scholarly journals Organizing principles of pulvino-cortical connectivity in humans

2017 ◽  
Author(s):  
Michael J. Arcaro ◽  
Mark A. Pinsk ◽  
Janice Chen ◽  
Sabine Kastner
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Parietal Cortex ◽  
Default Mode Network ◽  
Spatial Organization ◽  
Temporal Cortex ◽  
Cortical Areas ◽  
Organizing Principles ◽  
Human Specific

ABSTRACTThe pulvinar regulates information transmission to cortex and communication between cortical areas. The way the pulvinar interacts with cortex is governed by its intrinsic organization. Here, we show using fMRI that the human pulvinar is functionally heterogeneous, broadly separated into dorsal and ventral subdivisions based on characterization of response properties and functional connectivity with cortex. These differences mirrored the organization of the dorsal and ventral streams of visual cortex. The ventral subdivision of the pulvinar was functionally coupled with occipital and temporal cortex. The dorsal subdivision of the pulvinar was functionally coupled with frontal and parietal cortex. The dorsal subdivision was also coupled with the human-specific tool network and to the default mode network. The spatial organization of pulvino-cortical coupling reflected both the functional similarities and anatomical distances between cortical areas. Together, the human pulvinar appears to represent the entire visual system and the principles that govern its organization, though in a spatially compressed form.Author ContributionsMA, MP, and JC collected data; MA and JC analyzed the data; MA, MP, JC, and SK wrote the paper.

scholarly journals Age of Insomnia Onset Correlates with a Reversal of Default Mode Network and Supplementary Motor Cortex Connectivity

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Emiliano Santarnecchi ◽  
Chiara Del Bianco ◽  
Isabella Sicilia ◽  
Davide Momi ◽  
Giorgio Di Lorenzo ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Sleep Deprivation ◽  
Default Mode Network ◽  
Age Of Onset ◽  
Brain Connectivity ◽  
Disruptive Effect ◽  
Default Mode ◽  
Connectivity Patterns ◽  
The Impact

Insomnia might occur as result of increased cognitive and physiological arousal caused by acute or long acting stressors and associated cognitive rumination. This might lead to alterations in brain connectivity patterns as those captured by functional connectivity fMRI analysis, leading to potential insight about primary insomnia (PI) pathophysiology as well as the impact of long-term exposure to sleep deprivation. We investigated changes of voxel-wise connectivity patterns in a sample of 17 drug-naïve PI patients and 17 age-gender matched healthy controls, as well as the relationship between brain connectivity and age of onset, illness duration, and severity. Results showed a significant increase in resting-state functional connectivity of the bilateral visual cortex in PI patients, associated with decreased connectivity between the visual cortex and bilateral temporal pole. Regression with clinical scores originally unveiled a pattern of increased local connectivity as measured by intrinsic connectivity contrast (ICC), specifically resembling the default mode network (DMN). Additionally, age of onset was found to be correlated with the connectivity of supplementary motor area (SMA), and the strength of DMN←→SMA connectivity was significantly correlated with both age of onset (R2 = 41%) and disease duration (R2 = 21%). Chronic sleep deprivation, but most importantly early insomnia onset, seems to have a significant disruptive effect over the physiological negative correlation between DMN and SMA, a well-known fMRI marker of attention performance in humans. This suggests the need for more in-depth investigations on the prevention and treatment of connectivity changes and associated cognitive and psychological deficits in PI patients.

scholarly journals Pulvinar influences parietal delay activity and information transmission between dorsal and ventral visual cortex in macaques

2018 ◽  
Author(s):  
Yuri B. Saalmann ◽  
Ryan Ly ◽  
Mark A. Pinsk ◽  
Sabine Kastner
Keyword(s):  
Visual Cortex ◽  
Selective Attention ◽  
Information Transmission ◽  
Parietal Cortex ◽  
Sensory Information ◽  
Relevant Information ◽  
Attention Task ◽  
Sustained Activity ◽  
Cortical Areas ◽  
Visual Cortical

