Involvement of cognitive control in sentence comprehension: evidence from ERPs

The Effects of Social Status and Imposition on the Comprehension of Refusals in Chinese: An ERP Study

This study aims to examine how real-time processing of information about the social status of interlocutors (high vs. low) and the imposition of making a refusal by manipulating the indirectness of invitation forms (declining direct invitations vs. declining indirect invitations) affects the interpretation of refusals in Chinese. The event-related potentials results showed that high-status invitees who decline invitations from low-status inviters elicited weaker N400 effects followed by late mitigated negative effects, while high imposition refusals elicited stronger N400 effects followed by increased late negativities. The two factors of social status and imposition functioned independently during the comprehension of refusal utterances. These findings suggest that individuals take the social status of interlocutors and the imposition of making a refusal into consideration as an utterance unfolds, while face-threatening contexts create inferential difficulties for reinterpreting the pragmatic implications of an utterance.

Conventionality determines the time course of indirect replies comprehension: An ERP study

Indirect language comprehension requires decoding both the literal meaning and the intended meaning of an utterance, in which pragmatic inference is involved. This study tests the role of conventionality in the time course of indirect reply processing by comparing conventional and non-conventional indirect replies with direct reply, respectively. We constructed discourses which consist of a context and a dialogue with one question (e.g., May I buy a necklace for you) and one reply (e.g., I really have too many). The reply utterance was segmented into three phrases and presented orderly for EEG recording, e.g., with the subject as the first phrase (e.g., I), the adverbial as the second phrase (e.g., really), and the predicate as the third phrase (e.g., have too many). Our results showed that for conventional indirect replies, the second phrase elicited a larger anterior negativity, and the third phrase elicited a larger anterior N400 compared with those in direct replies. By contrast, for the non-conventional indirect reply, only the third phrase elicited a larger late negativity than the direct replies. These findings suggest that conventionality determines the time course of the pragmatic inferences for the most relevant interpretation during indirect replies comprehension.

An electrophysiological exploration of modifiers embedded in different hierarchies: Insight from short passives in Mandarin

This event-related potentials study explored the processing of Mandarin short passives. We used a syntactic violation paradigm to compare the processing of two auxiliary phrases (i.e., a verb-modifier di-phrase and a noun-modifier de-phrase). In the control condition, the syntactic hierarchy of the di-phrase was lower than that of the de-phrase. In the violation condition, the low-level violation was created by replacing di with de in the auxiliary phrase, while the high-level violation was created by replacing de with di in the auxiliary phrase. The ERP data showed that the noun-modifier elicited the greater left anterior negativity (LAN) and the P600 than the verb-modifier, in both the control condition and the violation condition. We also observed that the LAN induced by the verb-modifier phrase was greater in the control condition than that in the violation condition, while the LAN induced by the noun-modifier was greater in the violation condition than that in the control condition. These results suggested that the greater cortical LAN-P600 might differentiate the high-level hierarchy from the low-level hierarchy. In addition, we tentatively claimed that given the same predicate argument structure, long passives might be the default representational mode of short passives (generally, a constructional alternation might be activated during the processing of the target structure).

Executive Functions and Language Skills in Preschool Children: The Unique Contribution of Verbal Working Memory and Cognitive Flexibility

The development of language skills requires a range of linguistic abilities and cognitive processes, such as executive functions (EFs, i.e., a set of skills involved in goal-directed activities which are crucial for regulating thoughts and actions). Despite progress in understanding the link between language and EFs, the need for more research on the extent and directionality of this link is undeniable. This study examined whether specific components of EFs account for a significant amount of variance in language abilities above and beyond gender, age, and nonverbal intelligence. The sample comprised 79 typically developing children attending the last year of preschool (Mage = 64.5 months, SD = 3.47). EFs were assessed through tasks that explored three predictor variables: inhibitory control, working memory, and cognitive flexibility. The language outcomes included receptive and expressive language. After controlling for age, gender, and nonverbal intelligence, findings showed that working memory and cognitive flexibility, respectively, explained an additional 16% and 19% of the variance. Inhibition skills did not increase the amount of explained variance in language outcomes. These results highlight the potential added importance of assessing working memory and cognitive flexibility in the prediction of language skills in preschool children.

Functional connectivity of brain networks during semantic processing in older adults

The neural systems underlying semantic processing have been characterized with functional neuroimaging in young adults. Whether the integrity of these systems degrade with advanced age remains unresolved. The current study examined functional connectivity during abstract and concrete word processing. Thirty-eight adults, aged 55–91, engaged in semantic association decision tasks during a mixed event-related block functional magnetic resonance imaging (fMRI) paradigm. During the semantic trials, the task required participants to make a judgment as to whether pairs were semantically associated. During the rhyme trials, the task required participants to determine if non-word pairs rhymed. Seeds were placed in putative semantic hubs of the left anterior middle temporal gyrus (aMTG) and the angular gyrus (AG), and also in the left inferior frontal gyrus (IFG), an area considered important for semantic control. Greater connectivity between aMTG, AG, and IFG and multiple cortical areas occurred during semantic processing. Connectivity from the three seeds differed during semantic processing: the left AG and aMTG were strongly connected with frontal, parietal, and occipital areas bilaterally, whereas the IFG was most strongly connected with other frontal cortical areas and the AG in the ipsilateral left hemisphere. Notably, the strength and extent of connectivity differed for abstract and concrete semantic processing; connectivity from the left aMTG and AG to bilateral cortical areas was greater during abstract processing, whereas IFG connectivity with left cortical areas was greater during concrete processing. With advanced age, greater connectivity occurred only between the left AG and supramarginal gyrus during the processing of concrete word-pairs, but not abstract word-pairs. Among older adults, robust functional connectivity of the aMTG, AG, and IFG to widely distributed bilateral cortical areas occurs during abstract and concrete semantic processing in a manner consistent with reports from past studies of young adults. There was not a significant degradation of functional connectivity during semantic processing between the ages of 55 and 85 years. As the study focused on semantic functioning in older adults, a comparison group of young adults was not included, limiting generalizability. Future longitudinal neuroimaging studies that compare functional connectivity of young and older adults under different semantic demands will be valuable.

