scholarly journals Interacting networks of brain regions underlie human spatial navigation: a review and novel synthesis of the literature

2017 ◽  
Vol 118 (6) ◽  
pp. 3328-3344 ◽  
Author(s):  
Arne D. Ekstrom ◽  
Derek J. Huffman ◽  
Michael Starrett
Keyword(s):  
Cognitive Processes ◽  
Posterior Parietal Cortex ◽  
Spatial Navigation ◽  
Neural Model ◽  
Brain Regions ◽  
Cognitive Components ◽  
Current Task ◽  
Posterior Parietal ◽  
Interacting Networks ◽  
Multimodal Process

Navigation is an inherently dynamic and multimodal process, making isolation of the unique cognitive components underlying it challenging. The assumptions of much of the literature on human spatial navigation are that 1) spatial navigation involves modality independent, discrete metric representations (i.e., egocentric vs. allocentric), 2) such representations can be further distilled to elemental cognitive processes, and 3) these cognitive processes can be ascribed to unique brain regions. We argue that modality-independent spatial representations, instead of providing exact metrics about our surrounding environment, more often involve heuristics for estimating spatial topology useful to the current task at hand. We also argue that egocentric (body centered) and allocentric (world centered) representations are better conceptualized as involving a continuum rather than as discrete. We propose a neural model to accommodate these ideas, arguing that such representations also involve a continuum of network interactions centered on retrosplenial and posterior parietal cortex, respectively. Our model thus helps explain both behavioral and neural findings otherwise difficult to account for with classic models of spatial navigation and memory, providing a testable framework for novel experiments.

Reduced Cognitive Control Demands after Practice of Saccade Tasks in a Trial Type Probability Manipulation

2017 ◽  
Vol 29 (2) ◽  
pp. 368-381 ◽  
Author(s):  
Jordan E. Pierce ◽  
Jennifer E. McDowell
Keyword(s):  
Cognitive Control ◽  
Parietal Cortex ◽  
Trial Type ◽  
Posterior Parietal Cortex ◽  
Brain Regions ◽  
Mirror Image ◽  
Stimulus Response ◽  
Practice Group ◽  
Task Practice ◽  
Posterior Parietal

Cognitive control is engaged to facilitate stimulus–response mappings for novel, complex tasks and supervise performance in unfamiliar, challenging contexts—processes supported by pFC, ACC, and posterior parietal cortex. With repeated task practice, however, the appropriate task set can be selected in a more automatic fashion with less need for top–down cognitive control and weaker activation in these brain regions. One model system for investigating cognitive control is the ocular motor circuitry underlying saccade production, with basic prosaccade trials (look toward a stimulus) and complex antisaccade trials (look to the mirror image location) representing low and high levels of cognitive control, respectively. Previous studies have shown behavioral improvements on saccade tasks after practice with contradictory results regarding the direction of functional MRI BOLD signal change. The current study presented healthy young adults with prosaccade and antisaccade trials in five mixed blocks with varying probability of each trial type (0%, 25%, 50%, 75%, or 100% anti vs. pro) at baseline and posttest MRI sessions. Between the scans, participants practiced either the specific probability blocks used during testing or only a general 100% antisaccade block. Results indicated an overall reduction in BOLD activation within pFC, ACC, and posterior parietal cortex and across saccade circuitry for antisaccade trials. The specific practice group showed additional regions including ACC, insula, and thalamus with an activation decrease after practice, whereas the general practice group showed a little change from baseline in those clusters. These findings demonstrate that cognitive control regions recruited to support novel task behaviors were engaged less after practice, especially with exposure to mixed task contexts rather than a novel task in isolation.

scholarly journals Reconsidering the Border between the Visual and Posterior Parietal Cortex of Mice

2020 ◽  
Author(s):  
Sara R J Gilissen ◽  
Karl Farrow ◽  
Vincent Bonin ◽  
Lutgarde Arckens
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Spatial Navigation ◽  
Thalamic Nuclei ◽  
Anterior Cortex ◽  
Detailed Understanding ◽  
Cortical Input ◽  
Visual Areas ◽  
Posterior Parietal ◽  
Cortical Map

