scholarly journals Imagining Sounds and Images: Decoding the Contribution of Unimodal and Transmodal Brain Regions to Semantic Retrieval in the Absence of Meaningful Input

2019 ◽  
Vol 31 (11) ◽  
pp. 1599-1616 ◽  
Author(s):  
Charlotte Murphy ◽  
Shirley-Ann Rueschemeyer ◽  
Jonathan Smallwood ◽  
Elizabeth Jefferies
Keyword(s):  
Sensory Information ◽  
Brain Regions ◽  
External Input ◽  
Neural Systems ◽  
Middle Temporal Gyrus ◽  
Connectivity Analysis ◽  
Semantic Retrieval ◽  
Middle Temporal ◽  
Auditory Features

In the absence of sensory information, we can generate meaningful images and sounds from representations in memory. However, it remains unclear which neural systems underpin this process and whether tasks requiring the top–down generation of different kinds of features recruit similar or different neural networks. We asked people to internally generate the visual and auditory features of objects, either in isolation (car, dog) or in specific and complex meaning-based contexts (car/dog race). Using an fMRI decoding approach, in conjunction with functional connectivity analysis, we examined the role of auditory/visual cortex and transmodal brain regions. Conceptual retrieval in the absence of external input recruited sensory and transmodal cortex. The response in transmodal regions—including anterior middle temporal gyrus—was of equal magnitude for visual and auditory features yet nevertheless captured modality information in the pattern of response across voxels. In contrast, sensory regions showed greater activation for modality-relevant features in imagination (even when external inputs did not differ). These data are consistent with the view that transmodal regions support internally generated experiences and that they play a role in integrating perceptual features encoded in memory.

scholarly journals IN VIVO ASSESSMENT OF AMYLOID AND GLUCOSE SIGNATURES IN SUBJECTIVE COGNITIVE DECLINE SUBJECTS

2021 ◽  
pp. 2140018
Author(s):  
XIAOFENG YU ◽  
ZHILONG ZHU ◽  
SHUZHAN ZHENG ◽  
JIAN JIANG ◽  
JUANJUAN JIANG ◽  
...  
Keyword(s):  
Cognitive Decline ◽  
Characteristic Curve ◽  
Standardized Uptake Value ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Subjective Cognitive Decline ◽  
Middle Temporal ◽  
Main Effect ◽  
Heschl Gyrus

Subjective cognitive decline (SCD), characterized by self-perceived subtle cognitive impairment ahead of the appearance of explicit and measurable cognitive deficits, is regarded as the preclinical manifestation of the pathological change continuum of Alzheimer’s disease (AD). We were committed to exploring the amyloid and glucose metabolic signatures related to imminent brain metabolic changes in SCD subjects. This study included 39 subjects (mean age = 71.9 years; 14 males and 25 females) diagnosed with SCD disease and 39 gender-matched healthy controls (HCs) (mean age = 75.2; 16 males and 23 females) with brain [18F] fluorodeoxyglucose positron emission tomography (PET) images and [18F] florbetapir PET images. The standardized uptake value ratios (SUVRs) of PET images within the regions of interest (ROIs) were calculated. Inter-group SUVR differences were assessed by two-sample [Formula: see text]-testing and receiver operating characteristic curve (ROC) analyses. A generalized linear model (GLM) was employed to evaluate the correlations between amyloid and FDG uptake. Compared with HCs, SCD subjects showed significantly increased amyloid SUVR, as well as significantly increased glucose SUVR in the olfactory, amygdala, thalamus, heschl gyrus, superior and middle temporal gyrus and temporal pole (all [Formula: see text]). The amyloid SUVR of thalamus was found to have a better ROC result (area under the curve (AUC): 0.77, 95% confidence interval (CI): 0.66–0.86) in the HC group, as was the case with the glucose SUVR of the middle temporal gyrus (AUC: 0.83, 95% CI: 0.73–0.91). There were significant positive correlations between amyloid and glucose SUVRs ([Formula: see text]). The amyloid SUVR of the thalamus showed a significantly better main effect (odd ratio [Formula: see text] 2.91, 95% CI: 1.44–6.7, [Formula: see text]), and the glucose SUVR of the heschl gyrus indicated an enhanced main effect (odd ratio [Formula: see text] 5.08, 95% CI: 1.86–18.15, [Formula: see text]). SCD subjects demonstrated significant amyloid accumulation and glucose hypermetabolism in specific brain regions, and amyloid pathology overlapped with regions of glucose abnormality. These findings may advance the understanding of imminent pathological changes in the SCD stage and help to provide clinical guidelines for interventional management.

