RELATIONSHIPS BETWEEN FLICKER-FUSION THRESHOLD AND TWO PARAMETERS OF VISUAL MOTION AFTER-EFFECT

Measures of duration and velocity of the visual motion after-effect were both shown to be positively related to flicker-fusion threshold.     

PROBABILITY DISCORDANCE AND CHOICE REACTION TIME: I. Effects of discordant probability on choice reaction time during prolonged training

Successive development of disinhibitory action over long monotonous training periods was studied with choice RT stimuli possessing discordant properties related to their relative frequency and the direction of movement. The results indicate that stimuli with strong initial proactive interference on ensuing reaction to the critical probe-stimulus become, with prolonged training, the least interfering.     

Similarity semantics and minimal changes of belief

Different similarity relations on sets are introduced, and their logical properties are investigated. Close relationships are shown to hold between similarity relations that are based on symmetrical difference and operators of belief contraction that are based on relational selection functions. Two new rationality criteria for minimal belief contraction, the maximizing property and the reducing property, are proposed.     

On central control of body fluid homeostasis

The paper is a discussion of the manners in which cerebral receptor systems may perceive the changes in the internal environment which arise in consequence of deviations from fluid balance. Arguments are presented against the current osmoreceptor theory which implies that receptors in the hypothalamic region are stimulated directly by blood hypertonicity. Recent studies are reviewed which indicate that a possible alternative to hypothalamic osmoreceptors may be receptors in the close vicinity of the third ventricle which are influenced by the Na⁺ concentration of the cerebrospinal fluid. Evidence is presented that a sodium sensitive receptor system of this kind participates, not only in the control of water balance, but also in the regulation of the renal Na⁺ excretion and of the arterial blood pressure. The demonstration of a striking central sodium-angiotensin interaction implies that periventricular sodium sensitive receptors also may be a final link in a volumetric regulation of thirst and ADH release which is mediated by the reninangiotensin system.     

Sexual Debut Ages in Heterosexual,Lesbian, Gay,and Bisexual Young Adults in Norway

This study estimates sexual debut ages in young heterosexual, lesbian, gay, and bisexual men and women in Norway. A questionnaire survey was completed online by 27.2 % of a representative national web sample of 2090 persons aged 18–29 years. Three self-selected samples of 924 respondents completed an extended version of the survey online. Lesbian and bisexual women reported earlier experience of orgasm through masturbation than heterosexual women (median 13.1 vs. 15.2 years), and heterosexual men (median 13.5) reported earlier debut than heterosexual women. There was a statistically significant difference between heterosexual and lesbian and bisexual women’s age at the first experience of receptive vaginal sex (median 16.8 vs. 15.4 years). As regards experience of insertive vaginal sex, a significantly higher percentage of heterosexual men than women, and of heterosexual and lesbian and bisexual women, reported experience. It was more common among lesbian and bisexual women than heterosexual women to have had oral sex with another woman, but in neither group did the cumulative percent reach 50 % by the age of 29 years and the median could not be estimated. Gay and bisexual men reported earlier receptive anal sex debut than heterosexual men. With regard to insertive anal sex, gay and bisexual men accumulated experience earlier than heterosexual men, and lesbian and bisexual women acquired this experience earlier than heterosexual women. Compared to heterosexuals, LGB persons of both genders engage in more varied sexual activities. Lesbian and gay persons have same-sex experiences at an earlier age than bisexuals.     

Revisiting the mediating role of leader–member exchange in transformational leadership: the differential impact model

Transformational leadership (TFL) has been proposed as an essential antecedent of leader–member exchange (LMX), which in turn affects outcomes in organizations. We extend this mediation hypothesis in two ways by proposing a differential impact model, which we test on three organizational outcomes: employee job satisfaction, employee organizational commitment, and leader effectiveness. First, we extend LMX’s mediational impact—which has previously only been tested for employee outcomes—to leader effectiveness. Second, we argue that this mediation will be stronger for outcomes that are more proximal rather than distal to dyadic relations between leader and followers (high proximity: job satisfaction; medium proximity: organizational commitment; low proximity: leader effectiveness). Meta-analytic structural equation modelling based on 132 studies revealed that LMX mediates TFL’s relationships with employee outcomes (more strongly for job satisfaction than for commitment), but not with leader effectiveness, whereas TFL showed a stronger direct link to leader effectiveness. The findings suggest that TLF and LMX contribute differentially to organizational outcomes depending on their proximity to dyadic relations between leaders and followers. The differential impact model uncovers leadership effectiveness processes, integrates influential leadership theories, and highlights the importance of distinguishing between different outcome measures and the processes facilitating them.