scholarly journals The Effect of Focal Damage to the Right Medial Posterior Cerebellum on Word and Sentence Comprehension and Production

2021 ◽  
Vol 15 ◽  
Author(s):  
Sharon Geva ◽  
Letitia M. Schneider ◽  
Sophie Roberts ◽  
David W. Green ◽  
Cathy J. Price

Functional imaging studies of neurologically intact adults have demonstrated that the right posterior cerebellum is activated during verb generation, semantic processing, sentence processing, and verbal fluency. Studies of patients with cerebellar damage converge to show that the cerebellum supports sentence processing and verbal fluency. However, to date there are no patient studies that investigated the specific importance of the right posterior cerebellum in language processing, because: (i) case studies presented patients with lesions affecting the anterior cerebellum (with or without damage to the posterior cerebellum), and (ii) group studies combined patients with lesions to different cerebellar regions, without specifically reporting the effects of right posterior cerebellar damage. Here we investigated whether damage to the right posterior cerebellum is critical for sentence processing and verbal fluency in four patients with focal stroke damage to different parts of the right posterior cerebellum (all involving Crus II, and lobules VII and VIII). We examined detailed lesion location by going beyond common anatomical definitions of cerebellar anatomy (i.e., according to lobules or vascular territory), and employed a recently proposed functional parcellation of the cerebellum. All four patients experienced language difficulties that persisted for at least a month after stroke but three performed in the normal range within a year. In contrast, one patient with more damage to lobule IX than the other patients had profound long-lasting impairments in the comprehension and repetition of sentences, and the production of spoken sentences during picture description. Spoken and written word comprehension and visual recognition memory were also impaired, however, verbal fluency was within the normal range, together with object naming, visual perception and verbal short-term memory. This is the first study to show that focal damage to the right posterior cerebellum leads to language difficulties after stroke; and that processing impairments persisted in the case with most damage to lobule IX. We discuss these results in relation to current theories of cerebellar contribution to language processing. Overall, our study highlights the need for longitudinal studies of language function in patients with focal damage to different cerebellar regions, with functional imaging to understand the mechanisms that support recovery.

2007 ◽  
Vol 19 (7) ◽  
pp. 1193-1205 ◽  
Author(s):  
Elisabet Service ◽  
Päivi Helenius ◽  
Sini Maury ◽  
Riitta Salmelin

Electrophysiological methods have been used to study the temporal sequence of syntactic and semantic processing during sentence comprehension. Two responses associated with syntactic violations are the left anterior negativity (LAN) and the P600. A response to semantic violation is the N400. Although the sources of the N400 response have been identified in the left (and right) temporal lobe, the neural signatures of the LAN and P600 have not been revealed. The present study used magnetoencephalography to localize sources of syntactic and semantic activation in Finnish sentence reading. Participants were presented with sentences that ended in normally inf lected nouns, nouns in an unacceptable case, verbs instead of nouns, or nouns that were correctly inflected but made no sense in the context. Around 400 msec, semantically anomalous last words evoked strong activation in the left superior temporal lobe with significant activation also for word class errors (N400). Weaker activation was seen for the semantic errors in the right hemisphere. Later, 600-800 msec after word onset, the strongest activation was seen to word class and morphosyntactic errors (P600). Activation was significantly weaker to semantically anomalous and correct words. The P600 syntactic activation was localized to bilateral sources in the temporal lobe, posterior to the N400 sources. The results suggest that the same general region of the superior temporal cortex gives rise to both LAN and N400 with bilateral reactivity to semantic manipulation and a left hemisphere effect to syntactic manipulation. The bilateral P600 response was sensitive to syntactic but not semantic factors.


2001 ◽  
Vol 13 (6) ◽  
pp. 829-843 ◽  
Author(s):  
A. L. Roskies ◽  
J. A. Fiez ◽  
D. A. Balota ◽  
M. E. Raichle ◽  
S. E. Petersen

To distinguish areas involved in the processing of word meaning (semantics) from other regions involved in lexical processing more generally, subjects were scanned with positron emission tomography (PET) while performing lexical tasks, three of which required varying degrees of semantic analysis and one that required phonological analysis. Three closely apposed regions in the left inferior frontal cortex and one in the right cerebellum were significantly active above baseline in the semantic tasks, but not in the nonsemantic task. The activity in two of the frontal regions was modulated by the difficulty of the semantic judgment. Other regions, including some in the left temporal cortex and the cerebellum, were active across all four language tasks. Thus, in addition to a number of regions known to be active during language processing, regions in the left inferior frontal cortex were specifically recruited during semantic processing in a task-dependent manner. A region in the right cerebellum may be functionally related to those in the left inferior frontal cortex. Discussion focuses on the implications of these results for current views regarding neural substrates of semantic processing.