Abstract The posterior parietal cortex (PPC) contributes to multisensory and sensory-motor integration, as well as spatial navigation. Based on primate studies, the PPC is composed of several subdivisions with differing connection patterns, including areas that exhibit retinotopy. In mice the composition of the PPC is still under debate. We propose a revised anatomical delineation in which we classify the higher order visual areas rostrolateral area (RL), anteromedial area (AM), and Medio-Medial-Anterior cortex (MMA) as subregions of the mouse PPC. Retrograde and anterograde tracing revealed connectivity, characteristic for primate PPC, with sensory, retrosplenial, orbitofrontal, cingulate and motor cortex, as well as with several thalamic nuclei and the superior colliculus in the mouse. Regarding cortical input, RL receives major input from the somatosensory barrel field, while AM receives more input from the trunk, whereas MMA receives strong inputs from retrosplenial, cingulate, and orbitofrontal cortices. These input differences suggest that each posterior PPC subregion may have a distinct function. Summarized, we put forward a refined cortical map, including a mouse PPC that contains at least 6 subregions, RL, AM, MMA and PtP, MPta, LPta/A. These anatomical results set the stage for a more detailed understanding about the role that the PPC and its subdivisions play in multisensory integration-based behavior in mice.

Memory Engrams in the Neocortex

2020 ◽  
pp. 107385842094152
Author(s):  
Svenja Brodt ◽  
Steffen Gais
Keyword(s):  
Posterior Parietal Cortex ◽  
Brain Regions ◽  
Loss Of Function ◽  
Noninvasive Methods ◽  
New Era ◽  
Parallel Memory ◽  
Memory Representations ◽  
Posterior Parietal ◽  
Magnetic Resonance Imaging Mri ◽  
The Brain

While in the past much of our knowledge about memory representations in the brain has relied on loss-of-function studies in which whole brain regions were temporarily inactivated or permanently lesioned, the recent development of new methods has ushered in a new era of downright “engram excitement.” Animal research is now able to specifically label, track, and manipulate engram cells in the brain. While early studies have mostly focused on single brain regions like the hippocampus, recently more and more evidence for brain-wide distributed engram networks is emerging. Memory research in humans has also picked up pace, fueled by promising magnetic resonance imaging (MRI)-based methods like diffusion-weighted MRI (DW-MRI) and brain decoding. In this review, we will outline recent advancements in engram research, with a focus on human data and neocortical representations. We will illustrate the available noninvasive methods for the detection of engrams in different neocortical regions like the medial prefrontal cortex and the posterior parietal cortex and discuss evidence for systems consolidation and parallel memory encoding. Finally, we will explore how reactivation and prior knowledge can lead to and enhance engram formation in the neocortex.

Movement, Synchronization, and Partnering in Dance

2021 ◽  
pp. 195-198
Author(s):  
Steven Brown
Keyword(s):  
Parietal Cortex ◽  
Joint Action ◽  
Posterior Parietal Cortex ◽  
Spatial Navigation ◽  
Dance Movement ◽  
Motor Processes ◽  
Posterior Parietal ◽  
Neuroimaging Study ◽  
Sensory Processes ◽  
Movement Synchronization

In a neuroimaging study of tango dancers, the authors attempted to address two fundamental issues about dance: movement patterning (i.e., navigation of the legs in space) and synchronization of movement to the beat of music. The results of the study revealed the importance of the posterior parietal cortex to spatial navigation of movement and the cerebellum to synchronization to the beat. In a later two-person study of leading and following in dance, the author found that leaders accentuate motor processes, while followers accentuate sensory processes in their partnership. Dance is an interesting marriage of movement patterning, timing, and joint action.

Representation of Eye Position in the Human Parietal Cortex

2010 ◽  
Vol 104 (4) ◽  
pp. 2169-2177 ◽  
Author(s):  
Adrian L. Williams ◽  
Andrew T. Smith
Keyword(s):  
Parietal Cortex ◽  
Cortical Neurons ◽  
Posterior Parietal Cortex ◽  
Visual Stimulation ◽  
Block Design ◽  
Occipital Cortex ◽  
Brain Regions ◽  
Eye Position ◽  
Posterior Aspect ◽  
Posterior Parietal

