The Contribution of Different Cortical Regions to the Control of Spatially Decoupled Eye–Hand Coordination

2017 ◽  
Vol 29 (7) ◽  
pp. 1194-1211 ◽  
Author(s):  
Patricia F. Sayegh ◽  
Diana J. Gorbet ◽  
Kara M. Hawkins ◽  
Kari L. Hoffman ◽  
Lauren E. Sergio
Keyword(s):  
Single Unit ◽  
Meta Analysis ◽  
Premotor Cortex ◽  
Oscillatory Activity ◽  
Target Display ◽  
Neural Responses ◽  
Different Types ◽  
Control Research ◽  
Hand Coordination ◽  
Cortical Regions

Our brain's ability to flexibly control the communication between the eyes and the hand allows for our successful interaction with the objects located within our environment. This flexibility has been observed in the pattern of neural responses within key regions of the frontoparietal reach network. More specifically, our group has shown how single-unit and oscillatory activity within the dorsal premotor cortex (PMd) and the superior parietal lobule (SPL) change contingent on the level of visuomotor compatibility between the eyes and hand. Reaches that involve a coupling between the eyes and hand toward a common spatial target display a pattern of neural responses that differ from reaches that require eye–hand decoupling. Although previous work examined the altered spiking and oscillatory activity that occurs during different types of eye–hand compatibilities, they did not address how each of these measures of neurological activity interacts with one another. Thus, in an effort to fully characterize the relationship between oscillatory and single-unit activity during different types of eye–hand coordination, we measured the spike–field coherence (SFC) within regions of macaque SPL and PMd. We observed stronger SFC within PMdr and superficial regions of SPL (areas 5/PEc) during decoupled reaches, whereas PMdc and regions within SPL surrounding medial intrapareital sulcus had stronger SFC during coupled reaches. These results were supported by meta-analysis on human fMRI data. Our results support the proposal of altered cortical control during complex eye–hand coordination and highlight the necessity to account for the different eye–hand compatibilities in motor control research.

Differences in spectral profiles between rostral and caudal premotor cortex when hand-eye actions are decoupled

2013 ◽  
Vol 110 (4) ◽  
pp. 952-963 ◽  
Author(s):  
Patricia F. Sayegh ◽  
Kara M. Hawkins ◽  
Kari L. Hoffman ◽  
Lauren E. Sergio
Keyword(s):  
Visual Stimulus ◽  
Rhesus Macaques ◽  
Premotor Cortex ◽  
Standard Condition ◽  
Motor Task ◽  
Movement Control ◽  
Oscillatory Activity ◽  
Visually Guided ◽  
Control Research ◽  
Spectral Profiles

The aim of this research was to understand how the brain controls voluntary movement when not directly interacting with the object of interest. In the present study, we examined the role of premotor cortex in this behavior. The goal of this study was to characterize the oscillatory activity within the caudal and rostral subdivisions of dorsal premotor cortex (PMdc and PMdr) with a change from the most basic reaching movement to one that involves a simple dissociation between the actions of the eyes and hand. We were specifically interested in how PMdr and PMdc respond when the eyes and hand are decoupled by moving along different spatial planes. We recorded single-unit activity and local field potentials within PMdr and PMdc from two rhesus macaques during performance of two types of visually guided reaches. During the standard condition, a visually guided reach was performed whereby the visual stimulus guiding the movement was the target of the reach itself. During the nonstandard condition, the visual stimulus provided information about the direction of the required movement but was not the target of the motor output. We observed distinct task-related and topographical differences between PMdr and PMdc. Our results support functional differences between PMdr and PMdc during visually guided reaching. PMdr activity appears more involved in integrating the rule-based aspects of a visually guided reach, whereas PMdc is more involved in the online updating of the decoupled reach. More broadly, our results highlight the necessity of accounting for the nonstandard nature of a motor task when interpreting movement control research data.

scholarly journals Distributed task-specific processing of somatosensory feedback for voluntary motor control

eLife ◽  
2016 ◽  
Vol 5 ◽  
Author(s):  
Mohsen Omrani ◽  
Chantelle D Murnaghan ◽  
J Andrew Pruszynski ◽  
Stephen H Scott
Keyword(s):  
Primary Motor Cortex ◽  
Premotor Cortex ◽  
Target Selection ◽  
Neural Responses ◽  
Neural Basis ◽  
Motor Action ◽  
Motor Behaviors ◽  
Somatosensory Feedback ◽  
Area 5 ◽  
Cortical Regions

Corrective responses to limb disturbances are surprisingly complex, but the neural basis of these goal-directed responses is poorly understood. Here we show that somatosensory feedback is transmitted to many sensory and motor cortical regions within 25 ms of a mechanical disturbance applied to the monkey’s arm. When limb feedback was salient to an ongoing motor action (task engagement), neurons in parietal area 5 immediately (~25 ms) increased their response to limb disturbances, whereas neurons in other regions did not alter their response until 15 to 40 ms later. In contrast, initiation of a motor action elicited by a limb disturbance (target selection) altered neural responses in primary motor cortex ~65 ms after the limb disturbance, and then in dorsal premotor cortex, with no effect in parietal regions until 150 ms post-perturbation. Our findings highlight broad parietofrontal circuits that provide the neural substrate for goal-directed corrections, an essential aspect of highly skilled motor behaviors.

