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Stress at encoding affects memory processes, typically enhancing, or preserving, memory for emotional information. These effects have interesting implications for eyewitness accounts, which in real-world contexts typically involve encoding an aversive event under stressful conditions followed by potential exposure to misinformation. The present study investigated memory for a negative event encoded under stress and subsequent misinformation endorsement. Healthy young adults participated in a between-groups design with three experimental sessions conducted 48 h apart. Session one consisted of a psychosocial stress induction (or control task) followed by incidental encoding of a negative slideshow. During session two, participants were asked questions about the slideshow, during which a random subgroup was exposed to misinformation. Memory for the slideshow was tested during the third session. Assessment of memory accuracy across stress and no-stress groups revealed that stress induced just prior to encoding led to significantly better memory for the slideshow overall. The classic misinformation effect was also observed - participants exposed to misinformation were significantly more likely to endorse false information during memory testing. In the stress group, however, memory accuracy and misinformation effects were moderated by arousal experienced during encoding of the negative event. Misinformed-stress group participants who reported that the negative slideshow elicited high arousal during encoding were less likely to endorse misinformation for the most aversive phase of the story. Furthermore, these individuals showed better memory for components of the aversive slideshow phase that had been directly misinformed. Results from the current study provide evidence that stress and high subjective arousal elicited by a negative event act concomitantly during encoding to enhance emotional memory such that the most aversive aspects of the event are well remembered and subsequently more resistant to misinformation effects.
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Nivel de Alerta/fisiología , Decepción , Emociones/fisiología , Memoria Episódica , Estrés Psicológico/fisiopatología , Adolescente , Adulto , Comunicación , Femenino , Humanos , Masculino , Factores de Tiempo , Adulto JovenRESUMEN
We describe a method to administer a controlled, effective stressor to humans in the laboratory. The method combines the Trier Social Stress Test (TSST) and the Cold Pressor Test into a single, believable procedure called the Fear-Factor Stress Test (FFST). In the procedure, participants imagine auditioning for the reality television show Fear Factor. They stand before a video recorder and a panel of judges while (a) delivering a motivational speech, (b) performing a verbal arithmetic task, and (c) placing one hand into a bucket of ice water for up to 2 min. We measured subjective anxiety, heart rate, and salivary cortisol in three groups of young adults (n = 30 each, equal numbers of men and women): FFST, TSST, and Control (a placebo version of the FFST). Although the FFST and TSST groups were not distinguishable at the cortisol measure taken 5 min post-manipulation, at 35 min postmanipulation average cortisol levels in the TSST group had returned to baseline, whereas those in the FFST group continued to rise. The proportion of individual cortisol responders (≥ 2 nmol/l increase over baseline) in the TSST and FFST groups did not differ at the 5-min measure, but at the 35-min measure the FFST group contained significantly more responders. The findings indicate that the FFST induces a more robust and sustained cortisol response (which we assume is a marker of an HPA-axis response) than the TSST, and that it does so without increasing participant discomfort or incurring appreciably greater resource and time costs.
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Miedo/fisiología , Miedo/psicología , Hidrocortisona/metabolismo , Experimentación Humana no Terapéutica/ética , Estrés Psicológico/metabolismo , Estrés Psicológico/psicología , Adolescente , Adulto , Femenino , Humanos , Hidrocortisona/análisis , Masculino , Trastornos Fóbicos/diagnóstico , Trastornos Fóbicos/metabolismo , Trastornos Fóbicos/psicología , Saliva/química , Saliva/metabolismo , Estrés Psicológico/diagnóstico , Adulto JovenRESUMEN
Men often make riskier decisions than women across a wide range of real-life behaviors. Whether this sex difference is accentuated, diminished, or stable under stressful conditions is, however, contested in the scientific literature. A critical blind spot lies amid this contestation: Most studies use standardized, laboratory-based, cognitive measures of decision making rather than complex real-life social simulation tasks to assess risk-related behavior. To address this blind spot, we investigated the effects of acute psychosocial stress on risk decision making in men and women (N = 80) using a standardized cognitive measure (the Iowa Gambling Task; IGT) and a novel task that simulated a real-life social situation (an online chatroom in which participants interacted with other men and women in sexually suggestive scenarios). Participants were exposed to either an acute psychosocial stressor or an equivalent control condition. Stressor-exposed participants were further characterized as high- or low-cortisol responders. Results confirmed that the experimental manipulation was effective. On the IGT, participants characterized as low-cortisol responders (as well as those in the Non-Stress group) made significantly riskier decisions than those characterized as high-cortisol responders. Similarly, in the online chatroom, participants characterized as low-cortisol responders (but not those characterized as high-cortisol responders) were, relative to those in the Non-Stress group, significantly more likely to make risky decisions. Together, these results suggest that at lower levels of cortisol both men and women tend to make riskier decisions in both economic and social spheres.
