Effects of fluoxetine on play dominance in juvenile rats

In a series of three studies, we investigated the influence of a selective serotonin re-uptake inhibitor (fluoxetine) on the rough-and-tumble play of juvenile rats. In Experiment 1, both members of eight pairs of solitary-housed juvenile rats received either vehicle, 2.5, 5, or 10 mg/kg fluoxetine in a counterbalanced within-subject design 20 min before being allowed to play for 5 min periods on four successive test days. The 5 and 10 mg/kg pretreatments significantly reduced incidence of pins during play without affecting dorsal contacts. In Experiment 2, one member of each of 19 established play pairs received 5 mg/kg fluoxetine 20 min before play, while the other member received vehicle. Dominant rats showed no reduction in pins as a result of fluoxetine treatment, but subordinate rats who received fluoxetine exhibited significant reductions in pins. Subsequent dyadic analyses indicated that in pairs where the subordinate animal received fluoxetine, dominant animals maintained their pinning advantage over the 10 days of testing, but in pairs where the dominant animals received fluoxetine, this pinning asymmetry diminished. In Experiment 3, we replicated the above procedure with inexperienced play pairs, to control for the effects of prior social learning. Fluoxetine treatment (5 mg/kg) significantly reduced both pins and dorsal contacts in all treated rats. The results indicate that fluoxetine can reduce the playful pins of juvenile rats, but that prior social learning mediates the strength of these effects. © 1996 Wiley-Liss, Inc.     

Subordinate swordtail males escalate faster than dominants: A failure of the social conditioning principle

In previous studies we have shown that subordinate swordtail males (Xiphophorus helleri) direct more bites to their mirror image than dominants and, in confrontations with strange dominant males, approach the opponent more often during the pre-escalation period of fights. Consequently, we predicted that fights between two omega-males should escalate faster than fights between two alpha-males. Indeed, in omega-omega fights preescalation periods were shorter and biting rates were higher than in alpha-alpha fights before the fights escalated from the first retaliation bite onward. Another new observation was that in omega-alpha confrontations the first bite in the pre-escalation period was executed more often by the omega-male and there was also a tendency to bite more compared to the alpha-male in that stage of the encounters. We conclude that sub-ordinate males escalate faster and fight more offensively prior to escalation than do dominant males. The results cannot be explained by the “social conditioning principle.” On the ultimate level moderate costs of losing and high benefits of winning a fight, constraints on continued growth after maturing, short life-expectancy, and habitat saturation are probably factors promoting the offensive tactics of subordinate males. © 1993 Wiley-Liss, Inc.     

Comparison of hemispheric activation during mental word and rhyme generation using transcranial Doppler sonography

The Wada test is at present the method of choice for preoperative assessment of patients who require surgery close to cortical language areas. It is, however, an invasive test with an attached morbidity risk. By now, an alternative to the Wada test is to combine a lexical word generation paradigm with non-invasive imaging techniques. However, results of this approach are still not in complete agreement with the findings of the Wada test (r = .92; Knecht, Deppe, Ebner et al., 1998). We attempted to obtain a more distinct language lateralization with the development of a phonological rhyme generation paradigm based on pseudoword stimuli. To examine the predictive value of both paradigms we performed simultaneous bilateral functional transcranial Doppler ultrasonography on 19 right-handed male native German subjects. The rhyme generation condition produced a significantly stronger lateralization to the supposed hemisphere of language dominance than the classical word generation condition. The observed differences suggest that the rhyme generation paradigm is more robust in detecting hemispheric language dominance than other neuropsychological paradigms and might be most valuable for preoperative assessment of cortical language areas.     

