12,794 research outputs found

    Individual Differences in EWA Learning with Partial Payoff Information

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    We extend experience-weighted attraction (EWA) learning to games in which only the set of possible foregone payoffs from unchosen strategies are known, and estimate parameters separately for each player to study heterogeneity. We assume players estimate unknown foregone payoffs from a strategy, by substituting the last payoff actually received from that strategy, by clairvoyantly guessing the actual foregone payoff, or by averaging the set of possible foregone payoffs conditional on the actual outcomes. All three assumptions improve predictive accuracy of EWA. Individual parameter estimates suggest that players cluster into two separate subgroups (which differ from traditional reinforcement and belief learning)

    Clinical psychology of Internet addiction: a review of its conceptualization, prevalence, neuronal processes, and implications for treatment

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    Research into Internet addiction (IA) has grown rapidly over the last decade. The topic has generated a great deal of debate, particularly in relation to how IA can be defined conceptually as well as the many methodological limitations. The present review aims to further elaborate and clarify issues that are relevant to IA research in a number of areas including: definition and characterization, incidence and prevalence rates, associated neuronal processes, and implications for treatment, prevention, and patient-specific considerations. It is concluded that there is no consensual definition for IA. Prevalence rates among nationally representative samples across several countries vary greatly (from 1% to 18.7%), most likely reflecting the lack of methodological consistency and conceptual rigor of the studies. The overlaps between IA and other more traditional substance-based addictions and the possible neural substrates implicated in IA are also highlighted. In terms of treatment and prevention, both psychological and pharmacological treatments are examined in light of existing evidence alongside particular aspects inherent to the patient perspective. Based on the evidence analyzed, it is concluded that IA may pose a serious health hazard to a minority of people

    A trans-diagnostic perspective on obsessive-compulsive disorder

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    © Cambridge University Press 2017. This is an Open Access article, distributed under the terms of the Creative Commons Attribution licence (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted re-use, distribution, and reproduction in any medium, provided the original work is properly cited.Progress in understanding the underlying neurobiology of obsessive-compulsive disorder (OCD) has stalled in part because of the considerable problem of heterogeneity within this diagnostic category, and homogeneity across other putatively discrete, diagnostic categories. As psychiatry begins to recognize the shortcomings of a purely symptom-based psychiatric nosology, new data-driven approaches have begun to be utilized with the goal of solving these problems: specifically, identifying trans-diagnostic aspects of clinical phenomenology based on their association with neurobiological processes. In this review, we describe key methodological approaches to understanding OCD from this perspective and highlight the candidate traits that have already been identified as a result of these early endeavours. We discuss how important inferences can be made from pre-existing case-control studies as well as showcasing newer methods that rely on large general population datasets to refine and validate psychiatric phenotypes. As exemplars, we take 'compulsivity' and 'anxiety', putatively trans-diagnostic symptom dimensions that are linked to well-defined neurobiological mechanisms, goal-directed learning and error-related negativity, respectively. We argue that the identification of biologically valid, more homogeneous, dimensions such as these provides renewed optimism for identifying reliable genetic contributions to OCD and other disorders, improving animal models and critically, provides a path towards a future of more targeted psychiatric treatments.Peer reviewedFinal Published versio

    Cognitive finance: Behavioural strategies of spending, saving, and investing.

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    Research in economics is increasingly open to empirical results. The advances in behavioural approaches are expanded here by applying cognitive methods to financial questions. The field of "cognitive finance" is approached by the exploration of decision strategies in the financial settings of spending, saving, and investing. Individual strategies in these different domains are searched for and elaborated to derive explanations for observed irregularities in financial decision making. Strong context-dependency and adaptive learning form the basis for this cognition-based approach to finance. Experiments, ratings, and real world data analysis are carried out in specific financial settings, combining different research methods to improve the understanding of natural financial behaviour. People use various strategies in the domains of spending, saving, and investing. Specific spending profiles can be elaborated for a better understanding of individual spending differences. It was found that people differ along four dimensions of spending, which can be labelled: General Leisure, Regular Maintenance, Risk Orientation, and Future Orientation. Saving behaviour is strongly dependent on how people mentally structure their finance and on their self-control attitude towards decision space restrictions, environmental cues, and contingency structures. Investment strategies depend on how companies, in which investments are placed, are evaluated on factors such as Honesty, Prestige, Innovation, and Power. Further on, different information integration strategies can be learned in decision situations with direct feedback. The mapping of cognitive processes in financial decision making is discussed and adaptive learning mechanisms are proposed for the observed behavioural differences. The construal of a "financial personality" is proposed in accordance with other dimensions of personality measures, to better acknowledge and predict variations in financial behaviour. This perspective enriches economic theories and provides a useful ground for improving individual financial services

