MEG Evidence for Incremental Sentence Composition in the Anterior Temporal Lobe

Research investigating the brain basis of language comprehension has associated the left anterior temporal lobe (ATL) with sentence‐level combinatorics. Using magnetoencephalography (MEG), we test the parsing strategy implemented in this brain region. The number of incremental parse steps from a predictive left‐corner parsing strategy that is supported by psycholinguistic research is compared with those from a less‐predictive strategy. We test for a correlation between parse steps and source‐localized MEG activity recorded while participants read a story. Left‐corner parse steps correlated with activity in the left ATL around 350–500 ms after word onset. No other correlations specific to sentence comprehension were observed. These data indicate that the left ATL engages in combinatoric processing that is well characterized by a predictive left‐corner parsing strategy.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/137231/1/cogs12445-sup-0001-AppendixS1.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137231/2/cogs12445.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/137231/3/cogs12445_am.pd

Sentence processing in anterior superior temporal cortex shows a social-emotional bias

The anterior region of the left superior temporal gyrus/superior temporal sulcus (aSTG/STS) has been implicated in two very different cognitive functions: sentence processing and social-emotional processing. However, the vast majority of the sentence stimuli in previous reports have been of a social or social-emotional nature suggesting that sentence processing may be confounded with semantic content. To evaluate this possibility we had subjects read word lists that differed in phrase/constituent size (single words, 3-word phrases, 6-word sentences) and semantic content (social-emotional, social, and inanimate objects) while scanned in a 7T environment. This allowed us to investigate if the aSTG/STS responded to increasing constituent structure (with increased activity as a function of constituent size) with or without regard to a specific domain of concepts, i.e., social and/or social-emotional content. Activity in the left aSTG/STS was found to increase with constituent size. This region was also modulated by content, however, such that social-emotional concepts were preferred over social and object stimuli. Reading also induced content type effects in domain-specific semantic regions. Those preferring social-emotional content included aSTG/STS, inferior frontal gyrus, posterior STS, lateral fusiform, ventromedial prefrontal cortex, and amygdala, regions included in the "social brain", while those preferring object content included parahippocampal gyrus, retrosplenial cortex, and caudate, regions involved in object processing. These results suggest that semantic content affects higher-level linguistic processing and should be taken into account in future studies

What Role Does the Anterior Temporal Lobe Play in Sentence-level Processing? Neural Correlates of Syntactic Processing in Semantic Variant Primary Progressive Aphasia

Neuroimaging and neuropsychological studies have implicated the anterior temporal lobe (ATL) in sentence-level processing, with syntactic structure-building and/or combinatorial semantic processing suggested as possible roles. A potential challenge to the view that the ATL is involved in syntactic aspects of sentence processing comes from the clinical syndrome of semantic variant primary progressive aphasia (semantic PPA; also known as semantic dementia). In semantic PPA, bilateral neurodegeneration of the ATLs is associated with profound lexical semantic deficits, yet syntax is strikingly spared. The goal of this study was to investigate the neural correlates of syntactic processing in semantic PPA to determine which regions normally involved in syntactic processing are damaged in semantic PPA and whether spared syntactic processing depends on preserved functionality of intact regions, preserved functionality of atrophic regions, or compensatory functional reorganization. We scanned 20 individuals with semantic PPA and 24 age-matched controls using structural MRI and fMRI. Participants performed a sentence comprehension task that emphasized syntactic processing and minimized lexical semantic demands. We found that, in controls, left inferior frontal and left posterior temporal regions were modulated by syntactic processing, whereas anterior temporal regions were not significantly modulated. In the semantic PPA group, atrophy was most severe in the ATLs but extended to the posterior temporal regions involved in syntactic processing. Functional activity for syntactic processing was broadly similar in patients and controls; in particular, whole-brain analyses revealed no significant differences between patients and controls in the regions modulated by syntactic processing. The atrophic left ATL did show abnormal functionality in semantic PPA patients; however, this took the unexpected form of a failure to deactivate. Taken together, our findings indicate that spared syntactic processing in semantic PPA depends on preserved functionality of structurally intact left frontal regions and moderately atrophic left posterior temporal regions, but no functional reorganization was apparent as a consequence of anterior temporal atrophy and dysfunction. These results suggest that the role of the ATL in sentence processing is less likely to relate to syntactic structure-building and more likely to relate to higher-level processes such as combinatorial semantic processing

