Contrastive Hebbian Learning with Random Feedback Weights

Neural networks are commonly trained to make predictions through learning algorithms. Contrastive Hebbian learning, which is a powerful rule inspired by gradient backpropagation, is based on Hebb's rule and the contrastive divergence algorithm. It operates in two phases, the forward (or free) phase, where the data are fed to the network, and a backward (or clamped) phase, where the target signals are clamped to the output layer of the network and the feedback signals are transformed through the transpose synaptic weight matrices. This implies symmetries at the synaptic level, for which there is no evidence in the brain. In this work, we propose a new variant of the algorithm, called random contrastive Hebbian learning, which does not rely on any synaptic weights symmetries. Instead, it uses random matrices to transform the feedback signals during the clamped phase, and the neural dynamics are described by first order non-linear differential equations. The algorithm is experimentally verified by solving a Boolean logic task, classification tasks (handwritten digits and letters), and an autoencoding task. This article also shows how the parameters affect learning, especially the random matrices. We use the pseudospectra analysis to investigate further how random matrices impact the learning process. Finally, we discuss the biological plausibility of the proposed algorithm, and how it can give rise to better computational models for learning

Opinion Polarization by Learning from Social Feedback

We explore a new mechanism to explain polarization phenomena in opinion dynamics in which agents evaluate alternative views on the basis of the social feedback obtained on expressing them. High support of the favored opinion in the social environment, is treated as a positive feedback which reinforces the value associated to this opinion. In connected networks of sufficiently high modularity, different groups of agents can form strong convictions of competing opinions. Linking the social feedback process to standard equilibrium concepts we analytically characterize sufficient conditions for the stability of bi-polarization. While previous models have emphasized the polarization effects of deliberative argument-based communication, our model highlights an affective experience-based route to polarization, without assumptions about negative influence or bounded confidence.Comment: Presented at the Social Simulation Conference (Dublin 2017

Beyond ‘Interaction’: How to Understand Social Effects on Social Cognition

In recent years, a number of philosophers and cognitive scientists have advocated for an ‘interactive turn’ in the methodology of social-cognition research: to become more ecologically valid, we must design experiments that are interactive, rather than merely observational. While the practical aim of improving ecological validity in the study of social cognition is laudable, we think that the notion of ‘interaction’ is not suitable for this task: as it is currently deployed in the social cognition literature, this notion leads to serious conceptual and methodological confusion. In this paper, we tackle this confusion on three fronts: 1) we revise the ‘interactionist’ definition of interaction; 2) we demonstrate a number of potential methodological confounds that arise in interactive experimental designs; and 3) we show that ersatz interactivity works just as well as the real thing. We conclude that the notion of ‘interaction’, as it is currently being deployed in this literature, obscures an accurate understanding of human social cognition

Understanding Complexity

{Excerpt} In development agencies, paradigms of linear causality condition much thinking and practice. They encourage command-and-control hierarchies, centralize decision making, and dampen creativity and innovation. Globalization demands that organizations see our turbulent world as a collection of evolving ecosystems. To survive and flourish they must then be adaptable and fleet footed. Notions of complexity offer a wealth of insights and guidance to 21st century organizations that strive to do so

TRIZ: an alternate way to solve problem for student

Inventive problem solving is an alternative way of solving problem for student. 60 years ago, in 1956, Altshuller published a new, constructive and methodical approach ideas on problem solving to offer to the world. Even though TRIZ originally meant for fields of industry domains, it has solved problems in other field using some common principles. Thus, this methodology has spread to over 35 countries across the world. It is now being taught in several universities and it has been applied by a number of global organizations who have found it particularly useful to solve their problem. In 2017, KSSM curriculum has been revised to cope up this 21st century demand. This paper is a potentially useful for TRIZ beginner, as an alternative to solve problem comparable to common problem solving method. This paper also discussed the limitation of other common problem method which leads the advantages of using TRIZ

Coaching Practices and Prospects: The Flexible Leadership Awards Program in Context

Reviews trends in coaching in leadership development and examines how Flexible Leadership Awards program participants are using coaching and to what effect. Outlines elements of success, including clear, measurable goals linking leaders and organizations

The developmental dynamics of terrorist organizations

We identify robust statistical patterns in the frequency and severity of violent attacks by terrorist organizations as they grow and age. Using group-level static and dynamic analyses of terrorist events worldwide from 1968-2008 and a simulation model of organizational dynamics, we show that the production of violent events tends to accelerate with increasing size and experience. This coupling of frequency, experience and size arises from a fundamental positive feedback loop in which attacks lead to growth which leads to increased production of new attacks. In contrast, event severity is independent of both size and experience. Thus larger, more experienced organizations are more deadly because they attack more frequently, not because their attacks are more deadly, and large events are equally likely to come from large and small organizations. These results hold across political ideologies and time, suggesting that the frequency and severity of terrorism may be constrained by fundamental processes.Comment: 28 pages, 8 figures, 4 tables, supplementary materia

Filling-in the Forms: Surface and Boundary Interactions in Visual Cortex

Defense Advanced Research Projects Agency and the Office of Naval Research (NOOOI4-95-l-0409); Office of Naval Research (NOOO14-95-1-0657)

Beyond the Win: Pathways for Policy Implementation

When it comes to policy, a lot of attention is given to "the win." Whether it is something new and big like the Affordable Care Act, a piece of legislation in a large federal omnibus bill, or inclusion of critical language in a state policy, seeing the fruits of advocacy efforts put into law makes advocates and champions feel that their hard work, often many years in the making, has paid off.However, in reality, "the win" is just the beginning -- a necessary first step in a much longer and equally as fraught process of policy implementation. Once a policy is created, there are numerous factors that shape and determine how that policy is implemented -- and ultimately, the impact it will have -- regardless of how well the policy is formulated. Some of these factors include rulemaking, funding, capacity of local implementing agencies, and fights to repeal or modify wins, among many others.And, just as in the case of "the win," advocacy plays an important role in shaping implementation whether in advocating across these factors or participating in ongoing monitoring over time. Interestingly, while the role of advocacy in agenda setting, policy formulation, and policy adoption has been widely explored in theory and practice, the role of advocacy in the policy implementation process has received less attention in the literature.To learn more about the role of advocacy at the policy implementation stage, ORS Impact spoke with organizations that engage in, or provide funding for, advocacy efforts at the state and/or federal level. We focused on the following questions:When had advocates played a positive role in policy implementation?When had implementation not gone as well as expected, and what did advocates take away from that?Our conversations yielded important learnings about the unique characteristics of, and range of approaches to, advocacy efforts during the implementation phase. The two following scenarios illustrate some of the different types and levels of advocacy intervention, as well as the results they produce, to demonstrate the ways advocacy can play out when shifting from policymaking to implementation

The Influence of Hospitality Leaders’ Relational Transparency on Followers’ Trust and Deviance Behaviors: Mediating Role of Behavioral Integrity

This paper investigates the effect of leader\u27s relational transparency on follower organizational deviance through followers’ perception of leader\u27s behavioral integrity and their trust in leader. Multi-level modeling results from a multisource survey-based field-study with 24 hospitality student project teams (N = 149) show that behavioral integrity mediates the relationship between leader\u27s relational transparency and follower\u27s trust in leader. Furthermore, multi-level path analysis suggests that leader\u27s relational transparency, a team-level construct, exerts a cross-level effect on follower\u27s organizational deviance through the mediating roles of behavioral integrity and follower\u27s trust in leader. The study has yielded theoretical and practical implications that are useful for hospitality leaders. © 201