The influence of cognitive control on the processing of L2 garden path sentence among Chinese–English bilinguals

Few studies have examined the role of cognitive control in processing ambiguity, let alone the roles of different components of cognitive control. In the current study, the English (L2) Sentence Processing Task and a series of cognitive control tasks were administered among 111 young adult Chinese–English bilinguals to investigate the influence of different components of cognitive control on garden path sentence comprehension, with other factors such as age, socio-economic status, and language proficiency strictly matched. Data analysis results showed a significant garden path effect on response times (RTs) and accuracy among all the participants. The results of independent t-test analyses revealed that the high working memory (WM) group was faster in ambiguity resolution, and so was the high monitoring group. However, there were no differences between the high and low inhibition and shifting groups in ambiguity resolution. These findings reveal that only certain aspects of cognitive control influence garden path sentence comprehension.

Is sentence ambiguity comprehension affected after mild traumatic brain injury? Results suggest cognitive control is more important than diagnosis

BACKGROUND

Individuals with mild traumatic brain injury (mTBI) may experience chronic cognitive-linguistic impairments that are difficult to evaluate with existing measures. Garden path sentences are linguistically complex sentences that lead readers down a path to an incorrect interpretation. Previous research indicates many individuals, with or without mTBI, may have difficulty fully resolving the ambiguity of garden path sentences, a skill which may require cognitive control. Evidence suggests cognitive control can be impacted by mTBI. Thus, impairments in cognitive control are expected to correlate with interpreting ambiguous sentences.

AIMS

To examine the relationship between cognitive control and the processing of ambiguous garden path sentences in adults with mTBI. We predict individuals with mTBI will perform more poorly on ambiguous sentence tasks compared with a control group. Further, we predict that performance on this task will correlate with measures of cognitive control and working memory.

METHODS & PROCEDURES

A total of 20 adults with mTBI history and 44 adults with no significant neurological history were recruited from the community. Participants completed a computerized, ambiguous sentence measure with carefully designed comprehension questions and an abbreviated neuropsychological battery of cognitive-linguistic tasks.

OUTCOMES & RESULTS

Participants performed similarly on sentence ambiguity resolution measures across groups with a wide range in performance. A comprehension measure aimed at identifying full ambiguity resolution correlated with cognitive control across groups.

CONCLUSIONS & IMPLICATIONS

A link between cognitive control and linguistic ambiguity is confirmed in a comprehension measure by the current findings. mTBI history did not appear to change the nature of the relationship between cognitive control and ambiguity resolution. High individual variability on sentence and cognitive control measures across groups suggest that if an impairment were present, it would affect both types of tasks. Thus, testing cognitive communication following mTBI should specifically examine complex cognitive and linguistic processing.

WHAT THIS PAPER ADDS

What is already known on the subject Cognitive control and ambiguous sentence processing are known to be linked, but the circumstances and individual variability associated with when cognitive control is recruited to support sentence processing are not fully understood. Very little is known about sentence processing following TBI history, despite cognitive control commonly being impaired following mild TBI. Thus, our study was necessary to explore the theoretical and clinical relationships between cognitive control and ambiguous sentence processing in individuals with mild TBI history. What this paper adds to existing knowledge This study adds to our understanding of how cognitive control and ambiguous sentence processing are linked in those with mild TBI history, and similar to the few previous studies, there were no group differences in cognitive or sentence measures. The positive correlation between cognitive control on Stroop and a particular ambiguous sentence comprehension question targeting inhibitory control highlights that any relationship between abilities or assessment tasks must be very specific to tasks with overlapping requirements, such as inhibition. What are the potential or actual clinical implications of this work? The relationship between cognitive and ambiguous sentence measures highlights the need to assess all areas of cognition and communication in those with mild TBI history without assuming that impairments in cognitive performance will relate to communication. The overlap between abilities is highly specific and must be explored on a case-by-case basis in those with mild TBI. Evaluation and treatment should still be individualized based on the functional communication profile of the client.

Better I than He: Personal perspective modulates counterfactual processing

First-person narratives are more attentively and emotionally engaging than third-person narratives. This study examined whether and how personal perspective modulates counterfactual processing. Participants read counterfactual and causal conditionals written from the first-person or third-person perspective (e.g., If/Because I/he had read enough literature before, I/he would have finished my/his thesis easily.), followed by factual consequences that contained a critical word either consistent or inconsistent with preceding contexts (e.g., Therefore, when I/he was about to defend the thesis I/he felt panicked/confident). In both perspectives, inconsistent words showed a prolonged N400 vs. consistent words in the counterfactual condition, but a larger P600 in the causal condition. The critical word showed a larger P600 in the first- than the third-person condition in counterfactual scenarios, but not in causal scenarios. These findings suggest that personal perspective exerts different influences on counterfactual processing, presumably by modulating the amount of attentional resources involved.

