Neural signatures of cognitive flexibility and reward sensitivity following nicotinic receptor stimulation in dependent smokers : a randomized trial

IMPORTANCE Withdrawal from nicotine is an important contributor to smoking relapse. Understanding how reward-based decision making is affected by abstinence and by pharmacotherapies such as nicotine replacement therapy and varenicline tartrate may aid cessation treatment. OBJECTIVE To independently assess the effects of nicotine dependence and stimulation of the nicotinic acetylcholine receptor on the ability to interpret valence information (reward sensitivity) and subsequently alter behavior as reward contingencies change (cognitive flexibility) in a probabilistic reversal learning task. DESIGN, SETTING, AND PARTICIPANTS Nicotine-dependent smokers and nonsmokers completed a probabilistic reversal learning task during acquisition of functional magnetic resonance imaging (fMRI) in a 2-drug, double-blind placebo-controlled crossover design conducted from January 21, 2009, to September 29, 2011. Smokers were abstinent from cigarette smoking for 12 hours for all sessions. In a fully Latin square fashion, participants in both groups underwent MRI twice while receiving varenicline and twice while receiving a placebo pill, wearing either a nicotine or a placebo patch. Imaging analysis was performed from June 15, 2015, to August 10, 2016. MAIN OUTCOME AND MEASURES A well-established computational model captured effects of smoking status and administration of nicotine and varenicline on probabilistic reversal learning choice behavior. Neural effects of smoking status, nicotine, and varenicline were tested for on MRI contrasts that captured reward sensitivity and cognitive flexibility. RESULTS The study included 24 nicotine-dependent smokers (12 women and 12 men; mean [SD] age, 35.8 [9.9] years) and 20 nonsmokers (10 women and 10 men; mean [SD] age, 30.4 [7.2] years). Computational modeling indicated that abstinent smokers were biased toward response shifting and that their decisions were less sensitive to the available evidence, suggesting increased impulsivity during withdrawal. These behavioral impairments were mitigated with nicotine and varenicline. Similarly, decreased mesocorticolimbic activity associated with cognitive flexibility in abstinent smokers was restored to the level of nonsmokers following stimulation of nicotinic acetylcholine receptors (familywise error-corrected P<.05). Conversely, neural signatures of decreased reward sensitivity in smokers (vs nonsmokers; familywise error-corrected P<.05) in the dorsal striatum and anterior cingulate cortex were not mitigated by nicotine or varenicline. CONCLUSIONS AND RELEVANCE There was a double dissociation between the effects of chronic nicotine dependence on neural representations of reward sensitivity and acute effects of stimulation of nicotinic acetylcholine receptors on behavioral and neural signatures of cognitive flexibility in smokers. These chronic and acute pharmacologic effects were observed in overlapping mesocorticolimbic regions, suggesting that available pharmacotherapies may alleviate deficits in the same circuitry for certain mental computations but not for others

How hyperglycemia promotes atherosclerosis: molecular mechanisms

Both type I and type II diabetes are powerful and independent risk factors for coronary artery disease (CAD), stroke, and peripheral arterial disease. Atherosclerosis accounts for virtually 80% of all deaths among diabetic patients. Prolonged exposure to hyperglycemia is now recognized a major factor in the pathogenesis of atherosclerosis in diabetes. Hyperglycemia induces a large number of alterations at the cellular level of vascular tissue that potentially accelerate the atherosclerotic process. Animal and human studies have elucidated three major mechanisms that encompass most of the pathological alterations observed in the diabetic vasculature: 1) Nonenzymatic glycosylation of proteins and lipids which can interfere with their normal function by disrupting molecular conformation, alter enzymatic activity, reduce degradative capacity, and interfere with receptor recognition. In addition, glycosylated proteins interact with a specific receptor present on all cells relevant to the atherosclerotic process, including monocyte-derived macrophages, endothelial cells, and smooth muscle cells. The interaction of glycosylated proteins with their receptor results in the induction of oxidative stress and proinflammatory responses 2) oxidative stress 3) protein kinase C (PKC) activation with subsequent alteration in growth factor expression. Importantly, these mechanisms may be interrelated. For example, hyperglycemia-induced oxidative stress promotes both the formation of advanced glycosylation end products and PKC activation

I Don't Get any Inspiration Sitting at my Desk: The Patterns of Flow Experiences in Expert Researchers

This study describes the findings from coding the transcripts of personal interviews with associate and full professors within the University of North Carolina's School of Information and Library Science. The interviews were conducted to determine whether and how fully-present states of consciousness, known often as flow states in the literature, occurred in the research process. A definite pattern was discovered wherein fully-present states of consciousness were occurring, but most often not during the active work of research, such as reading or writing. Rather, flow came to researchers when they would take a break from their work to do something less intellectually demanding. Here they would receive a personal insight on how to proceed with their work. Then the researchers would return to work to address the challenge of how to package what they had synthesized in their flow experience into language that could be understood and accepted by other researchers.Master of Science in Library Scienc

