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31.
Riha PD Rojas JC Colorado RA Gonzalez-Lima F 《Neurobiology of learning and memory》2008,90(1):112-124
The posterior cingulate cortex (PCC) is the brain region displaying the earliest sign of energy hypometabolism in patients with amnestic mild cognitive impairment (MCI) who develop Alzheimer’s disease (AD). In particular, the activity of the mitochondrial respiratory enzyme cytochrome oxidase (C.O.) is selectively inhibited within the PCC in AD. The present study is the first experimental analysis designed to model in animals the localized cortical C.O. inhibition found as the earliest metabolic sign of early-stage AD in human neuroimaging studies. Rats were used to model local inhibition of C.O. by direct injection of the C.O. inhibitor sodium azide into the PCC. Learning and memory were examined in a spatial holeboard task and brains were analyzed using quantitative histochemical, morphological and biochemical techniques. Behavioral results showed that sodium azide-treated rats were impaired in their memory of the baited pattern in probe trials as compared to their training scores before treatment, without non-specific behavioral differences. Brain analyses showed that C.O. inhibition was specific to the PCC, and sodium azide increased lipid peroxidation, gliosis and neuron loss, and lead to a network functional disconnection between the PCC and interconnected hippocampal regions. It was concluded that impaired memory by local C.O. inhibition in the PCC may serve to model in animals a metabolic lesion similar to that found in patients with amnestic MCI and early-stage AD. This model may be useful as an in vivo testing platform to investigate neuroprotective strategies to prevent or reduce the amnestic effects produced by posterior cingulate energy hypometabolism. 相似文献
32.
Betancourt Mainhard R Corada Luis L Dominichetti Camus J Laborda Rojas M Martínez Miranda G Miguel Cavieres G 《Psicothema》2008,20(2):285-289
The Pavlovian analysis of drug tolerance describes how the contexts of drug administration participate in the elicitation of compensatory conditioned responses that are, at least partly, responsible for tolerance. Findings indicate that if an association is acquired in one context and extinguished in another one, when exposing the subjects to the acquisition context, renewal of the conditioned response will take place. Ambiguous evidence exists about whether or not this effect diminishes when extinguishing the association in multiple contexts. This investigation evaluates the existence of the phenomenon of renewal of tolerance to ethanol, and whether it diminishes by the extinction in multiple contexts. Evidence of renewal of tolerance to ethanol in rats was found, but no diminution was observed when extinguishing in multiple contexts. 相似文献
33.
Is it advisable to include negative attributes to assess the stereotype content? Yes,but only in the morality dimension 下载免费PDF全文
Pablo Sayans‐Jiménez Antonio José Rojas Tejada Isabel Cuadrado Guirado 《Scandinavian journal of psychology》2017,58(2):170-178
Competence, morality and sociability dimensions have shown to be essential to measure stereotypes. Theoretically, the attributes associated with the negative pole of morality are more reliable and have shown to have higher evaluative weight. However, the current research usually employs only positive attributes to measure each dimension. Since the advantages of the inclusion of negative morality are clear it would be interesting to know about the effects of the inclusion of such type of attributes (i.e., it is good or bad for the measurement). The purpose of this study is to examine if the addition of negative items makes possible to improve the stereotype content measures. This study compares the differences between scales with various compositions of positive and negative items of stereotypes to predict three related variables: anger, fear and a semantic differential of evaluation. The study was carried out with a sample of 550 Spaniards. The data found highlights the importance of using attributes of the negative pole of morality in studying stereotypes. Their use was able to explain the intergroup emotional responses and the semantic differential more efficiently. 相似文献
34.
Rojas Tejada AJ Lozano Rojas OM Navas Luque M Pérez Moreno PJ 《Psychological reports》2011,109(2):553-572
There have been two basic approaches for the study of minority group prejudice against the majority: to adapt instruments from the majority group, and to use qualitative techniques by analyzing the content of the discourse of the groups involved. Neither of these procedures solves the problem of measuring intergroup attitudes of majorities and minorities in interaction. This study shows the result of a prejudice scale which was developed to measure the attitude of both the minority and majority groups. Prejudice is conceived as an attitude which requires the beliefs or opinions about the out-group, the emotions it elicits, and the behavior or intentional behavior toward it to be known for its evaluation. The innovation in this work is that the psychometric development of the scale was based on the item response theory, and more specifically, the rating scale model. 相似文献
35.
AJ Flanagin 《人类交流研究》2000,26(4):618-646
Innovation adoption research has demonstrated that organizational features and perceived benefits of innovations play significant roles in explaining organizational‐level decisions to adopt new technologies. Beyond such motivations, however, social pressures operating at the interorganizational level have been proposed to influence the decision to adopt innovations, even without regard to any proven or anticipated benefit from the innovation itself. To empirically determine the influence of organizational features, perceived benefits, and social pressures on organizations' innovation adoption decisions, this study examined the decisions of 288 organizations to adopt Internet websites. Organizational social pressures were found to be the most significant discriminators of adopters and non adopters, although they were not particularly important in predicting the likelihood of future adoption for those organizations currently without websites. This finding suggests that social pressures are significant in innovation adoption, but that they may have their strongest effect during the early phases of innovation diffusion. Organizational features and perceived benefits were also reasonable discriminators of adopters and nonadopters as well as effective predictors of the likelihood of adoption for nonadopters. To a lesser degree, these factors were also predictive of the stage of adoption for those organizations that have already adopted websites. 相似文献
36.