AbstractThe fronto-parietal attention network represents attentional priorities and provides feedback about these priorities to sensory cortical areas. Sustained spiking activity in the posterior parietal cortex (PPC) carries such prioritized information, but how this activity is sustained in the absence of feedforward sensory information, and how it is transmitted to the ventral visual cortical pathway, is unclear. We hypothesized that the higher-order thalamic nucleus, the pulvinar, which is connected with both the PPC and ventral visual cortical pathway, influences information transmission within and between these cortical regions. To test this, we simultaneously recorded from the pulvinar, lateral intraparietal area (LIP) and visual cortical area V4 in macaques performing a selective attention task. Here we show that LIP influenced V4 during the delay period of the attention task, and that the pulvinar regulated LIP-V4 information exchange. Pulvino-cortical effects were consistent with the pulvinar supporting sustained activity in LIP. Taken together, these results suggest that pulvinar regulation of cortical functional connectivity generalizes to dorsal and ventral visual cortical pathways. Further, the pulvinar’s role in sustaining parietal delay activity during selective attention implicates the pulvinar in other cognitive processes supported by such delay activity, including decision-making, categorization and oculomotor functions.Significance StatementA network of areas on the brain’s surface, in frontal and parietal cortex, allocate attention to behaviorally relevant information around us. Such areas in parietal cortex show sustained activity during maintained attention and transmit behaviorally relevant information to visual cortical areas to enhance sensory processing of attended objects. How this activity is sustained and how it is transmitted to visual areas supporting object perception is unclear. We show that a subcortical area, the pulvinar in the thalamus, helps sustain activity in the cortex and regulates the information transmitted between the fronto-parietal attention network and visual cortex. This suggests that the thalamus, classically considered as a simple relay for sensory information, contributes to higher-level cognitive functions.

scholarly journals Distinct subdivisions of human medial parietal cortex are recruited differentially for memory recall of places and people

2019 ◽  
Author(s):  
Edward H Silson ◽  
Adam Steel ◽  
Alexis Kidder ◽  
Adrian W Gilmore ◽  
Chris I Baker
Keyword(s):  
Parietal Cortex ◽  
Cognitive Processes ◽  
Default Mode Network ◽  
Temporal Cortex ◽  
Visual Presentation ◽  
Memory Recall ◽  
Default Mode ◽  
Scene Processing ◽  
People First ◽  
Ventral Temporal Cortex

AbstractHuman medial parietal cortex (MPC) is implicated in multiple cognitive processes including memory recall, visual scene processing and navigation. It is also considered a core component of the default mode network. Here, we combine fMRI data across three independent experiments to demonstrate distinct subdivisions of MPC that are selectively recruited during memory recall of either specific places or specific people. First, distinct regions of MPC were identified on the basis of differential functional connectivity with medial and lateral regions of anterior ventral temporal cortex (VTC). Second, these same medial regions exhibited differential responses to the visual presentation of different stimulus categories, with clear preferences for scenes and faces, respectively. Third, and most critically, these regions were selectively recruited during either place or people memory recall. These subdivisions also showed a striking relationship with ventral and dorsal divisions of the default mode network. Taken together, these data reveal distinct subdivisions within MPC for the recall of places and people and moreover, suggest that the organizing principle defining the medial-lateral axis of VTC is reflected in MPC, but in the context of memory recall.

scholarly journals Functional connectivity gradients as a common neural architecture for predictive processing in the human brain

2021 ◽  
Author(s):  
Yuta Katsumi ◽  
Nada Kamona ◽  
Jiahe Zhang ◽  
Jamie G. Bunce ◽  
J. Benjamin Hutchinson ◽  
...  
Keyword(s):  
Cerebral Cortex ◽  
Functional Connectivity ◽  
Large Scale ◽  
Functional Organization ◽  
Predictive Processing ◽  
Functional Variation ◽  
Functional Relationships ◽  
Low Dimensional ◽  
Organizing Principles

