scholarly journals A functional dissociation between language and multiple-demand systems revealed in patterns of BOLD signal fluctuations

2014 ◽  
Vol 112 (5) ◽  
pp. 1105-1118 ◽  
Author(s):  
Idan Blank ◽  
Nancy Kanwisher ◽  
Evelina Fedorenko

What is the relationship between language and other high-level cognitive functions? Neuroimaging studies have begun to illuminate this question, revealing that some brain regions are quite selectively engaged during language processing, whereas other “multiple-demand” (MD) regions are broadly engaged by diverse cognitive tasks. Nonetheless, the functional dissociation between the language and MD systems remains controversial. Here, we tackle this question with a synergistic combination of functional MRI methods: we first define candidate language-specific and MD regions in each subject individually (using functional localizers) and then measure blood oxygen level-dependent signal fluctuations in these regions during two naturalistic conditions (“rest” and story-comprehension). In both conditions, signal fluctuations strongly correlate among language regions as well as among MD regions, but correlations across systems are weak or negative. Moreover, data-driven clustering analyses based on these inter-region correlations consistently recover two clusters corresponding to the language and MD systems. Thus although each system forms an internally integrated whole, the two systems dissociate sharply from each other. This independent recruitment of the language and MD systems during cognitive processing is consistent with the hypothesis that these two systems support distinct cognitive functions.

2019 ◽  
Vol 121 (4) ◽  
pp. 1244-1265 ◽  
Author(s):  
Alexander M. Paunov ◽  
Idan A. Blank ◽  
Evelina Fedorenko

Communication requires the abilities to generate and interpret utterances and to infer the beliefs, desires, and goals of others (“Theory of Mind”; ToM). These two abilities have been shown to dissociate: individuals with aphasia retain the ability to think about others’ mental states; and individuals with autism are impaired in social reasoning, but their basic language processing is often intact. In line with this evidence from brain disorders, functional MRI (fMRI) studies have shown that linguistic and ToM abilities recruit distinct sets of brain regions. And yet, language is a social tool that allows us to share thoughts with one another. Thus, the language and ToM brain networks must share information despite being implemented in distinct neural circuits. Here, we investigated potential interactions between these networks during naturalistic cognition using functional correlations in fMRI. The networks were functionally defined in individual participants, in terms of preference for sentences over nonwords for language, and for belief inference over physical-event processing for ToM, with both a verbal and a nonverbal paradigm. Although, across experiments, interregion correlations within each network were higher than between-network correlations, we also observed above-baseline synchronization of blood oxygenation level-dependent signal fluctuations between the two networks during rest and story comprehension. This synchronization was functionally specific: neither network was synchronized with the executive control network (functionally defined in terms of preference for a harder over easier version of an executive task). Thus, coordination between the language and ToM networks appears to be an inherent and specific characteristic of their functional architecture.NEW & NOTEWORTHY Humans differ from nonhuman primates in their abilities to communicate linguistically and to infer others’ mental states. Although linguistic and social abilities appear to be interlinked onto- and phylogenetically, they are dissociated in the adult human brain. Yet successful communication requires language and social reasoning to work in concert. Using functional MRI, we show that language regions are synchronized with social regions during rest and language comprehension, pointing to a possible mechanism for internetwork interaction.


2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Young-Bo Kim ◽  
Nambeom Kim ◽  
Jae Jun Lee ◽  
Seo-Eun Cho ◽  
Kyoung-Sae Na ◽  
...  

AbstractSubjective–objective discrepancy of sleep (SODS) might be related to the distorted perception of sleep deficit and hypersensitivity to insomnia-related stimuli. We investigated differences in brain activation to insomnia-related stimuli among insomnia patients with SODS (SODS group), insomnia patients without SODS (NOSODS group), and healthy controls (HC). Participants were evaluated for subjective and objective sleep using sleep diary and polysomnography. Functional magnetic resonance imaging was conducted during the presentation of insomnia-related (Ins), general anxiety-inducing (Gen), and neutral (Neu) stimuli. Brain reactivity to the contrast of Ins vs. Neu and Gen vs. Neu was compared among the SODS (n = 13), NOSODS (n = 15), and HC (n = 16) groups. In the SODS group compared to other groups, brain areas including the left fusiform, bilateral precuneus, right superior frontal gyrus, genu of corpus callosum, and bilateral anterior corona radiata showed significantly increased blood oxygen level dependent (BOLD) signal in the contrast of Ins vs. Neu. There was no brain region with significantly increased BOLD signal in the Gen vs. Neu contrast in the group comparisons. Increased brain activity to insomnia-related stimuli in several brain regions of the SODS group is likely due to these individuals being more sensitive to sleep-related threat and negative cognitive distortion toward insomnia.