Localising semantic and syntactic processing in spoken and written language comprehension: an Activation Likelihood Estimation meta-analysis

We conducted an Activation Likelihood Estimation (ALE) meta-analysis to identify brain regions that are recruited by linguistic stimuli requiring relatively demanding semantic or syntactic processing. We included 54 functional MRI studies that explicitly varied the semantic or syntactic processing load, while holding constant demands on earlier stages of processing. We included studies that introduced a syntactic/semantic ambiguity or anomaly, used a priming manipulation that specifically reduced the load on semantic/syntactic processing, or varied the level of syntactic complexity. The results confirmed the critical role of the posterior left Inferior Frontal Gyrus (LIFG) in semantic and syntactic processing. These results challenge models of sentence comprehension highlighting the role of anterior LIFG for semantic processing. In addition, the results emphasise the posterior (but not anterior) temporal lobe for both semantic and syntactic processing

Functional Neuroanatomy of Second Language Sentence Comprehension: An fMRI Study of Late Learners of American Sign Language

The neurobiology of sentence comprehension is well-studied but the properties and characteristics of sentence processing networks remain unclear and highly debated. Sign languages (i.e., visual-manual languages), like spoken languages, have complex grammatical structures and thus can provide valuable insights into the specificity and function of brain regions supporting sentence comprehension. The present study aims to characterize how these well-studied spoken language networks can adapt in adults to be responsive to sign language sentences, which contain combinatorial semantic and syntactic visual-spatial linguistic information. Twenty native English-speaking undergraduates who had completed introductory American Sign Language (ASL) courses viewed videos of the following conditions during fMRI acquisition: signed sentences, signed word lists, English sentences and English word lists. Overall our results indicate that native language (L1) sentence processing resources are responsive to ASL sentence structures in late L2 learners, but that certain L1 sentence processing regions respond differently to L2 ASL sentences, likely due to the nature of their contribution to language comprehension. For example, L1 sentence regions in Broca's area were significantly more responsive to L2 than L1 sentences, supporting the hypothesis that Broca's area contributes to sentence comprehension as a cognitive resource when increased processing is required. Anterior temporal L1 sentence regions were sensitive to L2 ASL sentence structure, but demonstrated no significant differences in activation to L1 than L2, suggesting its contribution to sentence processing is modality-independent. Posterior superior temporal L1 sentence regions also responded to ASL sentence structure but were more activated by English than ASL sentences. An exploratory analysis of the neural correlates of L2 ASL proficiency indicates that ASL proficiency is positively correlated with increased activations in response to ASL sentences in L1 sentence processing regions. Overall these results suggest that well-established fronto-temporal spoken language networks involved in sentence processing exhibit functional plasticity with late L2 ASL exposure, and thus are adaptable to syntactic structures widely different than those in an individual's native language. Our findings also provide valuable insights into the unique contributions of the inferior frontal and superior temporal regions that are frequently implicated in sentence comprehension but whose exact roles remain highly debated

Estudio de la interacción entre procesos lingüísticos y emocionales en el cerebro humano

La literatura científica de los últimos años ha investigado los efectos de las emociones sobre el lenguaje, no solo en el aspecto semántico de esta, sino además sobre los procesamientos sintácticos, supuestamente encapsulados y ajenos a cualquier modulación exterior, hasta hace poco. Un grupo de estos estudios ha tratado de determinar qué rol juega cada una las dimensiones emocionales (valencia y activación) en estos efectos. Los resultados hasta la fecha han sido muy heterogéneos, debido en parte al uso de diferentes diseños experimentales. Por ello, aún no se conoce con precisión en qué medida la valencia y la activación emocional son responsables de estas modulaciones. Esta tesis tiene como objetivo examinar los correlatos electrofisiológicos de los efectos que la valencia tiene en la comprensión del lenguaje, bajo un diseño experimental que iguala las condiciones positiva, negativa y neutra, con independencia de la activación, también estudiada. Para ello, se igualan los estímulos de las tres condiciones de valencia a una misma activación. Con el desarrollo de dos tareas (lectura de palabras emocionales vs. Stroop emocional)durante la presentación del estímulo se logran estudiar los efectos bajo niveles de activación diferentes, así como también diferente esfuerzo cognitivo y diferente carga memorística y grado de acceso al contenido semántico..