Predictive processing is emerging as a common neurocomputational hypothesis to account for diverse psychological functions subserved by a brain, enabling characterization of computational capacities of its distinct substructures. However, the literature is currently lacking a systems-level framework for understanding brain structure-function relationships based on the unified computational principles. Here, we contribute to this framework by examining gradients of functional connectivity as a low dimensional spatial representation of functional variation within a given structure. Specifically, we investigated functional connectivity gradients in the cerebral cortex, the cerebellum, and the hippocampus using resting-state functional MRI data collected from large samples of healthy young adults. We then evaluated the degree to which these structures share common principles of functional organization by assessing the correspondence of their gradients. We show that the organizing principles of these structures primarily follow two functional gradients consistent with the existing accounts of predictive processing: A model-error gradient that describes the flow of prediction and prediction error signals, and a model-precision gradient that differentiates regions involved in the representation and attentional modulation of such signals in the cerebral cortex. Using these gradients, we also demonstrate triangulation of functional connectivity involving distinct subregions of the three structures, suggesting the existence of parallel functional circuits that may subserve different aspects of predictive processing in the brain. These findings allow formulation of novel computational hypotheses about the functional relationships between the cerebral cortex, the cerebellum, and the hippocampus that may be instrumental for understanding the brain's dynamics within its large-scale predictive architecture.

scholarly journals Brain stimulation boosts perceptual learning by altering sensory GABAergic plasticity and functional connectivity

2021 ◽  
Author(s):  
Vasilis M Karlaftis ◽  
Polytimi Frangou ◽  
Cameron Higgins ◽  
Diego Vidaurre ◽  
Joseph J Ziminski ◽  
...  
Keyword(s):  
Visual Cortex ◽  
Magnetic Resonance ◽  
Functional Connectivity ◽  
Perceptual Learning ◽  
Parietal Cortex ◽  
Brain Stimulation ◽  
Posterior Parietal Cortex ◽  
Resonance Spectroscopy ◽  
Anodal Tdcs ◽  
Posterior Parietal

AbstractInterpreting cluttered scenes —a key skill for successfully interacting with our environment— relies on our ability to select relevant sensory signals while filtering out noise. Training is known to improve our ability to make these perceptual judgements by altering local processing in sensory brain areas. Yet, the brain-wide network mechanisms that mediate our ability for perceptual learning remain largely unknown. Here, we combine transcranial direct current stimulation (tDCS) with multi-modal brain measures to modulate cortical excitability during training on a signal-in-noise task (i.e. detection of visual patterns in noise) and test directly the link between processing in visual cortex and its interactions with decision-related areas (i.e. posterior parietal cortex). We test whether brain stimulation alters inhibitory processing in visual cortex, as measured by magnetic resonance spectroscopy (MRS) of GABA and functional connectivity between visual and posterior parietal cortex, as measured by resting state functional magnetic resonance imaging (rs-fMRI). We show that anodal tDCS during training results in faster learning and decreased GABA+ during training, before these changes occur for training without stimulation (i.e. sham). Further, anodal tDCS decreases occipito-parietal interactions and time-varying connectivity across the visual cortex. Our findings demonstrate that tDCS boosts learning by accelerating visual GABAergic plasticity and altering interactions between visual and decision-related areas, suggesting that training optimises gain control mechanisms (i.e. GABAergic inhibition) and functional inter-areal interactions to support perceptual learning.

scholarly journals Functional Connectivity of the Macaque Posterior Parahippocampal Cortex

2010 ◽  
Vol 103 (2) ◽  
pp. 793-800 ◽  
Author(s):  
Justin L. Vincent ◽  
Itamar Kahn ◽  
David C. Van Essen ◽  
Randy L. Buckner
Keyword(s):  
Functional Connectivity ◽  
Parietal Cortex ◽  
Memory Retrieval ◽  
Medial Temporal Lobe ◽  
Temporal Cortex ◽  
Superior Temporal Gyrus ◽  
Parahippocampal Cortex ◽  
Inferior Parietal Cortex ◽  
Alternative Processes ◽  
Posterior Midline

Neuroimaging experiments in humans suggest that regions in parietal cortex and along the posterior midline are functionally connected to the medial temporal lobe and are active during memory retrieval. It is unknown whether macaques have a similar network. We examined functional connectivity in isoflurane-anesthetized macaques to identify a network associated with posterior parahippocampal cortex (PPHC). Functional connectivity was observed between the PPHC and retrosplenial, posterior cingulate, superior temporal gyrus, and inferior parietal cortex. PPHC correlations were distinct from regions in parietal and temporal cortex activated by an oculomotor task. Comparison of macaque and human PPHC correlations revealed similarities that suggest the temporal-parietal region identified in the macaque may share a common lineage with human Brodmann area 39, a region thought to be involved in recollection. These results suggest that macaques and humans may have homologous PPHC-parietal pathways. By specifying the location of the putative macaque homologue in parietal cortex, we provide a target for future physiological exploration of this area's role in mnemonic or alternative processes.