Effects of Dangerous and Competitive Worldviews on Right-Wing Authoritarianism and Social Dominance Orientation over a Five-Month Period

The cross-lagged effects of dangerous and competitive social worldviews on Right-Wing Authoritarianism (RWA) and Social Dominance Orientation (SDO) were examined over a five-month period ( N   =  165). Analyses indicated that the motivational goal for group-based dominance and superiority indexed by SDO changed as a function of the degree to which the social world was perceived as a competitive place characterized by inequality and resource scarcity. The motivational goal for ingroup conformity and collective security indexed by RWA, in contrast, changed as a function of the degree to which the social world was perceived as a dangerous and threatening place prone to high levels of crime and immoral behavior. These findings are consistent with the causal pathways between social worldviews and ideological attitudes predicted by Duckitt's (2001 ) model of the dual motivational and cognitive processes underlying prejudice. An unexpected reciprocal effect in which RWA predicted longitudinal change in dangerous worldview was also identified, suggesting that the relationship between these two constructs may be more complex than previously hypothesized.     

儿童早期词汇获得的词类差

儿童早期词汇获得存在词类差异,很多语言中名词比例都要高于其他词类,因此一些研究者提出“名词优势”理论。但是,一些对汉语和韩语的研究发现,儿童早期获得的动词比例与名词没有显著差异,甚至高于名词,同时汉语和韩语动词比例也远大于英语动词比例。针对不同语言儿童早期获得的动、名词比例差异现象,研究者认为语言结构特征和成人对孩子的言语输入可以解释不同语言儿童早期词汇中动、名词比例的差异,其中成人言语中词类的频率、单词位置、词形变化复杂性和语用等因素都会影响儿童早期词汇获得。此外,不同的词汇测量方法、观察情境、词类定义、词汇量水平、单词理解与说出也会造成不同研究结果之间的差异     

Gradient language dominance affects talker learning

Traditional conceptions of spoken language assume that speech recognition and talker identification are computed separately. Neuropsychological and neuroimaging studies imply some separation between the two faculties, but recent perceptual studies suggest better talker recognition in familiar languages than unfamiliar languages. A familiar-language benefit in talker recognition potentially implies strong ties between the two domains. However, little is known about the nature of this language familiarity effect. The current study investigated the relationship between speech and talker processing by assessing bilingual and monolingual listeners’ ability to learn voices as a function of language familiarity and age of acquisition. Two effects emerged. First, bilinguals learned to recognize talkers in their first language (Korean) more rapidly than they learned to recognize talkers in their second language (English), while English-speaking participants showed the opposite pattern (learning English talkers faster than Korean talkers). Second, bilinguals’ learning rate for talkers in their second language (English) correlated with age of English acquisition. Taken together, these results suggest that language background materially affects talker encoding, implying a tight relationship between speech and talker representations.     

Vicariously Learned Helplessness: The Role of Perceived Dominance and Prestige of a Model

Prior research has examined the relationship between various model characteristics (e.g., age, competence, similarity) and the likelihood that the observers will experience vicariously learned helplessness. However, no research in this area has investigated dominance as a relevant model characteristic. This study explored whether the vicarious acquisition of learned helplessness could be mediated by the perceived dominance of a model. Participants observed a model attempting to solve anagrams. Across participant groups, the model displayed either dominant or nondominant characteristics and was either successful or unsuccessful at solving the anagrams. The characteristics displayed by the model significantly affected observers’ ratings of his dominance and prestige. After viewing the model, participants attempted to solve 40 anagrams. When the dominant model was successful, observers solved significantly more anagrams than when he was unsuccessful. This effect was not found when the model was nondominant.     

The Fairness of National Decision‐making Procedures: The Views of Adolescents in 18 European Countries

This study examines adolescents' evaluation of the fairness of three forms of democratic decision‐making procedures (direct democracy, representative democracy and group representation) and one non‐democratic procedure (oligarchy). Social dominance orientation‐Egalitarianism (SDO‐E), religious group identification and the countries' level of democracy are examined as predictors. The 2008 Europroject dataset was used, which contained 4441 native majority adolescents (mean age = 16.1 years) in 18 European countries. Adolescents evaluated direct democracy as most fair, followed by group representation, representative democracy and oligarchy. This rank order was found independent of the issue under consideration (moral or social), and of SDO‐E and religious identification, and across the countries. In addition, adolescents scoring higher on SDO‐E and on religious identification found group representation and non‐democratic oligarchy fairer. Copyright © 2014 John Wiley & Sons, Ltd.