Alliance experience and performance outcomes: A meta-analysis

2021 ◽  
pp. 147612702098287
Author(s):  
Peng Wang ◽  
Xu Jiang ◽  
Maggie Chuoyan Dong
Keyword(s):  
Strategic Alliance ◽  
Meta Analysis ◽  
Group Analysis ◽  
Performance Outcomes ◽  
Country Level ◽  
Different Types ◽  
Performance Consequences ◽  
Controversial Topic ◽  
Alliance Experience ◽  
And Performance

Alliance experience has been a frequent topic in strategic alliance research in recent decades. Nonetheless, its performance consequences, either as a whole or differentiated into general versus partner-specific alliance experience, are neither theoretically clear nor empirically consistent. We use a range of meta-analytic techniques to integrate the empirical findings of 143 studies and provide a more conclusive assessment compared to prior research. Our study thus addresses a long-standing, understudied, and controversial topic: the distinction between the two types of alliance experiences. Going beyond traditional sub-group analysis, we reveal the contextual contingencies by examining how different types of alliance experiences and performance outcomes jointly affect the alliance experience–performance relationship. Moreover, we identify critical country-level institutional contingencies that moderate the focal effect.

scholarly journals Quantifying the signals contained in heterogeneous neural responses and determining their relationships with task performance

2014 ◽  
Vol 112 (6) ◽  
pp. 1584-1598 ◽  
Author(s):  
Marino Pagan ◽  
Nicole C. Rust
Keyword(s):  
Task Performance ◽  
Single Neuron ◽  
Weighted Sums ◽  
Neural Responses ◽  
Signal Modulation ◽  
Neural Data ◽  
Match To Sample ◽  
Neural Populations ◽  
Different Types ◽  
High Level

The responses of high-level neurons tend to be mixtures of many different types of signals. While this diversity is thought to allow for flexible neural processing, it presents a challenge for understanding how neural responses relate to task performance and to neural computation. To address these challenges, we have developed a new method to parse the responses of individual neurons into weighted sums of intuitive signal components. Our method computes the weights by projecting a neuron's responses onto a predefined orthonormal basis. Once determined, these weights can be combined into measures of signal modulation; however, in their raw form these signal modulation measures are biased by noise. Here we introduce and evaluate two methods for correcting this bias, and we report that an analytically derived approach produces performance that is robust and superior to a bootstrap procedure. Using neural data recorded from inferotemporal cortex and perirhinal cortex as monkeys performed a delayed-match-to-sample target search task, we demonstrate how the method can be used to quantify the amounts of task-relevant signals in heterogeneous neural populations. We also demonstrate how these intuitive quantifications of signal modulation can be related to single-neuron measures of task performance ( d′).

scholarly journals Efficacy of Different Types of Exercise on Cognitive Function in People With MCI or Dementia: A Network Meta-Analysis

2020 ◽  
Vol 4 (Supplement_1) ◽  
pp. 293-293
Author(s):  
Qiaoqin Wan ◽  
Xiuxiu Huang ◽  
Xiaoyan Zhao ◽  
Bei Li ◽  
Ying Cai ◽  
...  
Keyword(s):  
Executive Function ◽  
Cognitive Function ◽  
Cognitive Dysfunction ◽  
Meta Analysis ◽  
Memory Function ◽  
Controlled Trials ◽  
Exercise Interventions ◽  
Exercise Treatment ◽  
Different Types ◽  
Global Cognition