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Stressful events frequently comprise both neutral and emotionally arousing information, yet the impact of stress on emotional and neutral events is still not fully understood. The hippocampus and frontal cortex have dense concentrations of receptors for stress hormones, such as cortisol, which at high levels can impair performance on hippocampally dependent memory tasks. Yet, the same stress hormones can facilitate memory for emotional information, which involves interactions between the hippocampus and amygdala. Here, we induced psychosocial stress prior to encoding and examined its long-term effects on memory for emotional and neutral episodes. The stress manipulation disrupted long-term memory for a neutral episode, but facilitated long-term memory for an equivalent emotional episode compared with a control condition. The stress manipulation also increased salivary cortisol, catecholamines as indicated by the presence of alpha-amylase, heart rate, and subjectively reported stress. Stressed subjects reported more false memories than nonstressed control subjects, and these false memories correlated positively with cortisol levels, providing evidence for a relationship between stress and false memory formation. Our results demonstrate that stress, when administered prior to encoding, produces different patterns of long-term remembering for neutral and emotional episodes. These differences likely emerge from differential actions of stress hormones on memory-relevant regions of the brain.
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Emociones/fisiología , Recuerdo Mental/fisiología , Reconocimiento en Psicología/fisiología , Represión Psicológica , Estrés Psicológico/fisiopatología , Amígdala del Cerebelo/fisiología , Catecolaminas/sangre , Femenino , Frecuencia Cardíaca , Hipocampo/fisiología , Humanos , Hidrocortisona/sangre , Masculino , Corteza Prefrontal/fisiologíaRESUMEN
Activation of the hypothalamic-pituitary-adrenal (HPA) axis (as might occur, for example, when the organism encounters a threat to allostatic balance) leads to the release of cortisol into the bloodstream and, ultimately, to altered neural functioning in particular brain regions (e.g., the prefrontal cortex (PFC)). Although previous studies suggest that exposure to acute psychosocial stress (and hence, presumably, elevation of circulating cortisol levels) enhances male performance on PFC-based working memory (WM) tasks, few studies have adequately investigated female performance on WM tasks under conditions of elevated cortisol. Hence, we compared associations between elevated (relative to baseline) levels of circulating cortisol and n-back performance in a South African sample (38 women in the late luteal phase of their menstrual cycle, 38 men). On Day 1, participants completed practice n-back tasks. On Day 2, some completed the Trier Social Stress Test (TSST), whereas others experienced a relaxation period, before completing 1-back and 3-back tasks. We measured self-reported anxiety and salivary cortisol at baseline, post-manipulation and end of session. We reconstituted group assignment so that all women with elevated cortisol were in one group (EC-Women; n = 17), all men with elevated cortisol were in another (EC-Men; n = 19), all women without elevated cortisol were in a third (NoEC-Women; n = 21), and all men without elevated cortisol were in a fourth (NoEC-Men; n = 19) group. Analyses suggested this reconstitution was effective: in EC, but not NoEC, groups cortisol levels rose significantly from baseline to post-manipulation. Analyses of n-back data detected significant relations to task load (i.e., better performance on 1-back than on 3-back tasks), but no significant relations to sex, performance accuracy/speed, or cortisol variation. The data patterns are inconsistent with reports describing sex differences in effects of stress on WM performance. We speculate that cross-study methodological differences account for these inconsistencies, and, particularly, that between-study variation in the magnitude of baseline cortisol levels might affect outcomes. For instance, diurnal cortisol rhythms of South African samples might have flatter curves, and lower baseline values, than predominantly Caucasian samples from the United States and western Europe due to greater prenatal and lifetime stress, more socioeconomic disadvantage and faster ancestral life history (LH) strategies. We describe ways to disconfirm this hypothesis, and urge further cross-national research exploring these possibilities.
