Developmental differences in beta and theta power during sentence processing

Neural consequences of binaural beat stimulation on auditory sentence comprehension: an EEG study

A growing literature has shown that binaural beat (BB)-generated by dichotic presentation of slightly mismatched pure tones-improves cognition. We recently found that BB stimulation of either beta (18 Hz) or gamma (40 Hz) frequencies enhanced auditory sentence comprehension. Here, we used electroencephalography (EEG) to characterize neural oscillations pertaining to the enhanced linguistic operations following BB stimulation. Sixty healthy young adults were randomly assigned to one of three listening groups: 18-Hz BB, 40-Hz BB, or pure-tone baseline, all embedded in music. After listening to the sound for 10 min (stimulation phase), participants underwent an auditory sentence comprehension task involving spoken sentences that contained either an object or subject relative clause (task phase). During the stimulation phase, 18-Hz BB yielded increased EEG power in a beta frequency range, while 40-Hz BB did not. During the task phase, only the 18-Hz BB resulted in significantly higher accuracy and faster response times compared with the baseline, especially on syntactically more complex object-relative sentences. The behavioral improvement by 18-Hz BB was accompanied by attenuated beta power difference between object- and subject-relative sentences. Altogether, our findings demonstrate beta oscillations as a neural correlate of improved syntactic operation following BB stimulation.

Time course of effective connectivity associated with perspective taking in utterance comprehension

This study discusses the effective connectivity in the brain and its time course in realizing perspective taking in verbal communication through electroencephalogram (EEG) associated with the understanding of Japanese utterances. We manipulated perspective taking in a sentence with the Japanese subsidiary verbs -ageru and -kureru, which mean "to give". We measured the EEG during the auditory presentation of the sentences with a multichannel electroencephalograph, and the partial directed coherence and its temporal variations were analyzed using the source localization method to examine causal interactions between nineteen regions of interest in the brain. Three different processing stages were recognized on the basis of the connectivity hubs, direction of information flow, increase or decrease in flow, and temporal variation. We suggest that perspective taking in speech comprehension is realized by interactions between the mentalizing network, mirror neuron network, and executive control network. Furthermore, we found that individual differences in the sociality of typically developing adult speakers were systematically related to effective connectivity. In particular, attention switching was deeply concerned with perspective taking in real time, and the precuneus played a crucial role in implementing individual differences.

Is beta in agreement with the relatives? Using relative clause sentences to investigate MEG beta power dynamics during sentence comprehension

There remains some debate about whether beta power effects observed during sentence comprehension reflect ongoing syntactic unification operations (beta-syntax hypothesis), or instead reflect maintenance or updating of the sentence-level representation (beta-maintenance hypothesis). In this study, we used magnetoencephalography to investigate beta power neural dynamics while participants read relative clause sentences that were initially ambiguous between a subject- or an object-relative reading. An additional condition included a grammatical violation at the disambiguation point in the relative clause sentences. The beta-maintenance hypothesis predicts a decrease in beta power at the disambiguation point for unexpected (and less preferred) object-relative clause sentences and grammatical violations, as both signal a need to update the sentence-level representation. While the beta-syntax hypothesis also predicts a beta power decrease for grammatical violations due to a disruption of syntactic unification operations, it instead predicts an increase in beta power for the object-relative clause condition because syntactic unification at the point of disambiguation becomes more demanding. We observed decreased beta power for both the agreement violation and object-relative clause conditions in typical left hemisphere language regions, which provides compelling support for the beta-maintenance hypothesis. Mid-frontal theta power effects were also present for grammatical violations and object-relative clause sentences, suggesting that violations and unexpected sentence interpretations are registered as conflicts by the brain's domain-general error detection system.

