processing view

Event-related brain potentials (ERPs) were recorded during a Chinese character decision task to examine whether N400 amplitude is modulated by stimulus font. Results revealed large negative-going ERPs in an N400 time window of 300–500ms to stimuli presented in degraded Xing Kai Ti (XKT) font compared with more intact Song Ti (ST) font regardless of whether the stimuli were real or pseudo-characters. ERPs for the pseudo-characters were more negative than for the real characters with similar timing and scalp distribution. The N400-like font effect on amplitude is interpreted as analogous to an N400 stimulus degradation effect, an extension to Holcomb (1993); the degraded perceptual cues provided by XKT supposedly account for this degradation effect. This effect is further interpreted to reflect relative difficulty, which results from orthographic processing difficulty, in retrieving the meaning of XKT stimuli compared with ST stimuli.

Multiple semantic processes at different levels of syntactic hierarchy: Does the higher-level process proceed in face of a lower-level failure?

Humans have special abilities in processing hierarchical, recursive structures. Here we investigated how an upcoming word embedded in a hierarchical structure is semantically integrated into the prior representation during sentence comprehension. Participants read Chinese sentences with a complex verb argument structure “subject noun+verb+numeral+classifier+object noun”, in which the object noun was constrained by the classifier in a local structure and by the verb in a higher-level structure. The semantic congruence between the classifier and the noun, between the verb and the noun, and between the verb and the classifier was manipulated individually or simultaneously to create a local mismatch (i.e., with classifier–noun mismatch), a sequential mismatch (with verb–classifier and classifier–noun mismatches) or a triple mismatch (with verb–classifier, classifier–noun, and verb–classifier mismatches) condition. Event-related potentials locked to the object noun showed increased N400 and late negativity responses over the local mismatch, the sequential mismatch and the triple mismatch conditions. The local mismatch additionally elicited a posterior positivity effect on the object noun. The verb–classifier mismatch elicited a right N400-like effect followed by a posterior positivity (P600) effect on the classifier. The N400 effects demonstrate that the semantic process at a higher syntactic level can proceed in face of the failure of semantic processes at lower levels when no structural re-interpretation is available, and that the semantic congruence between earlier sentence constituents can affect the integration of the upcoming word in the hierarchical structure. The P600 effects suggest the immediate triggering of a co-ordination process across syntactic levels whereas the late anterior negativity effects suggest the initiation of a second-pass semantic re-interpretation process.

Semantic violation effect on object-related action comprehension. N400-like event-related potentials for unusual and incorrect use

The present study examined the specific action-sentence compatibility effect. We examined the action representation and semantic processes indexed by event-related potentials (ERPs, N400 effect) when plausible or implausible actions were performed within a dynamic context (video tapes showing a sequence of four action frames). Two different semantic anomalies were reproduced in the final action frame, which consisted of an object that did not have the semantic properties required (functionally unusual) for the action goal (Experiment 1) or an object that was incorrectly used with regard to the instrumental properties required for the target action (Experiment 2). Fifteen participants performed an explicit task to distinguish congruous from incongruous actions for the final action frame. The ERP analysis showed a significant N400-like effect that was frontally distributed in response to incongruous conditions for both Experiment 1 and 2. Similarly, response times (RTs) increased in response to incongruous actions. Nevertheless, a temporo-parietal cortical distribution was more prevalent in the unusual object-action representation (Experiment 1) than in the incorrect object-action representation (Experiment 2). These results may be explained by assuming that in Experiment 1, the relationship between the action and its intentional goals was violated, with a cortical-specific temporo-parietal response, whereas in Experiment 2 the intentional goal to perform the action was not violated. It can be argued that the N400-like effect was similar to the N400, which is generally evoked by linguistic stimuli, and these results suggest that N400 increases as the difficulty in accessing the semantic memory increases.

The on-line processing of socio-emotional information in prototypical scenarios: inferences from brain potentials

Little is known about the time course of the mechanisms involved in the on-line processing of socio-emotional information. We used event-related brain potentials (ERPs) to investigate this issue using vignettes that described prototypical, social scenarios. An initial sentence established the social context and the following target sentence ended with a critical word that informed the reader of the character's socio-emotional response to the situation. Critical words that mismatched rather than matched with a character's expected feelings elicited a larger ERP negativity (N400) ~200-500 ms after word onset, followed by a larger frontal positivity. Dipole source modeling results indicated that an anterior temporal lobe source accounted for the N400-like effect, which we attribute to the increased demands of integrating general knowledge about social situations (e.g. scripts) with personal- and context-specific information. An additional mediofrontal source contributed to the later ERP effect and presumably reflects high-level mindreading functions. Together, these findings indicate that readers rapidly infer and evaluate on-line a character's likely socio-emotional response based on the prototypical information provided by the text.

