scholarly journals Unconstrained multivariate EEG decoding can help detect lexical-semantic processing in individual children

2019 ◽  
Author(s):  
Selene Petit ◽  
Nicholas A. Badcock ◽  
Tijl Grootswagers ◽  
Alexandra Woolgar
Keyword(s):  
Language Comprehension ◽  
Semantic Processing ◽  
Individual Variability ◽  
Group Level ◽  
Neural Responses ◽  
Neural Signals ◽  
Individual Subject ◽  
Lexical Semantic ◽  
Semantic Comprehension ◽  
Autistic Population

AbstractIn conditions such as minimally-verbal autism, standard assessments of language comprehension are often unreliable. Given the known heterogeneity within the autistic population, it is crucial to design tests of semantic comprehension that are sensitive in individuals. Recent efforts to develop neural signals of language comprehension have focused on the N400, a robust marker of lexical-semantic violation at the group level. However, homogeneity of response in individual neurotypical children has not been established. Here, we presented 20 neurotypical children with congruent and incongruent visual animations and spoken sentences while measuring their neural response using EEG. Despite robust group-level responses, we found high inter-individual variability in response to lexico-semantic anomalies. To overcome this, we analysed our data using temporally and spatially unconstrained MVPA, supplemented by descriptive analyses to examine the timecourse, topography, and strength of the effect. Our results show that neurotypical children exhibit heterogenous responses to lexical-semantic violation, implying that any application to heterogenous disorders such as ASD will require individual-subject analyses that are robust to variation in topology and timecourse of neural responses.

scholarly journals Towards an individualised neural assessment of receptive language in children

2019 ◽  
Author(s):  
Selene Petit ◽  
Nicholas A. Badcock ◽  
Tijl Grootswagers ◽  
Anina N. Rich ◽  
Jon Brock ◽  
...  
Keyword(s):  
Language Comprehension ◽  
Detection Rate ◽  
Multivariate Analyses ◽  
Univariate Analysis ◽  
Receptive Language ◽  
Individual Variability ◽  
Grade System ◽  
Neural Responses ◽  
Lexical Semantic ◽  
Research Grade

AbstractPurposeWe aimed to develop a non-invasive neural test of language comprehension to use with non-speaking children for whom standard behavioural testing is unreliable (e.g., minimally-verbal autism). Our aims were three-fold. First, we sought to establish the sensitivity of two auditory paradigms to elicit neural responses in individual neurotypical children. Second, we aimed to validate the use of a portable and accessible electroencephalography (EEG) system, by comparing its recordings to those of a research-grade system. Third, in light of substantial inter-individual variability in individuals’ neural responses, we assessed whether multivariate decoding methods could improve sensitivity.MethodsWe tested the sensitivity of two child-friendly covert N400 paradigms. Thirty-one typically developing children listened to identical spoken words that were either strongly predicted by the preceding context or violated lexical-semantic expectations. Context was given by a cue word (Experiment 1) or sentence frame (Experiment 2) and participants either made an overall judgement on word relatedness or counted lexical-semantic violations. We measured EEG concurrently from a research-grade system, Neuroscan’s SynAmps2, and an adapted gaming system, Emotiv’s EPOC+.ResultsWe found substantial inter-individual variability in the timing and topology of N400-like effects. For both paradigms and EEG systems, traditional N400 effects at the expected sensors and time points were statistically significant in around 50% of individuals. Using multivariate analyses, detection rate increased to 88% of individuals for the research-grade system in the sentences paradigm, illustrating the robustness of this method in the face of inter-individual variations in topography.ConclusionsThere was large inter-individual variability in neural responses, suggesting inter-individual variation in either the cognitive response to lexical-semantic violations, and/or the neural substrate of that response. Around half of our neurotypical participants showed the expected N400 effect at the expected location and time point. A low-cost, accessible EEG system provided comparable data for univariate analysis but was not well suited to multivariate decoding. However, multivariate analyses with a research-grade EEG system increased our detection rate to 88% of individuals. This approach provides a strong foundation to establish a neural index of language comprehension in children with limited communication.