Literacy improves the comprehension of object relatives

While there is a considerable body of research indicating that the acquisition of literacy has profound effects on many aspects of language and cognition, to our knowledge, very little is known about its effects on morphosyntax. In this paper, we explore the effects of literacy on the comprehension of Spanish object relative clauses, a structure which is typically acquired by literate children about the age of 10, i.e., after a considerable amount of exposure to written language. We tested three groups of native Spanish speakers (semi-literates, late-literates and high-literates) using a picture selection task. Subject relatives were used as a control condition. All three groups performed at ceiling on subject relatives (group means of 95% or above). In contrast, we observed very large differences in performance on object relatives, with the semi-literate group performing at chance (51% correct) and the late-literate group slightly above chance (65% correct). Performance in the high-literate group was much better, although not quite at ceiling (82% correct). The results appear to support the hypothesis that literacy helps in the acquisition of some aspects of grammar. This could be partly due to differences in IQ, metalinguistic awareness, working memory and/or executive functioning. The results are also consistent with the 'training wheels' hypothesis (Dąbrowska, 2020), according to which the availability of written representations facilitates the acquisition of difficult structures by easing memory load and enabling speakers to process sentences at their own pace.

Cognitive control mediates age-related changes in flexible anticipatory processing during listening comprehension

Effective listening comprehension not only requires processing local linguistic input, but also necessitates incorporating contextual cues available in the global communicative environment. Local sentence processing can be facilitated by pre-activation of likely upcoming input, or predictive processing. Recent evidence suggests that young adults can flexibly adapt local predictive processes based on cues provided by the global communicative environment, such as the reliability of specific speakers. Whether older comprehenders can also flexibly adapt to global contextual cues is currently unknown. Moreover, it is unclear whether the underlying mechanisms supporting local predictive processing differ from those supporting adaptation to global contextual cues. Critically, it is unclear whether these mechanisms change as a function of typical aging. We examined the flexibility of prediction in young and older adults by presenting sentences from speakers whose utterances were typically more or less predictable (i.e., reliable speakers who produced expected words 80% of the time, versus unreliable speakers who produced expected words 20% of the time). For young listeners, global speaker reliability cues modulated neural effects of local predictability on the N400. In contrast, older adults, on average, did not show global modulation of local processing. Importantly, however, cognitive control (i.e., Stroop interference effects) mediated age-related reductions in sensitivity to the reliability of the speaker. Both young and older adults with high cognitive control showed greater N400 effects of predictability during sentences produced by a reliable speaker, suggesting that cognitive control is required to regulate the strength of top-down predictions based on global contextual information. Critically, cognitive control predicted sensitivity to global speaker-specific information but not local predictability cues, suggesting that predictive processing in local sentence contexts may be supported by separable neural mechanisms from adaptation of prediction as a function of global context. These results have important implications for interpreting age-related change in predictive processing, and for drawing more generalized conclusions regarding domain-general versus language-specific accounts of prediction.

Proactive Control Mediates the Relationship Between Working Memory and Math Ability in Early Childhood

Based on the dual mechanisms of control (DMC) theory, there are two distinct mechanisms of cognitive control, proactive and reactive control. Importantly, accumulating evidence indicates that there is a developmental shift from predominantly using reactive control to proactive control during childhood, and the engagement of proactive control emerges as early as 5–7 years old. However, less is known about whether and how proactive control at this early age stage is associated with children’s other cognitive abilities such as working memory and math ability. To address this issue, the current study recruited 98 Chinese children under 5–7 years old. Among them, a total of 81 children (mean age = 6.29 years) contributed useable data for the assessments of cognitive control, working memory, and math ability. The results revealed that children at this age period predominantly employed a pattern of proactive control during an AX-Continuous Performance Task (AX-CPT). Moreover, the proactive control index estimated by this task was positively associated with both working memory and math performance. Further regression analysis showed that proactive control accounted for significant additional variance in predicting math performance after controlling for working memory. Most interestingly, mediation analysis showed that proactive control significantly mediated the association between working memory and math performance. This suggests that as working memory increases so does proactive control, which may in turn improve math ability in early childhood. Our findings may have important implications for educational practice.

An alternative structure rescues failed semantics? Strong global expectancy reduces local-mismatch N400 in Chinese flexible structures

During comprehension of a hierarchical structure, semantic integration between sequential, mismatched sentential constituents does not proceed when the later word in the sequence (e.g., the noun in the verb + classifier + noun) can be assigned an alternative role in the sentence (e.g., as a modifier of a subsequent object noun) (Zhang et al., 2011). Using electrophysiological measures, we examined how the availability of an alternative structure and whether the reader is motivated to generate an alternative structure affect semantic integration in a hierarchical structure. The same set of sentences was employed in three experiments in which the semantic congruency between the adjective and the object noun in the local structure and the sentential-contextual expectancy towards a noun were manipulated simultaneously. The reader's motivation was manipulated by tasks in which they made semantic acceptability judgment (Experiment 1), passively viewed sentences for comprehension (Experiment 2), or actively predicted the upcoming word and monitored the compatibility between the anticipated and the actual input (Experiment 3). Stronger contextual expectancy reduced N400 responses to the object noun regardless of semantic congruency, indicating that strengthening the constraints of an alternative argument decreased the effort of semantic integration between incompatible local constituents. Relative to weaker expectancy, the incongruent noun preceded by a stronger expectancy context elicited reduced N400 responses when no active prediction was demanded but showed equal amplitudes when such a demand was high. These findings demonstrate that the semantic failure in a flexible structure is likely to be resolved by the comprehender's motivation to generate an alternative structure based on the active use of contextual expectancy information, thus highlighting the "role-dependent semantic processing" during sentence comprehension.