The Neurobiology of Social Attachment

2013 ◽  
pp. 1112-1126 ◽  
Author(s):  
Adam S. Smith ◽  
Kelly Lei ◽  
Zuoxin Wang
Keyword(s):  
Mental Health ◽  
Current Knowledge ◽  
Human Life ◽  
Sensory Information ◽  
Neural Systems ◽  
Social Attachment ◽  
Individual Bond ◽  
Intrinsic Component ◽  
Social Attachments

Social attachment is an intrinsic component of human life. As Aristotle famously noted, “man is by nature a social animal”, and as such, social attachments are wellsprings for our survival, success, and mental health. This dynamic process – involving complex behaviors, multimodal sensory information, and cognitive processes – leads infants to bond to their caregivers or two people to fall in love. Now, the neurobiological basis of attachment is coming to light, illuminating the role of various monoamines and neuropeptides. It is the goal of this chapter to describe the current knowledge of the neurobiology behind social attachments by uncoupling the neurochemical and neuroanatomy of individual bond-related behaviors, reconstructing uniformed neural systems, and correlating these findings to our understanding of human analogs.

scholarly journals Individual differences in reading comprehension and off-task thought relate to perceptually-coupled and decoupled cognition

2018 ◽  
Author(s):  
Meichao Zhang ◽  
Nicola Savill ◽  
Daniel S. Margulies ◽  
Jonathan Smallwood ◽  
Elizabeth Jefferies
Keyword(s):  
Reading Comprehension ◽  
Visual Cortex ◽  
Individual Differences ◽  
Task Performance ◽  
Default Mode Network ◽  
Expository Text ◽  
External Input ◽  
Middle Temporal Gyrus ◽  
Middle Temporal ◽  
Intrinsic Connectivity

AbstractAlthough the default mode network (DMN) is associated with off-task states, recent evidence shows it can support tasks. This raises the question of how DMN activity can be both beneficial and detrimental to task performance. The decoupling hypothesis proposes that these opposing states occur because DMN supports modes of cognition driven by external input, as well as retrieval states unrelated to input. To test this account, we capitalised on the fact that during reading, regions in DMN are thought to represent the meaning of words through their coupling with visual cortex; the absence of visual coupling should occur when the attention drifts off from the text. We examined individual differences in reading comprehension and off-task thought while participants read an expository text in the laboratory, and related variation in these measures to (i) the neural response during reading in the scanner (Experiment 1), and (ii) patterns of intrinsic connectivity measured in the absence of a task (Experiment 2). The responsiveness of a region of DMN in middle temporal gyrus (MTG) to orthographic inputs during reading predicted good comprehension, while intrinsic decoupling of the same site from visual cortex at rest predicted more frequent off-task thought. In addition, good comprehension was associated with greater intrinsic connectivity between MTG and medial prefrontal regions also within DMN, demonstrating that DMN coupling can support task performance, not only off-task states. These findings indicate that the opposing roles of DMN in cognition reflect its capacity to support both perceptually-coupled and decoupled cognition.

scholarly journals Lexical selection with competing distractors: Evidence from left temporal lobe lesions

2016 ◽  
Author(s):  
Vitória Piai ◽  
Robert T. Knight
Keyword(s):  
Interference Effect ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Error Rates ◽  
Middle Temporal Gyrus ◽  
Lexical Selection ◽  
Semantic Interference ◽  
Middle Temporal ◽  
Relative Contribution ◽  
Unrelated Condition

AbstractAccording to the competition account of lexical selection in word production, conceptually driven word retrieval involves the activation of a set of candidate words in left temporal cortex, and competitive selection of the intended word from this set, regulated by frontal cortical mechanisms. However, the relative contribution of these brain regions to competitive lexical selection is uncertain. In the present study, five patients with left prefrontal cortex lesions (overlapping in ventral and dorsal lateral cortex), eight patients with left lateral temporal cortex lesions (overlapping in middle temporal gyrus), and 13 matched controls performed a picture-word interference task. Distractor words were semantically related or unrelated to the picture, or the name of the picture (congruent condition). Semantic interference (related vs unrelated), tapping into competitive lexical selection, was examined. An overall semantic interference effect was observed for the control and left-temporal groups separately. The left-frontal patients did not show a reliable semantic interference effect as a group. The left-temporal patients had increased semantic interference in the error rates relative to controls. Error distribution analyses indicated that these patients had more hesitant responses for the related than for the unrelated condition. We propose that left middle temporal lesions affect the lexical activation component, making lexical selection more susceptible to errors.

