scholarly journals Overarching principles and dimensions of the functional organisation in the inferior parietal cortex

2019 ◽  
Author(s):  
Gina F. Humphreys ◽  
Rebecca L. Jackson ◽  
Matthew A. Lambon Ralph
Keyword(s):  
Parietal Cortex ◽  
Cognitive Processes ◽  
Task Engagement ◽  
Statistical Structure ◽  
The Core ◽  
Inferior Parietal Cortex ◽  
Functional Organisation ◽  
Visual Tasks ◽  
Group Ica ◽  
Anterior Posterior

AbstractThe parietal cortex (PC) is implicated in a confusing myriad of different cognitive processes/tasks. Consequently, understanding the nature and organisation of the core underlying neurocomputations is challenging. According to the Parietal Unified Connectivity-biased Computation (PUCC) model two properties underpin PC function and organisation. Firstly, PC is a multi-domain, context-dependent buffer of time-and space-varying input, the function of which, over time, becomes sensitive to the statistical temporal/spatial structure of events. Secondly, over and above this core buffering computation, differences in long-range connectivity will generate graded variations in task engagement across subregions. The current study tested these hypotheses using a group ICA technique with two independent fMRI datasets (task and resting state data). Three functional organisational principles were revealed. Factor 1: inferior PC was sensitive to the statistical structure of sequences for all stimulus types (pictures, sentences, numbers). Factor 2: a dorsal-ventral variation in generally task-positive vs. task-negative (variable) engagement. Factor 3: An anterior-posterior dimension in inferior PC reflecting different engagement in verbal vs. visual tasks, respectively. Together the data suggest that the core neurocomputation implemented by PC is common across domains, with graded task engagement across regions reflecting variations in the connectivity of task-specific networks that interact with parietal cortex.

scholarly journals Overarching Principles and Dimensions of the Functional Organization in the Inferior Parietal Cortex

2020 ◽  
Vol 30 (11) ◽  
pp. 5639-5653 ◽  
Author(s):  
Gina F Humphreys ◽  
Rebecca L Jackson ◽  
Matthew A Lambon Ralph
Keyword(s):  
Parietal Cortex ◽  
Functional Organization ◽  
Task Engagement ◽  
The Core ◽  
Analysis Technique ◽  
Inferior Parietal Cortex ◽  
Visual Tasks ◽  
Organizational Principles ◽  
Group Independent Component Analysis ◽  
Anterior Posterior

Abstract The parietal cortex (PC) is implicated in a confusing myriad of different cognitive processes/tasks. Consequently, understanding the nature and organization of the core underlying neurocomputations is challenging. According to the Parietal Unified Connectivity-biased Computation model, two properties underpin PC function and organization. Firstly, PC is a multidomain, context-dependent buffer of time- and space-varying input, the function of which, over time, becomes sensitive to the statistical temporal/spatial structure of events. Secondly, over and above this core buffering computation, differences in long-range connectivity will generate graded variations in task engagement across subregions. The current study tested these hypotheses using a group independent component analysis technique with two independent functional magnetic resonance imaging datasets (task and resting state data). Three functional organizational principles were revealed: Factor 1, inferior PC was sensitive to the statistical structure of sequences for all stimulus types (pictures, sentences, numbers); Factor 2, a dorsal–ventral variation in generally task-positive versus task-negative (variable) engagement; and Factor 3, an anterior–posterior dimension in inferior PC reflecting different engagement in verbal versus visual tasks, respectively. Together, the data suggest that the core neurocomputation implemented by PC is common across domains, with graded task engagement across regions reflecting variations in the connectivity of task-specific networks that interact with PC.

scholarly journals Convergence of cortical types and functional motifs in the human mesiotemporal lobe

eLife ◽  
2020 ◽  
Vol 9 ◽  
Author(s):  
Casey Paquola ◽  
Oualid Benkarim ◽  
Jordan DeKraker ◽  
Sara Larivière ◽  
Stefan Frässle ◽  
...  
Keyword(s):  
High Resolution ◽  
Cognitive Processes ◽  
Large Scale ◽  
Effective Connectivity ◽  
Brain Disorders ◽  
Neuronal Density ◽  
Functional Organisation ◽  
Large Scale Networks ◽  
Anterior Posterior

