Acquisition and use of mental operators: effects of type of practice

Planning interactions with the physical world requires knowledge about operations; in short, mental operators. Abstractness of content and directionality of access are two important properties to characterize the representational units of this kind of knowledge. Combining these properties allows four classes of knowledge units to be distinguished that can be found in the literature: (a) rules, (b) mental models or schemata, (c) instances, and (d) episodes or chunks. The influence of practicing alphabet-arithmetic operators in a prognostic, diagnostic, or retrognostic way (A + 2 = ?, A? = C, or ? + 2 = C, respectively) on the use of that knowledge in a subsequent test was used to assess the importance of these dimensions. At the beginning, the retrognostic use of knowledge was worse than the prognostic use, although identical operations were involved (A + 2 = ? vs. ? - 2 = A). This disadvantage was reduced with increased practice. Test performance was best if the task and the letter pairs were the same as in the acquisition phase. Overall, the findings support theories proposing multiple representational units of mental operators. The disadvantage for the retrognosis task was recovered in the test phase, and may be evidence for the importance of the order of events independent of the order of experience.     

The Situational Context <Emphasis Type="Italic">on the Nature of Political Philosophy</Emphasis>

Rationalism in political philosophy is the view that politics should be governed by moral principles and that those principles can and should be justified independently of the situations and circumstances that make up political reality. This traditional view of political philosophy implies that the meaning of right political action is determined by moral principles the rational authority of which derives from abstract philosophical reasoning, not from the situations and circumstances that are the substance of political reality. In this essay I argue that rationalist moralities must presuppose the understanding of particular situations and circumstances for their meaningful and correct interpretation. This means, I argue, that the rightness of political judgement and action is immanent in particular situations, not in abstract moralities. And this, I argue, suggests a shift from the traditional view of political society as the embodiment of abstract principles, towards a view of political society as the embodiment of the activity of situational judgement. A society worth hoping for, then, is one in which we can live in the light of our understanding of the situations and circumstances that are the substance of everyday life, rather than in the shadow of abstract moralities. Such a society would be sensitive to the particularities and complexities of political reality, but at the same time it does not succumb to moral relativism and skepticism.     

Constructive Thinking and Burnout among Secondary School Teachers

The present study investigated the relationship between Epstein’s (1998, Constructive thinking: The key to emotional intelligence. London: Praeger publisher.) components of constructive thinking and burnout as experienced by a sample of Dutch secondary school teachers. A postal questionnaire was sent to teachers from randomly selected secondary schools. The response rate was 54.1% (N=433). Four components of constructive thinking significantly contributed to the explained variance in emotional exhaustion (17%), depersonalization (21%), and personal accomplishment (20%). The results of the study suggest that secondary school teachers’ maladaptive thinking processes prevent them from rational thinking during their work, which significantly contributes to the onset of burnout. Burnout intervention programs for teachers are likely to be more effective when the participator’s maladaptive thinking system is taken into consideration. This stems from the idea that personality factors are a probably easier point of departure to tackle burnout symptoms than organizational factors.     

Management Strategies of Sexual Dysfunctions

The purpose of this essay is to discuss on the possible impact on a couple's sexual relationships when the male partner's erectile problems contribute to a sexual dysfunction on the part of the female. The complex reciprocal nature of sexual interactions emphasizes the importance of the relationship for sexual function and dysfunction. The treatment of sexual dysfunction then takes into account the contribution of factors from the couple and the system. An integrated behavioural-systems approach is applied to address both sexual and non-sexual aspects of the interaction in the marital unit. This approach outlines a range of methods that may be used during the treatment of sexual dysfunctions in order to bring about relevant changes in sexual functioning and general relationships.     

