Overlapping Networks Engaged during Spoken Language Production and Its Cognitive Control

Geranmayeh, Fatemeh; Wise, Richard J. S.; Mehta, Amrish; Leech, Robert

doi:10.1523/jneurosci.0428-14.2014

Cited by 125 publications

(160 citation statements)

References 88 publications

Supporting

Mentioning

135

Contrasting

Order By: Relevance

“…Functional imaging work suggests this region may be involved in semantic processing 33 with involvement of the temporal poles in a broader language network. 34 The mild deficits in speech sequencing observed in this study may be the result of deterioration of high-level cognitive control and attentional processes, 35 possibly linked to decreased cortical connectivity within the salience network. 36 However, the link here may not be causative but concurrent, given the role temporal poles play in regulating emotion processing in behavioral disorders.…”

Section: -24mentioning

confidence: 78%

Motor speech signature of behavioral variant frontotemporal dementia

et al. 2017

View full text Add to dashboard Cite

Objective: To provide a comprehensive description of motor speech function in behavioral variant frontotemporal dementia (bvFTD).Methods: Forty-eight individuals (24 bvFTD and 24 age-and sex-matched healthy controls) provided speech samples. These varied in complexity and thus cognitive demand. Their language was assessed using the Progressive Aphasia Language Scale and verbal fluency tasks. Speech was analyzed perceptually to describe the nature of deficits and acoustically to quantify differences between patients with bvFTD and healthy controls. Cortical thickness and subcortical volume derived from MRI scans were correlated with speech outcomes in patients with bvFTD.Results: Speech of affected individuals was significantly different from that of healthy controls. The speech signature of patients with bvFTD is characterized by a reduced rate (75%) and accuracy (65%) on alternating syllable production tasks, and prosodic deficits including reduced speech rate (45%), prolonged intervals (54%), and use of short phrases (41%). Groups differed on acoustic measures derived from the reading, unprepared monologue, and diadochokinetic tasks but not the days of the week or sustained vowel tasks. Variability of silence length was associated with cortical thickness of the inferior frontal gyrus and insula and speech rate with the precentral gyrus. Conclusions:One in 8 patients presented with moderate speech timing deficits with a further twothirds rated as mild or subclinical. Subtle but measurable deficits in prosody are common in bvFTD and should be considered during disease management. Language function correlated with speech timing measures derived from the unprepared monologue only. Neurology ® 2017;89:837-844 GLOSSARY ALS 5 amyotrophic lateral sclerosis; AMR 5 alternating motion rate; bvFTD 5 behavioral variant of frontotemporal dementia; CBD 5 corticobasal degeneration; CI 5 confidence interval; DDK 5 diadochokinesis; FTD 5 frontotemporal dementia; lvPPA 5 logopenic variant primary progressive aphasia; nvPPA 5 nonfluent variant primary progressive aphasia; PALS 5 Progressive Aphasia Language Scale; PPA 5 primary progressive aphasia; PSP 5 progressive supranuclear palsy; ROI 5 region of interest; SMR 5 sequential motion rate; svPPA 5 semantic variant primary progressive aphasia.

show abstract

Section: -24mentioning

confidence: 78%

Motor speech signature of behavioral variant frontotemporal dementia

et al. 2017

View full text Add to dashboard Cite

show abstract

“…ref. 34). Specifically, the ATL and AG did not show common activation for semantic tasks but, rather, common deactivation during nonsemantic task performance.…”

Section: Discussionmentioning

confidence: 99%

Establishing task- and modality-dependent dissociations between the semantic and default mode networks

Humphreys

Hoffman

Visser

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

191

240

View full text Add to dashboard Cite

The default mode network (DMN) and semantic network (SN) are two of the most extensively studied systems, and both are increasingly used as clinical biomarkers in neurological studies. There are strong theoretical reasons to assume a relationship between the networks, as well as anatomical evidence that they might rely on overlapping cortical regions, such as the anterior temporal lobe (ATL) or angular gyrus (AG). Despite these strong motivations, the relationship between the two systems has received minimal attention. We directly compared the SN and DMN using a large (n = 69) distortion-corrected functional MRI (fMRI) dataset, spanning a range of semantic and nonsemantic tasks that varied input modality. The results showed that both networks fractionate depending on the semantic nature of the task, stimulus type, modality, and task difficulty. Furthermore, despite recent claims that both AG and ATL are semantic hubs, the two areas responded very differently, with results supporting the role of ATL, but not AG, in semantic representation. Specifically, the left ATL was positively activated for all semantic tasks, but deactivated during nonsemantic task performance. In contrast, the left AG was deactivated for all tasks, with the level of deactivation related to task difficulty. Thus, ATL and AG do not share a common interest in semantic tasks, but, rather, a common "disinterest" in nonsemantic tasks. The implications for the variability in the DMN, its cognitive coherence, and interpretation of resting-state fMRI data are discussed.semantic network | default mode network | distortion-corrected fMRI | anterior temporal lobe | angular gyrus T wo substantial bodies of research literature, spanning cognitive and clinical neuroscience fields, have been dedicated to exploring the function and components of the semantic network (SN) and the default mode network (DMN). The DMN is an anatomically defined network that shows task-related deactivation during many goal-directed tasks (i.e., rest > task) (1) and can be reliably delineated using techniques such as independent components analysis (ICA) of resting-state functional MRI (fMRI) (2). The SN is a fronto-temporo-parietal network that is sensitive to semantic content in comparisons of semantic tasks > rest/nonsemantic control tasks (3). Although investigations of the DMN and SN have been primarily independent of each other, there are good reasons to compare the two networks directly. First, the networks might share common cognitive functions. One prominent theory suggests that during "rest," the brain is engaged in the activation of rich conceptual representations, and thus default-mode processing places strong demands on the semantic system (4). Secondly, the DMN and SN engage some common anatomical areas. The DMN consistently includes medial prefrontal cortex, parietal areas [angular gyrus (AG), precuneus, posterior cingulate cortex (PCC)], and, somewhat more variably, the lateral anterior temporal lobe (ATL) and hippocampus (1, 5). Some of these areas are considered...