The mesiotemporal lobe (MTL) is implicated in many cognitive processes, is compromised in numerous brain disorders, and exhibits a gradual cytoarchitectural transition from six-layered parahippocampal isocortex to three-layered hippocampal allocortex. Leveraging an ultra-high-resolution histological reconstruction of a human brain, our study showed that the dominant axis of MTL cytoarchitectural differentiation follows the iso-to-allocortical transition and depth-specific variations in neuronal density. Projecting the histology-derived MTL model to in-vivo functional MRI, we furthermore determined how its cytoarchitecture underpins its intrinsic effective connectivity and association to large-scale networks. Here, the cytoarchitectural gradient was found to underpin intrinsic effective connectivity of the MTL, but patterns differed along the anterior-posterior axis. Moreover, while the iso-to-allocortical gradient parametrically represented the multiple-demand relative to task-negative networks, anterior-posterior gradients represented transmodal versus unimodal networks. Our findings establish that the combination of micro- and macrostructural features allow the MTL to represent dominant motifs of whole-brain functional organisation.

scholarly journals Parallel Hippocampal-Parietal Circuits for Self- and Goal-oriented Processing

2020 ◽  
Author(s):  
Annie Zheng ◽  
David F. Montez ◽  
Scott Marek ◽  
Adrian W. Gilmore ◽  
Dillan J. Newbold ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Cognitive Processes ◽  
Resting State ◽  
Resting State Fmri ◽  
Affective Processing ◽  
Resting State Functional Connectivity ◽  
Diverse Range ◽  
Memory Network ◽  
Stimulus Recognition ◽  
Anterior Posterior

SUMMARYThe hippocampus is critically important for a diverse range of cognitive processes, such as episodic memory, prospective memory, affective processing, and spatial navigation. The human hippocampus has been thought of as being solely functionally connected to a set of neocortical regions known as the default mode network (DMN), which supports self-referential cognition. Using individual-specific precision functional mapping of resting state fMRI data, we found the anterior hippocampus (head and body) to be preferentially connected to the DMN as expected. The hippocampal tail, however, was strongly preferentially connected to the parietal memory network (PMN), which supports goal-oriented cognition and stimulus recognition. This resting state functional connectivity (RSFC) anterior-posterior dichotomy was well-matched by differences in task deactivations and anatomical segmentations of the hippocampus. Task deactivations were localized to the head and body of the hippocampus (DMN), relatively sparing the tail (PMN). Anterior and posterior hippocampal connectivity was network-specific even though the DMN and PMN are interdigitated in medial parietal cortex. The functional dichotomization of the hippocampus into anterior DMN-connected and posterior PMN-connected parcels suggests parallel, but distinct circuits between the hippocampus and medial parietal cortex for self vs. goal-oriented processing.

scholarly journals Experimental Tests for Measuring Individual Attentional Characteristics in Songbirds

Animals ◽  
2021 ◽  
Vol 11 (8) ◽  
pp. 2233
Author(s):  
Loïc Pougnault ◽  
Hugo Cousillas ◽  
Christine Heyraud ◽  
Ludwig Huber ◽  
Martine Hausberger ◽  
...  
Keyword(s):  
Cognitive Processes ◽  
Comparative Research ◽  
Visual Stimuli ◽  
Experimental Tests ◽  
European Starling ◽  
Auditory Stimuli ◽  
The Core ◽  
Cognitive Studies ◽  
Individual Variations ◽  
Species Specific

Attention is defined as the ability to process selectively one aspect of the environment over others and is at the core of all cognitive processes such as learning, memorization, and categorization. Thus, evaluating and comparing attentional characteristics between individuals and according to situations is an important aspect of cognitive studies. Recent studies showed the interest of analyzing spontaneous attention in standardized situations, but data are still scarce, especially for songbirds. The present study adapted three tests of attention (towards visual non-social, visual social, and auditory stimuli) as tools for future comparative research in the European starling (Sturnus vulgaris), a species that is well known to present individual variations in social learning or engagement. Our results reveal that attentional characteristics (glances versus gazes) vary according to the stimulus broadcasted: more gazes towards unusual visual stimuli and species-specific auditory stimuli and more glances towards species-specific visual stimuli and hetero-specific auditory stimuli. This study revealing individual variations shows that these tests constitute a very useful and easy-to-use tool for evaluating spontaneous individual attentional characteristics and their modulation by a variety of factors. Our results also indicate that attentional skills are not a uniform concept and depend upon the modality and the stimulus type.

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