scholarly journals Dynamic semantic cognition: Characterising coherent and controlled conceptual retrieval through time using magnetoencephalography and chronometric transcranial magnetic stimulation

2017 ◽  
Author(s):  
Catarina Teige ◽  
Giovanna Mollo ◽  
Rebecca Millman ◽  
Nicola Savill ◽  
Jonathan Smallwood ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Temporal Lobe ◽  
Magnetic Stimulation ◽  
Temporal Dynamics ◽  
Temporal Cortex ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Semantic Retrieval ◽  
Current Task ◽  
Stimulation Of

AbstractDistinct neural processes are thought to support the retrieval of semantic information that is (i) coherent with strongly-encoded aspects of knowledge, and (ii) non-dominant yet relevant for the current task or context. While the brain regions that support coherent and controlled patterns of semantic retrieval are relatively well-characterised, the temporal dynamics of these processes are not well-understood. This study used magnetoencephalography (MEG) and dual-pulse chronometric transcranial magnetic stimulation (cTMS) in two separate experiments to examine temporal dynamics within the temporal lobe during the retrieval of strong and weak associations. MEG results revealed a dissociation within left temporal cortex: anterior temporal lobe (ATL) showed greater oscillatory response for strong than weak associations, while posterior middle temporal gyrus (pMTG) showed the reverse pattern. In the cTMS experiment, stimulation of ATL at ~150ms disrupted the efficient retrieval of strong associations, indicating a necessary role for ATL in coherent conceptual activations. Stimulation of pMTG at the onset of the second word disrupted the retrieval of weak associations, suggesting this site may maintain information about semantic context from the first word, allowing engagement of semantic control. Together these studies provide converging evidence for a functional dissociation within the temporal lobe, across both tasks and time.

scholarly journals Automatic and Controlled Semantic Retrieval: TMS Reveals Distinct Contributions of Posterior Middle Temporal Gyrus and Angular Gyrus

2015 ◽  
Vol 35 (46) ◽  
pp. 15230-15239 ◽  
Author(s):  
J. Davey ◽  
P. L. Cornelissen ◽  
H. E. Thompson ◽  
S. Sonkusare ◽  
G. Hallam ◽  
...  
Keyword(s):  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Semantic Retrieval ◽  
Middle Temporal

scholarly journals Exploring the role of the posterior middle temporal gyrus in semantic cognition: Integration of anterior temporal lobe with executive processes

NeuroImage ◽  
2016 ◽  
Vol 137 ◽  
pp. 165-177 ◽  
Author(s):  
James Davey ◽  
Hannah E. Thompson ◽  
Glyn Hallam ◽  
Theodoros Karapanagiotidis ◽  
Charlotte Murphy ◽  
...  
Keyword(s):  
Temporal Lobe ◽  
Middle Temporal Gyrus ◽  
Executive Processes ◽  
Anterior Temporal Lobe ◽  
Middle Temporal ◽  
Semantic Cognition

scholarly journals Indirect White Matter Pathways Are Associated With Treated Naming Improvement in Aphasia

2021 ◽  
pp. 154596832199905
Author(s):  
Janina Wilmskoetter ◽  
Julius Fridriksson ◽  
Alexandra Basilakos ◽  
Lorelei Phillip Johnson ◽  
Barbara Marebwa ◽  
...  
Keyword(s):  
White Matter ◽  
Treatment Outcomes ◽  
Inferior Frontal Gyrus ◽  
Brain Regions ◽  
Angular Gyrus ◽  
Middle Temporal Gyrus ◽  
Middle Temporal ◽  
Pars Opercularis ◽  
Left Hemisphere Stroke ◽  
Linear Regressions

Background White matter disconnection of language-specific brain regions associates with worse aphasia recovery. Despite a loss of direct connections, many stroke survivors may maintain indirect connections between brain regions. Objective To determine (1) whether preserved direct connections between language-specific brain regions relate to better poststroke naming treatment outcomes compared to no direct connections and (2) whether for individuals with a loss of direct connections, preserved indirect connections are associated with better treatment outcomes compared to individuals with no connections. Methods We computed structural whole-brain connectomes from 69 individuals with chronic left-hemisphere stroke and aphasia who completed a 3-week-long language treatment that was supplemented by either anodal transcranial direct current stimulation (A-tDCS) or sham stimulation (S-tDCS). We determined differences in naming improvement between individuals with direct, indirect, and no connections using 1-way analyses of covariance and multivariable linear regressions. Results Independently of tDCS modality, direct or indirect connections between the inferior frontal gyrus pars opercularis and angular gyrus were both associated with a greater increase in correct naming compared to no connections ( P = .027 and P = .039, respectively). Participants with direct connections between the inferior frontal gyrus pars opercularis and middle temporal gyrus who received S-tDCS and participants with indirect connections who received A-tDCS significantly improved in naming accuracy. Conclusions Poststroke preservation of indirect white matter connections is associated with better treated naming improvement in aphasia even when direct connections are damaged. This mechanistic information can be used to stratify and predict treated naming recovery in individuals with aphasia.