2019 ◽  
Author(s):  
Rosemary Cowell ◽  
Morgan Barense ◽  
Patrick Sadil

Thanks to patients Phineas Gage and Henry Molaison, we have long known that behavioral control depends on the frontal lobes, whereas declarative memory depends on the medial temporal lobes. For decades, cognitive functions – behavioral control, declarative memory – have served as labels for characterizing the division of labor in cortex. This approach has made enormous contributions to understanding how the brain enables the mind, providing a systems-level explanation of brain function that constrains lower-level investigations of neural mechanism. Today, the approach has evolved such that functional labels are often applied to brain networks rather than focal brain regions. Furthermore, the labels have diversified to include both broadly-defined cognitive functions (declarative memory, visual perception) and more circumscribed mental processes (recollection, familiarity, priming). We ask whether a process – a high-level mental phenomenon corresponding to an introspectively-identifiable cognitive event – is the most productive label for dissecting memory. For example, the process of recollection conflates a neurocomputational operation (pattern completion-based retrieval) with a class of representational content (associative, high-dimensional, episodic-like memories). Because a full theory of memory must identify operations and representations separately, and specify how they interact, we argue that processes like recollection constitute inadequate labels for characterizing neural mechanisms. Instead, we advocate considering the component operations and representations of mnemonic processes in isolation, when examining their neural underpinnings. For the neuroanatomical organization of memory, the evidence suggests that pattern completion is recapitulated widely across cortex, but the division of labor between cortical sites can be explained by representational content.


Author(s):  
Rajashree Chaurasia

Human beings are the only mammals to be able to utilize high-level cognitive functions to build knowledge, innovate, and communicate their complex ideas. Imagination, creativity, and innovation are interlinked in the sense that one leads to the other. This chapter details the concepts of imagery, imagination, and creativity and their inter-relationships in the first section. Next, the author discusses the historical perspectives of imagination pertaining to the accounts of famous philosophers and psychologists like Aristotle, Kant, Hume, Descartes, Sartre, Husserl, and Wittgenstein. Section 3 and 4 present the neuro-biological correlates of imagination and creativity, respectively. Brain regions, neuronal circuits, genetic basis, as well as the evolutionary perspective of imagination and creativity are elicited in these sections. Finally, creativity and innovation are explored as to how they will contribute to knowledge build-up and advances in science, engineering, and business in the fourth industrial revolution and the imagination age.


2018 ◽  
Vol 28 (4) ◽  
pp. 379-388 ◽  
Author(s):  
Kayla Ryan ◽  
Sandy Goncalves ◽  
Robert Bartha ◽  
Neil Duggal

OBJECTIVEThe authors used functional MRI to assess cortical reorganization of the motor network after chronic spinal cord compression and to characterize the plasticity that occurs following surgical intervention.METHODSA 3-T MRI scanner was used to acquire functional images of the brain in 22 patients with reversible cervical spinal cord compression and 10 control subjects. Controls performed a finger-tapping task on 3 different occasions (baseline, 6-week follow-up, and 6-month follow-up), whereas patients performed the identical task before surgery and again 6 weeks and 6 months after spinal decompression surgery.RESULTSAfter surgical intervention, an increased percentage blood oxygen level–dependent signal and volume of activation was observed within the contralateral and ipsilateral motor network. The volume of activation of the contralateral primary motor cortex was associated with functional measures both at baseline (r = 0.55, p < 0.01) and 6 months after surgery (r = 0.55, p < 0.01). The percentage blood oxygen level–dependent signal of the ipsilateral supplementary motor area 6 months after surgery was associated with increased function 6 months after surgery (r = 0.48, p < 0.01).CONCLUSIONSPlasticity of the contralateral and ipsilateral motor network plays complementary roles in maintaining neurological function in patients with spinal cord compression and may be critical in the recovery phase following surgery.


2017 ◽  
Vol 23 (2) ◽  
pp. 824-835 ◽  
Author(s):  
Jui-Yang Hong ◽  
Eva M. Müller-Oehring ◽  
Adolf Pfefferbaum ◽  
Edith V. Sullivan ◽  
Dongjin Kwon ◽  
...  

2015 ◽  
Vol 112 (16) ◽  
pp. 5201-5206 ◽  
Author(s):  
Brian Barton ◽  
Alyssa A. Brewer

Are silencing, ectopic shifts, and receptive field (RF) scaling in cortical scotoma projection zones (SPZs) the result of long-term reorganization (plasticity) or short-term adaptation? Electrophysiological studies of SPZs after retinal lesions in animal models remain controversial, because they are unable to conclusively answer this question because of limitations of the methodology. Here, we used functional MRI (fMRI) visual field mapping through population RF (pRF) modeling with moving bar stimuli under photopic and scotopic conditions to measure the effects of the rod scotoma in human early visual cortex. As a naturally occurring central scotoma, it has a large cortical representation, is free of traumatic lesion complications, is completely reversible, and has not reorganized under normal conditions (but can as seen in rod monochromats). We found that the pRFs overlapping the SPZ in V1, V2, V3, hV4, and VO-1 generally (i) reduced their blood oxygen level-dependent signal coherence and (ii) shifted their pRFs more eccentric but (iii) scaled their pRF sizes in variable ways. Thus, silencing, ectopic shifts, and pRF scaling in SPZs are not unique identifiers of cortical reorganization; rather, they can be the expected result of short-term adaptation. However, are there differences between rod and cone signals in V1, V2, V3, hV4, and VO-1? We did not find differences for all five maps in more peripheral eccentricities outside of rod scotoma influence in coherence, eccentricity representation, or pRF size. Thus, rod and cone signals seem to be processed similarly in cortex.


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