62 research outputs found

    Alcohol approach tendencies in heavy drinkers: comparison of effects in a relevant stimulus-response compatibility task and an approach/avoidance Simon task

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    Several recent studies suggest that alcohol-related cues elicit automatic approach tendencies in heavy drinkers. A variety of tasks have been used to demonstrate these effects, including Relevant Stimulus-Response Compatibility (R-SRC) tasks and variants of Simon tasks. Previous work with normative stimuli suggests that the R-SRC task may be more sensitive than Simon tasks because the activation of approach tendencies may depend on encoding of the stimuli as alcohol-related, which occurs in the R-SRC task but not in Simon tasks. Our aim was to directly compare these tasks for the first time in the context of alcohol use. We administered alcohol versions of an R-SRC task and a Simon task to 62 social drinkers, who were designated as heavy or light drinkers based on a median split of their weekly alcohol consumption. Results indicated that, compared to light drinkers, heavy drinkers were faster to approach, rather than avoid, alcohol-related pictures in the R-SRC task but not in the Simon task. Theoretical implications and methodological issues are discussed

    Learning on the IGT follows emergence of knowledge but not differential somatic activity

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    The importance of unconscious autonomic activity vs. knowledge in influencing behavior on the Iowa Gambling Task (IGT) has been the subject of debate. The task's developers, Bechara and colleagues, have claimed that behavior on the IGT is influenced by somatic activity and that this activity precedes the emergence of knowledge about the task contingencies sufficient to guide behavior. Since then others have claimed that this knowledge emerges much earlier on the task. However, it has yet to be established whether somatic activity which differentiates between advantageous and disadvantageous choices on the IGT is found before this point. This study describes an experiment to determine whether knowledge sufficient to guide behavior precedes differential autonomic activity or vice versa. This experiment used a computerized version of the IGT, knowledge probes after every 10 trials and skin conductance recording to measure somatic activity. Whereas in previous reports the majority of participants end the task with full conceptual knowledge of the IGT contingencies we found little evidence in support of this conclusion. However, full conceptual knowledge was not critical for advantageous deck selection to occur and most participants had knowledge sufficient to guide behavior after approximately 40 trials. We did not find anticipatory physiological activity sufficient to differentiate between deck types in the period prior to acquiring this knowledge. However, post-punishment physiological activity was found to be larger for the disadvantageous decks in the pre-knowledge period, but only for participants who displayed knowledge. Post-reward physiological activity distinguished between the advantageous and disadvantageous decks across the whole experiment but, again, only in participants who displayed knowledge and then only in later trials following their display of knowledge

    Learning on the IGT follows emergence of knowledge but not differential somatic activity

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    The importance of unconscious autonomic activity vs. knowledge in influencing behavior on the Iowa Gambling Task (IGT) has been the subject of debate. The task's developers, Bechara and colleagues, have claimed that behavior on the IGT is influenced by somatic activity and that this activity precedes the emergence of knowledge about the task contingencies sufficient to guide behavior. Since then others have claimed that this knowledge emerges much earlier on the task. However, it has yet to be established whether somatic activity which differentiates between advantageous and disadvantageous choices on the IGT is found before this point. This study describes an experiment to determine whether knowledge sufficient to guide behavior precedes differential autonomic activity or vice versa. This experiment used a computerized version of the IGT, knowledge probes after every 10 trials and skin conductance recording to measure somatic activity. Whereas in previous reports the majority of participants end the task with full conceptual knowledge of the IGT contingencies we found little evidence in support of this conclusion. However, full conceptual knowledge was not critical for advantageous deck selection to occur and most participants had knowledge sufficient to guide behavior after approximately 40 trials. We did not find anticipatory physiological activity sufficient to differentiate between deck types in the period prior to acquiring this knowledge. However, post-punishment physiological activity was found to be larger for the disadvantageous decks in the pre-knowledge period, but only for participants who displayed knowledge. Post-reward physiological activity distinguished between the advantageous and disadvantageous decks across the whole experiment but, again, only in participants who displayed knowledge and then only in later trials following their display of knowledge

    Repetition priming affects guessing not familiarity

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    <p>Abstract</p> <p>Background</p> <p>The claim that recollection and familiarity based memory processes have distinct retrieval mechanisms is based partly on the observation that masked repetition and semantic priming influence estimates of familiarity derived from <it>know </it>responses but have no effect on estimates of recollection derived from <it>remember </it>responses. Close inspection of the experiments on which this claim is based reveal the effect size to be small, potentially the result of a type-2 error, and/or inflated due to participants not having the opportunity to report <it>guesses</it>. This paper re-evaluates these claims by attempting a partial replication of two such Experiments.</p> <p>Methods</p> <p>In Experiment 1 participants made <it>remember</it>, <it>know</it>, and <it>guess </it>responses following primed and unprimed target words. In Experiment 2 participants made <it>sure</it>, <it>unsure</it>, and <it>guess </it>following primed and unprimed target words.</p> <p>Results</p> <p>In Experiment 1 the repetition priming effect occurred only for <it>guess </it>responses and only for unstudied items. In Experiment 2 the priming effect occurred for both <it>unsure </it>and <it>guess </it>responses, but again only for unstudied items.</p> <p>Conclusion</p> <p>The data are consistent with the view that <it>remembering </it>and <it>knowing </it>do not correspond to confidence ratings; and suggest that contrary to earlier findings, <it>recollection </it>and <it>familiarity </it>do not differ in retrieval mechanisms. As such the effects of repetition priming on subjective reports of remembering should not be cited as evidence for the distinction between recollection and familiarity based memory processes.</p