Age and vocabulary knowledge differentially influence the N400 and theta responses during semantic retrieval

Using electroencephalography (EEG) to study the neural oscillations supporting language development is increasingly common; however, a clear understanding of the relationship between neural oscillations and traditional Event Related Potentials (ERPs) is needed to disentangle how maturation of language-related neural networks supports semantic processing throughout grade school. Theta and the N400 are both thought to index semantic retrieval but, in adults, are only weakly correlated with one another indicating they may measure somewhat unique aspects of retrieval. Here, we studied the relationship between the N400 amplitude and theta power during semantic retrieval with key indicators of language abilities including age, vocabulary, reading comprehension and phonological memory in 226 children ages 8-15 years. The N400 and theta responses were positively correlated over posterior areas, but negatively correlated over frontal areas. When controlling for the N400 amplitude, the amplitude of the theta response was predicted by age, but not by language measures. On the other hand, when controlling theta amplitude, the amplitude of the N400 was predicted by both vocabulary knowledge and age. These findings indicate that while there is a clear relationship between the N400 and theta responses, they may each index unique aspects of development related to semantic retrieval.

Developmental differences in EEG oscillations supporting the identification of novel word meaning from context

Implicit learning about new words by picking up on associative information in the contexts they appear in is an important aspect of vocabulary growth. The current study investigated the neural correlates that underlie how school-aged children and adolescents identify the meaning of novel words embedded within sentence contexts. Importantly, we examine how differences in the brain response to novel words and their context differ as a function of 1) explicit learning success, i.e., whether novel word meanings can be correctly estimated in isolation after a learning opportunity, and 2) individual differences in offline language aptitude as well as age across our cohort (N = 82; 8-16 years). Using a regression-based analysis, we identified the unique influence of these individuals difference metrics by using both measures within the same series of models. The most notable finding from our analysis was a frequency-specific dissociation between the way age and language abilities held relationships with task-relevant oscillatory activity during the novel word meaning task: language abilities associated with task-relevant changes in beta band activity during sentence processing, while age associated with task-relevant changes in theta band activity during pseudoword processing. These effects reflect the how the neural correlates of mapping semantic meaning from sentence contexts-an important skill for word learning-is uniquely influenced by the maturity of language abilities as well as age.

Detrending Moving Average, Power Spectral Density, and Coherence: Three EEG-Based Methods to Assess Emotion Irradiation during Facial Perception

Understanding brain reactions to facial expressions can help in explaining emotion-processing and memory mechanisms. The purpose of this research is to examine the dynamics of electrical brain activity caused by visual emotional stimuli. The focus is on detecting changes in cognitive mechanisms produced by negative, positive, and neutral expressions on human faces. Three methods were used to study brain reactions: power spectral density, detrending moving average (DMA), and coherence analysis. Using electroencephalogram (EEG) recordings from 48 subjects while presenting facial image stimuli from the International Affective Picture System, the topographic representation of the evoked responses was acquired and evaluated to disclose the specific EEG-based activity patterns in the cortex. The theta and beta systems are two key cognitive systems of the brain that are activated differently on the basis of gender. The obtained results also demonstrate that the DMA method can provide information about the cortical networks’ functioning stability, so it can be coupled with more prevalent methods of EEG analysis.

Temporal and topographical changes in theta power between middle childhood and adolescence during sentence comprehension

Time frequency analysis of the EEG is increasingly used to study the neural oscillations supporting language comprehension. Although this method holds promise for developmental research, most existing work focuses on adults. Theta power (4–8 Hz) in particular often corresponds to semantic processing of words in isolation and in ongoing text. Here we investigated how the timing and topography of theta engagement to individual words during written sentence processing changes between childhood and adolescence (8–15 years). Results show that topographically, the theta response is broadly distributed in children, occurring over left and right central-posterior and midline frontal areas, and localizes to left central-posterior areas by adolescence. There were two notable developmental shifts. First, in response to each word, early (150–300 msec) theta engagement over frontal areas significantly decreases between 8 and 9 years and 10–11 years. Second, throughout the sentence, theta engagement over the right parietal areas significantly decreases between 10 and 11 years and 12–13 years with younger children’s theta response remaining significantly elevated between words compared to adolescents’. We found no significant differences between 12 and 13 years and 14–15 years. These findings indicate that children’s engagement of the language network during sentence processing continues to change through middle childhood but stabilizes into adolescence.