Effects of Two Teaching Strategies on Preschoolers' Oral Language Skills: Repeated Read-Aloud With Question and Answer Teaching Embedded and Repeated Read-Aloud With Executive Function Activities Embedded

The purpose of this study was to investigate the impact of two teaching strategies on preschoolers' oral language skills: repeated read-aloud with question and answer teaching embedded, and repeated read-aloud with executive function (EF) activities embedded. A quasi-experimental pretest-posttest design was employed. Children ranging in age from 4 years 6 months to 6 years and 4 months participated in the study (n = 53). They were recruited from preschools in Taitung, Taiwan, randomly assigned to the three study groups. 36 children were divided and assigned to the two experimental groups (question and answer teaching group and EF group), while the remaining 17, to the control group. The participating preservice teachers attended 32 h of training which included the theory, practice, and outcome evaluation measure for the teaching strategies implemented. The intervention spanned 2 months. Oral language tests (curriculum-based receptive vocabulary, inferential comprehension, and oral comprehension) were administered before and after the intervention. The findings revealed that both experimental groups positively impacted participants' receptive vocabulary and oral comprehension when compared with the control group, although the performances between the two experimental groups did not differ significantly. For inferential comprehension, there was no statistically significant difference across the three groups. Implications of the study findings are discussed and potential topics for future research proposed.

Bilingualism and Attention in Typically Developing Children and Children With Developmental Language Disorder

Purpose The aim of the current study was to investigate whether dual language experience modulates the efficiency of the 3 attentional networks (alerting, orienting, and executive control) in typically developing (TD) children and in children with developmental language disorder (DLD). Method We examined the attentional networks in monolingual and bilingual school-aged children (ages 8-12 years) with and without DLD. TD children (35 monolinguals, 23 bilinguals) and children with DLD (17 monolinguals, 9 bilinguals) completed the Attention Network Test (Fan et al., 2002; Fan, McCandliss, Fossella, Flombaum, & Posner, 2005). Results Children with DLD exhibited poorer executive control than TD children, but executive control was not modified by bilingual experience. The bilingual group with DLD and both TD groups exhibited an orienting effect, but the monolingual group with DLD did not. No group differences were found for alerting. Conclusions Children with DLD have weak executive control skills. These skills are minimally influenced by dual language experience, at least in this age range. A potential bilingual advantage in orienting may be present in the DLD group.

Rapid Serial Visual Presentation Interacts with Ambiguity During Sentence Comprehension

Conventional opinion about using Rapid Serial Visual Presentation (RSVP) for examining sentence comprehension maintains that RSVP taxes working memory (WM), which probably affects sentence processing. However, most RSVP studies only infer the involvement of WM. Other cognitive resources, such as cognitive control or vocabulary may also impact sentence comprehension and interact with RSVP. Further, sentence ambiguity is predicted to interact with RSVP and cognitive resources to impact sentence comprehension. To test these relationships, participants read ambiguous and unambiguous sentences using RSVP and Whole-Sentence presentation, followed by comprehension questions that were targeted to the ambiguous region of the sentences. Presentation type and ambiguity interacted to affect RT such that the effect of RSVP was exaggerated for ambiguous sentences. RT effects were moderated by WM and vocabulary. WM and cognitive control affected accuracy. Findings are discussed in light of depth of processing and the impact of cognitive resources on sentence comprehension.

Cross-modal integration of polyphonic characters in Chinese audio-visual sentences: a MVPA study based on functional connectivity

This study aimed to investigate the functional connectivity in the brain during the cross-modal integration of polyphonic characters in Chinese audio-visual sentences. The visual sentences were all semantically reasonable and the audible pronunciations of the polyphonic characters in corresponding sentences contexts varied in four conditions. To measure the functional connectivity, correlation, coherence and phase synchronization index (PSI) were used, and then multivariate pattern analysis was performed to detect the consensus functional connectivity patterns. These analyses were confined in the time windows of three event-related potential components of P200, N400 and late positive shift (LPS) to investigate the dynamic changes of the connectivity patterns at different cognitive stages. We found that when differentiating the polyphonic characters with abnormal pronunciations from that with the appreciate ones in audio-visual sentences, significant classification results were obtained based on the coherence in the time window of the P200 component, the correlation in the time window of the N400 component and the coherence and PSI in the time window the LPS component. Moreover, the spatial distributions in these time windows were also different, with the recruitment of frontal sites in the time window of the P200 component, the frontal-central-parietal regions in the time window of the N400 component and the central-parietal sites in the time window of the LPS component. These findings demonstrate that the functional interaction mechanisms are different at different stages of audio-visual integration of polyphonic characters.

Semantic integration of audio-visual information of polyphonic characters in a sentence context: an event-related potential study

In the Chinese language, a polyphone is a kind of special character that has more than one pronunciation, with each pronunciation corresponding to a different meaning. Here, we aimed to reveal the cognitive processing of audio-visual information integration of polyphones in a sentence context using the event-related potential (ERP) method. Sentences ending with polyphones were presented to subjects simultaneously in both an auditory and a visual modality. Four experimental conditions were set in which the visual presentations were the same, but the pronunciations of the polyphones were: the correct pronunciation; another pronunciation of the polyphone; a semantically appropriate pronunciation but not the pronunciation of the polyphone; or a semantically inappropriate pronunciation but also not the pronunciation of the polyphone. The behavioral results demonstrated significant differences in response accuracies when judging the semantic meanings of the audio-visual sentences, which reflected the different demands on cognitive resources. The ERP results showed that in the early stage, abnormal pronunciations were represented by the amplitude of the P200 component. Interestingly, because the phonological information mediated access to the lexical semantics, the amplitude and latency of the N400 component changed linearly across conditions, which may reflect the gradually increased semantic mismatch in the four conditions when integrating the auditory pronunciation with the visual information. Moreover, the amplitude of the late positive shift (LPS) showed a significant correlation with the behavioral response accuracies, demonstrating that the LPS component reveals the demand of cognitive resources for monitoring and resolving semantic conflicts when integrating the audio-visual information.