Is the distinction between intra- and extra-musical meaning implemented in the brain?: Comment on “Towards a neural basis of processing musical semantics” by Stefan Koelsch

Based on the results of a series of seminal studies very clearly reviewed in the paper, Stefan Koelsch proposes a neurobiological theory of musical meaning [4]. In this theory, the distinction between extraand intra-musical meaning [5] is implemented in the brain of the listener, with the N400 reflecting extra-musical meaning and the N5 associated with the processing of intra-musical meaning. The finding of an N400-like effect (unrelated minus related) in semantic priming experiments when the prime is a musical sound and the target a word (or vice versa) is indeed good evidence that the semantic properties of both elements are combined in an extra-musical conceptual space to determine whether they are semantically related or unrelated. Because the occurrence of words in an experimental design may encourage labeling of the musical sounds (e.g., mental generation of the word “heroic” when listening to an excerpt of Beethoven’s 3rd Symphony), one of the most interesting experimental condition is when two non-linguistic sounds are successively presented as prime and target. Importantly, Aramaki et al. [1], Frey et al. [2] and Grieser-Painter and Koelsch [3] reported an N400-like effect in such a condition of reduced linguistic mediation. However, if an N400 is generated in a purely musical condition (e.g., sound–sound) in which a musical element (be it a note, a chord, the first theme in the sonata form . . .) is driving expectations for another musical element, why should we consider the N400 as reflecting the processing of extra-musical meaning rather than the processing of intra-musical meaning? The possibility that the N400 also reflects intra-musical meaning is supported by the results of Steinbeis and Koelsch [6] showing an interaction between the N400 and the N5. This interaction implies that the processes underlying the N5 and N400 components are not independent and draw, at least partly, on the same pool of neural resources. It is thus possible that the N5 is, in fact, a delayed N400. In other words, the implementation in the brain of the extra-musical vs intra-musical meaning distinction may not be as straightforward as one would like it to

N400-like Potentials and Reaction Times Index Semantic Relations between Highly Repeated Individual Words

The N400 ERP is an electrophysiological index of semantic processing. Its amplitude varies with the semantic category of words, their concreteness, or whether their meaning matches that of a preceding context. The results of a number of studies suggest that these effects could be markedly reduced or suppressed for stimuli that are repeated. Nevertheless, we have recently shown that significant effects of semantic matching and category could be obtained on N400-like potentials elicited by massively repeated target words in a prime-target semantic categorization task. If such effects could be obtained when primes also are repeated, it would then be possible to study the semantic associations between individual words. The present study thus aimed to test this hypothesis while (1) controlling for a potential contribution of physical matching to the processing of repeated targets and (2) testing if the N400-like effects obtained in these conditions are modulated by task instruction, as are classic N400 effects. Two category words were used as primes and two exemplars as targets. In one block of trials, subjects had to respond according to the semantic relation between prime and target (semantic instruction) and, in another block, they had to report changes in letter case (physical instruction). Results showed that the amplitude of the N400-like ERP obtained was modulated by semantic matching and category but not by letter case. The effect of semantic matching was observed only in the semantic instruction block. Interestingly, the effect of category was not modulated by task instruction. An independent component analysis showed that the component that made the greatest contribution to the effect of semantic matching in the time window of the N400-like potential had a scalp distribution similar to that reported for the N400 and was best fit as a bilateral generator in the superior temporal gyrus. The use of repetition could thus allow, at least in explicit semantic tasks, a drastic simplification of N400 protocols. Highly repeated individual words could be used to study semantic relations between individual concepts.