Enhancing feedback and improving feedback: subjective perceptions, psychological consequences and behavioral outcomes

Three experiments examined subjective perceptions, psychological consequences, and behavioral outcomes of enhancing versus improving feedback. Across experiments, feedback delivery and assessment were sequential (i.e., at each testing juncture) or cumulative (i.e., at the end of the testing session). Although enhancing feedback was seen as more satisfying than useful, and improving feedback was not seen as more useful than satisfying, perceptions differed as a function of short-term versus long-term feedback delivery and assessment. Overall, however, enhancing feedback was more impactful psychologically and behaviorally. Enhancing feedback engendered greater success consistency, overall satisfaction and usefulness, optimism, state self-esteem, perceived ability, and test persistence intentions; improving feedback, on the other hand, engendered greater state improvement. The findings provide the fodder for theory development and applications

Addressing food insecurity and chronic conditions in community health centres: protocol of a quasi-experimental evaluation of Recipe4Health

IntroductionChronic conditions, such as diabetes, obesity, heart disease and depression, are highly prevalent and frequently co-occur with food insecurity in communities served by community health centres in the USA. Community health centres are increasingly implementing 'Food as Medicine' programmes to address the dual challenge of chronic conditions and food insecurity, yet they have been infrequently evaluated.Methods and analysisThe goal of this quasi-experimental study was to evaluate the effectiveness of Recipe4Health, a 'Food as Medicine' programme. Recipe4Health includes two components: (1) a 'Food Farmacy' that includes 16 weekly deliveries of produce and (2) a 'Behavioural Pharmacy' which is a group medical visit. We will use mixed models to compare pre/post changes among participants who receive the Food Farmacy alone (n=250) and those who receive the Food Farmacy and Behavioural Pharmacy (n=140). The primary outcome, fruit and vegetable consumption, and secondary outcomes (eg, food security status, physical activity, depressive symptoms) will be collected via survey. We will also use electronic health record (EHR) data on laboratory values, prescriptions and healthcare usage. Propensity score matching will be used to compare Recipe4Health participants to a control group of patients in clinics where Recipe4Health has not been implemented for EHR-derived outcomes. Data from surveys, EHR, group visit attendance and produce delivery is linked with a common identifier (medical record number) and then deidentified for analysis with use of an assigned unique study ID. This study will provide important preliminary evidence on the effectiveness of primary care-based strategies to address food insecurity and chronic conditions.Ethics and disseminationThis study was approved by the Stanford University Institutional Review Board (reference protocol ID 57239). Appropriate study result dissemination will be determined in partnership with the Community Advisory Board

Answering behavioral questions about energy efficiency in buildings

We identify behavioral questions that arise with 4 kinds of policy interventions for energy efficiency in buildings: information, incentives, standards, and technological research and development. A general strategy is described for answering such questions by using 6 analytical methods: formal models, analysis of existing data, surveys, ethnographic methods, small-scale experimentation, and evaluation research. We evaluate each method for addressing each behavioral question in policy analyses.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26718/1/0000268.pd

Comparing the effectiveness of monetary versus moral motives in environmental campaigning

Environmental campaigns often promote energy conservation by appealing to economic (for example, lower electricity bills) rather than biospheric concerns (for example, reduced carbon emissions), assuming that people are primarily motivated by economic self-interest. However, people also care about maintaining a favourable view of themselves (they want to maintain a 'positive self-concept'), and may prefer to see themselves as 'green' rather than 'greedy'. Consequently, people may find economic appeals less attractive than biospheric appeals. Across two studies, participants indicated feeling better about biospheric ('Want to protect the environment? Check your car's tire pressure') than economic ('Want to save money? Check your car's tire pressure') tyre-check appeals. In a field experiment, we found that an economic tyre-check appeal ('Do you care about your finances? Get a free tire check') elicited significantly less compliance than parallel biospheric and neutral appeals. Together, these studies discredit the conventional wisdom that appealing to economic self-interest is the best way to secure behaviour change. At least in some cases, our studies suggest, this strategy is not effective.</p

Stable isotope and minor element proxies for Eocene climate of Seymour Island, Antarctica

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/94846/1/palo900.pd

Attitude, Inference, Association: On the Propositional Structure of Implicit Bias

The overwhelming majority of those who theorize about implicit biases posit that these biases are caused by some sort of association. However, what exactly this claim amounts to is rarely specified. In this paper, I distinguish between different understandings of association, and I argue that the crucial senses of association for elucidating implicit bias are the cognitive structure and mental process senses. A hypothesis is subsequently derived: if associations really underpin implicit biases, then implicit biases should be modulated by counterconditioning or extinction but should not be modulated by rational argumentation or logical interventions. This hypothesis is false; implicit biases are not predicated on any associative structures or associative processes but instead arise because of unconscious propositionally structured beliefs. I conclude by discussing how the case study of implicit bias illuminates problems with popular dual-process models of cognitive architectur