scholarly journals Desynchronizing to be faster? Perceptual- and attentional-modulation of brain rhythms in sub-millisecond scale

2018 ◽  
Author(s):  
Yasuki Noguchi ◽  
Yi Xia ◽  
Ryusuke Kakigi
Keyword(s):  
Information Transfer ◽  
Visual Stimulation ◽  
Neural Population ◽  
Neural Computations ◽  
Mean And Variance ◽  
The Mean ◽  
Beta Rhythms ◽  
High Level ◽  
The Brain

AbstractNeural oscillatory signals has been associated with many high-level functions (e.g. attention and working memory), because they reflect correlated behaviors of neural population that would facilitate the information transfer in the brain. On the other hand, a decreased power of oscillation (event-related desynchronization or ERD) has been associated with an irregular state in which many neurons behave in an uncorrelated manner. In contrast to this view, here we show that the human ERD is linked to the increased regularity of oscillatory signals. Using magnetoencephalography, we found that presenting a visual stimulus not only induced the ERD of alpha (8-13 Hz) and beta (13-30 Hz) rhythms in the contralateral visual cortex but also reduced the mean and variance of their inter-peak intervals (IPIs). This indicates that the suppressed alpha/beta rhythms became faster (reduced mean) and more regular (reduced variance) during visual stimulation. The same changes in IPIs, especially those of beta rhythm, were observed when subjects allocated their attention to a contralateral visual field. Those results revealed a new role of the ERD and further suggested that our brain regulates and accelerates a clock for neural computations by actively inducing the desynchronization in task-relevant regions.

scholarly journals Reward skewness coding in the insula independent of probability and loss

2011 ◽  
Vol 106 (5) ◽  
pp. 2415-2422 ◽  
Author(s):  
Christopher J. Burke ◽  
Philippe N. Tobler
Keyword(s):  
Loss Aversion ◽  
Natural Environment ◽  
Potential Outcomes ◽  
Preference Formation ◽  
Individual Preferences ◽  
Data Support ◽  
Mean And Variance ◽  
The Mean ◽  
The Asymmetry ◽  
The Brain

Rewards in the natural environment are rarely predicted with complete certainty. Uncertainty relating to future rewards has typically been defined as the variance of the potential outcomes. However, the asymmetry of predicted reward distributions, known as skewness, constitutes a distinct but neuroscientifically underexplored risk term that may also have an impact on preference. By changing only reward magnitudes, we study skewness processing in equiprobable ternary lotteries involving only gains and constant probabilities, thus excluding probability distortion or loss aversion as mechanisms for skewness preference formation. We show that individual preferences are sensitive to not only the mean and variance but also to the skewness of predicted reward distributions. Using neuroimaging, we show that the insula, a structure previously implicated in the processing of reward-related uncertainty, responds to the skewness of predicted reward distributions. Some insula responses increased in a monotonic fashion with skewness (irrespective of individual skewness preferences), whereas others were similarly elevated to both negative and positive as opposed to no reward skew. These data support the notion that the asymmetry of reward distributions is processed in the brain and, taken together with replicated findings of mean coding in the striatum and variance coding in the cingulate, suggest that the brain codes distinct aspects of reward distributions in a distributed fashion.

scholarly journals The Prorenin and (Pro)renin Receptor: New Players in the Brain Renin-Angiotensin System?

2012 ◽  
Vol 2012 ◽  
pp. 1-8 ◽  
Author(s):  
Wencheng Li ◽  
Hua Peng ◽  
Dale M. Seth ◽  
Yumei Feng
Keyword(s):  
Renin Angiotensin System ◽  
Ang Ii ◽  
Future Perspectives ◽  
Vasopressin Release ◽  
Angiotensin System ◽  
Renin Angiotensin ◽  
Treatment Of Hypertension ◽  
High Level ◽  
The Brain