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Finding one's way through a labyrinth is both stressful and panicogenic for individuals suffering from panic disorder with agoraphobia (PDA), whilst normal subjects experience no stress. In this study the spatial exploratory behaviour of 15 subjects suffering from PDA, together with 15 patients with generalised anxiety disorder (GAD) and a further 15 normal control subjects - all female - was analysed during a walk through a labyrinth-like basement in an attempt to find the exit. The study covered behavioural variables, i.e., anxiety levels whilst route-searching and exploration-related movements (the frequency and intensity of trunk and head rotation, touching oneself and folding one's arms across the chest) and also physiological variables (blood pressure, heart rate) before and after the labyrinth walk. Data obtained in the PDA subjects were compared with those of the GAD and control subjects, and it was found that the PDA subjects' high blood pressure was associated with disturbed exploratory activity, which restricted their contact to the environment. As a consequence, they did not detect navigation signals to find the right route to the labyrinth exit. The interpretation focused on the analysis of the structure of human extraterritorial fear.
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Agorafobia/psicología , Conducta Exploratoria , Aprendizaje por Laberinto , Trastorno de Pánico/psicología , Percepción Espacial , Conducta Espacial , Adulto , Agorafobia/diagnóstico , Agorafobia/epidemiología , Trastornos de Ansiedad/diagnóstico , Trastornos de Ansiedad/epidemiología , Trastornos de Ansiedad/psicología , Presión Sanguínea/fisiología , Manual Diagnóstico y Estadístico de los Trastornos Mentales , Femenino , Frecuencia Cardíaca/fisiología , Humanos , Masculino , Trastorno de Pánico/diagnóstico , Trastorno de Pánico/epidemiología , Índice de Severidad de la Enfermedad , Factores de Tiempo , Grabación de Cinta de VideoRESUMEN
The aim of this article is to examine the relations between two approaches to the measurement of life history (LH) strategies: A traditional approach, termed here the biodemographic approach, measures developmental characteristics like birthweight, gestation length, interbirth intervals, pubertal timing, and sexual debut, and a psychological approach measures a suite of cognitive and behavioral traits such as altruism, sociosexual orientation, personality, mutualism, familial relationships, and religiosity. The biodemographic approach also tends not to invoke latent variables, whereas the psychological approach typically relies heavily upon them. Although a large body of literature supports both approaches, they are largely separate. This review examines the history and relations between biodemographic and psychological measures of LH, which remain murky at best. In doing so, we consider basic questions about the nature of LH strategies: What constitutes LH strategy (or perhaps more importantly, what does not constitute LH strategy)? What is gained or lost by including psychological measures in LH research? Must these measures remain independent or should they be used in conjunction as complementary tools to test tenets of LH theory? Although definitive answers will linger, we hope to catalyze an explicit discussion among LH researchers and to provoke novel research avenues that combine the strengths each approach brings to this burgeoning field.
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Desarrollo Humano , Rasgos de la Historia de Vida , Psicometría/métodos , HumanosRESUMEN
The purpose of the present article is to propose an alternative short form for the 199-item Arizona Life History Battery (ALHB), which we are calling the K-SF-42, as it contains 42 items as compared with the 20 items of the Mini-K, the short form that has been in greatest use for the past decade. These 42 items were selected from the ALHB, unlike those of the Mini-K, making direct comparisons of the relative psychometric performance of the two alternative short forms a valid and instructive exercise. A series of secondary data analyses were performed upon a recently completed five-nation cross-cultural survey, which was originally designed to assess the role of life history strategy in the etiology of interpersonal aggression. Only data from the ALHB that were collected in all five cross-cultural replications were used for the present analyses. The single immediate objective of this secondary data analysis was producing the K-SF-42 such that it would perform optimally across all five cultures sampled, and perhaps even generalize well to other modern industrial societies not currently sampled as a result of the geographic breadth of those included in the present study. A novel method, based on the use of the Cross-Sample Geometric Mean as a criterion for item selection, was used for generating such a cross-culturally valid short form.