Neurons that signal eye position are thought to make a vital contribution to distinguishing real world motion from retinal motion caused by eye movements, but relatively little is known about such neurons in the human brain. Here we present data from functional MRI experiments that are consistent with the existence of neurons sensitive to eye position in darkness in the human posterior parietal cortex. We used the enhanced sensitivity of multivoxel pattern analysis (MVPA) techniques, combined with a searchlight paradigm, to isolate brain regions sensitive to direction of gaze. During data acquisition, participants were cued to direct their gaze to the left or right for sustained periods as part of a block-design paradigm. Following the exclusion of saccade-related activity from the data, the multivariate analysis showed sensitivity to tonic eye position in two localized posterior parietal regions, namely the dorsal precuneus and, more weakly, the posterior aspect of the intraparietal sulcus. Sensitivity to eye position was also seen in anterior portions of the occipital cortex. The observed sensitivity of visual cortical neurons to eye position, even in the total absence of visual stimulation, is possibly a result of feedback from posterior parietal regions that receive eye position signals and explicitly encode direction of gaze.

scholarly journals From visual affordances in monkey parietal cortex to hippocampo–parietal interactions underlying rat navigation

1997 ◽  
Vol 352 (1360) ◽  
pp. 1429-1436 ◽  
Author(s):  
Michael A. Arbib
Keyword(s):  
Parietal Cortex ◽  
Visual Information ◽  
Posterior Parietal Cortex ◽  
Visual Motion ◽  
Graph Model ◽  
Brain Regions ◽  
Formal Similarity ◽  
Posterior Parietal ◽  
Level Model ◽  
Saccade Task

This paper explores the hypothesis that various subregions (but by no means all) of the posterior parietal cortex are specialized to process visual information to extract a variety of affordances for behaviour. Two biologically based models of regions of the posterior parietal cortex of the monkey are introduced. The model of the lateral intraparietal area (LIP) emphasizes its roles in dynamic remapping of the representation of targets during a double saccade task, and in combining stored, updated input with current visual input. The model of the anterior intraparietal area (AIP) addresses parietal–premotor interactions involved in grasping, and analyses the interaction between the AIP and premotor area F5. The model represents the role of other intraparietal areas working in concert with the inferotemporal cortex as well as with corollary discharge from F5 to provide and augment the affordance information in the AIP, and suggests how various constraints may resolve the action opportunities provided by multiple affordances. Finally, a systems–level model of hippocampo–parietal interactions underlying rat navigation is developed, motivated by the monkey data used in developing the above two models as well as by data on neurons in the posterior parietal cortex of the monkey that are sensitive to visual motion. The formal similarity between dynamic remapping (primate saccades) and path integration (rat navigation) is noted, and certain available data on rat posterior parietal cortex in terms of affordances for locomotion are explained. The utility of further modelling, linking the World Graph model of cognitive maps for motivated behaviour with hippocampal–parietal interactions involved in navigation, is also suggested. These models demonstrate that posterior parietal cortex is not only itself a network of interacting subsystems, but functions through cooperative computation with many other brain regions.

scholarly journals Distinct effects of prefrontal and parietal cortex inactivations on an accumulation of evidence task in the rat

eLife ◽  
2015 ◽  
Vol 4 ◽  
Author(s):  
Jeffrey C Erlich ◽  
Bingni W Brunton ◽  
Chunyu A Duan ◽  
Timothy D Hanks ◽  
Carlos D Brody
Keyword(s):  
Decision Making ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Neural Correlates ◽  
Brain Regions ◽  
Integration Time ◽  
Detailed Model ◽  
Evidence Accumulation ◽  
Posterior Parietal ◽  
Cortical Regions

Numerous brain regions have been shown to have neural correlates of gradually accumulating evidence for decision-making, but the causal roles of these regions in decisions driven by accumulation of evidence have yet to be determined. Here, in rats performing an auditory evidence accumulation task, we inactivated the frontal orienting fields (FOF) and posterior parietal cortex (PPC), two rat cortical regions that have neural correlates of accumulating evidence and that have been proposed as central to decision-making. We used a detailed model of the decision process to analyze the effect of inactivations. Inactivation of the FOF induced substantial performance impairments that were quantitatively best described as an impairment in the output pathway of an evidence accumulator with a long integration time constant (>240 ms). In contrast, we found a minimal role for PPC in decisions guided by accumulating auditory evidence, even while finding a strong role for PPC in internally-guided decisions.

scholarly journals A cortical cell ensemble in the posterior parietal cortex controls past experience-dependent memory updating