The role of executive control in resolving grammatical number conflict in sentence comprehension

In sentences with a complex subject noun phrase, like "The key to the cabinets is lost", the grammatical number of the head noun (key) may be the same or different from that of the modifier noun phrase (cabinets). When the number is the same, comprehension is usually easier than when it is different. Grammatical number computation may occur while processing the modifier noun (integration phase) or while processing the verb (checking phase). We investigated at which phase number conflict and plausibility of the modifier noun as subject for the verb affect processing, and we imposed a gaze-contingent tone discrimination task in either phase to test whether number computation involves executive control. At both phases, gaze durations were longer when a concurrent tone task was present. Additionally, at the integration phase, gaze durations were longer under number conflict, and this effect was enhanced by the presence of a tone task, whereas no effects of plausibility of the modifier were observed. The finding that the effect of number match was larger under load shows that computation of the grammatical number of the complex noun phrase requires executive control in the integration phase, but not in the checking phase.

Functional significance of the semantic P600: evidence from the event-related brain potential source localization

Previous event-related potentials studies of sentence comprehension have usually associated syntactic repair/reanalysis processes with the P600 component. However, the functional significance of the P600 was recently questioned on the basis of the observation of P600 effects in response to the processing of semantically anomalous sentences. In the present study, we investigated the functional significance of the 'semantic P600' using a semantic violation paradigm with a focus-on-syntax instruction. Using a source localization analysis, we tested three alternative hypotheses on the function of the P600: (i) a syntactic function, (ii) an executive function, and (iii) a semantic/integrational function. We assumed that distinct neuronal generators should reflect each of these functions. Although the syntactic generators are expected to be mainly located in the left inferior frontal gyrus, the semantic generators should be observed in the left superior temporal gyrus as well as in the right anterior prefrontal cortex (semantic retrieval); moreover, the generator of executive function (conflict monitoring) should be found in the anterior cingulate cortex. Critically, we defined a dipole model using 17 dipoles, 14 of which were placed in the three regions of interest corresponding to our hypotheses, namely, syntactic, executive, and semantic regions. Our data showed that the P600 effect was significant in the anterior cingulate cortex and marginally significant in the right anterior prefrontal cortex. This finding suggests that the P600 might reflect more general mechanisms of conflict monitoring and semantic reinterpretation leading to a retrieval of world knowledge from long-term memory rather purely syntactic processes.

Roses Are Red, Socks Are Blue: Switching Dimensions Disrupts Young Children's Language Comprehension

Language is used to identify objects in many different ways. An apple can be identified using its name, color, and other attributes. Skilled language comprehension requires listeners to flexibly shift between different dimensions. We asked whether this shifting would be difficult for 3-year-olds, who have relatively immature executive function skills and struggle to switch between dimensions in card sorting tasks. In the current experiment, children first heard a series of sentences identifying objects using a single dimension (either names or colors). In the second half of the experiment, the labeling dimension was switched. Children were significantly less accurate in fixating the correct object following the dimensional switch. This disruption, however, was temporary; recognition accuracy recovered with increased exposure to the new labeling dimension. These findings provide the first evidence that children's difficulty in shifting between dimensions impacts their ability to comprehend speech. This limitation may affect children's ability to form rich, multi-dimensional representations when learning new words.

Processing structure in language and music: a case for shared reliance on cognitive control

The relationship between structural processing in music and language has received increasing interest in the past several years, spurred by the influential Shared Syntactic Integration Resource Hypothesis (SSIRH; Patel, Nature Neuroscience, 6, 674-681, 2003). According to this resource-sharing framework, music and language rely on separable syntactic representations but recruit shared cognitive resources to integrate these representations into evolving structures. The SSIRH is supported by findings of interactions between structural manipulations in music and language. However, other recent evidence suggests that such interactions also can arise with nonstructural manipulations, and some recent neuroimaging studies report largely nonoverlapping neural regions involved in processing musical and linguistic structure. These conflicting results raise the question of exactly what shared (and distinct) resources underlie musical and linguistic structural processing. This paper suggests that one shared resource is prefrontal cortical mechanisms of cognitive control, which are recruited to detect and resolve conflict that occurs when expectations are violated and interpretations must be revised. By this account, musical processing involves not just the incremental processing and integration of musical elements as they occur, but also the incremental generation of musical predictions and expectations, which must sometimes be overridden and revised in light of evolving musical input.

Executive Function and Ambiguous Sentence Comprehension

PURPOSE

Sentence comprehension is a critical skill in today's literate society. Recent evidence suggests that processing and comprehending language taps cognitive as well as linguistic abilities, a finding that has critical import for clinicians who have clients with language disorders. To promote awareness of the impact of cognition, especially executive function (EF) and working memory (WM), this opinion article presents current views of how sentences are processed and links the various steps of the process to specific EF and WM subcomponents.

METHOD

The article focuses on ambiguous sentences, pointing out the similar types of processing needed when resolving an ambiguity and performing EF tasks.

RESULTS

We discuss the potential overlap between the neurobiology of sentence processing and EF and the evidence supporting a link between EF and sentence processes.

CONCLUSION

Awareness of the potential role of EF and WM in sentence comprehension will help clinicians be more aware of potential cognitive-linguistic deficits in their clients. Future research will help to clarify the link between EF and sentence comprehension.

Cue Recognition and Integration - Eye Tracking Evidence of Processing Differences in Sentence Comprehension in Aphasia

Purpose

We aimed at further elucidating whether aphasic patients’ difficulties in understanding non-canonical sentence structures, such as Passive or Object-Verb-Subject sentences, can be attributed to impaired morphosyntactic cue recognition, and to problems in integrating competing interpretations.

Methods

A sentence-picture matching task with canonical and non-canonical spoken sentences was performed using concurrent eye tracking. Accuracy, reaction time, and eye tracking data (fixations) of 50 healthy subjects and 12 aphasic patients were analysed.