Abstract With the accelerating progress of population aging, cognitive dysfunction is becoming increasingly prevalent. Exercise, as a promising non-pharmaceutical therapy, showed favorable effects on cognitive function. But which type is the most effective exercise treatment is still unclear. This study compared the efficacy of different types of exercise interventions based on network meta-analysis and aimed to explore the optimal exercise treatment for cognitive decline. The electronic databases of PubMed, Web of Science, Embase, Cochrane Central Register of Controlled Trials, SPORTDiscus, PsycInfoy, and OpenGrey were searched from inception to September 2019. We only included randomized controlled trials that examined the effectiveness of exercise interventions in people with MCI or dementia. Primary outcomes were global cognition, executive function and memory function. Standard mean difference (SMD) and its 95% confidence interval (CI) were calculated to estimate the effect sizes. Finally, 73 articles with 5748 participants were included. The results showed all kinds of exercise interventions were effective on global cognition and resistance exercise was probably the most effective exercise treatment to prevent the decrease of global cognition (SMD=1.05, 95%CI 0.56-1.54), executive function (SMD=0.85, 95%CI 0.21-1.49) and memory function (SMD=0.32, 95%CI 0.01-0.63) for people with cognitive dysfunction. Subgroup analysis revealed multi-component exercise showed more favorable effects on global cognition (SMD=0.99, 95%CI 0.44-1.54) and executive function (SMD=0.72, 95%CI 0.06-1.38) in people with MCI. In conclusion, resistance exercise tended to be the optimal exercise type for people with cognitive dysfunction, especially for people with dementia. And multi-component exercise also should be recommended for people with MCI.

Corticospinal Tract Microstructure Correlates With Beta Oscillatory Activity in the Primary Motor Cortex After Stroke

Stroke ◽  
2021 ◽  
Author(s):  
Robert Schulz ◽  
Marlene Bönstrup ◽  
Stephanie Guder ◽  
Jingchun Liu ◽  
Benedikt Frey ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Fractional Anisotropy ◽  
Primary Motor Cortex ◽  
Supplementary Motor Area ◽  
Premotor Cortex ◽  
Motor Impairment ◽  
Motor Area ◽  
Oscillatory Activity ◽  
Premotor Area ◽  
Beta Power

Background and Purpose: Cortical beta oscillations are reported to serve as robust measures of the integrity of the human motor system. Their alterations after stroke, such as reduced movement-related beta desynchronization in the primary motor cortex, have been repeatedly related to the level of impairment. However, there is only little data whether such measures of brain function might directly relate to structural brain changes after stroke. Methods: This multimodal study investigated 18 well-recovered patients with stroke (mean age 65 years, 12 males) by means of task-related EEG and diffusion-weighted structural MRI 3 months after stroke. Beta power at rest and movement-related beta desynchronization was assessed in 3 key motor areas of the ipsilesional hemisphere that are the primary motor cortex (M1), the ventral premotor area and the supplementary motor area. Template trajectories of corticospinal tracts (CST) originating from M1, premotor cortex, and supplementary motor area were used to quantify the microstructural state of CST subcomponents. Linear mixed-effects analyses were used to relate tract-related mean fractional anisotropy to EEG measures. Results: In the present cohort, we detected statistically significant reductions in ipsilesional CST fractional anisotropy but no alterations in EEG measures when compared with healthy controls. However, in patients with stroke, there was a significant association between both beta power at rest ( P =0.002) and movement-related beta desynchronization ( P =0.003) in M1 and fractional anisotropy of the CST specifically originating from M1. Similar structure-function relationships were neither evident for ventral premotor area and supplementary motor area, particularly with respect to their CST subcomponents originating from premotor cortex and supplementary motor area, in patients with stroke nor in controls. Conclusions: These data suggest there might be a link connecting microstructure of the CST originating from M1 pyramidal neurons and beta oscillatory activity, measures which have already been related to motor impairment in patients with stroke by previous reports.

scholarly journals A Statistical Method for Synthesizing Meta-Analyses

2013 ◽  
Vol 2013 ◽  
pp. 1-9 ◽  
Author(s):  
Liansheng Larry Tang ◽  
Michael Caudy ◽  
Faye Taxman
Keyword(s):  
Statistical Method ◽  
Effect Size ◽  
Meta Analysis ◽  
Effect Sizes ◽  
Weighted Mean ◽  
Summary Effect ◽  
Different Types ◽  
Meta Analyses ◽  
Size Estimates ◽  
Similar Search

Multiple meta-analyses may use similar search criteria and focus on the same topic of interest, but they may yield different or sometimes discordant results. The lack of statistical methods for synthesizing these findings makes it challenging to properly interpret the results from multiple meta-analyses, especially when their results are conflicting. In this paper, we first introduce a method to synthesize the meta-analytic results when multiple meta-analyses use the same type of summary effect estimates. When meta-analyses use different types of effect sizes, the meta-analysis results cannot be directly combined. We propose a two-step frequentist procedure to first convert the effect size estimates to the same metric and then summarize them with a weighted mean estimate. Our proposed method offers several advantages over existing methods by Hemming et al. (2012). First, different types of summary effect sizes are considered. Second, our method provides the same overall effect size as conducting a meta-analysis on all individual studies from multiple meta-analyses. We illustrate the application of the proposed methods in two examples and discuss their implications for the field of meta-analysis.

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