2,078 research outputs found

    Cumulative dominance and heuristic performance in binary multi-attribute choice

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    Working paper 895, Department of Economics and Business, Universitat Pompeu FabraSeveral studies have reported high performance of simple decision heuristics in multi-attribute decision making. In this paper, we focus on situations where attributes are binary and analyze the performance of Deterministic-Elimination-By-Aspects (DEBA) and similar decision heuristics. We consider non-increasing weights and two probabilistic models for the attribute values: one where attribute values are independent Bernoulli randomvariables; the other one where they are binary random variables with inter-attribute positive correlations. Using these models, we show that good performance of DEBA is explained by the presence of cumulative as opposed to simple dominance. We therefore introduce the concepts of cumulative dominance compliance and fully cumulative dominance compliance and show that DEBA satisfies those properties. We derive a lower bound with which cumulative dominance compliant heuristics will choose a best alternative and show that, even with many attributes, this is not small. We also derive an upper bound for the expected loss of fully cumulative compliance heuristics and show that this is moderate even when the number of attributes is large. Both bounds are independent of the values of the weights.Postprint (author’s final draft

    Extinction of cue-evoked drug-seeking relies on degrading hierarchical instrumental expectancies

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    There has long been need for a behavioural intervention that attenuates cue-evoked drug-seeking, but the optimal method remains obscure. To address this, we report three approaches to extinguish cue-evoked drug-seeking measured in a Pavlovian to instrumental transfer design, in non-treatment seeking adult smokers and alcohol drinkers. The results showed that the ability of a drug stimulus to transfer control over a separately trained drug-seeking response was not affected by the stimulus undergoing Pavlovian extinction training in experiment 1, but was abolished by the stimulus undergoing discriminative extinction training in experiment 2, and was abolished by explicit verbal instructions stating that the stimulus did not signal a more effective response-drug contingency in experiment 3. These data suggest that cue-evoked drug-seeking is mediated by a propositional hierarchical instrumental expectancy that the drug-seeking response is more likely to be rewarded in that stimulus. Methods which degraded this hierarchical expectancy were effective in the laboratory, and so may have therapeutic potential

    Ultra-brief breath counting (mindfulness) training promotes recovery from stress-induced alcohol-seeking in student drinkers

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    This is the final version. Available on open access from Elsevier via the DOI in this recordThe therapeutic effect of mindfulness interventions on problematic drinking is thought to be driven by increased resilience to the impact of stress on negative mood and alcohol-seeking behaviour, but this claim needs empirical support. To address this hypothesis, the current study tested whether brief training of one component of mindfulness – breath counting – would reduce drinkers’ sensitivity to the effect of noise stress on subjective mood and alcohol-seeking behaviour. Baseline alcohol-seeking was measured by choice to view alcohol versus food thumbnail pictures in 192 student drinkers. Participants then received a 6-minute audio file which either trained breath counting or recited a popular science extract, in separate groups. All participants were then stressed by a loud industrial noise and alcohol-seeking was measured again, simultaneously (to quantify the change from baseline). Subjective mood was measured after all three stages (baseline, post intervention, post stress test). The breath counting group were instructed to deploy this technique during the stress test. Results showed that the breath counting versus control intervention improved subjective mood relative to baseline, attenuated the worsening of subjective mood produced by stress induction, and accelerated recovery from a stress induced increase in alcohol-seeking behaviour. Exploratory moderation analysis showed that this accelerated recovery from stress induced alcohol-seeking by breath counting was weaker in more alcohol dependent participants. Mindfulness therapies may improve problematic drinking by increasing resilience to stress induced negative mood and alcohol-seeking, observed in this study. The weaker therapeutic effect of breath counting in more dependent drinkers may reveal limitations to this intervention strategy.Medical Research Council (MRC)Alcohol Research U

    Improving Navy recruiting with data farming

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    Proceedings of the 2016 Winter Simulation Conference T. M. K. Roeder, P. I. Frazier, R. Szechtman, E. Zhou, T. Huschka, and S. E. Chick, eds.Secretary of the Navy Ray Mabus states that people provide “the Navy and Marine Corps’ greatest edge” (Mabus, 2015). To help recruit and manage this dynamic workforce of more than 300,000 active duty Sailors, the Navy uses mathematical models and simulation to assess the potential impacts and risks of changes to force structure, budgets, policies, and the economy. One important model is the Planned Re-source Optimization (PRO) model. PRO is currently being used to inform recruiting resourcing decisions. The decisions may involve, for example, advertising, enlistment bonuses, number of production recruiters, etc. A limitation of PRO is the lack of an interface to facilitate extensive experimentation. This paper summarizes an effort underway to enhance the analytic utility of the PRO model by embedding it in a data farming environment. This enhanced tool is called the “Planned Resource Optimization Model with Ex-perimental Design” (PROM-WED)

    Double Carbon−Hydrogen Activation of 2-Vinylpyridine: Synthesis of Tri- and Pentanuclear Clusters Containing the μ-NC\u3csub\u3e5\u3c/sub\u3eH\u3csub\u3e4\u3c/sub\u3eCH═C Ligand

