Twelve rats made repeated choices on an adjusting-delay schedule between a smaller reinforcer (A) that was delivered immediately after a response and a larger reinforcer (B) that was delivered after a delay which increased or decreased by 20% depending on the subject's choices in successive blocks of trials. In two phases of the experiment (100 sessions and 40 sessions), reinforcer sizes were selected which enabled theoretical parameters expressing the rate of delay discounting and sensitivity to reinforcer size to be estimated from the ratio of the indifference delays obtained in the two phases. Indifference delays, calculated from adjusting delays in the last 10 sessions of each phase, were shorter when the sizes of A and B were 14 and 25 μl of a 0.6 M sucrose solution than when they were 25 and 100 μl of the same solution. The ratio of the indifference delays was significantly smaller than that predicted on the basis of an assumed linear relation between reinforcer size and instantaneous reinforcer value, consistent with a previous proposal that this relation may be hyperbolic in form. Estimates of the rate of delay discounting based on the ratio of the two indifference delays (mean, 0.08 s(-1)) were similar to values obtained previously using different intertemporal choice protocols. Estimates of the size-sensitivity parameter (mean 113 μl) were similar to estimates recently derived from performance on progressive-ratio schedules. In both phases of the experiment, adjusting delays in successive blocks of trials were analyzed using the Fourier transform. The power spectrum obtained from individual rats had a dominant frequency that corresponded to a period of oscillation of the adjusting delay between 30 and 100 trial blocks (mean, 78). Power in the dominant frequency band was highest in the early sessions of the first phase and declined with extended training. It is suggested that this experimental protocol may have utility in neurobehavioral studies of intertemporal choice. 相似文献
Evidence suggests that parental marital discord contributes to the development of internalizing and externalizing symptoms
in children and adolescents. Few studies, however, have examined the association between parental marital discord and youth’s
response to treatment. The present study examined the impact of interparental discord on treatment response in a randomized
control trial of adolescents with major depression enrolled in the Treatment for Adolescents with Depression Study (TADS).
Participants were 260 adolescents from two-parent households randomly assigned to one of four treatment groups: fluoxetine
(FLX), cognitive behavior therapy (CBT), their combination (COMB), or placebo (PBO). Logistic regressions revealed that parental
marital discord interacted with youth gender and co-morbid oppositionality symptoms to predict group differences in treatment
response. 相似文献
In this paper we present a model for action preparation and decision making in cooperative tasks that is inspired by recent experimental findings about the neuro-cognitive mechanisms supporting joint action in humans. It implements the coordination of actions and goals among the partners as a dynamic process that integrates contextual cues, shared task knowledge and predicted outcome of others’ motor behavior. The control architecture is formalized by a system of coupled dynamic neural fields representing a distributed network of local but connected neural populations. Different pools of neurons encode task-relevant information about action means, task goals and context in the form of self-sustained activation patterns. These patterns are triggered by input from connected populations and evolve continuously in time under the influence of recurrent interactions. The dynamic model of joint action is evaluated in a task in which a robot and a human jointly construct a toy object. We show that the highly context sensitive mapping from action observation onto appropriate complementary actions allows coping with dynamically changing joint action situations. 相似文献
The influence of students' sociocultural background on academic achievement is a well established fact. Research also points out that sociocultural background is related to students' cognitive abilities and these have an effect on their academic achievement. However, the mediator role of cognitive abilities on the relationship between sociocultural background and academic achievement is less well known. A structural equation model that represents these relationships was tested in a sample (N= 728) of Portuguese junior high school students. Multigroup analysis of the model showed the importance of the cognitive ability mediation effect between sociocultural background and academic achievement in the 7th and 9th grades, but not in the 8th grade. This difference may be the result of the academic transition experienced in the 7th and 9th grades in the Portuguese educational system, which requires parents' higher involvement in school. 相似文献
BCI (Brain-Computer Interface) is a system that allows interaction between the human brain and a computer. It is based on analyzing electroencephalographic signals (EEG) and processing them to generate control commands. The study analyzed the possible influence of psychological variables, such as the imaginative kinesthetic capacity and anxiety, in relation to performance in a BCI. All participants (4 male and 19 female students) completed the questionnaires and carried out a session of BCI to control their EEG signals in a virtual setting of a car along a straight road. The group was divided into two subgroups according to their EEG signals or differential responses obtained in the left-right discrimination. Study results showed no significant differences in cognitive variables of imagination or in anxiety. By comparing the degree of participants' BCI control, a new quantitative parameter for comparing performances and making decisions in signal processing was found. The findings, the ongoing research process to refine the control of a BCI, and the interaction of psychological and computer procedures are discussed. 相似文献
The evaluation and identification of needs profiles for youth in residential care, through qualitative and quantitative methodologies involving different stakeholders, are still relatively uncommon, even though they are essential in developing specific and effective services. This article will present two studies, one with youth and another with professionals. To assess needs from the standpoint of youth, four focus groups were held with youth in residential care (n = 21). To identify needs profiles of youth from the standpoint of professionals, 47 professionals evaluated a sample of youth in residential care (n = 110) using the RCYNA questionnaire. The results of the study with youth point to needs in three main areas: living situation, social and family relationships, and education. The results of the study with professionals reveal three needs profiles with distinct risk levels: low risk, without emerging needs; intermediate risk, with needs in terms of the economic and living situation; and high risk, with needs in terms of relationships, behavioural, psychological and emotional skills, and education and employment. 相似文献
Self-esteem is defined as sense of self-worth and self-respect, being crucial for understanding people’s well-being and success. It is one of the most studied constructs in the social sciences, with the Rosenberg Self-Esteem Scale (RSES) being the most used measure. Across four studies (N = 1450), we tested the psychometric parameters of an abbreviated version of the RSES. Through Item Response Theory, the five best items were selected to form the unidimensional Brief Rosenberg Self-Esteem Scale (B-RSES), a reliable and valid measure of self-esteem, which is invariant across age groups and gender. In addition, both RSES and B-RSES correlated very similarly with the Big Five Personality Factors. Also, the B-RSES was strongly correlated with three other short measures of self-esteem, besides being more strongly associated with a range of variables such as conscientiousness and self-competence in comparison to the other three short scales. Together, the B-RSES is especially useful in research that requires rapid evaluation and the use of multiple variables.
In this work, the first of a series, we study the nature of informal inconsistency in physics, focusing mainly on the foundations of quantum theory, and appealing to the concept of quasi-truth. We defend a pluralistic view of the philosophy of science, grounded on the existence of inconsistencies and on quasi-truth. Here, we treat only the ‘classical aspects’ of the subject, leaving for a forthcoming paper the ‘non-classical’ part. 相似文献