scholarly journals Why and how the brain weights contributions from a mixture of experts

2020 ◽  
Author(s):  
John O'Doherty ◽  
Sangwan Lee ◽  
Reza Tadayonnejad ◽  
Jeffrey Cockburn ◽  
Kiyohito Iigaya ◽  
...  
Keyword(s):  
Expert Systems ◽  
Control Mechanism ◽  
Behavioral Control ◽  
Mixture Of Experts ◽  
Multiple Systems ◽  
Control Behavior ◽  
Learning Domains ◽  
Anterior Prefrontal Cortex ◽  
The Brain ◽  
Specific Contribution

It has long been suggested that human behavior reflects the contributions of multiple systems that cooperate or compete for behavioral control. Here we propose that the brain acts as a “Mixture of Experts” in which different expert systems propose strategies for action. It will be argued that the brain determines which experts should control behavior at any one moment in time by keeping track of the reliability of the predictions within each system, and by allocating control over behavior in a manner that depends on the relative reliabilities across experts. fMRI and neurostimulation studies suggest a specific contribution of the anterior prefrontal cortex in this process. Further, such a mechanism also takes into consideration the complexity of the expert, favoring simpler over more cognitively complex experts. Results from the study of different expert systems in both experiential and social-learning domains hint at the possibility that this reliability-based control mechanism is domain general, exerting control over many different expert systems simultaneously in order to produce sophisticated behavior.

Is conscious content available only to the skeletal muscle system?

2016 ◽  
Vol 39 ◽  
Author(s):  
Andreas Keller
Keyword(s):  
Skeletal Muscle ◽  
Behavioral Control ◽  
Muscle System ◽  
Control Behavior ◽  
The Brain

AbstractI applaud Morsella et al.'s approach to investigate consciousness in terms of behavioral control. After all, the function of the brain is to control behavior, and consciousness contributes to the function of the brain. However, I question whether conscious content is available only to the skeletal muscle system, as the principle of parallel responses into skeletal muscle (PRISM) (Morsella 2005) proposes.

The Influence of Attitudes, Subjective, Norms, and Behavior Controls on Intention to Choose Islamic Banks With Islamic Religiosity as a Moderating Variable (Case Study at Bri Syariah Purwokerto Customers)

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Akhmad Khoyrun Najakh ◽  
Dwiwiyati Astogini ◽  
Sri Martini
Keyword(s):  
Behavioral Control ◽  
Sampling Technique ◽  
Subjective Norm ◽  
Subjective Norms ◽  
Islamic Banks ◽  
Control Behavior ◽  
Before And After ◽  
And Behavior ◽  
Number Of Customers

The purpose of this study was to analyze the influence of attitudes on the intention to choose Islamic banks, to analyze the effect of subjective norm on the intention to choose Islamic banks. to analyze the effect of the control behavior of the intention to choose the Islamic banks, to analyze the moderating influence of religiosity on the relationship attitudes, subjective norms and behavioral control of the intention to choose the Islamic banks . The method used is a survey with a sampling technique used purposive sampling with a sample size of this study was 100 respondents . Further analysis tools used in this study is multiple regression analysis using SPSS 16.0 software . Based on this study it can be concluded that the attitude does not affect to the intention of choose Bank BRISyariah. Subjective norm positive effect on intention choose Bank BRISyariah. Control behavior does not affect to the intention choose Bank BRISyariah. Relationship between Attitudes, Subjective Norms and Behavior Control with the intention to select Bank BRISyariah not moderated by religiosity.Based on these conclusions can be said that the Bank BRISyariah should improve understanding related to the subjective norm in order to increase the number of customers who use the services of Islamic Banking . Further research is recommended in order to follow up and develop this research to further explore the independent and dependent variables continued before and after behavioral intention or intention to perform a specific action .

scholarly journals Why and how the brain weights contributions from a mixture of experts

2021 ◽  
Vol 123 ◽  
pp. 14-23
Author(s):  
John P. O’Doherty ◽  
Sang Wan Lee ◽  
Reza Tadayonnejad ◽  
Jeff Cockburn ◽  
Kyo Iigaya ◽  
...  
Keyword(s):  
Mixture Of Experts ◽  
The Brain

scholarly journals A global framework for a systemic view of brain modeling

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Frederic Alexandre
Keyword(s):  
Instrumental Conditioning ◽  
The Body ◽  
Posterior Cortex ◽  
Reciprocal Relationships ◽  
Brain Modeling ◽  
Brain Theory ◽  
Habitual Behavior ◽  
Definition Of ◽  
The Brain ◽  
Specific Contribution