Improving Sentence Comprehension Post-Stroke Using Neuroimaging and Neuropsychological Approaches

abstract: Cognitive deficits often accompany language impairments post-stroke. Past research has focused on working memory in aphasia, but attention is largely underexplored. Therefore, this dissertation will first quantify attention deficits post-stroke before investigating whether preserved cognitive abilities, including attention, can improve auditory sentence comprehension post-stroke. In Experiment 1a, three components of attention (alerting, orienting, executive control) were measured in persons with aphasia and matched-controls using visual and auditory versions of the well-studied Attention Network Test. Experiment 1b then explored the neural resources supporting each component of attention in the visual and auditory modalities in chronic stroke participants. The results from Experiment 1a indicate that alerting, orienting, and executive control are uniquely affected by presentation modality. The lesion-symptom mapping results from Experiment 1b associated the left angular gyrus with visual executive control, the left supramarginal gyrus with auditory alerting, and Broca’s area (pars opercularis) with auditory orienting attention post-stroke. Overall, these findings indicate that perceptual modality may impact the lateralization of some aspects of attention, thus auditory attention may be more susceptible to impairment after a left hemisphere stroke. Prosody, rhythm and pitch changes associated with spoken language may improve spoken language comprehension in persons with aphasia by recruiting intact cognitive abilities (e.g., attention and working memory) and their associated non-lesioned brain regions post-stroke. Therefore, Experiment 2 explored the relationship between cognition, two unique prosody manipulations, lesion location, and auditory sentence comprehension in persons with chronic stroke and matched-controls. The combined results from Experiment 2a and 2b indicate that stroke participants with better auditory orienting attention and a specific left fronto-parietal network intact had greater comprehension of sentences spoken with sentence prosody. For list prosody, participants with deficits in auditory executive control and/or short-term memory and the left angular gyrus and globus pallidus relatively intact, demonstrated better comprehension of sentences spoken with list prosody. Overall, the results from Experiment 2 indicate that following a left hemisphere stroke, individuals need good auditory attention and an intact left fronto-parietal network to benefit from typical sentence prosody, yet when cognitive deficits are present and this fronto-parietal network is damaged, list prosody may be more beneficial.Dissertation/ThesisDoctoral Dissertation Speech and Hearing Science 201

La influencia de la información facial en la comprensión del lenguaje : estudio con potenciales cerebrales evento-relacionados sobre sintaxis y semántica

Tesis inédita de la Universidad Complutense de Madrid, Facultad de Psicología, Departamento de Psicobología y Metodología en Ciencias del Comportamiento, leída el 25/11/2019Psycholinguistic research has traditionally focused on the study of the processes that make possible the comprehension of a linguistic message. Despite language is an inherent social capacity, face-to-face contexts have not received enough attention. In such situations, language comprehension entails an audiovisual processing, that is, auditory speech rapidly combines with visual information from the speaker’s face. Further, just seeing the speaker situates language processing in a social context. In this dissertation I investigate the effect of speaker’s face-related factors on semantic and morphosyntactic processing. Along three studies, participants listened to connected speech while seeing the speaker’s face. Meanwhile, an electroencephalogram (EEG) was recorded. The event related-potentials (ERPs) were computed to the critical words, which varied either on semantic congruency, expectancy or morphosyntactic correctness...Tradicionalmente, la investigación en psicolingüística se ha centrado en el estudio de los procesos que hacen posible la comprensión de un mensaje lingüístico. Sin embargo, a pesar de que el lenguaje es una capacidad humana inherentemente social, los contextos cara a cara no han recibido atención suficiente. En tales situaciones la comprensión del lenguaje es un proceso audiovisual y el habla auditiva se combina rápidamente con información visual procedente de la cara del hablante. Además, solo ver al hablante es suficiente para contextualizar socialmente el procesamiento lingüístico. A lo largo de tres estudios, esta tesis investiga el efecto que tienen diferentes variables relacionadas con la cara del hablante sobre el procesamiento semántico y morfosintáctico. Los participantes escucharon oraciones mientras veían la cara del hablante y al mismo tiempo se registró su actividad eléctrica cerebral mediante un electroencefalograma (EEG). Además, se calcularon potenciales evento-relacionados (PERs) a las palabras críticas, las cuales, dependiendo del experimento, variaban en congruencia semántica, expectativa o corrección morfosintáctica...Depto. de Psicobiología y Metodología en Ciencias del ComportamientoFac. de PsicologíaTRUEunpu