Comprehending comprehension: Insights from neuronal oscillations on the neuronal basis of language

Contains fulltext : 165629.pdf (publisher's version ) (Open Access)Radboud University, 10 februari 2017Promotor : Hagoort, P. Co-promotor : Schoffelen, J.M.191 p

Frequency-specific directed interactions in the human brain network for language

Contains fulltext : 175222.pdf (publisher's version ) (Open Access)The brain's remarkable capacity for language requires bidirectional interactions between functionally specialized brain regions. We used magnetoencephalography to investigate interregional interactions in the brain network for language while 102 participants were reading sentences. Using Granger causality analysis, we identified inferior frontal cortex and anterior temporal regions to receive widespread input and middle temporal regions to send widespread output. This fits well with the notion that these regions play a central role in language processing. Characterization of the functional topology of this network, using data-driven matrix factorization, which allowed for partitioning into a set of subnetworks, revealed directed connections at distinct frequencies of interaction. Connections originating from temporal regions peaked at alpha frequency, whereas connections originating from frontal and parietal regions peaked at beta frequency. These findings indicate that the information flow between language-relevant brain areas, which is required for linguistic processing, may depend on the contributions of distinct brain rhythms.6 p

Corrigendum: Robust neuronal oscillatory entrainment to speech displays individual variation in lateralisation

Item does not contain fulltextLam, N. H. L., Hultén, A., Hagoort, P & Schoffelen, J.-M. (2018) Robust neuronal oscillatory entrainment to speech displays individual variation in lateralisation. Language, Cognition and Neuroscience, https://doi.org/10.1080/23273798.2018.1437456. When the above article was first published online, the word 'entrainment' was entered wrongly as 'entertainment' in the title. This has now been corrected in both the print and online version. The authors apologize for this error.1 p

How the brain makes sense beyond the processing of single words: An MEG study

Contains fulltext : 198200.pdf (Publisher’s version ) (Closed access)Human language processing involves combinatorial operations that make human communication stand out in the animal kingdom. These operations rely on a dynamic interplay between the inferior frontal and the posterior temporal cortices. Using source reconstructed magnetoencephalography, we tracked language processing in the brain, in order to investigate how individual words are interpreted when part of sentence context. The large sample size in this study (n = 68) allowed us to assess how event-related activity is associated across distinct cortical areas, by means of inter-areal co-modulation within an individual. We showed that, within 500 ms of seeing a word, the word's lexical information has been retrieved and unified with the sentence context. This does not happen in a strictly feed-forward manner, but by means of co-modulation between the left posterior temporal cortex (LPTC) and left inferior frontal cortex (LIFC), for each individual word. The co-modulation of LIFC and LPTC occurs around 400 ms after the onset of each word, across the progression of a sentence. Moreover, these core language areas are supported early on by the attentional network. The results provide a detailed description of the temporal orchestration related to single word processing in the context of ongoing language.9 p

Neural activity during sentence processing as reflected in theta, alpha, beta, and gamma oscillations

Item does not contain fulltextWe used magnetoencephalography (MEG) to explore the spatiotemporal dynamics of neural oscillations associated with sentence processing in 102 participants. We quantified changes in oscillatory power as the sentence unfolded, and in response to individual words in the sentence. For words early in a sentence compared to those late in the same sentence, we observed differences in left temporal and frontal areas, and bilateral frontal and right parietal regions for the theta, alpha, and beta frequency bands. The neural response to words in a sentence differed from the response to words in scrambled sentences in left-lateralized theta, alpha, beta, and gamma. The theta band effects suggest that a sentential context facilitates lexical retrieval, and that this facilitation is stronger for words late in the sentence. Effects in the alpha and beta bands may reflect the unification of semantic and syntactic information, and are suggestive of easier unification late in a sentence. The gamma oscillations are indicative of predicting the upcoming word during sentence processing. In conclusion, changes in oscillatory neuronal activity capture aspects of sentence processing. Our results support earlier claims that language (sentence) processing recruits areas distributed across both hemispheres, and extends beyond the classical language regions.12 p