scholarly journals Distinct subdivisions of human medial parietal cortex support recollection of people and places

eLife ◽  
2019 ◽  
Vol 8 ◽  
Author(s):  
Edward H Silson ◽  
Adam Steel ◽  
Alexis Kidder ◽  
Adrian W Gilmore ◽  
Chris I Baker
Keyword(s):  
Functional Connectivity ◽  
Parietal Cortex ◽  
Cognitive Processes ◽  
Temporal Cortex ◽  
Visual Presentation ◽  
Memory Recall ◽  
Core Component ◽  
Scene Processing ◽  
Ventral Temporal Cortex ◽  
Lateral Axis

Human medial parietal cortex (MPC) is implicated in multiple cognitive processes including memory recall, visual scene processing and navigation, and is a core component of the default mode network. Here, we demonstrate distinct subdivisions of MPC that are selectively recruited during memory recall of either specific people or places. First, distinct regions of MPC exhibited differential functional connectivity with medial and lateral regions of ventral temporal cortex (VTC). Second, these same medial regions showed selective, but negative, responses to the visual presentation of different stimulus categories, with clear preferences for scenes and faces. Finally, and most critically, these regions were differentially recruited during memory recall of either people or places with a strong familiarity advantage. Taken together, these data suggest that the organizing principle defining the medial-lateral axis of VTC is reflected in MPC, but in the context of memory recall.

scholarly journals Sensorimotor-independent development of hands and tools selectivity in the visual cortex

2017 ◽  
Vol 114 (18) ◽  
pp. 4787-4792 ◽  
Author(s):  
Ella Striem-Amit ◽  
Gilles Vannuscorps ◽  
Alfonso Caramazza
Keyword(s):  
Visual Cortex ◽  
Functional Connectivity ◽  
Upper Limb ◽  
Similar Pattern ◽  
Functional Organization ◽  
Temporal Cortex ◽  
Object Manipulation ◽  
Motor Experience ◽  
Hand Tool ◽  
Visual Characteristics

The visual occipito-temporal cortex is composed of several distinct regions specialized in the identification of different object kinds such as tools and bodies. Its organization appears to reflect not only the visual characteristics of the inputs but also the behavior that can be achieved with them. For example, there are spatially overlapping responses for viewing hands and tools, which is likely due to their common role in object-directed actions. How dependent is occipito-temporal cortex organization on object manipulation and motor experience? To investigate this question, we studied five individuals born without hands (individuals with upper limb dysplasia), who use tools with their feet. Using fMRI, we found the typical selective hand–tool overlap (HTO) not only in typically developed control participants but also in four of the five dysplasics. Functional connectivity of the HTO in the dysplasics also showed a largely similar pattern as in the controls. The preservation of functional organization in the dysplasics suggests that occipito-temporal cortex specialization is driven largely by inherited connectivity constraints that do not require sensorimotor experience. These findings complement discoveries of intact functional organization of the occipito-temporal cortex in people born blind, supporting an organization largely independent of any one specific sensory or motor experience.

Engaging regularly with fiction influences connectivity in cortical areas for language and mentalizing

2017 ◽  
Author(s):  
Roel M. Willems ◽  
Franziska Hartung
Keyword(s):  
Functional Connectivity ◽  
Time Course ◽  
Language Skills ◽  
Brain Regions ◽  
Brain Areas ◽  
Daily Lives ◽  
Cortical Areas ◽  
Social Abilities ◽  
Behavioral Evidence ◽  
Amount Of Reading

Behavioral evidence suggests that engaging with fiction is positively correlated with social abilities. The rationale behind this link is that engaging with fictional narratives offers a ‘training modus’ for mentalizing and empathizing. We investigated the influence of the amount of reading that participants report doing in their daily lives, on connections between brain areas while they listened to literary narratives. Participants (N=57) listened to two literary narratives while brain activation was measured with fMRI. We computed time-course correlations between brain regions, and compared the correlation values from listening to narratives to listening to reversed speech. The between-region correlations were then related to the amount of fiction that participants read in their daily lives. Our results show that amount of fiction reading is related to functional connectivity in areas known to be involved in language and mentalizing. This suggests that reading fiction influences social cognition as well as language skills.

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