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    Reactions of 2-vinylpyridine with the triruthenium complexes [Ru3(CO)12] and [Ru3(CO)10(μ-dppm)] leads to a previously unknown double carbon−hydrogen bond activation of the β-carbon of the vinyl group to afford the pentaruthenium and triruthenium complexes [Ru5(CO)14(μ4-C5H4CH═C)(μ-H)2] (1) and [Ru3Cl(CO)5(μ-CO)(μ-dppm)(μ3-NC5H4CH═C)(μ-H)] (2), respectively. Crystal structures reveal two different forms of bridging of the dimetalated 2-vinylpyridyl ligand, capping a square face in 1 and a triangular face in 2

    Plain cigarette packs do not exert Pavlovian to instrumental transfer of control over tobacco-seeking

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    Journal ArticleResearch Support, Non-U.S. Gov'tCopyright © 2014 The Authors. Addiction published by John Wiley & Sons Ltd on behalf of Society for the Study of AddictionAIMS: To gain insight into the potential impact of plain tobacco packaging policy, two experiments were undertaken to test whether 'prototype' plain compared with branded UK cigarette pack stimuli would differentially elicit instrumental tobacco-seeking in a nominal Pavlovian to instrumental transfer (PIT) procedure. DESIGN, SETTING AND PARTICIPANTS: Two experiments were undertaken at the University of Bristol UK, with a convenience sample of adult smokers (experiment 1, n = 23, experiment 2, n = 121). MEASUREMENT: In both experiments, smokers were trained on a concurrent choice procedure in which two responses earned points for cigarettes and chocolate, respectively, before images of branded and plain packs were tested for capacity to elicit the tobacco-seeking response in extinction. The primary outcome was percentage choice of the tobacco- over the chocolate-seeking response in plain pack, branded pack and no-stimulus conditions. FINDINGS: Both experiments found that branded packs primed a greater percentage of tobacco-seeking (overall mean = 62%) than plain packs (overall mean = 53%) and the no-stimulus condition (overall mean = 52%; Ps ≤ 0.01, ŋp (2) s ≥ 0.16), and that there was no difference in percentage tobacco-seeking between plain packs and the no-stimulus condition (Ps ≥ 0.17, ŋp (2) s ≤ 0.04). Plain tobacco packs showed an overall 9% reduction in the priming of a tobacco choice response compared to branded tobacco packs. CONCLUSIONS: Plain packaging may reduce smoking in current smokers by degrading cue-elicited tobacco-seeking.British Heart FoundationCancer Research UKNIHRMRCESR

    Using Adobe Flash Lite on mobile phones for psychological research: reaction time measurement reliability and inter-device variability

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    Mobile telephones have significant potential for use in psychological research, possessing unique characteristics—not least their ubiquity—that may make them useful tools for psychologists. We examined whether it is possible to measure reaction times (RTs) accurately using Adobe Flash Lite on mobile phones. We ran simple and choice RT experiments on two widely available mobile phones, a Nokia 6110 Navigator and a Sony Ericsson W810i, using a wireless application protocol (WAP) connection to access the Internet from the devices. RTs were compared within subjects with those obtained using a Linux-based millisecond-accurate measurement system. Results show that measured RTs were significantly longer on mobile devices, and that overall RTs and distribution of RTs varied across device

    Evaluation of Un-Medicated, Self-Paced Alcohol Withdrawal

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    It is currently unclear how effective un-medicated, self-paced alcohol withdrawal is in reducing alcohol consumption in alcohol dependent clients. To address this question, the current study examined the reduction in alcohol consumption, assessed by breath alcohol and drink diary self-report, of 405 alcohol-dependent clients over a 10-day, un-medicated, self-paced alcohol reduction program that included group discussion of strategies for titrating between withdrawal and intoxication. It was found that attendance at treatment sessions was associated with a reduction in alcohol consumption, reflected in both breath alcohol and diary measures, and these two measures were significantly correlated. Overall, 35% of clients achieved a zero breath alcohol reading by their final session, although this percentage increased to 56% of clients who attended all 10 sessions. Withdrawal seizures occurred in only 0.5% of clients despite 17.2% having a history of seizures in other settings. It is concluded that the alcohol reduction protocol outlined here provides an effective and safe method for reducing alcohol consumption in severely alcohol dependent clients, and that methods for augmenting attendance, such as contingency management, should enhance the effectiveness of this treatment

    Wearable device to assist independent living.

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    Older people increasingly want to remain living independently in their own homes. The aim of the ENABLE project is to develop a wearable device that can be used both within and outside of the home to support older people in their daily lives and which can monitor their health status, detect potential problems, provide activity reminders and offer communication and alarm services. In order to determine the specifications and functionality required for development of the device user surveys and focus groups were undertaken and use case analysis and scenario modeling carried out. The project has resulted in the development of a wrist worn device and mobile phone combination that can support and assist older and vulnerable wearers with a range of activities and services both inside and outside of their homes. The device is currently undergoing pilot trials in five European countries. The aim of this paper is to describe the ENABLE device, its features and services, and the infrastructure within which it operates
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