On the Acquisition of Polarity Items: 11- to 12-Year-Olds' Comprehension of German NPIs and PPIs

Existing work on the acquisition of polarity-sensitive expressions (PSIs) suggests that children show an early sensitivity to the restricted distribution of negative polarity items (NPIs), but may be delayed in the acquisition of positive polarity items (PPIs). However, past studies primarily targeted PSIs that are highly frequent in children's language input. In this paper, we report an experimental investigation on children's comprehension of two NPIs and two PPIs in German. Based on corpus data indicating that the four tested PSIs are present in child-directed speech but rare in young children's utterances, we conducted an auditory rating task with adults and 11- to 12-year-old children. The results demonstrate that, even at 11-12 years of age, children do not yet show a completely target-like comprehension of the investigated PSIs. While they are adult-like in their responses to one of the tested NPIs, their responses did not demonstrate a categorical distinction between licensed and unlicensed PSI uses for the other tested expressions. The effect was led by a higher acceptance of sentences containing unlicensed PSIs, indicating a lack of awareness for their distributional restrictions. The results of our study pose new questions for the developmental time scale of the acquisition of polarity items.

Semantic and syntactic specialization during auditory sentence processing in 7-8-year-old children

Previous studies indicate that adults show specialized syntactic and semantic processes in both the temporal and frontal lobes during language comprehension. Neuro-cognitive models of language development argue that this specialization appears earlier in the temporal than the frontal lobe. However, there is little evidence supporting this proposed progression. Our recently published study (Wang, Rice, & Booth, 2020), using multivoxel pattern analyses, detected that children as young as 5 to 6 years old exhibit specialization and integration in the temporal lobe, but not the frontal lobe. In the current study, we used the same approach to examine semantic and syntactic specialization in children ages 7 to 8 years old. We found support for semantic specialization in the left middle temporal gyrus (MTG) for correct sentences and in the triangular part of the left inferior frontal gyrus (IFG) for incorrect sentences. We also found that the left superior temporal gyrus (STG) played an integration role and was sensitive to both semantic and syntactic processing during both correct and incorrect sentence processing. However, there was no support for syntactic specialization in 7- to 8-year-old children. As compared to our previous study on 5- to 6-year-old children, which only showed semantic specialization in the temporal lobe, the current study suggests a developmental progression to semantic specialization in the frontal lobe. This project represents an important step forward in testing neuro-cognitive models of language processing in children.

Modulation of Theta Phase Synchrony during Syllable Processing as a Function of Interactive Acoustic Experience in Infancy

Plasticity, a prominent characteristic of the infant brain, supports formation of cortical representations as infants begin to interact with and adapt to environmental sensory events. Enhanced acoustic processing efficiency along with improved allocation of attentional resources at 7 months and establishment of well-defined phonemic maps at 9 months have been shown to be facilitated by early interactive acoustic experience (IAE). In this study, using an oddball paradigm and measures of theta phase synchrony at source level, we examined short- and long-term effects of nonspeech IAE on syllable processing. Results demonstrated that beyond maturation alone, IAE increased the efficiency of syllabic representation and discrimination, an effect that endured well beyond the immediate training period. As compared with naive controls, the IAE-trained group at 7, 9, and 18 months showed less theta phase synchrony for the standard syllable and at 7 and 18 months for the deviant syllable. The decreased theta phase synchrony exhibited by the trained group suggests more mature, efficient, acoustic processing, and thus, better cortical representation and discrimination of syllabic content. Further, the IAE modulatory effect observed on theta phase synchrony in left auditory cortex at 7 and 9 months was differentially associated with receptive and expressive language scores at 12 and 18 months of age.

N-Pep-12 supplementation after ischemic stroke positively impacts frequency domain QEEG

BACKGROUND

N-Pep-12 is a dietary supplement with neuroprotective and pro-cognitive effects, as shown in experimental models and clinical studies on patients after ischemic stroke. We tested the hypothesis that N-Pep-12 influences quantitative electroencephalography (QEEG) parameters in patients with subacute to chronic supratentorial ischemic lesions.

METHODS

We performed secondary data analysis on an exploratory clinical trial (ISRCTN10702895), assessing the efficacy and safety of 90 days of once-daily treatment with 90 mg N-Pep-12 on neurocognitive function and neurorecovery outcome in patients with post-stroke cognitive impairment against a control group. All participants performed two 32-channel QEEG in resting and active states at baseline (30-120 days after stroke) and 90 days later. Power spectral density on the alpha, beta, theta, delta frequency bands, delta/alpha power ratio (DAR), and (delta+theta)/(alpha+beta) ratio (DTABR) were computed and compared across study groups using means comparison and descriptive methods. Secondarily, associations between QEEG parameters and available neuropsychological tests were explored.