AbstractThe brain is a complex system, due to the heterogeneity of its structure, the diversity of the functions in which it participates and to its reciprocal relationships with the body and the environment. A systemic description of the brain is presented here, as a contribution to developing a brain theory and as a general framework where specific models in computational neuroscience can be integrated and associated with global information flows and cognitive functions. In an enactive view, this framework integrates the fundamental organization of the brain in sensorimotor loops with the internal and the external worlds, answering four fundamental questions (what, why, where and how). Our survival-oriented definition of behavior gives a prominent role to pavlovian and instrumental conditioning, augmented during phylogeny by the specific contribution of other kinds of learning, related to semantic memory in the posterior cortex, episodic memory in the hippocampus and working memory in the frontal cortex. This framework highlights that responses can be prepared in different ways, from pavlovian reflexes and habitual behavior to deliberations for goal-directed planning and reasoning, and explains that these different kinds of responses coexist, collaborate and compete for the control of behavior. It also lays emphasis on the fact that cognition can be described as a dynamical system of interacting memories, some acting to provide information to others, to replace them when they are not efficient enough, or to help for their improvement. Describing the brain as an architecture of learning systems has also strong implications in Machine Learning. Our biologically informed view of pavlovian and instrumental conditioning can be very precious to revisit classical Reinforcement Learning and provide a basis to ensure really autonomous learning.

scholarly journals Parental control in interpersonal acceptance-rejection theory: a study with a Spanish sample using Parents’ Version of Parental Acceptation-Rejection/Control Questionnaire

2017 ◽  
Vol 33 (3) ◽  
pp. 652 ◽  
Author(s):  
Carmen-María Fernández-García ◽  
Carmen Rodríguez-Menéndez ◽  
José-Vicente Peña-Calvo
Keyword(s):  
Social Cognitive ◽  
Behavioral Control ◽  
Parental Control ◽  
Emotional Adjustment ◽  
Control Behavior ◽  
Parental Behavioral Control ◽  
Perceived Acceptance ◽  
Control Dimension ◽  
Parenting Dimensions ◽  
Main Dimension

Interpersonal Acceptance-Rejection theory (IPARTheory) provides a good theoretical framework to explain the parenting dimensions that influence children’s social, cognitive and emotional adjustment. This theory develops one main dimension, warmth-rejection, where warmth would be one pole of the dimension and rejection the opposite one.  Besides, the theory has also defined behavioral control dimension with two poles: permissiveness-strictness. In the context of this theory, our study was conducted with a sample of Spanish parents to (a) examine whether parental perceived acceptance-rejection was related to parental behavioral control; (2) analyze how behavioral control dimension worked in acceptance-rejection theory; and (3) examine whether there were differences in the relations obtained between fathers and mothers. We have to conclude that control behavior correlates positively with warmth behaviors. Fathers’ and mothers’ correlations among these dimensions show that parents can develop certain control behaviors but that they are compatible with affection conducts.

Abstract 178: Cholesterol Limits Macrophage Activation in Response to Intracerebral Hemorrhage-Relevant Signals

Stroke ◽  
2020 ◽  
Vol 51 (Suppl_1) ◽  
Author(s):  
Jonathan H DeLong ◽  
Sofia Velazquez ◽  
Margaret J Landreneau ◽  
Lauren H Sansing
Keyword(s):  
Intracerebral Hemorrhage ◽  
Macrophage Activation ◽  
Cholesterol Content ◽  
Brain Parenchyma ◽  
Activation Markers ◽  
Multiple Systems ◽  
Murine Bone Marrow ◽  
Inflammatory Phenotype ◽  
Injury Models ◽  
The Brain

Introduction: In response to intracerebral hemorrhage (ICH), monocytes are recruited to the brain parenchyma, where they differentiate into macrophages and contribute to a pathological inflammatory response. However, by day 3 after ICH, brain macrophages have adopted a more reparative phenotype and are important for clearance of apoptotic cells and recovery. The signals that control this inflammatory to reparative differentiation are incompletely understood, but cholesterol has been found to limit macrophage activation in multiple systems. The brain has the highest cholesterol content of any organ and we hypothesized that cholesterol uptake by macrophages limits inflammation and promotes the development of reparative macrophages following ICH. Methods and Results: Murine bone marrow-derived macrophages were stimulated with a cocktail of thrombin, S100A8, and IL-1b in order to mimic the Danger-Associated Molecular Patterns present in the brain after ICH (ICH-DAMP), LPS, or vehicle for 14-18 hours. Cytokine production was quantified by cytometric bead array and activation markers by flow cytometry. ICH-DAMP was found to upregulate CCL2, IL-6 and TNF, recapitulating the inflammatory phenotype seen in the first days after ICH. However, when cells were stimulated in the presence of cholesterol, production of CCL2, IL-6, and TNF were limited. Dectin-1 has inhibitory properties in some sterile injury models. ICH-DAMP was found to limit expression of dectin-1, and cholesterol reversed this inhibition. Exposure to exogenous cholesterol also upregulated the cholesterol transporter ABCA1, allowing cells to efflux excess cholesterol. The drug Valspodar was therefore used to block cholesterol efflux and was found to further limit ICH-DAMP-mediated upregulation of CCL2. Conclusion: These results suggest that the cholesterol in the brain may limit macrophage activation in response to the stimuli present during intracerebral hemorrhage.

