scholarly journals State Estimation in Posterior Parietal Cortex: Distinct Poles of Environmental and Bodily States

2019 ◽  
Author(s):  
W. Pieter Medendorp ◽  
Tobias Heed
Keyword(s):  
Parietal Cortex ◽  
Information Seeking ◽  
Posterior Parietal Cortex ◽  
Functional Organization ◽  
Novelty Detection ◽  
The Body ◽  
Main Role ◽  
Motor Processing ◽  
Posterior Parietal ◽  
And Function

Posterior parietal cortex (PPC) has been implicated in sensory and motor processing, but its underlying organization is still debated. Sensory-based accounts suggest that PPC is mainly involved in attentional selection and multisensory integration, serving novelty detection and information seeking. Motor-specific accounts suggest a parietal subdivision into lower-dimensional, effector-specific subspaces for planning motor action. More recently, function-based interpretations have been put forward based on coordinated responses across multiple effectors evoked by circumscribed PPC regions. In this review, we posit that an overarching interpretation of PPC’s functional organization must integrate, rather than contrast, these various accounts of PPC. We propose that PPC’s main role is that of a state estimator, which extends into two poles: a rostral, body-related pole, which projects the environment onto the body and a caudal, environment-related pole that projects the body into an environment landscape. The combined topology interweaves perceptual, motor, and function-specific principles, and suggests that actions are specified by top-down guided optimization of body-environment interactions.

scholarly journals Functional organization of human posterior parietal cortex: grasping- and reaching-related activations relative to topographically organized cortex

2013 ◽  
Vol 109 (12) ◽  
pp. 2897-2908 ◽  
Author(s):  
Christina S. Konen ◽  
Ryan E. B. Mruczek ◽  
Jessica L. Montoya ◽  
Sabine Kastner
Keyword(s):  
Neural Networks ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Functional Organization ◽  
Macaque Monkey ◽  
Superior Parietal Lobule ◽  
Movement Type ◽  
The Neural Networks ◽  
Posterior Parietal ◽  
The Relationship

The act of reaching to grasp an object requires the coordination between transporting the arm and shaping the hand. Neurophysiological, neuroimaging, neuroanatomic, and neuropsychological studies in macaque monkeys and humans suggest that the neural networks underlying grasping and reaching acts are at least partially separable within the posterior parietal cortex (PPC). To better understand how these neural networks have evolved in primates, we characterized the relationship between grasping- and reaching-related responses and topographically organized areas of the human intraparietal sulcus (IPS) using functional MRI. Grasping-specific activation was localized to the left anterior IPS, partially overlapping with the most anterior topographic regions and extending into the postcentral sulcus. Reaching-specific activation was localized to the left precuneus and superior parietal lobule, partially overlapping with the medial aspects of the more posterior topographic regions. Although the majority of activity within the topographic regions of the IPS was nonspecific with respect to movement type, we found evidence for a functional gradient of specificity for reaching and grasping movements spanning posterior-medial to anterior-lateral PPC. In contrast to the macaque monkey, grasp- and reach-specific activations were largely located outside of the human IPS.

scholarly journals Transcranial Magnetic Stimulation Over the Human Medial Posterior Parietal Cortex Disrupts Depth Encoding During Reach Planning

2020 ◽  
Vol 31 (1) ◽  
pp. 267-280
Author(s):  
Rossella Breveglieri ◽  
Annalisa Bosco ◽  
Sara Borgomaneri ◽  
Alessia Tessari ◽  
Claudio Galletti ◽  
...  
Keyword(s):  
Transcranial Magnetic Stimulation ◽  
Parietal Cortex ◽  
Magnetic Stimulation ◽  
Posterior Parietal Cortex ◽  
Critical Role ◽  
The Body ◽  
Visually Guided ◽  
Visually Guided Reaching ◽  
Posterior Parietal