show abstract

“…Using ICA as an initial step to identify the nodes in a functional network, effective connectivity methods such as DCM and Granger Causality can be employed as a secondary step to test for causal modulations of activity within the network, gaining maximal benefit from both methods. ICA often identifies additional neural activity not evident in univariate analyses (Geranmayeh, Wise, Mehta, & Leech, 2014;Simmonds, Leech, Collins, Redjep, & Wise, 2014). This likely reflects the fact that the same voxel can contribute to multiple overlapping functional networks: task-related activity within these overlapping networks can be modulated in opposite directions, hence differential responses can sometimes be obscured in univariate analyses that effectively average over these independent networks (Xu et al, 2013).…”

Section: Future Directionsmentioning

confidence: 99%

Comprehending auditory speech: previous and potential contributions of functional MRI

Evans

McGettigan

2017

Language, Cognition and Neuroscience

View full text Add to dashboard Cite

Functional neuroimaging revolutionized the study of human language in the late 20 th Century, allowing researchers to investigate its underlying cognitive processes in the intact brain. Here, we review how functional MRI (fMRI) in particular has contributed to our understanding of speech comprehension, with a focus on studies of intelligibility. We highlight the use of carefully controlled acoustic stimuli to reveal the underlying hierarchical organization of speech processing systems and cortical (a)symmetries, and discuss the contributions of novel design and analysis techniques to the contextualization of perisylvian regions within wider speech processing networks. Within this, we outline the methodological challenges of fMRI as a technique for investigating speech and describe the innovations that have overcome or mitigated these difficulties. Focussing on multivariate approaches to fMRI, we highlight how these techniques have allowed both local neural representations and broader scale brain systems to be described. 3 General IntroductionThe emergence of functional neuroimaging in the 1990s offered the unprecedented opportunity to examine the processing of spoken language in the intact, functioning human brain with a spatial resolution on the order of millimetres. Building upon the highly influential neuropsychological literature of the late 19 th and 20 th Centuries, a key aim of empirical study was uncovering the neural substrates for the comprehension of speech. Here, we offer a review and synthesis of the contributions of functional imaging -in particular, functional magnetic resonance imaging (fMRI) -to our understanding of the functional neuroanatomy of speech comprehension. We also offer an evaluation of the method and ask whether fMRI will continue to contribute substantially to our knowledge, or whether other modalities (or combinations of techniques) hold more promise for the future of the field.Other authors have offered excellent overviews of the state of the art in the functional imaging of language processes more generally (e.g. Price, 2012), and in the specific methodological challenges of examining auditory processing with fMRI (Peelle 2014). For this review, we felt that it was timely to limit our discussion to the use of fMRI in the investigation of speech comprehension. The study of speech comprehension has been at the centre of significant theoretical debate in the last decade, for example in addressing the role of hemispheric asymmetries and motor contributions to speech perception. Advances in experimental design and data analysis have played an important role in refining our understanding of these issues.Here, we highlight in particular the contributions and future opportunities afforded by multivariate analyses of the BOLD response in examining the nature and content of neural representations of the speech signal. Approaches such as Representational Similarity Analysis (Kriegeskorte et al., 2008), provide promise for integrating multiple imaging modalities, allowing examinatio...

show abstract

Overlapping Networks Engaged during Spoken Language Production and Its Cognitive Control

Cited by 125 publications

References 88 publications

Motor speech signature of behavioral variant frontotemporal dementia

Motor speech signature of behavioral variant frontotemporal dementia

Establishing task- and modality-dependent dissociations between the semantic and default mode networks

Comprehending auditory speech: previous and potential contributions of functional MRI

Contact Info

Product

Resources

About