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Rasgos de la Historia de Vida , Psicometría/instrumentación , Encuestas y Cuestionarios/normas , Adulto , Australia/etnología , Comparación Transcultural , Femenino , Humanos , Italia/etnología , Masculino , México/etnología , Singapur/etnología , Estados Unidos/etnología , Adulto JovenRESUMEN
BACKGROUND: Stress and stress hormones modulate emotional learning in rats and might have similar effects in humans. Theoretic accounts of posttraumatic stress disorder (PTSD), for example, implicate the stress-induced modulation of fear conditioning in the development of intrusive emotional reactions. The present study examined the impact of acute stress and cortisol (CORT) on classically conditioned fear in men and women. METHODS: Ninety-four healthy undergraduates were exposed to a mild stressor (or control condition) while subjective anxiety and glucocorticoid stress responses (salivary CORT) were measured. One hour later, all participants participated in a differential fear conditioning procedure while conditioned skin conductance responses (SCR) were recorded. RESULTS: Exposure to the stressor increased subjective anxiety and elevated CORT levels. In men, stress exposure facilitated fear conditioning; whereas in women, stress appeared to inhibit fear conditioning. The impact of stress on differential conditioning in men was associated with increased CORT levels. CONCLUSIONS: Consistent with animal models, these results demonstrate that stress exposure can modulate classical conditioning in humans, possibly via hormonal mechanisms. The enhancing effects of stress on the formation of conditioned fear might provide a useful model for the formation of pathological emotional reactions, such as those found in PTSD.
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Nivel de Alerta/fisiología , Condicionamiento Clásico/fisiología , Miedo/fisiología , Hidrocortisona/sangre , Estrés Psicológico/complicaciones , Adolescente , Adulto , Ansiedad/complicaciones , Ansiedad/fisiopatología , Femenino , Humanos , MasculinoRESUMEN
Despite the high prevalence of stress exposure healthy adaptation or resilience is a common response. Theoretical work and recent empirical evidence suggest that a robust reward system, in part, supports healthy adaptation by preserving positive emotions even under exceptionally stressful circumstances. We tested this prediction by examining empirical relations among behavioral and self-reported measures of sensitivity to reward, trait resilience, and measures of affect in the context of experimentally induced stress. Using a quasi-experimental design we obtained measures of sensitivity to reward (self-report and behavioral), as well as affective and physiological responses to experimental psychosocial stress in a sample of 140 healthy college-age participants. We used regression-based moderation and mediational models to assess associations among sensitivity to reward, affect in the context of stress, and trait resilience and found that an interaction between exposure to experimental stress and self-reported sensitivity to reward predicted positive affect following experimental procedure. Participants with high sensitivity to reward reported higher positive affect following stress. Moreover, positive affect during or after stress mediated the relation between sensitivity to reward and trait resilience. Consistent with the prediction that a robust reward system serves as a protective factor against stress-related negative outcomes, our results found predictive associations among sensitivity to reward, positive affect, and resilience.
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Afecto/fisiología , Conducta/fisiología , Motivación/fisiología , Recompensa , Estrés Psicológico/psicología , Adolescente , Adulto , Femenino , Humanos , Masculino , Pruebas Psicológicas , Distribución Aleatoria , Resiliencia Psicológica , Autoinforme , Adulto JovenRESUMEN
BACKGROUND: We used an economic model based on evolutionary theory to guide an examination of relations among self-reported depressive symptoms and ratings of mate values of self, social, and sexual partners. This model treats assortative mating as a form of social exchange between partners of socially and sexually desirable traits. METHODS: Two studies used variants of the Mate Value Inventory (MVI), a multivariate assessment of attributes desired in social or sexual partners. For study 1, 115 male and 124 female undergraduates provided self reports on four forms of the MVI-11 and on the Beck Depression Inventory (BDI); for study 2, 208 male and 277 female undergraduates provided self reports on seven forms of the MVI-7 and on the BDI-II. RESULTS: Both multisample structural equations models indicated that the parameters were statistically equivalent between female and male subsamples and provided an adequate fit to the data. The models revealed significant relations between the mate values ascribed to the self and those ascribed to short- and long-term partners as well as best friends. Furthermore, greater BDI scores significantly predicted lesser ratings of mate value for the self, and hence indirectly predicted lesser ratings of mate value for all types of partners evaluated. LIMITATIONS: Although the data obtained from the MVI demonstrated good psychometric validity, external validity has not yet been established. CONCLUSIONS: The results are consistent with models predicting: (1) assortative mating by mate value, (2) differential exchange rates of mate value for different types of partners, (3) a negative relation between depressive symptoms and assessment of one's own mate value, and (4) a possibly consequential mismatch of mate values when one partner exhibits or recovers from significant depressive symptoms. The results are inconsistent with models predicting (5) a generalized negativity bias due to depression.