Results

Patients showed increased error rates and reaction times, as well as delayed fixation preferences for target pictures in non-canonical sentences. Patients’ fixation patterns differed from healthy controls and revealed deficits in recognizing and immediately integrating morphosyntactic cues.

Conclusion

Our study corroborates the notion that difficulties in understanding syntactically complex sentences are attributable to a processing deficit encompassing delayed and therefore impaired recognition and integration of cues, as well as increased competition between interpretations.

Who is respectful? Effects of social context and individual empathic ability on ambiguity resolution during utterance comprehension

Verbal communication is often ambiguous. By employing the event-related potential (ERP) technique, this study investigated how a comprehender resolves referential ambiguity by using information concerning the social status of communicators. Participants read a conversational scenario which included a minimal conversational context describing a speaker and two other persons of the same or different social status and a directly quoted utterance. A singular, second-person pronoun in the respectful form (nin/nin-de in Chinese) in the utterance could be ambiguous with respect to which of the two persons was the addressee (the “Ambiguous condition”). Alternatively, the pronoun was not ambiguous either because one of the two persons was of higher social status and hence should be the addressee according to social convention (the “Status condition”) or because a word referring to the status of a person was additionally inserted before the pronoun to help indicate the referent of the pronoun (the “Referent condition”). Results showed that the perceived ambiguity decreased over the Ambiguous, Status, and Referent conditions. Electrophysiologically, the pronoun elicited an increased N400 in the Referent than in the Status and the Ambiguous conditions, reflecting an increased integration demand due to the necessity of linking the pronoun to both its antecedent and the status word. Relative to the Referent condition, a late, sustained positivity was elicited for the Status condition starting from 600 ms, while a more delayed, anterior negativity was elicited for the Ambiguous condition. Moreover, the N400 effect was modulated by individuals' sensitivity to the social status information, while the late positivity effect was modulated by individuals' empathic ability. These findings highlight the neurocognitive flexibility of contextual bias in referential processing during utterance comprehension.

Language and Memory Improvements following tDCS of Left Lateral Prefrontal Cortex

Recent research demonstrates that performance on executive-control measures can be enhanced through brain stimulation of lateral prefrontal regions. Separate psycholinguistic work emphasizes the importance of left lateral prefrontal cortex executive-control resources during sentence processing, especially when readers must override early, incorrect interpretations when faced with temporary ambiguity. Using transcranial direct current stimulation, we tested whether stimulation of left lateral prefrontal cortex had discriminate effects on language and memory conditions that rely on executive-control (versus cases with minimal executive-control demands, even in the face of task difficulty). Participants were randomly assigned to receive Anodal, Cathodal, or Sham stimulation of left lateral prefrontal cortex while they (1) processed ambiguous and unambiguous sentences in a word-by-word self-paced reading task and (2) performed an n-back memory task that, on some trials, contained interference lure items reputed to require executive-control. Across both tasks, we parametrically manipulated executive-control demands and task difficulty. Our results revealed that the Anodal group outperformed the remaining groups on (1) the sentence processing conditions requiring executive-control, and (2) only the most complex n-back conditions, regardless of executive-control demands. Together, these findings add to the mounting evidence for the selective causal role of left lateral prefrontal cortex for executive-control tasks in the language domain. Moreover, we provide the first evidence suggesting that brain stimulation is a promising method to mitigate processing demands encountered during online sentence processing.

Differential neural control in early bilinguals and monolinguals during response inhibition

We tested the hypothesis that early bilinguals and monolinguals use different brain areas when performing nonlinguistic executive control tasks. For this, we explored brain activity of early bilinguals and monolinguals during a manual stop-signal paradigm. Behaviorally, bilinguals and monolinguals did not show significant differences in the task, which led us to compare brain activation that cannot be attributed to differences in performance. Analyses demonstrated that monolinguals activated the anterior cingulate cortex more than bilinguals when performing the stop-signal task. These results offer direct support for the notion that early bilingualism exerts an effect on neural circuitry responsible for executive control. Consistent with recent reports, we found that bilinguals used the anterior cingulate more efficiently than monolinguals to monitor nonlinguistic cognitive conflicts.

Neural basis of semantic and syntactic interference in sentence comprehension

According to the cue-based parsing approach (Lewis, Vasishth, & Van Dyke, 2006), sentence comprehension difficulty derives from interference from material that partially matches syntactic and semantic retrieval cues. In a 2 (low vs. high semantic interference)×2 (low vs. high syntactic interference) fMRI study, greater activation was observed in left BA44/45 for high versus low syntactic interference conditions following sentences and in left BA45/47 for high versus low semantic interference conditions following comprehension questions. A conjunction analysis showed BA45 associated with both types of interference, while BA47 was associated with only semantic interference. Greater activation was also observed in the left STG in the high interference conditions. Importantly, the results for the LIFG could not be attributed to greater working memory capacity demands for high interference conditions. The results favor a fractionation of the LIFG wherein BA45 is associated with post-retrieval selection and BA47 with controlled retrieval of semantic information.

Language comprehension interrupted: both language errors and word degradation activate Broca's area

The proposal of a general conflict resolution mechanism in lIFG was investigated further in relation to language errors. In an fMRI study participants read sentences containing syntactic and plausibility violations. Furthermore, they were presented with sentences that were difficult to comprehend, due to degradation of the bottom-up signal (i.e., the visual form) of the language. We were interested whether comprehension difficulties caused by degradation would activate cognitive control mechanisms in the same manner as other language violations. To localize cognitive control processes participants performed a Stroop task. Both the violations and the visual degradation condition elicited co-localized lIFG activation with the Stroop conflict. These results indicate that lIFG implements control adjustments to resolve situations in which extra attention is needed more generally. Next to biasing attention to resolve representational conflicts arising from different types of errors, lIFG may also adjust control to compensate for a temporary lack of bottom-up information.