Integration of Stochastic Models by Minimizing α-Divergence

2007 ◽  
Vol 19 (10) ◽  
pp. 2780-2796 ◽  
Author(s):  
Shun-ichi Amari
Keyword(s):  
Stochastic Models ◽  
Probability Distributions ◽  
Predictive Distribution ◽  
Natural Generalization ◽  
Bayesian Framework ◽  
Hellinger Distance ◽  
Mixture Of Experts ◽  
Mixtures Of Distributions ◽  
Leibler Divergence ◽  
The Brain

When there are a number of stochastic models in the form of probability distributions, one needs to integrate them. Mixtures of distributions are frequently used, but exponential mixtures also provide a good means of integration. This letter proposes a one-parameter family of integration, called α-integration, which includes all of these well-known integrations. These are generalizations of various averages of numbers such as arithmetic, geometric, and harmonic averages. There are psychophysical experiments that suggest that α-integrations are used in the brain. The α-divergence between two distributions is defined, which is a natural generalization of Kullback-Leibler divergence and Hellinger distance, and it is proved that α-integration is optimal in the sense of minimizing α-divergence. The theory is applied to generalize the mixture of experts and the product of experts to the α-mixture of experts. The α-predictive distribution is also stated in the Bayesian framework.

scholarly journals In situ architecture of neuronal α-Synuclein inclusions

2020 ◽  
Author(s):  
Victoria A. Trinkaus ◽  
Irene Riera-Tur ◽  
Antonio Martínez-Sánchez ◽  
Felix J.B. Bäuerlein ◽  
Qiang Guo ◽  
...  
Keyword(s):  
Amyloid Fibrils ◽  
Electron Tomography ◽  
Structural Flexibility ◽  
Multiple Systems ◽  
Cryo Electron Tomography ◽  
Multiple Systems Atrophy ◽  
The Brain ◽  
Cellular Organelles

Summaryα-Synuclein (α-Syn) aggregation is a hallmark of devastating neurodegenerative disorders including Parkinson’s disease (PD) and multiple systems atrophy (MSA)1,2. α-Syn aggregates spread throughout the brain during disease progression2, suggesting mechanisms of intercellular seeding. Formation of α-Syn amyloid fibrils is observed in vitro3,4 and fibrillar α-Syn has been purified from patient brains5,6, but recent reports questioned whether disease-relevant α-Syn aggregates are fibrillar in structure7-9. Here we use cryo-electron tomography (cryo-ET) to image neuronal Lewy body-like α-Syn inclusions in situ at molecular resolution. We show that the inclusions consist of α-Syn fibrils crisscrossing a variety of cellular organelles such as the endoplasmic reticulum (ER), mitochondria and autophagic structures, without interacting with membranes directly. Neuronal inclusions seeded by recombinant or MSA patient-derived α-Syn aggregates have overall similar architecture, although MSA-seeded fibrils show higher structural flexibility. Using gold-labeled seeds we find that aggregate nucleation is predominantly mediated by α-Syn oligomers, with fibrils growing unidirectionally from the seed. Our results conclusively demonstrate that neuronal α-Syn inclusions contain α-Syn fibrils intermixed with cellular membranes, and illuminate the mechanism of aggregate nucleation.

Eating Disorders in Borderline Personality Disorder

2017 ◽  
Author(s):  
Eunice Chen
Keyword(s):  
Eating Disorders ◽  
Borderline Personality Disorder ◽  
Personality Disorder ◽  
Borderline Personality ◽  
History Of Childhood ◽  
Control Behavior ◽  
Dialectical Tension ◽  
History Of ◽  
Shared Risk ◽  
The Brain

Eating disorders (EDs) often arise from a complex interplay of biological, psychological, and social processes in which there is a dialectical tension between the overabundance of food and an obsession with thinness. The DSM-5 recognizes three specific types of EDs that are common in borderline personality disorder (BPD): anorexia nervosa (AN), bulimia nervosa (BN), and binge eating disorder (BED). The impulsive, self-destructive tendencies of those with BPD may also make them particularly vulnerable to developing an ED. Recent advances in neuroscience have resulted in great understanding of the brain mechanisms and processes that control behavior associated with EDs and BPD. Research has supported the idea that the co-occurrence of both disorders may be caused by an inability to tolerate and skillfully manage negative or unpleasant emotions. Other possible commonalities between EDs and BPD involve shared risk factors, such as a history of childhood trauma.

Sign in / Sign up

Export Citation Format

Share Document