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Akinobu Suzuki ◽  
Sakurako Kosugi ◽  
Emi Murayama ◽  
Eri Sasakawa ◽  
Noriaki Ohkawa ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Cortical Cell ◽  
Brain Regions ◽  
Past Experience ◽  
Anterior Cingulate ◽  
Current Information ◽  
Posterior Parietal ◽  
Past Experiences ◽  
The Impact

AbstractWhen processing current sensory inputs, animals refer to related past experiences. Current information is then incorporated into the related neural network to update previously stored memories. However, the neuronal mechanism underlying the impact of memories of prior experiences on current learning is not well understood. Here, we found that a cellular ensemble in the posterior parietal cortex (PPC) that is activated during past experience mediates an interaction between past and current information to update memory through a PPC-anterior cingulate cortex circuit in mice. Moreover, optogenetic silencing of the PPC ensemble immediately after retrieval dissociated the interaction without affecting individual memories stored in the hippocampus and amygdala. Thus, a specific subpopulation of PPC cells represents past information and instructs downstream brain regions to update previous memories.

scholarly journals Neurometabolite Changes in Hyperthyroid Patients Before and After Antithyroid Treatment: An in vivo1H MRS Study

2021 ◽  
Vol 15 ◽  
Author(s):  
Mukesh Kumar ◽  
Sadhana Singh ◽  
Poonam Rana ◽  
Pawan Kumar ◽  
Tarun Sekhri ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Brain Regions ◽  
Before And After ◽  
Antithyroid Treatment ◽  
Posterior Parietal ◽  
Positive Correlations ◽  
The Brain ◽  
Hyperthyroid Patients

Purpose: Patients with hyperthyroidism have frequent neuropsychiatric symptoms such as lack of attention, concentration, poor memory, impaired executive functions, depression, and anxiety. These neurocognitive impairments such as memory, attention, and executive functions appear to be associated with dysfunction in brain regions. This study was conducted to investigate the metabolic changes in the brain subcortical regions, i.e., posterior parietal cortex and dorsolateral prefrontal cortex (DLPFC), in patients with hyperthyroidism before and after antithyroid treatment using proton magnetic resonance spectroscopy (1H MRS).Materials and Methods: We collected neuropsychological and 1H MRS data from posterior parietal cortex and DLPFC, in both control (N = 30) and hyperthyroid (N = 30) patients. In addition, follow-up data were available for 19 patients treated with carbimazole for 30 weeks. The relative ratios of the neurometabolites were calculated using the Linear Combination Model (LCModel). Analysis of co-variance using Bonferroni correction was performed between healthy controls and hyperthyroid patients, and a paired t-test was applied in patients at baseline and follow-up. Spearman’s rank-order correlation was used to analyze bivariate associations between thyroid hormone levels and metabolite ratios, and the partial correlation analysis was performed between neuropsychological scores and metabolite ratios, with age and sex as covariates, in the patients before and after treatment.Results: Our results revealed a significant decrease in choline/creatine [glycerophosphocholine (GPC) + phosphocholine (PCh)/creatine (tCr)] in both the posterior parietal cortex and DLPFC in hyperthyroid patients, and these changes were reversible after antithyroid treatment. The posterior parietal cortex also showed significantly reduced glutamate/creatine (Glu/tCr), (glutamate + glutamine)/creatine (Glx/tCr), and increased glutathione/creatine (GSH/tCr) ratios in the hyperthyroid patients over control subjects. In DLPFC, only (N-acetyl aspartate + N-acetyl aspartyl-glutamate)/creatine (NAA + NAAG)/tCr was increased in the hyperthyroid patients. After antithyroid treatment, (GPC + PCh)/tCr increased, and Glx/tCr decreased in both brain regions in the patients at follow-up. Gln/tCr in the posterior parietal cortex was decreased in patients at follow-up. Interestingly, (GPC + PCh)/tCr in DLPFC showed a significantly inverse correlation with free tri-iodothyronine (fT3) in hyperthyroid patients at baseline, whereas NAA/tCr showed positive correlations with fT3 and free thyroxine (fT4) in hyperthyroid patients before and after antithyroid treatment, in the posterior parietal cortex. In DLPFC, only (NAA + NAAG)/tCr showed positive correlations with fT3 and fT4 in the patients before treatment.Conclusion: The overall findings suggest that all the brain metabolite changes were not completely reversed in the hyperthyroid patients after antithyroid treatment, even after achieving euthyroidism.

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