RESULTS

Our analysis showed a statistically significant main effect of EEG segments (p<0.001) in alpha, beta, delta, theta, DA, and DTAB power spectral density. An interaction effect between EEG segments and time was noticed in the alpha power. There was a significant difference in theta spectral power between patients with N-Pep-12 supplementation versus placebo at 0.05 alpha level (p=0.023), independent of time points.

CONCLUSION

A 90-day, 90 mg daily administration of N-Pep-12 had significant impact on some QEEG indicators in patients after supratentorial ischemic stroke, confirming possible enhancement of post-stroke neurorecovery. Further research is needed to consolidate our findings.

Neural oscillations reveal differences in the process of word learning among school-aged children from lower socioeconomic status backgrounds

Building a robust vocabulary in grade school is essential for academic success. Children from lower socioeconomic status (SES) households on average perform below their higher SES peers on word learning tasks, negatively impacting their vocabulary; however, significant variability exists within this group. Many children from low SES homes perform as well as, or better than, their higher SES peers on measures of word learning. The current study addresses what processes underlie this variability, by comparing the neural oscillations of 44 better versus worse word learners (ages 8-15 years) from lower SES households as they infer the meaning of unknown words. Better word learners demonstrated increases in theta and beta power as a word was learned, whereas worse word learners exhibited decreases in alpha power. These group differences in neural oscillatory engagement during word learning indicate there may be different strategies employed based on differences in children's skills. Notably, children with greater vocabulary knowledge are more likely to exhibit larger beta increases; a strategy which is associated with better word learning. This sheds new light on the mechanisms that support word learning in children from low SES households.

Integration of conflict resolution and positive emotions: Electrophysiological evidence

Previous studies have shown that conflict monitoring is integrated with negative emotions. However, the idea that conflict resolution facilitates positive stimuli processing has not reached a consistent conclusion. We suggested that conflict resolution was integrated with positive emotions. The present study used ERPs, took the flanker task as primes, set different durations (i.e., 600 ms and 1200 ms) between the resolution of conflicts and the presentation of targets, and chose affective words as targets to investigate the affective effect of cognitive conflict during the resolution stage. Participants' task was to react to the flanker task and then evaluate the valence of the target words. The findings of experiment1 (600 ms) and experiment2 (1200 ms) were consistent. Behavioral results showed that the conflict effect was significant, and the positive signal effect of conflict resolution was found. In ERPs results, the enhanced N2 amplitudes for incongruent primes showed a significant conflict effect. The enhanced conflict SP amplitudes for incongruent primes reflected conflict resolution. As expected, the enhanced N400 amplitudes for positive targets after incongruent primes indicated that conflict resolution facilitated positive stimuli processing. Time-frequency analyses showed that incongruent primes elicited larger theta (4-8 Hz) power than congruent primes over the frontal areas. More importantly, we found that theta (4-8 Hz) power for positive targets after incongruent primes was lower than those after congruent primes over the central areas. These findings suggested that conflict resolution facilitated positive stimulus processing, and this positive effect was a carry-over effect, which indicated that conflict resolution was integrated with positive emotions.

Visual and Verbal Narrative Comprehension in Children and Adolescents with Autism Spectrum Disorders: An ERP Study

We examined semantic processing in ASD children by presenting sentences with congruent or incongruent final words and visual narratives with congruent or incongruent final panels. An N400 effect to incongruent words appeared as compared to congruent ones, which was attenuated for the ASD children. We observed a negativity sustained to incongruous than congruous words, but only for the TD children. Incongruent panels evoked a greater fronto-central N400 amplitude than congruent panels in both groups. In addition, incongruent panels evoked a centro-parietal late positivity, only in controls. In conclusion, ASD children face processing deficits in both verbal and visual materials when integrating meaning across information, though such impairments may arise in different parts of the interpretive process, depending on the modality.