Switching Modalities in A Sentence Verification Task: ERP Evidence for Embodied Language Processing

In an event related potential (ERP) experiment using written language materials only, we investigated a potential modulation of the N400 by the modality switch effect. The modality switch effect occurs when a first sentence, describing a fact grounded in one modality, is followed by a second sentence describing a second fact grounded in a different modality. For example, “A cellar is dark” (visual), was preceded by either another visual property “Ham is pink” or by a tactile property “A mitten is soft.” We also investigated whether the modality switch effect occurs for false sentences (“A cellar is light”). We found that, for true sentences, the ERP at the critical word “dark” elicited a significantly greater frontal, early N400-like effect (270–370 ms) when there was a modality mismatch than when there was a modality-match. This pattern was not found for the critical word “light” in false sentences. Results similar to the frontal negativity were obtained in a late time window (500–700 ms). The obtained ERP effect is similar to one previously obtained for pictures. We conclude that in this paradigm we obtained fast access to conceptual properties for modality-matched pairs, which leads to embodiment effects similar to those previously obtained with pictorial stimuli.

Applauding with Closed Hands: Neural Signature of Action-Sentence Compatibility Effects

BackgroundBehavioral studies have provided evidence for an action–sentence compatibility effect (ACE) that suggests a coupling of motor mechanisms and action-sentence comprehension. When both processes are concurrent, the action sentence primes the actual movement, and simultaneously, the action affects comprehension. The aim of the present study was to investigate brain markers of bidirectional impact of language comprehension and motor processes.Methodology/Principal FindingsParticipants listened to sentences describing an action that involved an open hand, a closed hand, or no manual action. Each participant was asked to press a button to indicate his/her understanding of the sentence. Each participant was assigned a hand-shape, either closed or open, which had to be used to activate the button. There were two groups (depending on the assigned hand-shape) and three categories (compatible, incompatible and neutral) defined according to the compatibility between the response and the sentence. ACEs were found in both groups. Brain markers of semantic processing exhibited an N400-like component around the Cz electrode position. This component distinguishes between compatible and incompatible, with a greater negative deflection for incompatible. Motor response elicited a motor potential (MP) and a re-afferent potential (RAP), which are both enhanced in the compatible condition.Conclusions/SignificanceThe present findings provide the first ACE cortical measurements of semantic processing and the motor response. N400-like effects suggest that incompatibility with motor processes interferes in sentence comprehension in a semantic fashion. Modulation of motor potentials (MP and RAP) revealed a multimodal semantic facilitation of the motor response. Both results provide neural evidence of an action-sentence bidirectional relationship. Our results suggest that ACE is not an epiphenomenal post-sentence comprehension process. In contrast, motor-language integration occurring during the verb onset supports a genuine and ongoing brain motor-language interaction.

Semantic processing of highly repeated concepts presented in single-word trials: Electrophysiological and behavioral correlates

Repetition has often been associated with a reduction or a suppression of semantic effects. However, several studies have reported that semantic processing can still be effective for repeated target stimuli when the context, prime word or sentence frame, changes from trial to trial. This type of context-target designs allows to study semantic associations between repeated words. However, it is not optimal to study single concepts or categories and therefore structural aspects of semantic memory. Here, we tested whether semantic effects could be observed if single-word trials were used. Concrete and Abstract words were presented multiple times in two concrete-abstract classification experiments. In the first experiment, 6 words of each category were repeatedly presented. In the second experiment, only one word of each category was used. Results of both experiments showed significant effects of concreteness on reaction times and N400-like event-related potentials (ERPs), which were comparable to those reported in non-repeated conditions. In the second experiment, in which repetitions occurring in consecutive and non-consecutive trials were contrasted, N400-like effects were observed only for non-consecutive repetitions. These findings suggest that it could be possible to study the brain activity corresponding to individual concepts in experimental designs using single-word trials, provided that consecutive repetitions are avoided.

Brain potential correlates of the “internal features advantage” in face recognition

Whereas some behavioral studies have shown that internal features are crucial for efficient face recognition in healthy adults, compared to external features, the brain mechanisms underlying this “internal features advantage” are still unknown. In the present study, the differential relevance of both subsets of facial features is addressed analyzing N400-like potentials elicited in a face-feature matching task, where external or internal features and complete face targets were displayed consecutively in each trial. Experiment 1 revealed a larger and longer-lasting N400-like effect with the prior presentation of internal features, which suggests more efficient processing of long-term face-related information. An analysis of neural sources in Experiment 2 revealed greater activation of frontal and left temporal brain areas in the processing of mismatching targets when preceded by internal features. Thus, brain electrical correlates of the “internal features advantage” could be verified around 300-400 ms post-stimulus and supported by a face-identity related neural network.