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Trastorno Depresivo/psicología , Modelos Psicológicos , Escalas de Valoración Psiquiátrica , Conducta Sexual , Conducta Social , Adolescente , Adulto , Evolución Biológica , Femenino , Amigos , Humanos , Relaciones Interpersonales , Masculino , Modelos Económicos , Psicometría , AutoimagenRESUMEN
Although many researchers have discussed replication as a means to facilitate self-correcting science, in this article, we identify meta-analyses and evaluating the validity of correlational and causal inferences as additional processes crucial to self-correction. We argue that researchers have a duty to describe sampling decisions they make; without such descriptions, self-correction becomes difficult, if not impossible. We developed the Replicability and Meta-Analytic Suitability Inventory (RAMSI) to evaluate the descriptive adequacy of a sample of studies taken from current psychological literature. Authors described only about 30% of the sampling decisions necessary for self-correcting science. We suggest that a modified RAMSI can be used by authors to guide their written reports and by reviewers to inform editorial recommendations. Finally, we claim that when researchers do not describe their sampling decisions, both readers and reviewers may assume that those decisions do not matter to the outcome of the study, do not affect inferences made from the research findings, do not inhibit inclusion in meta-analyses, and do not inhibit replicability of the study. If these assumptions are in error, as they often are, and the neglected decisions are relevant, then the neglect may create a good deal of mischief in the field.
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Metaanálisis como Asunto , Psicología/métodos , Guías como Asunto , Humanos , Estadística como AsuntoRESUMEN
The purpose of this paper is to examine the convergent and nomological validity of a GPS-based measure of daily activity, operationalized as Number of Places Visited (NPV). Relations among the GPS-based measure and two self-report measures of NPV, as well as relations among NPV and two factors made up of self-reported individual differences were examined. The first factor was composed of variables related to an Active Lifestyle (AL) (e.g., positive affect, extraversion ) and the second factor was composed of variables related to a Sedentary Lifestyle (SL) (e.g., depression, neuroticism ). NPV was measured over 4 days. This timeframe was made up of two week and two weekend days. A bi-variate analysis established one level of convergent validity and a Split-Plot GLM examined convergent validity, nomological validity, and alternative hypotheses related to constraints on activity throughout the week simultaneously. The first analysis revealed significant correlations among NPV measures- weekday, weekend, and the entire 4-day time period, supporting the convergent validity of the Diary-, Google Maps-, and GPS-NPV measures. Results from the second analysis, indicating non-significant mean differences in NPV regardless of method, also support this conclusion. We also found that AL is a statistically significant predictor of NPV no matter how NPV was measured. We did not find a statically significant relation among NPV and SL. These results permit us to infer that the GPS-based NPV measure has convergent and nomological validity.
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The high likelihood of recurrence in depression is linked to a progressive increase in emotional reactivity to stress (stress sensitization). Mindfulness-based therapies teach mindfulness skills designed to decrease emotional reactivity in the face of negative affect-producing stressors. The primary aim of the current study was to assess whether Mindfulness-Based Cognitive Therapy (MBCT) is efficacious in reducing emotional reactivity to social evaluative threat in a clinical sample with recurrent depression. A secondary aim was to assess whether improvement in emotional reactivity mediates improvements in depressive symptoms. Fifty-two individuals with partially remitted depression were randomized into an 8-week MBCT course or a waitlist control condition. All participants underwent the Trier Social Stress Test (TSST) before and after the 8-week trial period. Emotional reactivity to stress was assessed with the Spielberger State Anxiety Inventory at several time points before, during, and after the stressor. MBCT was associated with decreased emotional reactivity to social stress, specifically during the recovery (post-stressor) phase of the TSST. Waitlist controls showed an increase in anticipatory (pre-stressor) anxiety that was absent in the MBCT group. Improvements in emotional reactivity partially mediated improvements in depressive symptoms. Limitations include small sample size, lack of objective or treatment adherence measures, and non-generalizability to more severely depressed populations. Given that emotional reactivity to stress is an important psychopathological process underlying the chronic and recurrent nature of depression, these findings suggest that mindfulness skills are important in adaptive emotion regulation when coping with stress.
