scholarly journals Motor Cortical Representation of Position and Velocity During Reaching

2007 ◽  
Vol 97 (6) ◽  
pp. 4258-4270 ◽  
Author(s):  
Wei Wang ◽  
Sherwin S. Chan ◽  
Dustin A. Heldman ◽  
Daniel W. Moran
Keyword(s):  
Neural Activity ◽  
Cortical Neurons ◽  
Three Dimensional ◽  
Reaching Movements ◽  
Hand Position ◽  
Cortical Representation ◽  
Reaching Task ◽  
Position Signal ◽  
Motor Cortical ◽  
Highly Correlated

This study examines motor cortical representation of hand position and its relationship to the representation of hand velocity during reaching movements. In all, 978 motor cortical neurons were recorded from the proximal arm area of rostral motor cortex. The results demonstrate that position and velocity are simultaneously encoded by single motor cortical neurons in an additive fashion and that the relative weights of the position and velocity signals change dynamically during reaching. The two variables—hand position and hand velocity—are highly correlated in the standard center-out reaching task. A new reaching task (standard reaching) is introduced to minimize these correlations. Likewise, a new decoding method (indirect OLE) was developed to analyze the data by simultaneously decoding both three-dimensional (3D) hand position and 3D hand velocity from correlated neural activity. This method shows that, on average, the reconstructed velocity led the actual hand velocity by 122 ms, whereas the reconstructed position signal led the actual hand position by 81 ms.

scholarly journals Aging Does Not Affect Beta Modulation during Reaching Movements

2019 ◽  
Vol 2019 ◽  
pp. 1-11 ◽  
Author(s):  
Serena Ricci ◽  
Ramtin Mehraram ◽  
Elisa Tatti ◽  
Aaron B. Nelson ◽  
Martina Bossini-Baroggi ◽  
...  
Keyword(s):  
Modulation Depth ◽  
Movement Time ◽  
Peak Latency ◽  
Reaching Movements ◽  
Performance Indices ◽  
Reaching Task ◽  
Beta Power ◽  
Total Movement ◽  
Older Subjects ◽  
Highly Correlated

During movement, modulation of beta power occurs over the sensorimotor areas, with a decrease just before its start (event-related desynchronization, ERD) and a rebound after its end (event-related synchronization, ERS). We have recently found that the depth of ERD-to-ERS modulation increases during practice in a reaching task and the following day decreases to baseline levels. Importantly, the magnitude of the beta modulation increase during practice is highly correlated with the retention of motor skill tested the following day. Together with other evidence, this suggests that the increase of practice-related modulation depth may be the expression of sensorimotor cortex’s plasticity. Here, we determine whether the practice-related increase of beta modulation depth is equally present in a group of younger and a group of older subjects during the performance of a 30-minute block of reaching movements. We focused our analyses on two regions of interest (ROIs): the left sensorimotor and the frontal region. Performance indices were significantly different in the two groups, with the movements of older subjects being slower and less accurate. Importantly, both groups presented a similar increase of the practice-related beta modulation depth in both ROIs in the course of the task. Peak latency analysis revealed a progressive delay of the ERS peak that correlated with the total movement time. Altogether, these findings support the notion that the depth of beta modulation in a reaching movement task does not depend on age and confirm previous findings that only ERS peak latency but not ERS magnitude is related to performance indices.

scholarly journals Primary motor cortical neurons reflect visuomotor coordination during arm-reaching movements

IBRO Reports ◽  
2019 ◽  
Vol 6 ◽  
pp. S166
Author(s):  
Min-Ki Kim ◽  
Soyoung Chae ◽  
Seong-Min Kim ◽  
Jeong-Woo Sohn ◽  
Sung-Phil Kim
Keyword(s):  
Cortical Neurons ◽  
Reaching Movements ◽  
Visuomotor Coordination ◽  
Arm Reaching ◽  
Motor Cortical

Role of motor cortex in coordinating multi-joint movements: Is it time for a new paradigm?

2000 ◽  
Vol 78 (11) ◽  
pp. 923-933 ◽  
Author(s):  
Stephen H Scott
Keyword(s):  
Motor Cortex ◽  
Neural Activity ◽  
Cortical Activity ◽  
Reaching Movements ◽  
Cortical Region ◽  
Joint Movement ◽  
Global Features ◽  
Motor Patterns ◽  
New Device ◽  
Motor Cortical