It is well known that the brain renin-angiotensin (RAS) system plays an essential role in the development of hypertension, mainly through the modulation of autonomic activities and vasopressin release. However, how the brain synthesizes angiotensin (Ang) II has been a debate for decades, largely due to the low renin activity. This paper first describes the expression of the vasoconstrictive arm of RAS components in the brain as well as their physiological and pathophysiological significance. It then focus on the (pro)renin receptor (PRR), a newly discovered component of the RAS which has a high level in the brain. We review the role of prorenin and PRR in peripheral organs and emphasize the involvement of brain PRR in the pathogenesis of hypertension. Some future perspectives in PRR research are heighted with respect to novel therapeutic target for the treatment of hypertension and other cardiovascular diseases.

scholarly journals Persepsi dan Tahap Pengetahuan Peserta Dan Agen Takaful Terhadap Pelaksanaan Zakat Takaful: Kajian Di Shah Alam, Selangor (Perceptions and Knowledge Levels of Takaful Participants and Agencies towards Implementation of Takaful Zakat: A Study In Shah Alam, Selangor)

2019 ◽  
Vol 6 (2-2) ◽  
Author(s):  
Nur Amirah Jaafar ◽  
Hairunnizam Wahid ◽  
Mohd Ali Mohd Noor
Keyword(s):  
Sampling Method ◽  
The Body ◽  
Permanent Disability ◽  
Level Of Knowledge ◽  
The Mean ◽  
The Right ◽  
High Level ◽  
Push Factor ◽  
Knowledge And Acceptance

When it comes to zakat obligations, people only know certain types of zakat that are obligated to be issued. There are two types of zakat; zakat fitrah and zakat property. However, zakat’s division may vary according to the state's fatwa. In Selangor, Lembaga Zakat Selangor (LZS) is the body that governs the administration and implementation of Zakat. The breakdown of zakat property is Zakat on Income, Zakat on Business, Zakat on Savings, Zakat on Gold and Silver, Zakat on Investments and Shares, Zakat on KWSP, Zakat on Paddy, Zakat on Agriculture, Zakat on Wealth and Treasure, and the Zakat on Takaful. However, this study will only focus on Zakat Takaful. Under Zakat Takaful, there are several divisions which are Zakat Wang Takaful/Takaful Investment, Zakat on Maturity Policy, Takaful Compensation, Tabarruq Fund, Benefit of Total and Permanent Disability, and Compensation of Conventional Insurance Policy. Each of these sections has its calculation method which will be explained further. This study was conducted to identify the level of knowledge and acceptance of Takaful Muslim consumers on the implementation of Zakat Takaful that has been introduced by LZS. Besides, this study will also look at the knowledge of Takaful agents and their willingness to disseminate information of Zakat Takaful to their customers. This study was conducted by using the sampling method and descriptive data analysis. The study found that on average, respondents' knowledge on Zakat Takaful is low with a mean of 2.32. However, the mean for acceptance is 3.93 which is set at a high level thus showed a good acceptance of the survey respondents. Through this study, it can be concluded that knowledge and acceptance are both very important in achieving the objective of implementing Zakat Takaful. Knowledge by Takaful participants who are also assisted by agents who play the role of conveying knowledge of Zakat Takaful is directly perceived to have a more effective effect in addition to the behavior/attitude that forms the intention of Takaful participnts to accept the implementation and to pay Zakah Takaful. This study is also expected to be the push factor among the zakat agents to play a role in disseminating the right information about Zakat Takaful to their customers, which also can be regarded as one of the da'wah forms.

scholarly journals S100A6 and Its Brain Ligands in Neurodegenerative Disorders

2020 ◽  
Vol 21 (11) ◽  
pp. 3979
Author(s):  
Anna Filipek ◽  
Wiesława Leśniak
Keyword(s):  
Mammalian Cells ◽  
Brain Structures ◽  
Cell Types ◽  
Cytoskeletal Organization ◽  
High Level ◽  
S100a6 Protein ◽  
Different Cell Types ◽  
The Brain ◽  
Lateral Sclerosis