Author(s):  
Angela D. Friederici ◽  
Noam Chomsky

An adequate description of the neural basis of language processing must consider the entire network both with respect to its structural white matter connections and the functional connectivities between the different brain regions as the information has to be sent between different language-related regions distributed across the temporal and frontal cortex. This chapter discusses the white matter fiber bundles that connect the language-relevant regions. The chapter is broken into three sections. In the first, we look at the white matter fiber tracts connecting the language-relevant regions in the frontal and temporal cortices; in the second, the ventral and dorsal pathways in the right hemisphere that connect temporal and frontal regions; and finally in the third, the two syntax-relevant and (at least) one semantic-relevant neuroanatomically-defined networks that sentence processing is based on. From this discussion, it becomes clear that online language processing requires information transfer via the long-range white matter fiber pathways that connect the language-relevant brain regions within each hemisphere and between hemispheres.


Author(s):  
Fernanda Ferreira ◽  
James Nye

Today, the modular view of sentence processing is unpopular, but the arguments against modularity are not as strong as this apparent consensus would suggest. Almost all experimental investigations of modularity have focused on properties pertaining to information encapsulation, and most of those studies have evaluated just one specific modular architecture. A review of these studies of sentence comprehension suggests that the evidence against information encapsulation is really evidence against that one architecture only, and a whole range of other possible modular architectures remain untested. Although psycholinguistic work has largely ignored the modularity claims relating to shallow outputs, new findings from studies to test “good enough” language processing suggest that the output of the language processing module can be characterized as shallow or minimal. Perhaps, then, the modularity hypothesis was prematurely rejected. Evidence for shallow outputs provides intriguing new support for the idea that sentence processing is indeed modular.


Entropy ◽  
2020 ◽  
Vol 22 (4) ◽  
pp. 446
Author(s):  
Yair Lakretz ◽  
Stanislas Dehaene ◽  
Jean-Rémi King

Sentence comprehension requires inferring, from a sequence of words, the structure of syntactic relationships that bind these words into a semantic representation. Our limited ability to build some specific syntactic structures, such as nested center-embedded clauses (e.g., “The dog that the cat that the mouse bit chased ran away”), suggests a striking capacity limitation of sentence processing, and thus offers a window to understand how the human brain processes sentences. Here, we review the main hypotheses proposed in psycholinguistics to explain such capacity limitation. We then introduce an alternative approach, derived from our recent work on artificial neural networks optimized for language modeling, and predict that capacity limitation derives from the emergence of sparse and feature-specific syntactic units. Unlike psycholinguistic theories, our neural network-based framework provides precise capacity-limit predictions without making any a priori assumptions about the form of the grammar or parser. Finally, we discuss how our framework may clarify the mechanistic underpinning of language processing and its limitations in the human brain.


1998 ◽  
Vol 172 (2) ◽  
pp. 142-146 ◽  
Author(s):  
Matthias Weisbrod ◽  
Sabine Maier ◽  
Sabine Harig ◽  
Ulrike Himmelsbach ◽  
Manfred Spitzer

BackgroundIn schizophrenia, disturbances in the development of physiological hemisphere asymmetry are assumed to play a pathogenetic role. The most striking difference between hemispheres is in language processing. The left hemisphere is superior in the use of syntactic or semantic information, whereas the right hemisphere uses contextual information more effectively.MethodUsing psycholinguistic experimental techniques, semantic associations were examined in 38 control subjects, 24 non-thought-disordered and 16 thought-disordered people with schizophrenia, for both hemispheres separately.ResultsDirect semantic priming did not differ between the hemispheres in any of the groups. Only thought-disordered people showed significant indirect semantic priming in the left hemisphere.ConclusionsThe results support: (a) a prominent role of the right hemisphere for remote associations; (b) enhanced spreading of semantic associations in thought-disordered subjects; and (c) disorganisation of the functional asymmetry of semantic processing in thought-disordered subjects.