Reaching movements to spatial targets require motor patterns at the shoulder to be coordinated carefully with those at the elbow to smoothly move the hand through space. While the motor cortex is involved in this volitional task, considerable debate remains about how this cortical region participates in planning and controlling movement. This article reviews two opposing interpretations of motor cortical function during multi-joint movements. On the one hand, studies performed predominantly on single-joint movement generally support the notion that motor cortical activity is intimately involved in generating motor patterns at a given joint. In contrast, studies on reaching demonstrate correlations between motor cortical activity and features of movement related to the hand, suggesting that the motor cortex may be involved in more global features of the task. Although this latter paradigm involves a multi-joint motor task in which neural activity is correlated with features of movement related to the hand, this neural activity is also correlated to other movement variables. Therefore it is difficult to assess if and how the motor cortex contributes to the coordination of motor patterns at different joints. In particular, present paradigms cannot assess whether motor cortical activity contributes to the control of one joint or multiple joints during whole-arm tasks. The final point discussed in this article is the development of a new experimental device (KINARM) that can both monitor and manipulate the mechanics of the shoulder and elbow independently during multi-joint motor tasks. It is hoped that this new device will provide a new approach for examining how the motor cortex is involved in motor coordination.Key words: reaching movements, biomechanics, motor coordination, proximal arm.

Dopaminergic modulation of transcallosal activity of cat motor cortical neurons

1999 ◽  
Vol 33 (1) ◽  
pp. 33-40 ◽  
Author(s):  
Kadrul Huda ◽  
Thucidydes L. Salunga ◽  
Syed A. Chowdhury ◽  
Takashi Kawashima ◽  
Ken’ichi Matsunami
Keyword(s):  
Cortical Neurons ◽  
Dopaminergic Modulation ◽  
Motor Cortical

scholarly journals Comparative three-dimensional connectome map of motor cortical projections in the mouse brain

2016 ◽  
Vol 6 (1) ◽  
Author(s):  
Minju Jeong ◽  
Yongsoo Kim ◽  
Jeongjin Kim ◽  
Daniel D. Ferrante ◽  
Partha P. Mitra ◽  
...  
Keyword(s):  
Mouse Brain ◽  
Three Dimensional ◽  
Cortical Projections ◽  
Motor Cortical

Effect of Nicorandil on the Spatial Arrangement of Primary Motor Cortical Neurons in the Sub-Acute Phase of Stroke in a Rat Model

2021 ◽  
pp. 102000
Author(s):  
Maryam Owjfard ◽  
Zohreh Taghadosi ◽  
Mohammad Reza Bigdeli ◽  
Anahid Safari ◽  
Asadollah Zarifkar ◽  
...  
Keyword(s):  
Acute Phase ◽  
Rat Model ◽  
Cortical Neurons ◽  
Spatial Arrangement ◽  
Motor Cortical

scholarly journals Growth and structural discrimination of cortical neurons on randomly oriented and vertically aligned dense carbon nanotube networks

2014 ◽  
Vol 5 ◽  
pp. 1575-1579 ◽  
Author(s):  
Christoph Nick ◽  
Sandeep Yadav ◽  
Ravi Joshi ◽  
Christiane Thielemann ◽  
Jörg J Schneider
Keyword(s):  
Carbon Nanotubes ◽  
Carbon Nanotube ◽  
Cortical Neurons ◽  
Three Dimensional ◽  
Vertically Aligned Carbon Nanotubes ◽  
Aligned Carbon Nanotubes ◽  
Vertically Aligned ◽  
The Individual ◽  
Carbon Nanotube Networks ◽  
Communication Paths

The growth of cortical neurons on three dimensional structures of spatially defined (structured) randomly oriented, as well as on vertically aligned, carbon nanotubes (CNT) is studied. Cortical neurons are attracted towards both types of CNT nano-architectures. For both, neurons form clusters in close vicinity to the CNT structures whereupon the randomly oriented CNTs are more closely colonised than the CNT pillars. Neurons develop communication paths via neurites on both nanoarchitectures. These neuron cells attach preferentially on the CNT sidewalls of the vertically aligned CNT architecture instead than onto the tips of the individual CNT pillars.

scholarly journals Striatal Dopamine Transporter Spect Quantification: Head-To-Head Comparison Between Two Three-Dimensional Automatic Tools

2020 ◽  
Author(s):  
Silvia Morbelli ◽  
Dario Arnaldi ◽  
Eugenia Cella ◽  
Stefano Raffa ◽  
Isabella Donegani ◽  
...  
Keyword(s):  
Dopamine Transporter ◽  
Gold Standard ◽  
Rating Scale ◽  
Three Dimensional ◽  
Correlation Coefficients ◽  
Striatal Dopamine ◽  
Dat Spect ◽  
Disease Rating ◽  
Highly Correlated ◽  
Visual Reading