    Byzantine Attack and Defense in Cognitive Radio Networks: A Survey

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    The Byzantine attack in cooperative spectrum sensing (CSS), also known as the spectrum sensing data falsification (SSDF) attack in the literature, is one of the key adversaries to the success of cognitive radio networks (CRNs). In the past couple of years, the research on the Byzantine attack and defense strategies has gained worldwide increasing attention. In this paper, we provide a comprehensive survey and tutorial on the recent advances in the Byzantine attack and defense for CSS in CRNs. Specifically, we first briefly present the preliminaries of CSS for general readers, including signal detection techniques, hypothesis testing, and data fusion. Second, we analyze the spear and shield relation between Byzantine attack and defense from three aspects: the vulnerability of CSS to attack, the obstacles in CSS to defense, and the games between attack and defense. Then, we propose a taxonomy of the existing Byzantine attack behaviors and elaborate on the corresponding attack parameters, which determine where, who, how, and when to launch attacks. Next, from the perspectives of homogeneous or heterogeneous scenarios, we classify the existing defense algorithms, and provide an in-depth tutorial on the state-of-the-art Byzantine defense schemes, commonly known as robust or secure CSS in the literature. Furthermore, we highlight the unsolved research challenges and depict the future research directions.Comment: Accepted by IEEE Communications Surveys and Tutoiral

    Psychological team diversity and strategy implementation

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    The overwhelming majority of team or group composition studies are restricted to analyzing the link between team demographics and the content of specific strategic choices. We argue that in order to make progress in this domain it is now time to broaden the approach by focusing on psychological team composition and issues of effective implementation. In addition, we propose a more sophisticated theoretical and methodological approach to the use of specific team composition measures. We conducted an experimental study in order to explore the potential of addressing these major limitations of past research. Specifically, we hypothesize on and analyze the relationship between the psychological composition of management teams (in terms of their members'' control perceptions) and two aspects of effective strategy implementation: meticulous planning and the configuration of consistent action patterns. We find that homogeneous ''internal'' teams adapt their strategy-making behavior to the requirements of the environment, whereas homogeneous ''external'' teams do not. As expected, mixed (i.e., heterogeneous) teams experienced most problems in effectively implementing their strategies. The findings provide support for the potential value of analyzing both psychological composition of decision making teams and strategy implementation issues. Furthermore, it underscores the importance of properly matching theoretical expectations and measurement methodology in multi-level research.management and organization theory ;

    Laruelle Qua Stiegler: On Non-Marxism and the Transindividual

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    Alexander R. Galloway and Jason R. LaRiviére’s article “Compression in Philosophy” seeks to pose François Laruelle’s engagement with metaphysics against Bernard Stiegler’s epistemological rendering of idealism. Identifying Laruelle as the theorist of genericity, through which mankind and the world are identified through an index of “opacity,” the authors argue that Laruelle does away with all deleterious philosophical “data.” Laruelle’s generic immanence is posed against Stiegler’s process of retention and discretization, as Galloway and LaRiviére argue that Stiegler’s philosophy seeks to reveal an enchanted natural world through the development of noesis. By further developing Laruelle and Stiegler’s Marxian projects, I seek to demonstrate the relation between Stiegler's artefaction and “compression” while, simultaneously, I also seek to create further bricolage between Laruelle and Stiegler. I also further elaborate on their distinct engagement(s) with Marx, offering the mold of synthesis as an alternative to compression when considering Stiegler’s work on transindividuation. In turn, this paper seeks to survey some of the contemporary theorists drawing from Stiegler (Yuk Hui, Al-exander Wilson and Daniel Ross) and Laruelle (Anne-Françoise Schmidt, Gilles Grelet, Ray Brassier, Katerina Kolozova, John Ó Maoilearca and Jonathan Fardy) to examine political discourse regarding the posthuman and non-human, with a particular interest in Kolozova’s unified theory of standard philosophy and Capital
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