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.

Cortical dynamics of semantic processing during sentence comprehension: evidence from event-related optical signals

Using the event-related optical signal (EROS) technique, this study investigated the dynamics of semantic brain activation during sentence comprehension. Participants read sentences constituent-by-constituent and made a semantic judgment at the end of each sentence. The EROSs were recorded simultaneously with ERPs and time-locked to expected or unexpected sentence-final target words. The unexpected words evoked a larger N400 and a late positivity than the expected ones. Critically, the EROS results revealed activations first in the left posterior middle temporal gyrus (LpMTG) between 128 and 192 ms, then in the left anterior inferior frontal gyrus (LaIFG), the left middle frontal gyrus (LMFG), and the LpMTG in the N400 time window, and finally in the left posterior inferior frontal gyrus (LpIFG) between 832 and 864 ms. Also, expected words elicited greater activation than unexpected words in the left anterior temporal lobe (LATL) between 192 and 256 ms. These results suggest that the early lexical-semantic retrieval reflected by the LpMTG activation is followed by two different semantic integration processes: a relatively rapid and transient integration in the LATL and a relatively slow but enduring integration in the LaIFG/LMFG and the LpMTG. The late activation in the LpIFG, however, may reflect cognitive control.

Individual variation in the late positive complex to semantic anomalies

It is well-known that, within ERP paradigms of sentence processing, semantically anomalous words elicit N400 effects. Less clear, however, is what happens after the N400. In some cases N400 effects are followed by Late Positive Complexes (LPC), whereas in other cases such effects are lacking. We investigated several factors which could affect the LPC, such as contextual constraint, inter-individual variation, and working memory. Seventy-two participants read sentences containing a semantic manipulation (Whipped cream tastes sweet/anxious and creamy). Neither contextual constraint nor working memory correlated with the LPC. Inter-individual variation played a substantial role in the elicitation of the LPC with about half of the participants showing a negative response and the other half showing an LPC. This individual variation correlated with a syntactic ERP as well as an alternative semantic manipulation. In conclusion, our results show that inter-individual variation plays a large role in the elicitation of the LPC and this may account for the diversity in LPC findings in language research.

The role of gender information in pronoun resolution: evidence from Chinese

Although previous studies have consistently demonstrated that gender information is used to resolve pronouns, the mechanisms underlying the use of gender information continue to be controversial. The present study used event-related potentials (ERPs) to investigate whether working memory modulates the effect of gender information on pronoun resolution. The critical pronoun agreed or disagreed with its antecedent in gender. Moreover, the distance between a pronoun and its antecedent was varied to assess the influence of working memory. Compared with the congruent pronouns, the incongruent pronouns elicited an N400 effect in the short distance condition and a P600 effect in the long distance condition. The results suggest that the effect of gender information on pronoun comprehension is modulated by working memory.

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.

Cognitive control in Russian-german bilinguals

Bilingual speakers are faced with the problem to keep their languages apart, but do so with interindividually varying success. Cognitive control abilities might be an important factor to explain such interindividual differences. Here we compare two late, balanced and highly proficient bilingual groups (mean age 24 years, L1 Russian, L2 German) which were established according to their language control abilities on a bilingual picture-naming task. One group had difficulties to remain in the instructed target language and switched unintentionally to the non-target language ("switchers"), whereas the other group rarely switched unintentionally ("non-switchers"). This group-specific behavior could not be explained by language background, socio-cultural, or demographic variables. Rather, the non-switchers also demonstrated a faster and better performance on four cognitive control tests (Tower of Hanoi, Ruff Figural Fluency Test, Divided Attention, Go/Nogo). Here, we focus on two additional executive function tasks, the Wisconsin Card Sorting Test (WCST) and the Flanker task requiring conflict monitoring and conflict resolution. Non-switchers outperformed switchers with regard to speed and accuracy, and were better at finding and applying the correct rules in the WCST. Similarly, in the Flanker task non-switchers performed faster and better on conflict trials and had a higher correction rate following an error. Event-related potential recordings furthermore revealed a smaller error-related negativity in the non-switchers, taken as evidence for a more efficient self-monitoring system. We conclude that bilingual language performance, in particular switching behavior, is related to performance on cognitive control tasks. Better cognitive control, including conflict monitoring, results in decreased unintentional switching.

Examining the evidence for an independent semantic analyzer: an ERP study in Spanish

Recent ERP findings challenge the widespread assumption that syntactic and semantic processes are tightly coupled. Syntactically well-formed sentences that are semantically anomalous due to thematic mismatches elicit a P600, the component standardly associated with syntactic anomaly. This 'thematic P600' effect has been attributed to detection of semantically plausible thematic relations that conflict with the surface syntactic structure of the sentence, implying a processing architecture with an independent semantic analyzer. A key finding is that the P600 is selectively sensitive to the presence of plausible verb-argument relations, and that otherwise an N400 is elicited (The hearty meal was devouring … vs. The dusty tabletop was devouring …: Kim & Osterhout, 2005). The current study investigates in Spanish whether the evidence for an independent semantic analyzer is better explained by a standard architecture that rapidly integrates multiple sources of lexical, syntactic, and semantic information. The study manipulated the presence of plausible thematic relations, and varied the choice of auxiliary between passive-biased fue and active-progressive biased estaba. Results show a late positivity that appeared as soon as comprehenders detected an improbable combination of subject animacy, auxiliary bias, or verb voice morphology. This effect appeared at the lexical verb in the fue conditions and at the auxiliary in the estaba conditions. The late positivity elicited by surface thematic anomalies was the same, regardless of the presence of a plausible non-surface interpretation, and no N400 effects were elicited. These findings do not implicate an independent semantic analyzer, and are compatible with standard language processing architectures.