The S100A6 protein is present in different mammalian cells and tissues including the brain. It binds Ca2+ and Zn2+ and interacts with many target proteins/ligands. The best characterized ligands of S100A6, expressed at high level in the brain, include CacyBP/SIP and Sgt1. Research concerning the functional role of S100A6 and these two ligands indicates that they are involved in various signaling pathways that regulate cell proliferation, differentiation, cytoskeletal organization, and others. In this review, we focused on the expression/localization of these proteins in the brain and on their possible role in neurodegenerative diseases. Published results demonstrate that S100A6, CacyBP/SIP, and Sgt1 are expressed in various brain structures and in the spinal cord and can be found in different cell types including neurons and astrocytes. When it comes to their possible involvement in nervous system pathology, it is evident that their expression/level and/or subcellular localization is changed when compared to normal conditions. Among diseases in which such changes have been observed are Alzheimer’s disease (AD), amyotrophic lateral sclerosis (ALS), epileptogenesis, Parkinson’s disease (PD), Huntington’s disease (HD), and others.

The Role of Executive Function in Shaping Reinforcement Learning

2020 ◽  
Author(s):  
Milena Rmus ◽  
Samuel McDougle ◽  
Anne Collins
Keyword(s):  
Decision Making ◽  
Reinforcement Learning ◽  
Instrumental Behavior ◽  
Complex Environments ◽  
Neural Computations ◽  
Human Decision ◽  
Brain And Behavior ◽  
And Behavior ◽  
The Brain

Reinforcement learning (RL) models have advanced our understanding of how animals learn and make decisions, and how the brain supports some aspects of learning. However, the neural computations that are explained by RL algorithms fall short of explaining many sophisticated aspects of human decision making, including the generalization of learned information, one-shot learning, and the synthesis of task information in complex environments. Instead, these aspects of instrumental behavior are assumed to be supported by the brain’s executive functions (EF). We review recent findings that highlight the importance of EF in learning. Specifically, we advance the theory that EF sets the stage for canonical RL computations in the brain, providing inputs that broaden their flexibility and applicability. Our theory has important implications for how to interpret RL computations in the brain and behavior.

scholarly journals Social Support And Job Satisfaction Among Academicians: A Comparison Between Public And Private University In Malaysia

2019 ◽  
Vol 8 (5C) ◽  
pp. 449-456
Keyword(s):  
Social Support ◽  
Job Satisfaction ◽  
Positive Impact ◽  
Private University ◽  
Public And Private ◽  
Mean Values ◽  
The Mean ◽  
University Level ◽  
High Level

The role of social support at workplace become one of the most important variables that can give impact on employee’s attitude. Closely related to employee’s performance, many studies have confirmed the role of social support in enhancing employee’s job satisfaction. The aims of this research is two-folds. First, to investigate the differences and second to compare the effect of social support on job satisfaction among academicians in Malaysia. Overall, a total of 420 samples were obtained, wherein 210 participants withdrawn from each setting. Data was collected using self-administrated questionnaire, and analyzed using SPSS version 22. The finding suggested that social support levels (i.e. supervisor support and co-worker support) are higher among academicians in private university. Level of job satisfaction, otherwise is higher among public university. Overall, the mean values indicated high level of social support and job satisfaction among academicians in both university. Analysis of t-Test revealed that there is no significant differences in terms of social support, however the significant being observed in terms of job satisfaction between academicians in Malaysia public and private university. This study also ascertained the positive impact of social support on job satisfaction to both samples. Implication of this study includes empirical contribution and deliberation on social support and job satisfaction. Suggestion from this study includes improving social support to enhance overall academicians’ job satisfaction.

scholarly journals UTERINE SCAR FORMATION AND EXPRESSION OF SPECIFIC CONNECTIVE TISSUE PROTEINS

2020 ◽  
pp. 132-136
Author(s):  
D. M. Zhelezov ◽  
T. O. Savenko
Keyword(s):  
Connective Tissue ◽  
Pregnant Women ◽  
Uterine Wall ◽  
Collagen Types ◽  
Previous Surgery ◽  
Perinatal Center ◽  
The Mean ◽  
Uterine Scar ◽  
High Level