Abstract Accumulating evidence supports the view that the medial part of the posterior parietal cortex (mPPC) is involved in the planning of reaching, but while plenty of studies investigated reaching performed toward different directions, only a few studied different depths. Here, we investigated the causal role of mPPC (putatively, human area V6A–hV6A) in encoding depth and direction of reaching. Specifically, we applied single-pulse transcranial magnetic stimulation (TMS) over the left hV6A at different time points while 15 participants were planning immediate, visually guided reaching by using different eye-hand configurations. We found that TMS delivered over hV6A 200 ms after the Go signal affected the encoding of the depth of reaching by decreasing the accuracy of movements toward targets located farther with respect to the gazed position, but only when they were also far from the body. The effectiveness of both retinotopic (farther with respect to the gaze) and spatial position (far from the body) is in agreement with the presence in the monkey V6A of neurons employing either retinotopic, spatial, or mixed reference frames during reach plan. This work provides the first causal evidence of the critical role of hV6A in the planning of visually guided reaching movements in depth.

scholarly journals From thought to action: The brain–machine interface in posterior parietal cortex

2019 ◽  
Vol 116 (52) ◽  
pp. 26274-26279 ◽  
Author(s):  
Richard A. Andersen ◽  
Tyson Aflalo ◽  
Spencer Kellis
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
The Body ◽  
Assistive Device ◽  
Brain Machine Interface ◽  
Wide Range ◽  
Cord Injury ◽  
Posterior Parietal ◽  
Machine Interface ◽  
The Brain

A dramatic example of translational monkey research is the development of neural prosthetics for assisting paralyzed patients. A neuroprosthesis consists of implanted electrodes that can record the intended movement of a paralyzed part of the body, a computer algorithm that decodes the intended movement, and an assistive device such as a robot limb or computer that is controlled by these intended movement signals. This type of neuroprosthetic system is also referred to as a brain–machine interface (BMI) since it interfaces the brain with an external machine. In this review, we will concentrate on BMIs in which microelectrode recording arrays are implanted in the posterior parietal cortex (PPC), a high-level cortical area in both humans and monkeys that represents intentions to move. This review will first discuss the basic science research performed in healthy monkeys that established PPC as a good source of intention signals. Next, it will describe the first PPC implants in human patients with tetraplegia from spinal cord injury. From these patients the goals of movements could be quickly decoded, and the rich number of action variables found in PPC indicates that it is an appropriate BMI site for a very wide range of neuroprosthetic applications. We will discuss research on learning to use BMIs in monkeys and humans and the advances that are still needed, requiring both monkey and human research to enable BMIs to be readily available in the clinic.

Neurons in Area 5 of the Posterior Parietal Cortex in the Cat Contribute to Interlimb Coordination During Visually Guided Locomotion: A Role in Working Memory

2010 ◽  
Vol 103 (4) ◽  
pp. 2234-2254 ◽  
Author(s):  
Kim Lajoie ◽  
Jacques-Étienne Andujar ◽  
Keir Pearson ◽  
Trevor Drew
Keyword(s):  
Working Memory ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Interlimb Coordination ◽  
The Body ◽  
Visually Guided ◽  
Discharge Activity ◽  
Area 5 ◽  
Posterior Parietal ◽  
Step Over

We tested the hypothesis that area 5 of the posterior parietal cortex (PPC) contributes to interlimb coordination in locomotor tasks requiring visual guidance by recording neuronal activity in this area in three cats in two locomotor paradigms. In the first paradigm, cats were required to step over obstacles attached to a moving treadmill belt. We recorded 47 neurons that discharged in relationship to the hindlimbs. Of these, 31/47 discharged between the passage of the fore- and hindlimbs (FL-HL cells) over the obstacle. The activity of most of these neurons (25/31) was related to the fore- and hindlimb contralateral to the recording site when the contralateral forelimb was the first to pass over the obstacle. In many cells, discharge activity was limb-independent in that it was better related to the ipsilateral limbs when they were the first to step over the obstacle. The other 16/47 neurons discharged only when the hindlimbs stepped over the obstacle with the majority of these (12/16) discharging between the passage of the two hindlimbs over the obstacle. We tested 15/47 cells, including 11/47 FL-HL cells, in a second paradigm in which cats stepped over an obstacle on a walkway. Discharge activity in all of these cells was significantly modulated when the cat stepped over the obstacle and remained modified for periods of ≤1 min when forward progress of the cat was delayed with either the fore- and hindlimbs, or the two hindlimbs, straddling the obstacle. We suggest that neurons in area 5 of the PPC contribute to interlimb coordination during locomotion by estimating the spatial and temporal attributes of the obstacle with respect to the body. We further suggest that the discharge observed both during the steps over the obstacle and in the delayed locomotor paradigm is a neuronal correlate of working memory.