2009 ◽  
Vol 21 (12) ◽  
pp. 2434-2444 ◽  
Author(s):  
David January ◽  
John C. Trueswell ◽  
Sharon L. Thompson-Schill

For over a century, a link between left prefrontal cortex and language processing has been accepted, yet the precise characterization of this link remains elusive. Recent advances in both the study of sentence processing and the neuroscientific study of frontal lobe function suggest an intriguing possibility: The demands to resolve competition between incompatible characterizations of a linguistic stimulus may recruit top–down cognitive control processes mediated by prefrontal cortex. We use functional magnetic resonance imaging to test the hypothesis that individuals use shared prefrontal neural circuitry during two very different tasks—color identification under Stroop conflict and sentence comprehension under conditions of syntactic ambiguity—both of which putatively rely on cognitive control processes. We report the first demonstration of within-subject overlap in neural responses to syntactic and nonsyntactic conflict. These findings serve to clarify the role of Broca's area in, and the neural and psychological organization of, the language processing system.


2021 ◽  
Vol 12 ◽  
Author(s):  
Veena D. Dwivedi ◽  
Janahan Selvanayagam

We examined whether the N400 Event-Related Potential (ERP) component would be modulated by dispositional affect during sentence processing. In this study, 33 participants read sentences manipulated by direct object type (congruent vs. incongruent) and object determiner type (definite vs. demonstrative). We were particularly interested in sentences of the form: (i) The connoisseur tasted thewineon the tour vs. (ii) The connoisseur tasted the #roof… We expected that processing incongruent direct objects (#roof) vs. congruent objects (wine) would elicit N400 effects. Previous ERP language experiments have shown that participants in (induced) positive and negative moods were differentially sensitive to semantic anomaly, resulting in different N400 effects. Presently, we ask whether individual dispositional affect scores (as measured by the Positive and Negative Affect Schedule; PANAS) would modulate N400 effects as shown previously. Namely, previous results showed larger N400 effects associated with happy moods and attenuated amplitudes associated with sad moods. Results revealed significant N400 effects, driven by the #roof vs. the wine, where larger amplitude differences were found for individuals showing smaller negative affect (NA) scores, thus partially replicating previous findings. We discuss our results in terms of theories of local (lexical) inhibition, such that low NA promotes stronger lexico-semantic links in sentences. Finally, our results support accounts of language processing that include social and biological characteristics of individuals during real-time sentence comprehension.


2016 ◽  
Vol 59 (4) ◽  
pp. 759-771 ◽  
Author(s):  
Sarah E. Key-DeLyria

PurposeSentence processing can be affected following a traumatic brain injury (TBI) due to linguistic or cognitive deficits. Language-related event-related potentials (ERPs), particularly the P600, have not been described in individuals with TBI history.MethodFour young adults with a history of closed head injury participated. Two had severe injuries, and 2 had mild–moderate injuries more than 24 months prior to testing. ERPs were recorded while participants read sentences designed to be grammatically correct or incorrect. Participants also completed cognitive and sentence comprehension measures.ResultsOne participant with TBI was significantly different than the control group on several behavioral sentence measures and 1 cognitive measure. However, none of the participants with TBI had a reliable P600 effect. Nonparametric bootstrapping indicated that the ERP was reliable in 10 control participants but no participants with TBI history.ConclusionsThere were few behavioral differences between individuals with TBI history and the control group, though all reported subjective difficulty with reading. The P600 was absent in the TBI group in this study. Given the heterogeneity of individuals with TBI and the difficulty in assessing subtle language impairments, exploring the P600 further may provide useful insight into language processing difficulties.


2016 ◽  
Vol 27 (3) ◽  
pp. 355-380
Author(s):  
INGA HENNECKE

ABSTRACTCurrent research on conceptual and semantic representations is mainly based on prototypical word classes, such as nouns and verbs. Hence, most models of language processing and language representation rely on experimental investigations on these word classes. Until today, only a few psycholinguistic studies centre on the processing of pragmatic markers and hedges and their effect on speech comprehension. The present article aims to give experimental evidence for the processing of semantic meaning patterns and pragmatic functions of pragmatic markers. The focus will be on the question, if pragmatic markers and hedges play a role in sentence processing. This main problem will be illustrated and discussed by means of experimental data. In a monolingual sentence verification task with lexical decision, the meaning patterns and functions of the partially equivalent pragmatic French markerscommeandgenreare investigated in Canadian and European French. The results of the sentence word verification task provide evidence for an impact of pragmatic functions and semantic meaning patterns of pragmatic markers on sentence processing.


Sign in / Sign up

Export Citation Format

Share Document