Embodied Comprehension of Stories: Interactions between Language Regions and Modality-specific Neural Systems

2014 ◽  
Vol 26 (2) ◽  
pp. 279-295 ◽  
Author(s):  
Ho Ming Chow ◽  
Raymond A. Mar ◽  
Yisheng Xu ◽  
Siyuan Liu ◽  
Suraji Wagage ◽  
...  
Keyword(s):  
Language Processing ◽  
Inferior Frontal Gyrus ◽  
Past Research ◽  
Brain Regions ◽  
Neural Systems ◽  
Affective Processing ◽  
Middle Temporal Gyrus ◽  
Story Comprehension ◽  
Story Content ◽  
Visual Spatial

The embodied view of language processing proposes that comprehension involves multimodal simulations, a process that retrieves a comprehender's perceptual, motor, and affective knowledge through reactivation of the neural systems responsible for perception, action, and emotion. Although evidence in support of this idea is growing, the contemporary neuroanatomical model of language suggests that comprehension largely emerges as a result of interactions between frontotemporal language areas in the left hemisphere. If modality-specific neural systems are involved in comprehension, they are not likely to operate in isolation but should interact with the brain regions critical to language processing. However, little is known about the ways in which language and modality-specific neural systems interact. To investigate this issue, we conducted a functional MRI study in which participants listened to stories that contained visually vivid, action-based, and emotionally charged content. Activity of neural systems associated with visual-spatial, motor, and affective processing were selectively modulated by the relevant story content. Importantly, when functional connectivity patterns associated with the left inferior frontal gyrus (LIFG), the left posterior middle temporal gyrus (pMTG), and the bilateral anterior temporal lobes (aTL) were compared, both LIFG and pMTG, but not the aTL, showed enhanced connectivity with the three modality-specific systems relevant to the story content. Taken together, our results suggest that language regions are engaged in perceptual, motor, and affective simulations of the described situation, which manifest through their interactions with modality-specific systems. On the basis of our results and past research, we propose that the LIFG and pMTG play unique roles in multimodal simulations during story comprehension.

scholarly journals Experimental trauma rapidly modifies functional connectivity

2020 ◽  
Author(s):  
Geraldine Gvozdanovic ◽  
Erich Seifritz ◽  
Philipp Stämpfli ◽  
Antonietta Canna ◽  
Björn Rasch ◽  
...  
Keyword(s):  
Functional Connectivity ◽  
Trauma Exposure ◽  
Brain Regions ◽  
Middle Temporal Gyrus ◽  
Comprehensive Treatment ◽  
Post Traumatic Stress ◽  
Middle Temporal ◽  
Control Film ◽  
Psychiatric Syndrome ◽  
Experimental Trauma

Abstract Traumatic events can produce emotional, cognitive and autonomous physical responses. This may ultimately lead to post-traumatic stress disorder (PTSD), a psychiatric syndrome which requires comprehensive treatment. Trauma exposure alters functional connectivity; however, onset and nature of these changes are unknown. Here, we explore functional connectivity changes at rest directly after experimental trauma exposure. Seventy-three healthy subjects watched either a trauma or a control film. Resting state functional magnetic resonance imaging measurements were conducted before and directly after the film. Seed-based analyses revealed trauma-related changes in functional connectivity, specifically including decreases of connectivity between amygdala and middle temporal gyrus and increases between hippocampus and precuneus. These central effects were accompanied by trauma-related increases in heart rate. Moreover, connectivity between the amygdala and middle temporal gyrus predicted subsequent trauma-related valence. Our results demonstrate rapid functional connectivity changes in memory-related brain regions at rest after experimental trauma, selectively relating to changes in emotions evoked by the trauma manipulation. Results could represent an early predictive biomarker for the development of trauma-related PTSD and thus provide an indication for the need of early targeted preventive interventions.

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