Neural Processes Underlying Nonword Rhyme Differentiate Eventual Stuttering Persistence and Recovery

Purpose Phonological skills have been associated with developmental stuttering. The current study aimed to determine whether the neural processes underlying phonology, specifically for nonword rhyming, differentiated stuttering persistence and recovery. Method Twenty-six children who stutter (CWS) and 18 children who do not stutter, aged 5 years, completed an auditory nonword rhyming task. Event-related brain potentials were elicited by prime, rhyming, and nonrhyming targets. CWS were followed longitudinally to determine eventual persistence (n = 14) or recovery (n = 12). This is a retrospective analysis of data acquired when all CWS presented as stuttering. Results CWS who eventually recovered and children who do not stutter exhibited the expected rhyme effect, with larger event-related brain potential amplitudes elicited by nonrhyme targets compared to rhyme targets. In contrast, CWS who eventually persisted exhibited a reverse rhyme effect, with larger responses to rhyme than nonrhyme targets. Conclusions These findings suggest that CWS who eventually persisted are not receiving the same benefit of phonological priming as CWS who eventually recovered for complex nonword rhyming tasks. These results indicate divergent patterns of phonological processing in young CWS who eventually persisted, especially for difficult tasks with limited semantic context, and suggest that the age of 5 years may be an important developmental period for phonology in CWS. Supplemental Material https://doi.org/10.23641/asha.12682874.

The Importance of Cursive Handwriting Over Typewriting for Learning in the Classroom: A High-Density EEG Study of 12-Year-Old Children and Young Adults

To write by hand, to type, or to draw – which of these strategies is the most efficient for optimal learning in the classroom? As digital devices are increasingly replacing traditional writing by hand, it is crucial to examine the long-term implications of this practice. High-density electroencephalogram (HD EEG) was used in 12 young adults and 12, 12-year-old children to study brain electrical activity as they were writing in cursive by hand, typewriting, or drawing visually presented words that were varying in difficulty. Analyses of temporal spectral evolution (TSE, i.e., time-dependent amplitude changes) were performed on EEG data recorded with a 256-channel sensor array. For young adults, we found that when writing by hand using a digital pen on a touchscreen, brain areas in the parietal and central regions showed event-related synchronized activity in the theta range. Existing literature suggests that such oscillatory neuronal activity in these particular brain areas is important for memory and for the encoding of new information and, therefore, provides the brain with optimal conditions for learning. When drawing, we found similar activation patterns in the parietal areas, in addition to event-related desynchronization in the alpha/beta range, suggesting both similarities but also slight differences in activation patterns when drawing and writing by hand. When typewriting on a keyboard, we found event-related desynchronized activity in the theta range and, to a lesser extent, in the alpha range in parietal and central brain regions. However, as this activity was desynchronized and differed from when writing by hand and drawing, its relation to learning remains unclear. For 12-year-old children, the same activation patterns were found, but to a lesser extent. We suggest that children, from an early age, must be exposed to handwriting and drawing activities in school to establish the neuronal oscillation patterns that are beneficial for learning. We conclude that because of the benefits of sensory-motor integration due to the larger involvement of the senses as well as fine and precisely controlled hand movements when writing by hand and when drawing, it is vital to maintain both activities in a learning environment to facilitate and optimize learning.

The oscillatory mechanisms associated with syntactic binding in healthy ageing

Older adults frequently display differential patterns of brain activity compared to young adults in the same task, alongside widespread neuroanatomical changes. Differing functional activity patterns in older adults are commonly interpreted as being compensatory (e.g., Cabeza et al., 2002). We examined the oscillatory activity in the EEG during syntactic binding in young and older adults, as well as the relationship between oscillatory activity and behavioural performance on a syntactic judgement task within the older adults. 19 young and 41 older adults listened to two-word sentences that differentially load onto morpho-syntactic binding: correct syntactic binding (morpho-syntactically correct, e.g., "I dotch"); incorrect syntactic binding (morpho-syntactic agreement violation, e.g., "they dotches") and no syntactic binding (minimizing morpho-syntactic binding, e.g., "dotches spuff"). Behavioural performance, assessed in a syntactic judgement task, was characterized by inter-individual variability especially in older adults, with accuracy ranging from 76 to 100% in young adults and 58-100% in older adults. Compared to young adults, older adults were slower, but not less accurate. Functional neural signatures for syntactic binding were assessed as the difference in oscillatory power between the correct and no syntactic binding condition. In older adults, syntactic binding was associated with a smaller increase in theta (4-7 Hz), alpha (8-12 Hz) and beta (15-20 Hz) power in a time window surrounding the second word. There was a significant difference between the older and young adults: in the alpha range, the condition difference seemed to be in the opposite direction for older versus young adults. Our findings thus suggest that the neural signature associated with syntactic binding in older adults is different from young adults. However, we found no evidence of a significant association between behavioural performance and the neural signatures of syntactic binding for older adults, which does not readily support the predictions of compensatory models of language and ageing.

