Working memory deficits in retinoid X receptor gamma-deficient mice

Retinoid signaling has been recently shown to be required for mnemonic functions in rodents. To dissect the behavioral and molecular mechanisms involved in this requirement, we have analyzed the spatial and recognition working memory in mice carrying null mutations of retinoid receptors RARbeta and RXRgamma. Double mutants appeared deficient in spatial working memory as tested in spontaneous alternation in the Y-maze and delayed nonmatch to place (DNMTP) test in the T-maze. These mutant mice did acquire, however, spatial place reference or right/left discrimination tasks in the T-maze set-up, indicating that basic sensorimotor functions, spatial orientation, and motivational factors are unlikely to account for deficits in working memory-sensitive tasks. Double-mutant mice were also deficient in novel object recognition at intermediate, but not short delays. RXRgamma appeared to be the functionally predominant receptor in modulation of the working memory, as RXRgamma, but not RARbeta single null mutant mice exhibited deficits similar to those observed in the double mutants. The mechanism of this modulation is potentially related to functions of RXRgamma in frontal and perirhinal cortex, structures in which we detected RXRgamma expression and which are functionally implicated in working memory processes.     

Exploratory behavior as a function of environmental novelty and complexity in male and female rats

Laboratory rats show a positive response to low- and nonstressful novel events. The novel event may involve a number of aspects of the stimulus field. It is usually associated with a change in amount of environmental complexity. Most studies concerning novelty-related behavior involve the introduction of novel objects or the rearrangement of familiar objects. The present purpose was to measure exploratory behavior in response to environments of increased and decreased complexity. Both directions of environmental change are conditions of novelty. A two-way manipulation of increasing and decreasing the complexity of the environment was used. Rats of both sexes showed increased exploration to exposure to novelty, no matter which manipulation was applied; however, female and male rats behaved differently to the two types of novelty. Males responded more to novelty from the introduction of an unfamiliar object. The results indicate novel stimulation, whether of increasing or decreasing complexity, has reward properties. Perhaps the male-specific behavior directed toward unfamiliar objects may serve an adaptive function.     

Algebraic Models of Mental Number Axes: Part II

The paper presents a formal model of the system of number representations as a multiplicity of mental number axes with a hierarchical structure. The hierarchy is determined by the mind as it acquires successive types of mental number axes generated by virtue of some algebraic mechanisms. Three types of algebraic structures, responsible for functioning these mechanisms, are distinguished: BASAN-structures, CASAN-structures and CAPPAN-structures. A foundational order holds between these structures. CAPPAN-structures are derivative from CASAN-structures which are extensions of BASAN-structures. The constructed formal model unifies two competitive conceptions of cognitive arithmetic: namely, the conception of the mental number line and the conception of parallel individuation. The paper is the continuation of a paper entitled Representational structures of arithmetical thinking, in which rich empirical evidence supporting the model is presented. The main result achieved in the present paper may be philosophically interpreted as an attempt to formalize the Kantian conception of the pure idea of time, understood as the a priori form of human arithmetical thinking. In this way, our theory may be comprehended as a result of applying the hard method of logical reconstruction of fundamental epistemological categories.     

The chameleon effect,the temporal aspects of mimicry and their impact on service measurement

BackgroundIn an experiment conducted in a natural setting, we test the link between mimicry, the amount of time during which the mimicry behavior takes place, and its impact on service quality.MethodsCable TV clients (n = 120) were randomly assigned to six experimental conditions (2 mimicry conditions: verbal mimicry vs. no mimicry x 3 interaction time: 5 vs. 10 vs. 15 minutes). Perceived service quality served as the dependent measurement.ResultsA main effect of mimicry was found on service quality: a cable TV representative was perceived more favorably when he mimicked the customer. Importantly, it was shown that even small portions of mimicry are beneficial, meaning that practitioners do not have to mimic someone for a long time to achieve benefits.ConclusionThe paper shows new benefits for the mimicker: more positive judgments by the mimickee regarding the impact on several different levels of service quality.     

Homelessness in the US and Germany: a cross‐national analysis

A public opinion survey was administered by telephone to nationally representative samples in the US and Germany to assess prevalence of homelessness as well as attitudes, opinions and knowledge regarding homelessness. Lower prevalence rates were found in Germany as compared with the US. German respondents demonstrated higher levels of general compassion, greater support for the public rights of the homeless, a greater tendency to view the homeless as trustworthy, and were more likely to view economic factors and less likely to view personal failings as integral to the problem of homelessness. Respondent age, gender, and political affiliation predicted many public opinion variables. Copyright © 2003 John Wiley & Sons, Ltd.     

The Human Factor in Maritime Transport: Personality and Aggression Levels of Master Mariners and Navigation Students

The current study sought to identify groups of navigation students and master mariners (captains) characterized by different constellations of the Big Five personality traits and aggression levels. We hypothesized that master mariners would exhibit the resilient personality type and that navigation students would additionally exhibit personality types other than the resilient (e.g., over- or undercontrolled). A sample of 108 navigation students (men, in their second or third year of naval school, all active athletes) and 76 master mariners took part in the study and completed the Polish version of the NEO Five-Factor Inventory (Costa & McCrae, 1992; Zawadzki et al., 1998) and the Aggression Questionnaire (Buss & Perry, 1992; Tucholska, 1998). The hypothesis about the resilient personality type among master mariners was confirmed. The second hypothesis about personality types other than the resilient among navigation students was also confirmed: 33% of the students exhibited the overcontrolling personality type. The article also highlights the need to include psychological assessment in naval school enrolment procedures.     

Kierkegaard on Imitation and Ethics: Toward a Secular Project?

This essay demonstrates the prominence of imitation in Kierkegaard’s ethics. I move beyond his idea of authentic existence modeled on Christ and explore the secular dimension of Kierkegaard’s insights about human nature and imitation. I start with presenting imitation as key to understanding the ethical dimension of the relationship between the universal and individual aspects of the human self in Kierkegaard. I then show that Kierkegaard’s moral concepts of “primitivity” and “comparison” are a response to his sociological and psychological observations about imitation from an ethical point of view. In the final section of this paper, I briefly engage Friedrich Schleiermacher’s “ethics of individuality” and Gabriel Tarde’s “laws of imitation” to explore Kierkegaard’s consideration of ethics and imitation as situated within the context of a broader conversation on imitation.