Structural model of acculturation attitudes and related psychosocial variables: Empirical evidence in native Spaniards 下载免费PDF全文
Pedro J. Pérez Moreno Antonio J. Rojas Tejada Marisol Navas Luque Oscar M. Lozano Rojas 《International journal of psychology》2014,49(3):175-182
This work falls within the framework of the study of acculturation processes of natives and immigrants. Its goal is to test an explanatory multi‐group model of natives' acculturation attitudes as a function of diverse psychosocial variables: Prejudice and natives' appraisal of their own culture (in a direct way) and inter‐group contact and perceived inter‐group similarity (in an indirect way). Participants were 499 Spaniards surveyed for their attitude towards Romanian immigrants and 493 towards Ecuadorian immigrants. The indicators used took into account three socio‐cultural spheres: peripheral, intermediate and central areas. This multi‐group model shows an adequate fit to the data. 相似文献
37.
Álvaro I. Langer Valentina G. Ulloa Adolfo J. Cangas Graciela Rojas Mariane Krause 《Estudios de Psicología》2013,34(3):533-570
AbstractIn order to study the effects of mindfulness meditation interventions administered to adolescents within their educational institutions, a qualitative systematic review was conducted. Sixteen studies published in main databases were analysed. The results show that mindfulness, as a prevention strategy in educational contexts, resulted in significant changes in the followings variables: (a) psychological (e.g., reduction in depressive symptoms); (b) psychosocial (e.g., increased social skills); and (c) physiological (e.g., improvement of blood pressure). Although the results were conclusive, their interpretation and generalization should be carefully analysed as there were no medium- and long-term follow-up evaluations, in addition to the fact that there has been a minimal assessment of the psychological mechanisms involved in the change processes. 相似文献
38.
Rottenbacher de Rojas JM 《The Spanish journal of psychology》2010,13(2):798-807
This study analyzes the relation between national identity and the appreciation of the characters and events of Peruvian history in a sample of public school teachers from the city of Lima (N = 99). Adapted versions of the NATID Scale (Keillor et al., 1996) and the CSES Scale (Luhtanen & Crocker, 1992) are used as measures of national identity. National pride and interest in knowing about Peruvian history are variables also included in this study. The study shows that appreciation of historical characters is more positive than appreciation of historical events. There is a positive association between national identity and appreciation of Peruvian historical characters. A multiple linear regression model is proposed; this model shows that appreciation of cultural heritage and national pride has a positive impact on the appreciation of characters of Peruvian history. 相似文献
39.
Pablo Sayans-Jiménez Frenk van Harreveld Jonas Dalege Antonio J. Rojas Tejada 《European journal of social psychology》2019,49(3):604-621
In this work we present empirical network models as a new approach in the investigation of stereotype structure. We will argue that empirical network models can provide more insight into stereotype structure because they do not suffer from the inherent constraints of factor analysis and multidimensional scaling (e.g., group features interpreted homogeneously only on the basis of their shared variance, impossibility to adequately represent cognitive schemas, difficulties to make inferences on the basis of dimensions potentially overlapping). In the present research we show how empirical network models can represent stereotypes as dynamic cognitive structures clustered in different substructures. These structures will be based on both the stereotype content and the co-occurrence of features in each group target. Additionally, this research shows how using empirical networks can contribute to broadening the interpretation of stereotypes representing them in the framework of prejudice or intergroup attitudes. 相似文献
40.
Antje von Suchodoletz Natalia M. Rojas Iryna Nadyukova Ross A. A. Larsen Fitim Uka 《American journal of community psychology》2019,63(3-4):286-297
Teachers’ stress is a dynamic combination of the individual teacher's characteristics and characteristics of the classroom and school environment. To date, there are limited studies on teachers’ stress in the context of lower‐middle‐income countries (LMICs), where working conditions as well as general political and economic circumstances might pose a considerable threat for teachers’ well‐being. This study explores whether certain combinations of individual and environmental experiences of teachers in LMICs may result in stress, assessed as patterns of diurnal cortisol rhythm. Participants were kindergarten teachers in Kosovo and Ukraine, two LMICs in Europe. Latent Profile Analysis identified three subgroups of teachers that significantly differed on teachers’ education and experience. Preliminary results of Latent Growth Modeling suggested differences between profiles in baseline waking cortisol and patterns of diurnal decline. Teachers in the profile that was characterized by the longest experience working in the field but the lowest level of education showed blunted cortisol in the morning and a flatter slope; a pattern that could indicate a maladaptive cortisol response. Future directions for studying stress processes among teachers in LMICs and implications for policy and practice on how to support teacher well‐being in low‐resource contexts are discussed. 相似文献