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Terapia Cognitivo-Conductual/métodos , Depresión/terapia , Estrés Psicológico/terapia , Adulto , Ansiedad/psicología , Ansiedad/terapia , Trastornos de Ansiedad/psicología , Trastornos de Ansiedad/terapia , Depresión/psicología , Trastorno Depresivo/psicología , Trastorno Depresivo/terapia , Emociones , Femenino , Humanos , Masculino , Persona de Mediana Edad , Escalas de Valoración Psiquiátrica , Recurrencia , Estrés Psicológico/psicología , Resultado del TratamientoRESUMEN
Programmatic social interventions attempt to produce appropriate social-norm-guided behavior in an open environment. A marriage of applicable psychological theory, appropriate program evaluation theory, and outcome of evaluations of specific social interventions assures the acquisition of cumulative theory and the production of successful social interventions--the marriage permits us to advance knowledge by making use of both success and failures. We briefly review well-established principles within the field of program evaluation, well-established processes involved in changing social norms and social-norm adherence, the outcome of several program evaluations focusing on smoking prevention, pro-environmental behavior, and rape prevention and, using the principle of learning from our failures, examine why these programs often do not perform as expected. Finally, we discuss the promise of learning from our collective experiences to develop a cumulative science of program evaluation and to improve the performance of extant and future interventions.
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Conductas Relacionadas con la Salud , Promoción de la Salud , Servicios Preventivos de Salud , Evaluación de Programas y Proyectos de Salud , Conocimientos, Actitudes y Práctica en Salud , Humanos , Evaluación de Programas y Proyectos de Salud/métodos , Violación/prevención & control , Cese del Hábito de Fumar , Prevención del Hábito de Fumar , Conducta SocialRESUMEN
This article proposes an evolutionary model of risky behavior in adolescence and contrasts it with the prevailing developmental psychopathology model. The evolutionary model contends that understanding the evolutionary functions of adolescence is critical to explaining why adolescents engage in risky behavior and that successful intervention depends on working with, instead of against, adolescent goals and motivations. The current article articulates 5 key evolutionary insights into risky adolescent behavior: (a) The adolescent transition is an inflection point in development of social status and reproductive trajectories; (b) interventions need to address the adaptive functions of risky and aggressive behaviors like bullying; (c) risky adolescent behavior adaptively calibrates over development to match both harsh and unpredictable environmental conditions; (d) understanding evolved sex differences is critical for understanding the psychology of risky behavior; and (e) mismatches between current and past environments can dysregulate adolescent behavior, as demonstrated by age-segregated social groupings. The evolutionary model has broad implications for designing interventions for high-risk youth and suggests new directions for research that have not been forthcoming from other perspectives.
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Conducta del Adolescente/psicología , Evolución Biológica , Ambiente , Modelos Psicológicos , Asunción de Riesgos , Adaptación Fisiológica , Adaptación Psicológica , Adolescente , Síntomas Conductuales/psicología , Síntomas Conductuales/terapia , ADN-Citosina Metilasas , Humanos , Motivación , Políticas , Caracteres SexualesRESUMEN
BACKGROUND: The adverse effects of a failed ventilator weaning trial on the subsequent weaning attempts are not well understood. OBJECTIVES: To examine physiological and psychological factors that may be predictive of risk for repeated weaning failures and prolonged mechanical ventilation. METHODS: A prospective predictive study of 102 subjects, age 34 to 91 years, whose first ventilator weaning trial was unsuccessful but who were physiologically ready for another weaning attempt. Subjects were recruited from intensive care units and a respiratory care center of a tertiary medical center. Validated self-report scales and a Bicore monitoring system were used to measure ventilator patients' psychophysiological performance during the second weaning trial. Structural equation modeling was used to analyze the data and test the model. RESULTS: Significant causal pathways were found between fear and anxiety (r = 0.77; P < .001), anxiety and respiratory function (r = 0.24; P < .05), and respiratory function and weaning outcomes (r = 0.42; P < .001). The overall model predicted that both physiological and psychological factors were important in determining repeated failure of ventilator weaning, and the data were in support of the model (χ(2) = 29.49, P > .05). CONCLUSIONS: Patients whose first ventilator weaning trial is unsuccessful may be markedly fearful. Left unaddressed, these fears cause high anxiety levels that significantly compromise respiratory function and contribute to subsequent weaning failures. Thus begins a vicious cycle of repeated failure of ventilator weaning and prolonged mechanical ventilation.