Individual Differences in Verb Bias Sensitivity in Children and Adults With Developmental Language Disorder

A number of experiments support the hypothetical utility of statistical information for language learning and processing among both children and adults. However, tasks in these studies are often very general, and only a few include populations with developmental language disorder (DLD). We wanted to determine whether a stronger relationship might be shown when the measure of statistical learning is chosen for its relevance to the language task when including a substantial number of participants with DLD. The language ability we measured was sensitivity to verb bias - the likelihood of a verb to appear with a certain argument or interpretation. A previous study showed adults with DLD were less sensitive to verb bias than their typical peers. Verb bias sensitivity had not yet been tested in children with DLD. In Study 1, 49 children, ages 7-9 years, 17 of whom were classified as having DLD, completed a task designed to measure sensitivity to verb bias through implicit and explicit measures. We found children with and without DLD showed sensitivity to verb bias in implicit but not explicit measures, with no differences between groups. In Study 2, we used a multiverse approach to investigate whether individual differences in statistical learning predicted verb bias sensitivity in these participants as well as in a dataset of adult participants. Our analysis revealed no evidence of a relationship between statistical learning and verb bias sensitivity in children, which was not unexpected given we found no group differences in Study 1. Statistical learning predicted sensitivity to verb bias as measured through explicit measures in adults, though results were not robust. These findings suggest that verb bias may still be relatively unstable in school age children, and thus may not play the same role in sentence processing in children as in adults. It would also seem that individuals with DLD may not be using the same mechanisms during processing as their typically developing (TD) peers in adulthood. Thus, statistical information may differ in relevance for language processing in individuals with and without DLD.

THE POWER OF NEURAL OSCILLATIONS TO INFORM SENTENCE COMPREHENSION: A LINGUISTIC PERSPECTIVE

The field of psycholinguistics is currently experiencing an explosion of interest in the analysis of neural oscillations - rhythmic brain activity synchronized at different temporal and spatial levels. Given that language comprehension relies on a myriad of processes, which are carried out in parallel in distributed brain networks, there is hope that this methodology might bring the field closer to understanding some of the more basic (spatially and temporally distributed, yet at the same time often overlapping) neural computations that support language function. In this review we discuss existing proposals linking oscillatory dynamics in different frequency bands to basic neural computations, and review relevant theories suggesting associations between band-specific oscillations and higher-level cognitive processes. More or less consistent patterns of oscillatory activity related to certain types of linguistic processing can already be derived from the evidence that has accumulated over the past few decades. The centerpiece of the current review is a synthesis of such patterns grouped by linguistic phenomenon. We restrict our review to evidence linking measures of oscillatory power to the comprehension of sentences, as well as linguistically (and/or pragmatically) more complex structures. For each grouping, we provide a brief summary and a table of associated oscillatory signatures that a psycholinguist might expect to find when employing a particular linguistic task. Summarizing across different paradigms, we conclude that a handful of basic neural oscillatory mechanisms are likely recruited in different ways and at different times for carrying out a variety of linguistic computations.

Detrended Fluctuation, Coherence, and Spectral Power Analysis of Activation Rearrangement in EEG Dynamics During Cognitive Workload