Abstract Purpose. Our aim was the head-to-head comparison between two automatic tools for semi-quantification of striatal dopamine transporter (DAT) specific-to-non displaceable (SBR) ratio brain SPECT values in a naturalistic cohort of patients. Procedures. We analyzed consecutive scans from one-hundred and fifty-one outpatients submitted to brain DAT SPECT for a suspected parkinsonism. Images were post-processed using a commercial (Datquant®) and a free (BasGanV2) software. Reading by expert was the gold-standard. A subset of patients with pathological or borderline scan was evaluated with the clinical Unified Parkinson’s disease rating scale, motor part (MDS-UPDRS-III). Results. SBR, putamen-to-caudate (P/C) ratio, and both P and C asymmetries were highly correlated between the two software with Pearson’s ‘r’ correlation coefficients ranging from .706 to .887. Correlation coefficients with the MDS-UPDRS III score were higher with caudate than with putamen SBR values with both software, and in general higher with BasGanV2 than with Datquant® . Datquant® correspondence with expert reading was 84.1% (94.0% by additionally considering the P/C ratio as a further index). BasGanV2 correspondence with expert reading was 80.8% (86.1% by additionally considering the P/C ratio). Conclusions. Both Datquant® and BasGanV2 work reasonably well and similarly one another in semi-quantification of DAT SPECT. Both tools have their own strength and pitfalls that must be known in detail by users in order to obtain the best help in visual reading and reporting of DAT SPECT.

scholarly journals The Two-dimensional and Three-dimensional T2 Weighted Imaging-based Radiomic Signatures Selected for the Preoperative Discrimination of Ovarian Borderline Tumors and Epithelial Cancer.

2021 ◽  
Author(s):  
Xuefen Liu ◽  
Tianping Wang ◽  
Guofu Zhang ◽  
Keqin Hua ◽  
Hua Jiang ◽  
...  
Keyword(s):  
Three Dimensional ◽  
Operator Method ◽  
Two Dimensional ◽  
Borderline Tumors ◽  
Segmentation Methods ◽  
Highly Correlated ◽  
Selection Operator ◽  
2D And 3D ◽  
Testing Group ◽  
Segmentation Models

Abstract Background: Accurate discrimination between ovarian borderline tumors (BOTs) and malignancies with imaging play an important role in management.Purpose: To evaluate the ability of T2-weighted imaging (T2WI)-based radiomics to discriminate ovarian borderline tumors (BOTs) from malignancies based on two-dimensional (2D) and three-dimensional (3D) lesion segmentation methods.Methods: A total of 95 patients with pathologically proven ovarian BOTs and 101 patients with malignancies were retrospectively included in this study. We evaluated the diagnostic performance of the signatures derived from T2WI-based radiomics in their ability to differentiate between BOTs and malignancies and compared the performance differences in the 2D and 3D segmentation models. The least absolute shrinkage and selection operator method (LASSO) was used for radiomics feature selection and machine learning processing.Results: The radiomics score between BOTs and malignancies in four types of selected T2WI-based radiomics models differed significantly at the statistical level (p < 0.0001). For the classification between BOTs and malignant masses, the 2D and 3D coronal T2WI-based radiomics models yielded accuracy values of 0.79 and 0.83 in the testing group, respectively; the 2D and 3D sagittal fat-suppressed (fs) T2WI-based radiomics models yielded an accuracy of 0.78 and 0.99, respectively.Conclusion: Our results suggest that T2WI-based radiomic features were highly correlated with ovarian tumor subtype classification. 3D-sagittal MRI radiomics features may help clinicians differentiate ovarian BOTs from malignancies with high accuracy (ACC).

The Spatial Dependency of Shoulder Muscle Demands for Seated Lateral Hand Force Exertions

2014 ◽  
Vol 30 (1) ◽  
pp. 1-11 ◽  
Author(s):  
Alison C. McDonald ◽  
Elora C. Brenneman ◽  
Alan C. Cudlip ◽  
Clark R. Dickerson
Keyword(s):  
Repeated Measures ◽  
Muscle Activation ◽  
Three Dimensional ◽  
Emg Activity ◽  
Hand Position ◽  
Individual Muscle ◽  
Repeated Measures Analysis ◽  
Spatial Parameters ◽  
Shoulder Complex ◽  
The Right

As the modern workplace is dominated by submaximal repetitive tasks, knowledge of the effect of task location is important to ensure workers are unexposed to potentially injurious demands imposed by repetitive work in awkward or sustained postures. The purpose of this investigation was to develop a three-dimensional spatial map of the muscle activity for the right upper extremity during laterally directed submaximal force exertions. Electromyographic (EMG) activity was recorded from fourteen muscles surrounding the shoulder complex as the participants exerted 40N of force in two directions (leftward, rightward) at 70 defined locations. Hand position in both push directions strongly influenced total and certain individual muscle demands as identified by repeated measures analysis of variance (P< .001). During rightward exertions individual muscle activation varied from 1 to 21% MVE and during leftward exertions it varied from 1 to 27% MVE with hand location. Continuous prediction equations for muscular demands based on three-dimensional spatial parameters were created with explained variance ranging from 25 to 73%. The study provides novel information for evaluating existing and proactive workplace designs, and may help identify preferred geometric placements of lateral exertions in occupational settings to lower muscular demands, potentially mitigating fatigue and associated musculoskeletal risks.

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