Is the unilateral lesion of the left substantia nigra pars compacta sufficient to induce working memory impairment in rats?

Adult male Wistar rats with a substantia nigra pars compacta (SNc) lesion induced by intranigral administration of 1 micromol 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine (MPTP) were used as a model of early phase Parkinson's disease (PD). This lesion caused a partial depletion of striatal dopamine (DA). The animals were submitted to a spatial working memory version of the water maze task in which they had to find a hidden (submersed) platform using online-maintained information that the platform remains in the same place during four consecutive trials, but that it is moved to another place every training day. Left, but not right SNc-lesioned rats were impaired in finding the platform in the second trial. This result suggests that the left SNc plays a key role in spatial working memory. Control experiments ruled out the possibility that motor impairment, sensory neglect, and/or impairment in the mental representation of the contralateral spatial environment had affected performance of the SNc-lesioned rats.     

A goal activation approach to the study of executive function: an application to antisaccade tasks

We argue that a general control process, responsible for the activation and maintenance of task goals, is central to the concept of executive function. Failures of this process can become manifest as goal neglect: disregard of a task requirement even though it has been understood (Duncan, 1995). We discuss the results of several published and new experiments using various versions of the antisaccade task in order to investigate the circumstances under which goal neglect is likely to occur. Potentially conflicting results in the literature on adaptive control of saccadic eye movements are argued to be attributable to the extent to which different task versions elicit goal neglect. The results suggest an increased susceptibility to goal neglect of high-functioning older adults (Experiment 1) and of first-episode schizophrenia patients (Experiment 2), but not of patients with obsessive-compulsive disorder (Experiment 3). However, the degree to which such differences in susceptibility become manifest in task performance, is shown to be strongly influenced by manipulations of the relative saliency of task requirements. Theoretical and methodological implications for the study of executive function are discussed.     

Religiosity, values, and horizontal and vertical individualism-collectivism: a study of Turkey, the United States, and the Philippines

The authors examined the links between two dimensions that have been useful in understanding cross-cultural differences and similarities, namely, individualism-collectivism (I-C) and value orientations. The authors examined the relations and parallels between the two variables by directly relating them and examining the patterns of relations that both have with a third variable, religiosity. Participants were 475 college students from the Philippines, the United States, and Turkey who responded to measures of horizontal and vertical I-C, value orientations, and religiosity. The authors found partial support for the parallels between I-C and value types, particularly for collectivism and conservative values. Moreover, religiosity was associated positively with conservative values and collectivism, across all three cultures. The authors found individualism to also relate to openness-to-change values, though the patterns were not as consistent as those that they found between collectivism and conservation. Differences and similarities emerged in links of I-C-values to religiosity across the three samples.     

Relationships between physical activity and motor skills in middle school children

The purpose of this study was to examine the relationships between physical activity measured as pedometer steps and performance on three motor skill tests. A secondary purpose was to determine if middle school children are meeting the recommendation for the number of daily steps. A sample (n =217) of 6th, 7th and 8th grade students participated. Each subject wore a Digi-Walker pedometer for three consecutive days. Subjects additionally recorded their pedometer steps in two 45 min.-physical education classes. There were strong significant correlations between daily steps taken by boys and girls, pedometer steps during physical education class and the AAHPERD Passing Test and the Bass Stick Balance. Similar correlations were weaker for the Side-Step Agility Test. Multivariate analysis of variance was utilized to examine variability of the three skills test by sex and year in school. Differences between students in Grades 7 and 8 on the AAHPERD Passing Test were significant. In addition, significant differences between daily pedometer steps and steps during physical education between Grades 6 and 7 were observed. Boys and girls had similar means on the AAHPERD Passing Test and Bass Stick Balance Test, but not on the Side-Step Agility Test. Scores on the three movement skills tested in this study were not strongly related to physical activity of the entire sample. Steps taken by middle school children appear not to be related to these measures of motor skills.     

The role of external cues for endogenous advance reconfiguration in task switching

Most studies of task-set switching rely on cuing paradigms, in which external cues indicate the upcoming task. The present study used an entirely predictable task sequence in a variant of the alternating-runs paradigm of Rogers and Monsell (1995). Preparation effects with purely internal memory cues were compared with those in another experimental group with additional external cues presented prior to the stimulus. External cues led to strongly reduced shift costs with prolonged preparation time. However, this effect was much smaller with internal cues only. To account for this differential effect of preparation time as a function of cue type, it is suggested that internal cues select the next task set, which is sufficient to perform the task. External cues additionally facilitate preparatory retrieval of task-specific stimulus-response rules. This account may also explain why incidental task-sequence learning based on internal cues did not reduce shift costs.     

