184 research outputs found

    Anxiety: An Evolutionary Approach

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    Anxiety disorders are among the most common mental illnesses, with huge attendant suffering. Current treatments are not universally effective, suggesting that a deeper understanding of the causes of anxiety is needed. To understand anxiety disorders better, it is first necessary to understand the normal anxiety response. This entails considering its evolutionary function as well as the mechanisms underlying it. We argue that the function of the human anxiety response, and homologues in other species, is to prepare the individual to detect and deal with threats. We use a signal detection framework to show that the threshold for expressing the anxiety response ought to vary with the probability of threats occurring, and the individual's vulnerability to them if they do occur. These predictions are consistent with major patterns in the epidemiology of anxiety. Implications for research and treatment are discussed

    Reorienting adolescent sexual and reproductive health research: reflections from an international conference

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    On December 4th 2014, the International Centre for Reproductive Health (ICRH) at Ghent University organized an international conference on adolescent sexual and reproductive health (ASRH) and well-being. This viewpoint highlights two key messages of the conference - 1) ASRH promotion is broadening on different levels and 2) this broadening has important implications for research and interventions – that can guide this research field into the next decade. Adolescent sexuality has long been equated with risk and danger. However, throughout the presentations, it became clear that ASRH and related promotion efforts are broadening on different levels: from risk to well-being, from targeted and individual to comprehensive and structural, from knowledge transfer to innovative tools. However, indicators to measure adolescent sexuality that should accompany this broadening trend, are lacking. While public health related indicators (HIV/STIs, pregnancies) and their behavioral proxies (e.g. condom use, number of partners) are well developed and documented, there is a lack of consensus on indicators for the broader construct of adolescent sexuality, including sexual well-being and aspects of positive sexuality. Furthermore, the debate during the conference clearly indicated that experimental designs may not be the only appropriate study design to measure effectiveness of comprehensive, context-specific and long-term ASRH programmes, and that alternatives need to be identified and applied. Presenters at the conference clearly expressed the need to develop validated tools to measure different sub-constructs of adolescent sexuality and environmental factors. There was a plea to combine (quasi-)experimental effectiveness studies with evaluations of the development and implementation of ASRH promotion initiatives.IS

    Speed/Accuracy Trade-Off between the Habitual and the Goal-Directed Processes

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    Instrumental responses are hypothesized to be of two kinds: habitual and goal-directed, mediated by the sensorimotor and the associative cortico-basal ganglia circuits, respectively. The existence of the two heterogeneous associative learning mechanisms can be hypothesized to arise from the comparative advantages that they have at different stages of learning. In this paper, we assume that the goal-directed system is behaviourally flexible, but slow in choice selection. The habitual system, in contrast, is fast in responding, but inflexible in adapting its behavioural strategy to new conditions. Based on these assumptions and using the computational theory of reinforcement learning, we propose a normative model for arbitration between the two processes that makes an approximately optimal balance between search-time and accuracy in decision making. Behaviourally, the model can explain experimental evidence on behavioural sensitivity to outcome at the early stages of learning, but insensitivity at the later stages. It also explains that when two choices with equal incentive values are available concurrently, the behaviour remains outcome-sensitive, even after extensive training. Moreover, the model can explain choice reaction time variations during the course of learning, as well as the experimental observation that as the number of choices increases, the reaction time also increases. Neurobiologically, by assuming that phasic and tonic activities of midbrain dopamine neurons carry the reward prediction error and the average reward signals used by the model, respectively, the model predicts that whereas phasic dopamine indirectly affects behaviour through reinforcing stimulus-response associations, tonic dopamine can directly affect behaviour through manipulating the competition between the habitual and the goal-directed systems and thus, affect reaction time

    “El Sexo no es Malo”: Maternal Values Accompanying Contraceptive Use Advice to Young Latina Adolescent Daughters

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    In this study, we utilized observational methods to identify maternal values and concerns accompanying contraceptive use advice in Latina mother–daughter sexuality conversations. The sample included non-sexually active early adolescents around 12 years of age and their mostly Spanish-speaking Latina mothers. Videotaped conversations were coded for the prevalence of messages related to four sexual values (abstinence, delay sex until older, sex is “normal”, sex is “improper”) and concerns about pregnancy and STD transmission. We examined whether the duration of time spent conversing about these messages was associated with participant characteristics, general communication openness, and the amount of time the dyads spent discussing contraceptive use. Results indicated that Latina mothers who had fewer years of education and lower family income talked longer to their daughters about the need to delay sex, avoid risky situations that would increase their chances of getting pregnant or acquiring an STD, and engage in self-protective practices. Less perceived openness in general communication as reported by both the mothers and the daughters was associated with increased time discussing that sex is improper. Although the duration of contraceptive use messages was brief, mothers and daughters who discussed the fact that sex is normal, and who communicated more about the importance of delaying sex, talked longer about contraceptive use practices compared to mothers and daughters who engaged in minimal discussion of these sexual values
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