In the study of human cognitive activity using electroencephalogram (EEG), the brain dynamics parameters and characteristics play a crucial role. They allow to investigate the changes in functionality depending on the environment and task performance process, and also to access the intensity of the brain activity in various locations of the cortex and its dependencies. Usually, the dynamics of activation of different brain areas during the cognitive tasks are being studied by spectral analysis based on power spectral density (PSD) estimation, and coherence analysis, which are de facto standard tools in quantitative characterization of brain activity. PSD and coherence reflect the strength of oscillations and similarity of the emergence of these oscillations in the brain, respectively, while the concept of stability of brain activity over time is not well defined and less formalized. We propose to employ the detrended fluctuation analysis (DFA) as a measure of the EEG persistence over time, and use the DFA scaling exponent as its quantitative characteristics. We applied DFA to the study of the changes in activation in brain dynamics during mental calculations and united it with PSD and coherence estimation. In the experiment, EEGs during resting state and mental serial subtraction from 36 subjects were recorded and analyzed in four frequency ranges: θ1 (4.1-5.8 Hz), θ2 (5.9-7.4 Hz), β1 (13-19.9 Hz), and β2 (20-25 Hz). PSD maps to access the intensity of cortex activation and coherence to quantify the connections between different brain areas were calculated, the distribution of DFA scaling exponent over the head surface was exploited to measure the time characteristics of the dynamics of brain activity. Obtained arrangements of DFA scaling exponent suggest that normal functioning of the brain is characterized by long-term temporal correlations in the cortex. Topographical distribution of the DFA scaling exponent was comparable for θ and β frequency bands, demonstrating the largest values of DFA scaling exponent during cognitive activation. The study shows that the long-term temporal correlations evaluated by DFA can be of great interest for diagnosis of the variety of brain dysfunctions of different etiology in the future.

Reading Shakespearean tropes in a foreign tongue: Age of L2 acquisition modulates neural responses to functional shifts

Functional shifts (FSs) - morphosyntactically marked words evoking coherent but novel meanings - are ubiquitous in English and, specially, in Shakespearean literature. While their neural signatures have been explored in native speakers, no study has targeted foreign-language users, let alone comparing early and late bilinguals. Here, we administered a validated FS paradigm to subjects from both populations and evaluated time-frequency modulations evoked by FS and control sentences. Early bilinguals exhibited greater sensitivity towards FSs, indexed by reduced fronto-posterior theta-band oscillations across semantic- and structural-integration windows. Such oscillatory modulations may represent a key marker of age-of-acquisition effects during foreign-language wordplay processing.

Developmental differences in the neural oscillations underlying auditory sentence processing in children and adults

Although very young children seem to process ongoing language quickly and effortlessly, neuroimaging and behavioral studies reveal that children continue to mature in their language skills through adolescence. During this prolonged development, children likely engage the same basic cognitive processes and neural mechanisms to perform language tasks as adults, but in somewhat different ways. In this study we used time frequency analysis of EEG to identify developmental differences in the engagement of neural oscillations between children (ages 10-12) and adults while listening to naturally-paced sentences. Adults displayed consistent beta changes throughout the sentence compared to children, thought to be related to efficient syntactic integration, and children displayed more broadly distributed theta changes than adults, thought to be related to more effortful semantic integration. Few differences in alpha, related to verbal working memory, existed between groups. These findings shed new light on developmental changes in the neuronal processes underlying language comprehension.

Differences in Neurocognitive Mechanisms Underlying the Processing of Center-Embedded and Non–embedded Musical Structures

In music, chords are organized into hierarchical structures based on recursive or embedded syntax. How the brain extracts recursive grammar is a central question in musical cognition and other cognitive neuroscience, but the precise mechanism remains unclear. By analyzing event related potentials (ERPs) and neural oscillatory activity, the present study investigated neurocognitive mechanisms underlying the processing of center-embedded structure in music by examining the differences in center-embedded and non-embedded structure processing and evaluating how these differences are affected by musical proficiency. Based on Western musical proficiency, the subjects were divided into two groups, non-experts and experts. The results revealed that for non-experts, the processing of center-embedded structure elicited greater early right-anterior negativity (ERAN) and N5 components as well as, reduced alpha and gamma activities than did the non-embedded structure. For experts, no significant difference in the ERP response was observed between the processing of non-embedded and center-embedded structures; however, the processing of center-embedded structure elicited increased beta activity compared to non-embedded structure. These findings indicate that listeners different in proficiency would rely on different cognitive neural mechanisms in music processing with the syntactic complexity increases.