The aim of the study – to evaluate the role of expression of specific connective tissue proteins in the formation of the scar on the uterus. Materials and Methods. The study was performed on the basis of the regional perinatal center and KU PB No. 5 during 2017–2019. 426 women with a scar on the uterus were examined, including 115 (27.0 %) with two or more scars. The mean age of the subjects was (33.4±1.1) years. The results of sonographic studies were analyzed. For pathomorphological examination, three cases of intranatal rupture of the uterine wall along the “old” scar after cesarean section from middle-aged women with a gestational age of 33 to 40 weeks are presented. The expression of collagen types 1 and 3 and the protein of the intermediate filaments of the muscle tissue of desmin was determined using a semi-quantitative method with the calculation of H-score. Results and Discussion. Analysis of ultrasound data showed that the average assessment of the degree of insolvency of the scar on the uterus was in the examined women X=(1.3±0.2) points, a high level of insolvency was found in 114 (26.8 %) pregnant women. At the same time, 225 (52.8 %) pregnant women showed no signs of scar failure at all. In 87 (20.4 %) one sign of uterine scar failure was found, in 76 (17.8 %) – two signs, in 20 (4.7 %) – three signs, and in 18 (4.2 %) – four signs. Subsequently, 44 (10.3 %) women were born operatively, the rest gave birth per via naturales. Local myometrial defect after ultrasound delivery was detected in 25 of 182 (13.7 %) women who gave birth independently. Conclusions. A high level of scar failure risk is found in 26.8 % of pregnant women. H-score valuesfor collagen types 1 and 3 averaged (212±24) and (188±22), for desmin – (193±17). Thus, reparative processes at the site of previous surgery on the uterine wall are by incomplete regeneration (substitution) and compensatory hyperplasia of structural tissue elements.

scholarly journals The Role of Social Communication Networks in Constructing Public Opinion among Students at Saudi Arabian Universities (Umm AlQura University as a model)

2016 ◽  
Vol 7 (2) ◽  
pp. 395
Author(s):  
Osamah Ghazi Almadani
Keyword(s):  
Public Opinion ◽  
Communication Networks ◽  
Social Communication ◽  
Saudi Arabian ◽  
Survey Method ◽  
The Internet ◽  
Significant Difference ◽  
The Mean ◽  
High Level

The study aimed to investigate the role of social communication networks in constructing public opinion among students at Saudi Arabian Universities. This study is descriptive in nature and used the survey method. The sample of the study consisted of N 200 students from Umm Alqura university from the practical and theoretical colleges (College of social sciences- Colleges of medical sciences- Colleges of applied sciences). The tools of the study included a questionnaire – public opinion construction scale for the students at Saudi Arabian universities. The results of the study indicated that a high level percentage in constructing public opinion came from the students who used the social communication websites which was 41.86%, where the intermediate level was 55.23%, while the low level was 2.91%.The results showed also that there is a statistically significant difference between the mean score of the study sample in the scale of the role of social communication networks in constructing public opinion among the students according to the different levels in using different social communication networks. There is a statistically significant difference between the mean score of the study sample in the scale of the role of social communication networks in using social communication through the internet according to the different level of experience in using the internet among the participants. 

scholarly journals Residual dynamics resolves recurrent contributions to neural computation

2021 ◽  
Author(s):  
Aniruddh R Galgali ◽  
Maneesh Sahani ◽  
Valerio Mante
Keyword(s):  
Decision Making ◽  
Large Scale ◽  
Neural Circuit ◽  
Neural Population ◽  
Perceptual Decision Making ◽  
Neural Recordings ◽  
Fine Grained ◽  
Neural Computations ◽  
Population Trajectory ◽  
The Mean

Relating neural activity to behavior requires an understanding of how neural computations arise from the coordinated dynamics of distributed, recurrently connected neural populations. However, inferring the nature of recurrent dynamics from partial recordings of a neural circuit presents significant challenges. Here, we show that some of these challenges can be overcome by a fine-grained analysis of the dynamics of neural residuals, i.e. trial-by-trial variability around the mean neural population trajectory for a given task condition. Residual dynamics in macaque pre-frontal cortex (PFC) in a saccade-based perceptual decision-making task reveals recurrent dynamics that is time-dependent, but consistently stable, and implies that pronounced rotational structure in PFC trajectories during saccades are driven by inputs from upstream areas. The properties of residual dynamics restrict the possible contributions of PFC to decision-making and saccade generation, and suggest a path towards fully characterizing distributed neural computations with large-scale neural recordings and targeted causal perturbations.

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