Disrupting morphosyntactic and lexical semantic processing has opposite effects on the sample entropy of neural signals

2015 ◽  
Vol 1604 ◽  
pp. 1-14 ◽  
Author(s):  
André Fonseca ◽  
Vezha Boboeva ◽  
Sanne Brederoo ◽  
Giosuè Baggio
Keyword(s):  
Semantic Processing ◽  
Sample Entropy ◽  
Neural Signals ◽  
Lexical Semantic

scholarly journals Toward an Individualized Neural Assessment of Receptive Language in Children

2020 ◽  
Vol 63 (7) ◽  
pp. 2361-2385 ◽  
Author(s):  
Selene Petit ◽  
Nicholas A. Badcock ◽  
Tijl Grootswagers ◽  
Anina N. Rich ◽  
Jon Brock ◽  
...  
Keyword(s):  
Language Comprehension ◽  
Detection Rate ◽  
Multivariate Analyses ◽  
Interindividual Variability ◽  
Receptive Language ◽  
Grade System ◽  
Neural Responses ◽  
Time Points ◽  
Lexical Semantic ◽  
Research Grade

Purpose We aimed to develop a noninvasive neural test of language comprehension to use with nonspeaking children for whom standard behavioral testing is unreliable (e.g., minimally verbal autism). Our aims were threefold. First, we sought to establish the sensitivity of two auditory paradigms to elicit neural responses in individual neurotypical children. Second, we aimed to validate the use of a portable and accessible electroencephalography (EEG) system, by comparing its recordings to those of a research-grade system. Third, in light of substantial interindividual variability in individuals' neural responses, we assessed whether multivariate decoding methods could improve sensitivity. Method We tested the sensitivity of two child-friendly covert N400 paradigms. Thirty-one typically developing children listened to identical spoken words that were either strongly predicted by the preceding context or violated lexical–semantic expectations. Context was given by a cue word (Experiment 1) or sentence frame (Experiment 2), and participants either made an overall judgment on word relatedness or counted lexical–semantic violations. We measured EEG concurrently from a research-grade system, Neuroscan's SynAmps2, and an adapted gaming system, Emotiv's EPOC+. Results We found substantial interindividual variability in the timing and topology of N400-like effects. For both paradigms and EEG systems, traditional N400 effects at the expected sensors and time points were statistically significant in around 50% of individuals. Using multivariate analyses, detection rate increased to 88% of individuals for the research-grade system in the sentences paradigm, illustrating the robustness of this method in the face of interindividual variations in topography. Conclusions There was large interindividual variability in neural responses, suggesting interindividual variation in either the cognitive response to lexical–semantic violations and/or the neural substrate of that response. Around half of our neurotypical participants showed the expected N400 effect at the expected location and time points. A low-cost, accessible EEG system provided comparable data for univariate analysis but was not well suited to multivariate decoding. However, multivariate analyses with a research-grade EEG system increased our detection rate to 88% of individuals. This approach provides a strong foundation to establish a neural index of language comprehension in children with limited communication. Supplemental Material https://doi.org/10.23641/asha.12606311

scholarly journals Neural correlates of semantic number: A cross-linguistic investigation

2021 ◽  
Author(s):  
Donald Dunagan ◽  
Shulin Zhang ◽  
Jixing Li ◽  
Shohini Bhattasali ◽  
Christophe Pallier ◽  
...  
Keyword(s):  
Language Comprehension ◽  
Semantic Processing ◽  
Native Speakers ◽  
Neural Correlates ◽  
Cortical Activation ◽  
Dorsomedial Prefrontal Cortex ◽  
French And English ◽  
General Number ◽  
Cortical Regions ◽  
Semantic Comprehension

One aspect of natural language comprehension is understanding how many of what or whom a speaker is referring to. While previous work has documented the neural correlates of general number comprehension and quantity comparison, we investigate semantic number from a cross-linguistic perspective with the goal of identifying cortical regions involved in distinguishing plural from singular nouns. We use three fMRI datasets in which Chinese, French, and English native speakers listen to an audiobook of a children's story in their native language. We select these three languages because they differ in their number semantics. While Chinese lacks nominal pluralization, French and English nouns are overtly marked for number. We find a number of known semantic processing regions in common, including dorsomedial prefrontal cortex and the pars orbitalis, in which cortical activation is greater for plural than singular nouns and posit a cross-linguistic role for number in semantic comprehension.

scholarly journals Letter transpositions and morphemic boundaries in the second language processing of derived words: An exploratory study of individual differences

2021 ◽  
Vol 42 (2) ◽  
pp. 417-446
Author(s):  
Hasibe Kahraman ◽  
Bilal Kırkıcı
Keyword(s):  
Individual Differences ◽  
Language Processing ◽  
Exploratory Study ◽  
Reading Proficiency ◽  
Individual Variability ◽  
Morphological Processing ◽  
Group Level ◽  
Priming Effects ◽  
Second Language Processing ◽  
Morphological Priming