Multiple constraints on semantic integration in a hierarchical structure: ERP evidence from German

A recent ERP study on Chinese demonstrated dissociable neural responses to semantic integration processes at different levels of syntactic hierarchy (Zhou et al., 2010). However, it is unclear whether such findings are restricted to a non-case marked language that relies heavily on word order and semantic information for the construction of sentence representation. This study aimed to further investigate, in a case-marked language, how semantic processes in a hierarchical structure take place during sentence reading. We used German sentences with the structure "subject noun+verb+article/determiner+adjective+object noun+prepositional phrase", in which the object noun was constrained either at the lower level by the adjective or at the higher level by the verb, and manipulated the semantic congruency between the adjective and the object noun and/or between the verb and the object noun. EEGs were recorded while participants read sentences and judged for their semantic acceptability. Compared with correct sentences, a biphasic pattern of an N400 effect followed by a late positivity effect was observed on the object noun for sentences with either lower- or higher-level mismatch or with double mismatches. Both the N400 effect and the late positivity (P600) effect were larger for the double mismatch condition than for either of the single mismatch conditions. These findings demonstrate cross-language mechanisms for processing multiple semantic constraints at different levels of syntactic hierarchy during sentence comprehension.

When word identification fails: ERP correlates of recognition without identification and of word identification failure

Recognition without identification (RWI) refers to people's ability to discriminate studied from unstudied items when the items themselves fail to be identified, as when people fail to identify words from fragments. We sought to identify the ERP correlates of word fragment RWI in an effort to better understand its underlying mechanisms; in so doing, we also examined the ERP correlates of word identification failure vs. success. We found the ERP correlate of the RWI effect to be the N300; greater negativity was shown for unidentified fragments of studied words than for unidentified fragments of unstudied words between 300-325 ms post test fragment onset. We further separated the ERPs according to whether subjects showed the behavioral RWI effect or not; the N300 effect emerged only among those subjects who showed the behavioral effect, suggesting that the N300 is related to the behavioral effect itself. With regard to the ERP correlates of word identification failure vs. success, we found very early indicators of later word identification success vs. failure (starting at 125 ms) that were independent of priming. These early effects may be preconscious markers of downstream word identification success vs. failure. We also found a later persistent negativity associated with successfully identified words that we propose to be associated with executive function and possibly the successful suppression of irrelevant words that might initially come to mind when attempting to complete a unique word fragment; word fragment identification failure may sometimes be due to a failure to suppress irrelevant or incorrect words.

A case for conflict across multiple domains: memory and language impairments following damage to ventrolateral prefrontal cortex

Patients with focal lesions to the left inferior frontal gyrus (LIFG; BA 44/45) exhibit difficulty with language production and comprehension tasks, although the nature of their impairments has been somewhat difficult to characterize. No reported cases suggest that these patients are Broca's aphasics in the classic agrammatic sense. Recent case studies, however, do reveal a consistent pattern of deficit regarding their general cognitive processes: they are reliably impaired on tasks in which conflicting representations must be resolved by implementing top-down cognitive control (e.g., Stroop; memory tasks involving proactive interference). In the present study, we ask whether the language production and comprehension impairments displayed by a patient with circumscribed LIFG damage can best be understood within a general conflict resolution deficit account. We focus on one patient in particular--patient I.G.--and discuss the implications for language processing abilities as a consequence of a general cognitive control disorder. We compared I.G. and other frontal patients to age-matched control participants across four experiments. Experiment 1 tested participants' general conflict resolution abilities within a modified working memory paradigm in an attempt to replicate prior case study findings. We then tested language production abilities on tasks of picture naming (Experiment 2) and verbal fluency (Experiment 3), tasks that generated conflict at the semantic and/or conceptual levels. Experiment 4 tested participants' sentence processing and comprehension abilities using both online (eye movement) and offline measures. In this task, participants carried out spoken instructions containing a syntactic ambiguity, in which early interpretation commitments had to be overridden in order to recover an alternative, intended analysis of sentence meaning. Comparisons of I.G.'s performance with frontal and healthy control participants supported the following claim: I.G. suffers from a general conflict resolution impairment, which affects his ability to produce and comprehend language under specific conditions--namely, when semantic, conceptual, and/or syntactic representations compete and must be resolved.

Electroencephalogram oscillations differentiate semantic and prosodic processes during sentence reading

How prosodic information is processed at the neural level during silent sentence reading is an unsolved issue. In this study, we investigate whether and how the processing of prosodic constraints can be distinguished from the processing of semantic constraints by measuring changes in event-related electroencephalogram (EEG) power. We visually presented Chinese sentences containing verb-noun combinations that were semantically congruent or incongruent and that had normal or abnormal rhythmic patterns and asked participants to judge whether the sentences were semantically and rhythmically acceptable. In Chinese, the rhythmic pattern refers to the combination of words with different syllable lengths. While the [1+1] pattern is normal for a verb-noun combination, the [2+1] pattern is abnormal. With the critical nouns, we found that the violation of semantic constraints was associated with the low beta (16-20 Hz) decrease in the early window (0-200 ms post onset) and the alpha (10-15 Hz) and low beta decrease in the later window (400-657 ms) while the processing of the abnormal rhythmic pattern was associated with the theta (4-6 Hz) and the alpha increase in the early window and the alpha and upper beta (20-24 Hz) decrease in the later window. These findings suggest that although the processing of semantic constraints and the processing of rhythmic pattern may partially share neuro-cognitive processes, as reflected by the similar decreases in alpha band power, they can nevertheless be differentiated in EEG responses during sentence reading.