    Factors affecting learning and decision-making in the Iowa Gambling Task

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    Damasio's somatic marker hypothesis (SMH; Damasio, 1994, 1996) integrates emotion with rational decision-making using evidence drawn from neurology, neuroscience and performance on a now widely cited decision-making test developed to model real-life in a laboratory setting (the Iowa Gambling Task; Bechara, Damasio, Damasio and Anderson, 1994). The SMH posits a critical input from an embodied emotional system (somatic markers) in making decisions in choice situations. But Damasio's consideration of how the undamaged brain interacts with the body has some interesting and somewhat controversial implications in the context of modern psychological research on choice behaviour. In interpreting behaviour on the IGT in accordance with the SMH three central assumptions have been made: a) that somatic markers indicate the goodness or badness of alternatives and without them decision-making cannot become optimal, b) this somatic biasing or guidance can occur unconsciously or in the absence of explicit knowledge, and c) that the system operates so as to maximize or achieve the best outcome in the long-term. The Experiments described in this thesis have explored the validity of the second and third assumptions and found that they are not accurately reflected in behaviour on the IGT. The importance of information about the IGT in the instructions participants receive suggested that explicit knowledge about the task is a more critical factor than any somatic input. No evidence of a somatic influence prior to the emergence of explicit knowledge sufficient to guide behaviour was found. Instead there were indications that knowledge precedes somatic activity on the IGT. Novel manipulations of the reinforcement contingencies in individual decks also revealed that immediate outcomes of choices are an important determinant of subsequent behaviour. Selection does not solely depend on long-term outcomes

    Factors affecting learning and decision-making in the Iowa Gambling Task

    Get PDF
    Damasio's somatic marker hypothesis (SMH; Damasio, 1994, 1996) integrates emotion with rational decision-making using evidence drawn from neurology, neuroscience and performance on a now widely cited decision-making test developed to model real-life in a laboratory setting (the Iowa Gambling Task; Bechara, Damasio, Damasio and Anderson, 1994). The SMH posits a critical input from an embodied emotional system (somatic markers) in making decisions in choice situations. But Damasio's consideration of how the undamaged brain interacts with the body has some interesting and somewhat controversial implications in the context of modern psychological research on choice behaviour. In interpreting behaviour on the IGT in accordance with the SMH three central assumptions have been made: a) that somatic markers indicate the goodness or badness of alternatives and without them decision-making cannot become optimal, b) this somatic biasing or guidance can occur unconsciously or in the absence of explicit knowledge, and c) that the system operates so as to maximize or achieve the best outcome in the long-term. The Experiments described in this thesis have explored the validity of the second and third assumptions and found that they are not accurately reflected in behaviour on the IGT. The importance of information about the IGT in the instructions participants receive suggested that explicit knowledge about the task is a more critical factor than any somatic input. No evidence of a somatic influence prior to the emergence of explicit knowledge sufficient to guide behaviour was found. Instead there were indications that knowledge precedes somatic activity on the IGT. Novel manipulations of the reinforcement contingencies in individual decks also revealed that immediate outcomes of choices are an important determinant of subsequent behaviour. Selection does not solely depend on long-term outcomes

    Obesity in individuals with schizophrenia:a case controlled study in Scotland

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    We would like to thank Dr Moira Connolly, Professor Steve Lawrie and Dr Carol Robertson who, along with the authors, were part of a protocol development group funded by the NHS Research Scotland Mental Health Network (NRS MHN) formerly known as the Scottish Mental Health Research Network (SMHRN). We are grateful to the NRS MHN for funding the data acquisition and to the PCCIU for providing the data. We also thank Professor Gordon Murray for statistical advice.Peer reviewedPublisher PD

    Ketamine as the anaesthetic for electroconvulsive therapy:the KANECT randomised controlled trial

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    C.AS. reports grants from Vifor Pharma, outside the submitted work. I.C.R. (deceased) declared personal fees from AstraZeneca, Sanofi Aventis and Sunovion, and non-financial support from Lundbeck, between 2009 and 2014 and all outside the submitted work. Volume 212, Issue 5 May 2018 , p. 323 Ketamine as the anaesthetic for electroconvulsive therapy: the KANECT randomised controlled trial – CORRIGENDUM Gordon Fernie, James Currie, Jennifer S. Perrin, Caroline A. Stewart... https://doi.org/10.1192/bjp.2018.76 Published online: 06 April 2018 Summary: This notice describes a correction to the above mentioned paper.Peer reviewedPublisher PD
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