AbstractResearch into nonnative (L2) morphological processing has produced largely conflicting findings. To contribute to the discussions surrounding the contradictory findings in the literature, we examined L2 morphological priming effects along with a transposed-letter (TL) methodology. Critically, we also explored the potential effects of individual differences in the reading networks of L2 speakers using a test battery of reading proficiency. A masked primed lexical decision experiment was carried out in which the same target (e.g., ALLOW) was preceded by a morphological prime (allowable), a TL-within prime (allwoable), an substituted letter (SL)-within prime (allveable), a TL-across prime (alloawble), an SL-across prime (alloimble), or an unrelated prime (believable). The average data yielded morphological priming but no significant TL priming. However, the results of an exploratory analysis of the potential effects of individual differences suggested that individual variability mediated the group-level priming patterns in L2 speakers. TL-within and TL-across priming effects were obtained only when the performance of participants on nonword reading was considered, while the magnitude of the morphological priming effects diminished as the knowledge of vocabulary expanded. The results highlight the importance of considering individual differences while testing L2 populations.

scholarly journals Brain Activation During Reading in Deep Dyslexia: An MEG Study

2000 ◽  
Vol 12 (4) ◽  
pp. 622-634 ◽  
Author(s):  
Matti Laine ◽  
Riitta Salmelin ◽  
Päivi Helenius ◽  
Reijo Marttila
Keyword(s):  
Semantic Processing ◽  
Semantic Analysis ◽  
Right Hemisphere ◽  
Word Reading ◽  
Brain Activity ◽  
Temporal Cortex ◽  
Single Word ◽  
Lexical Semantic ◽  
Deep Dyslexia ◽  
Single Word Reading

Magnetoencephalographic (MEG) changes in cortical activity were studied in a chronic Finnish-speaking deep dyslexic patient during single-word and sentence reading. It has been hypothesized that in deep dyslexia, written word recognition and its lexical-semantic analysis are subserved by the intact right hemisphere. However, in our patient, as well as in most nonimpaired readers, lexical-semantic processing as measured by sentence-final semantic-incongruency detection was related to the left superior-temporal cortex activation. Activations around this same cortical area could be identified in single-word reading as well. Another factor relevant to deep dyslexic reading, the morphological complexity of the presented words, was also studied. The effect of morphology was observed only during the preparation for oral output. By performing repeated recordings 1 year apart, we were able to document significant variability in both the spontaneous activity and the evoked responses in the lesioned left hemisphere even though at the behavioural level, the patient's performance was stable. The observed variability emphasizes the importance of estimating consistency of brain activity both within and between measurements in brain-damaged individuals.

scholarly journals Conceptual Priming and Familiarity: Different Expressions of Memory during Recognition Testing with Distinct Neurophysiological Correlates

2010 ◽  
Vol 22 (11) ◽  
pp. 2638-2651 ◽  
Author(s):  
Joel L. Voss ◽  
Heather D. Lucas ◽  
Ken A. Paller
Keyword(s):  
Implicit Memory ◽  
Explicit Memory ◽  
Neural Correlates ◽  
Neural Responses ◽  
Neural Signals ◽  
Conceptual Information ◽  
Conceptual Priming ◽  
Familiarity And Recollection ◽  
Recognition Testing ◽  
Different Characteristics

Familiarity and recollection are qualitatively different explicit-memory phenomena evident during recognition testing. Investigations of the neurocognitive substrates of familiarity and recollection, however, have typically disregarded implicit-memory processes likely to be engaged during recognition tests. We reasoned that differential neural responses to old and new items in a recognition test may reflect either explicit or implicit memory. Putative neural correlates of familiarity in prior experiments, for example, may actually reflect contamination by implicit memory. In two experiments, we used obscure words that subjects could not formally define to tease apart electrophysiological correlates of familiarity and one form of implicit memory, conceptual priming. In Experiment 1, conceptual priming was observed for words only if they elicited meaningful associations. In Experiment 2, two distinct neural signals were observed in conjunction with familiarity-based recognition: late posterior potentials for words that both did and did not elicit meaningful associations and FN400 potentials only for the former. Given that symbolic meaning is a prerequisite for conceptual priming, the combined results specifically link late posterior potentials and FN400 potentials with familiarity and conceptual priming, respectively. These findings contradict previous interpretations of FN400 potentials as generic signals of familiarity and show that repeated stimuli in recognition tests can engender facilitated processing of conceptual information in addition to retrieval processing that leads to the awareness of memory retrieval. The different characteristics of the electrical markers of these two types of process further underscore the biological validity of the distinction between implicit memory and explicit memory.

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