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Modelos Psicológicos , Desconexión del Ventilador/métodos , Adulto , Anciano , Anciano de 80 o más Años , Femenino , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Respiración Artificial/efectos adversos , Unidades de Cuidados Respiratorios , Estudios Retrospectivos , Desconexión del Ventilador/psicologíaRESUMEN
In this article we suggest a relation between people's metacognitively guided study time allocation strategies and animal foraging. These two domains are similar insofar as people use specific metacognitive cues to assist their study time allocation just as other species use cues, such as scent marking. People decline to study items that they know they already know, just as other species use a win-shift strategy - avoiding already visited and depleted patches - in foraging. People selectively study the easiest as-yet-unlearned items first, before turning to more difficult items just as other species take the 'just right' size and challenge of prey-the so-called Goldilocks principle. People use a stop rule by which they give up on one item and turn to another when the returns diminish just as others species use a stop rule that guides shifting from one patch to another. The value that each item is assigned on the criterion test, if known during study, influences which items people choose to study and how long they study them just as knowledge of the nutritional or energy value of the food influences choices and perseverance in foraging. Finally, study time allocation strategies can differ in their effectiveness depending upon the expertise of the student just as some species forage close to optimally while others do not.
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Actitud , Concienciación , Cognición , Conducta Alimentaria , Animales , Señales (Psicología) , Humanos , Aprendizaje , Teoría Psicológica , Factores de TiempoRESUMEN
Humans learn how to behave directly through environmental experience and indirectly through rules and instructions. Behavior analytic research has shown that instructions can control behavior, even when such behavior leads to sub-optimal outcomes (Hayes, S. (Ed.). 1989. Rule-governed behavior: cognition, contingencies, and instructional control. Plenum Press.). Here we examine the control of behavior through instructions in a reinforcement learning task known to depend on striatal dopaminergic function. Participants selected between probabilistically reinforced stimuli, and were (incorrectly) told that a specific stimulus had the highest (or lowest) reinforcement probability. Despite experience to the contrary, instructions drove choice behavior. We present neural network simulations that capture the interactions between instruction-driven and reinforcement-driven behavior via two potential neural circuits: one in which the striatum is inaccurately trained by instruction representations coming from prefrontal cortex/hippocampus (PFC/HC), and another in which the striatum learns the environmentally based reinforcement contingencies, but is "overridden" at decision output. Both models capture the core behavioral phenomena but, because they differ fundamentally on what is learned, make distinct predictions for subsequent behavioral and neuroimaging experiments. Finally, we attempt to distinguish between the proposed computational mechanisms governing instructed behavior by fitting a series of abstract "Q-learning" and Bayesian models to subject data. The best-fitting model supports one of the neural models, suggesting the existence of a "confirmation bias" in which the PFC/HC system trains the reinforcement system by amplifying outcomes that are consistent with instructions while diminishing inconsistent outcomes.
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Conducta de Elección/fisiología , Desempeño Psicomotor/fisiología , Refuerzo en Psicología , Ganglios Basales/fisiología , Simulación por Computador , Dopamina/fisiología , Hipocampo/fisiología , Humanos , Modelos Neurológicos , Red Nerviosa/fisiología , Redes Neurales de la Computación , Corteza Prefrontal/fisiologíaRESUMEN
BACKGROUND: Based on the hypothesis that declarative memory and navigation ability depend on hippocampal integrity, and the fact that declarative memory declines early in Alzheimer's disease (AD), the authors suggest that topographical disorientation (TD) will be an early manifestation of AD. SUBJECTS AND METHODS: Patients diagnosed with AD based on DSM-IV criteria, residing at home, were studied in a clinic at a 1000-bed referral medical center. Patient characteristics, disease condition, performance on neuropsychological tests, and navigation function were compared between patients with and without current TD. Information regarding the extent and duration of TD and the level of current navigational function were collected during a clinical interview. RESULTS: 112 patients (61 males and 51 females) with mean age of 74 years and disease duration of 37 months completed the study. Among them, 61 currently experienced TD, 20 had required an escort to their home by others, and 28 had TD as an incipient symptom. Those with current TD tended to have a longer disease duration, required an escort to their home by others, and reported a history of repeated change of residence, TD as an incipient symptom, a restricted spatial range within which they felt comfortable (safety range), and disorientation when they were out of familiar territory. In addition, care-givers reported a high level of concern for the safety of those with TD when he or she traveled alone. CONCLUSION: TD in community-dwelling AD patient is common. Caregivers should pay attention to those with longer disease duration and try to avoid changing residence. Developing a brief and valid test for topographical orientation will be helpful for the early detection of TD.