scholarly journals Differences in Intrinsic Functional Organization Between Dorsolateral Prefrontal and Posterior Parietal Cortex

2013 ◽  
Vol 24 (9) ◽  
pp. 2334-2349 ◽  
Author(s):  
F. Katsuki ◽  
X.-L. Qi ◽  
T. Meyer ◽  
P. M. Kostelic ◽  
E. Salinas ◽  
...  
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Functional Organization ◽  
Dorsolateral Prefrontal ◽  
Posterior Parietal

Somatosensory processes subserving perception and action

2007 ◽  
Vol 30 (2) ◽  
pp. 189-201 ◽  
Author(s):  
H. Chris Dijkerman ◽  
Edward H. F. de Haan
Keyword(s):  
Information Processing ◽  
Object Recognition ◽  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Perception And Action ◽  
Somatosensory System ◽  
The Body ◽  
Proprioceptive Information ◽  
Tactile Information ◽  
Posterior Parietal

AbstractThe functions of the somatosensory system are multiple. We use tactile input to localize and experience the various qualities of touch, and proprioceptive information to determine the position of different parts of the body with respect to each other, which provides fundamental information for action. Further, tactile exploration of the characteristics of external objects can result in conscious perceptual experience and stimulus or object recognition. Neuroanatomical studies suggest parallel processing as well as serial processing within the cerebral somatosensory system that reflect these separate functions, with one processing stream terminating in the posterior parietal cortex (PPC), and the other terminating in the insula. We suggest that, analogously to the organisation of the visual system, somatosensory processing for the guidance of action can be dissociated from the processing that leads to perception and memory. In addition, we find a second division between tactile information processing about external targets in service of object recognition and tactile information processing related to the body itself. We suggest the posterior parietal cortex subserves both perception and action, whereas the insula principally subserves perceptual recognition and learning.

scholarly journals Cortical and thalamic connectivity of posterior parietal visual cortical areas PPc and PPr of the domestic ferret (Mustela putorius furo).

2018 ◽  
Author(s):  
Leigh-Anne Dell ◽  
Giorgio M Innocenti ◽  
Claus C Hilgetag ◽  
Paul R Manger
Keyword(s):  
Parietal Cortex ◽  
Posterior Parietal Cortex ◽  
Mustela Putorius ◽  
Dorsal Thalamus ◽  
Area 7 ◽  
Model Animal ◽  
Visual Areas ◽  
Posterior Parietal ◽  
Visual Cortical ◽  
And Function

The present study describes the ipsilateral and contralateral cortico-cortical and cortico-thalamic connectivity of the parietal visual areas PPc and PPr in the ferret using standard anatomical tract-tracing methods. The two divisions of posterior parietal cortex of the ferret are strongly interconnected, however area PPc shows stronger connectivity with the occipital and suprasylvian visual cortex, while area PPr shows stronger connectivity with the somatomotor cortex, reflecting the functional specificity of these two areas. This pattern of connectivity is mirrored in the contralateral callosal connections. In addition, PPc and PPr are connected with the visual and somatomotor nuclei of the dorsal thalamus. Numerous connectional similarities exist between the posterior parietal cortex of the ferret (PPc and PPr) and the cat (area 7 and 5), indicative of the homology of these areas within the Carnivora. These findings highlight the existence of a fronto-parietal network as a shared feature of the organization of parietal cortex across Euarchontoglires and Laurasiatherians, with the degree of expression varying in relation to the expansion and areal complexity of the posterior parietal cortex. This observation indicates that the ferret is a potentially valuable experimental model animal for understanding the evolution and function of the posterior parietal cortex and the fronto-parietal network across mammals. The data generated will also contribute to the Ferretome (www.ferretome.org) connectomics databank, to further cross-species analyses of connectomes and illuminate wiring principles of cortical connectivity across mammals.

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