Communication constraints on the linguistic intergroup bias

We examined whether the linguistic intergroup bias (LIB) is a context-free, invariant process or influenced by communicative purpose. The reported experiment shows that biased language use (positive behaviors of a partner and negative behaviors of an opponent are described with abstract predicates, negative partner and positive opponent behaviors are described with concrete predicates) occurs only when the communication has a clear purpose, but not when it does not. The implications of communicative purpose as a constraint on the psychological processes driving the LIB are discussed as well as the possible impact of biased language use upon recipients.     

Dimensions of Perfectionism and Anxiety Sensitivity

The current study investigated the extent to which dimensions of perfectionism are associated with components of the anxiety sensitivity construct. A sample of 177 undergraduate students completed the Multidimensional Perfectionism Scale, the Perfectionism Cognitions Inventory, the Perfectionistic Self-Presentation Scale, and the Expanded Anxiety Sensitivity Index developed by Taylor and Cox (1998). The results confirmed that automatic thoughts involving perfectionism and the interpersonal aspects of the perfectionism construct are associated with anxiety sensitivity. Examination of the Anxiety Sensitivity Index factors showed that perfectionism cognitions were associated primarily with anxiety sensitivity involving fears of cognitive dyscontrol, while socially prescribed perfectionism and perfectionistic self-presentation were associated primarily with fears of publicly observable anxiety reactions in a manner suggesting that the interpersonal perfectionism dimensions are linked closely with an anxious sensitivity to negative social evaluation and subsequent panic attacks. The theoretical and treatment implications of the link between perfectionism and anxiety sensitivity are discussed.     

Antecedents and Components of Majority Attitudes toward Multiculturalism in the Netherlands

Les prédicteurs et les composantes des attitudes envers le multiculturalisme ont étéétudies chez 341 Néerlandais tout‐venant. Les attitudes relèvent d’une structure unidimensionnelle, mais le niveau d’adhésion au multiculturalisme varie significativement selon les domaines. Le niveau culturel et le fait de vivre en ville avec peu d’immigrés étaient les seules variables positivement corrélées avec l’adhésion au multiculturalisme. Un modèle en pistes causales s’est révélé pertinent, les attitudes et les comportements dépendant des variables psychologiques suivantes; connaissances, satisfaction générale, perspectives d’avenir, désirabilité sociale et perception des normes sociales favorables au multiculturalisme ou en faisant au contraire une menace. Globalement, l’exclusion était désapprouvée par la majorité des Néerlandais, mais le pluralisme culturel nétait pas ressenti comme étant un atout précieux pour leur société, et ils nétaient pas disposés à faire beaucoup d’efforts pour faciliter l’intégration des minorités. Predictors and components of attitudes toward multiculturalism were studied in 341 native Dutch people. Attitudes were found to have a unidimensional structure, but the level of support for multiculturalism was found to vary significantly over societal domains. Level of education and living in city districts with few non‐natives were the only background variables that were (positively) related to support for multiculturalism. A path model, with psychological background variables (knowledge, life satisfaction, life opportunities, perceived social norms about multiculturalism as a threat and support for multiculturalism, and social desirability) predicting attitudes and behavior, showed a good fit. Generally, exclusionist positions were not endorsed by majority Dutch, but cultural pluralism was not seen as a valuable asset of their society, and they are not inclined to put much effort into minority integration.     

Inhibition of response mode in task switching

Task inhibition was explored in two experiments that employed a paradigm in which participants switched among three tasks. Two tasks required manual choice responses based on numerical judgment (parity or magnitude), whereas a third task required an unconditional double-press of both response keys. Both experiments showed that switching to a just-abandoned task (n-2 task repetition) generally leads to a performance cost relative to switching to another task. Specifically, this task inhibition effect also occurred for the double-press task, suggesting inhibition of response mode. Prolonging the task-cuing interval showed that advance task preparation reduced only inhibition of the double-press task but not of the choice tasks (Experiment 1). Prolonging the response-cue interval led to a decrease of the inhibition effect in all tasks (Experiment 2), suggesting a time-based release of task inhibition. Together, the experiments support the notion of a response-related component of task inhibition.