Identifying the relationship between oscillatory dynamics and event-related responses

Event related potentials (ERPs) and time frequency analysis of the EEG can identify the temporally distinct coordination of groups of neurons across brain regions during sentence processing. Although there are strong arguments that ERP components and neural oscillations are driven by the same changes in the neural signal, others argue that the lack of clear associations between the two suggests oscillatory dynamics are more than just time frequency representations of ERP components, making it unclear how the two are related. The current study seeks to examine the neural activity underlying auditory sentence processing of both semantic and syntactic errors to clarify if ERP and time frequency analyses identify the same or unique neural responses. Thirty-nine adults completed an auditory semantic judgment task and a grammaticality judgment task. As expected, the semantic judgment task elicited a larger N400 and greater increase in theta power for semantic errors compared to correct sentences and the syntactic judgment task elicited a greater P600 and beta power decrease for both grammatical error types compared to syntactically correct sentences. Importantly, we identified a significant relationship between the N400 and P600 ERPs and theta and beta oscillatory dynamics during semantic and syntactic processing. These findings suggest that ERPs and neural oscillations measure similar neural processes; however, unaccounted for variance may indicate that neural oscillations provide additional information regarding fluctuations in power within a given frequency band. Future studies that vary semantic and syntactic complexity are necessary to understand the cognitive processes that are indexed by these oscillations.

Oscillatory brain activity differentially reflects false belief understanding and complementation syntax processing

False belief understanding (FBU) enables people to consider conflicting beliefs about the same situation. While language has been demonstrated to be a correlate of FBU, there is still controversy about the extent to which a specific aspect of language, complementation syntax, is a necessary condition for FBU. The present study tested an important notion from the debate proposing that complementation syntax task is redundant to FBU measures. Specifically, we examined electrophysiological correlates of false belief, false complementation, and their respective true conditions in adults using electroencephalography (EEG), focusing on indices of oscillatory brain activity and large-scale connectivity. The results showed strong modulation of parieto-occipital alpha (8-12 Hz) and beta (13-20 Hz) power by the experimental manipulations, with heightened sustained alpha power reflective of effortful internal processing observed in the false compared to the true conditions and reliable beta power reductions sensitive to mentalizing and/or syntactic demands in the belief versus the complementation conditions. In addition, higher coupling between parieto-occipital regions and widespread frontal sites in the beta band was found for the false-belief condition selectively. The result of divergence in beta oscillatory activity and in connectivity between false belief and false complementation does not support the redundancy hypothesis.

Neural patterns elicited by sentence processing uniquely characterize typical development, SLI recovery, and SLI persistence

Background

A substantial amount of work has examined language abilities in young children with specific language impairment (SLI); however, our understanding of the developmental trajectory of language impairment is limited. Along with studying the behavioral changes that occur across development, it is important to examine the neural indices of language processing for children with different language trajectories. The current study sought to examine behavioral and neural bases of language processing in adolescents showing three different trajectories: those with normal language development (NL), those exhibiting persistent SLI (SLI-Persistent), and those with a history of SLI who appear to have recovered (SLI-Recovered).

Methods

Through a sentence judgment task, we examined semantic and syntactic processing. Adolescents judged whether or not each sentence was semantically and syntactically correct. Stimuli consisted of naturally spoken sentences that were either correct, contained a semantic verb error, or contained a syntactic verb agreement error. Verb agreement errors consisted of omission and commission violations of the third-person singular -s. Behavioral button-press responses and electroencephalographic recordings were collected. Behavioral judgments and mean amplitude of the N400 and P600 components were examined.

Results

Adolescents in the SLI-Persistent group had lower sentence judgment accuracy overall, relative to the NL and SLI-Recovered groups. Accuracy in judging omission and commission syntactic errors were marginally different, with marginally lower accuracy for commission errors. All groups demonstrated an N400 component elicited by semantic violations. However, adolescents in the SLI-Persistent group demonstrated a less robust P600 component for syntactic violations. Furthermore, adolescents in the SLI-Recovered group exhibited a similar neural profile to the NL group for the semantic and syntactic omission violations. However, a unique profile with initial negativity was observed in the SLI-Recovered group in the commission violation condition.

Conclusions

Adolescents with persistent language impairment continue to demonstrate delays in language processing at the behavioral and neural levels. Conversely, the adolescents in the SLI-Recovered group appear to have made gains in language processing skills to overcome their initial impairments. However, our findings suggest that the adolescents in the SLI-Recovered group may have compensatory processing strategies for some aspects of language, as evidenced by a unique event-related potential profile.