Visual search for dimensionally redundant pop-out targets: evidence for parallel-coactive processing of dimensions

In two visual search experiments, the detection of singleton feature targets redundantly defined on multiple dimensions was investigated. Targets differed from the distractors in orientation, color, or both (redundant targets). In Experiment 1, the various target types were presented either in separate blocks or in random order within blocks. Reaction times to redundant targets significantly violated the race model inequality (Miller, 1982), but only when there was constancy of the target-defining dimension(s) within trial blocks. In Experiment 2, there was dimensional variability within blocks. Consistent with Experiment 1, constancy of the target-defining dimension(s), but this time across successive trials (rather than within blocks), was critical for observing violations of the race model inequality. These results provide evidence for parallel-coactive processing of multiple dimensions, consistent with the dimension-weighting account of Müller, Heller, and Ziegler (1995).     

Brain-computer communication: unlocking the locked in

With the increasing efficiency of life-support systems and better intensive care, more patients survive severe injuries of the brain and spinal cord. Many of these patients experience locked-in syndrome: The active mind is locked in a paralyzed body. Consequently, communication is extremely restricted or impossible. A muscle-independent communication channel overcomes this problem and is realized through a brain-computer interface, a direct connection between brain and computer. The number of technically elaborated brain-computer interfaces is in contrast with the number of systems used in the daily life of locked-in patients. It is hypothesized that a profound knowledge and consideration of psychological principles are necessary to make brain-computer interfaces feasible for locked-in patients.     

Time course of the blindness to response-compatible stimuli

This article examines the time course of a deficit in identifying a stimulus sharing a compatible feature with a response that is executed in parallel ("blindness to response-compatible stimuli," J. Müsseler & B. Hommel, 1997a). In 5 experiments, participants performed a timed response, and the presentation point of time of a to-be-identified stimulus was varied in respect to response execution. A blindness effect was observed when the stimulus was presented between response cue offset and response execution. In contrast, the identification of a stimulus presented before the response cue or after response execution was not affected by stimulus-response compatibility--a finding that rules out a retention-based explanation. These results support an explanation that states that the perceptual processing of a stimulus feature is impaired as long as the shared perception-action feature code is integrated into the representation of a to-be-executed response.     

Parallel working memory for spatial location and food-related object cues in foraging pigeons: binocular and lateralized monocular performance

During foraging, animals can increase their success by both remembering feeding sites and remembering food-related object cues. Because earlier studies have tested either the site or object memory in isolation, the aim of the present study was to evaluate how efficiently birds can utilize both memories simultaneously. Furthermore, the idea was tested that lateralization might be the principle of brain organization that allows for efficient parallel processing. Pigeons learned to search for food in a complex maze with 16 baited sites. To obtain the maximum reward they had to perform two tasks in parallel, a spatial working memory task and an object-specific working memory task. Birds performed well on this dual task but, compared with spatial working memory alone, they were impaired during the first choices of a trial (Experiment 1). When the left and the right brain hemispheres were tested separately by means of monocular occlusion (Experiment 2), object discrimination was better when birds used their right eye/left hemisphere. This was most pronounced during the first choices of a trial. On the spatial component of the task, performance on binocular trials was better than on monocular trials, but monocularly both hemispheres performed at the same level. Results show that on this dual task, discrimination of food-related object cues predominantly involved the left brain hemisphere whereas both hemispheres contributed equally to spatial performance.     

Effective Leadership and Culture in Iran: An Empirical Study

On analyse dans cet article les caractéristiques du leadership efficace en Iran, puis on envisage les liens possibles entre ce profil de leadership et les dimensions culturelles du pays. A partir des données fournies par 300 managers provenant de plus de 60 organisations relevant de trois secteurs industriels, on commence par utiliser les dimensions du projet GLOBE pour évaluer la culture iranienne dont les scores sont comparés à ceux d'autres pays. S'appuyant à la fois sur l' emic et l' etic du leadership, les auteurs développent sept dimensions du leadership: encourageant, dictatorial, visionnaire, familial, modeste, loyal et réceptif. Ils soutiennent que certaines de ces dimensions traduisent les aspects universels (ou etic ) du leadership (éncourageant, dictatorial), alors que d'autres procèdent de l' emic , c'est‐à‐dire de la spécificité culturelle du leadership (modeste, familial, loyal). Les résultats sont discutés en terme de positionnement de la culture iranienne entre des entrelacements fondamentaux et des traditions culturelles complexes. On aborde enfin la question des retombées sur les recherches à venir.