Variational investigation of low dimensional correlated electron systems via the limit of high dimensions

We show that the limit of large dimensions (d=) can be used to obtain accurate variational results even for low dimensional (d=1, 2) fermionic systems, such as the Hubbard model or the periodic Anderson model. Using explicit correlated variational wave functions this is achieved by evaluating the expectation values for d= with the correct d-dimensional density of states and including 1/d-corrections. For example, an application of this approach to the periodic Anderson model in d=1 shows that the result for the ground state energy, the momentum distributions of c- and f-electrons, and the spin-spin and density-density correlations functions for the f-electrons are in excellent agreement with the variational Monte Carlo data of Shiba.Dedicated to L. Tewordt on the occasion of his 65th birthday.     

The architecture of intuition: Fluency and affect determine intuitive judgments of semantic and visual coherence and judgments of grammaticality in artificial grammar learning.

People can intuitively detect whether a word triad has a common remote associate (coherent) or does not have one (incoherent) before and independently of actually retrieving the common associate. The authors argue that semantic coherence increases the processing fluency for coherent triads and that this increased fluency triggers a brief and subtle positive affect, which is the experiential basis of these intuitions. In a series of 11 experiments with 3 different fluency manipulations (figure-ground contrast, repeated exposure, and subliminal visual priming) and 3 different affect inductions (short-timed facial feedback, subliminal facial priming, and affect-laden word triads), high fluency and positive affect independently and additively increased the probability that triads would be judged as coherent, irrespective of actual coherence. The authors could equalize and even reverse coherence judgments (i.e., incoherent triads were judged to be coherent more frequently than were coherent triads). When explicitly instructed, participants were unable to correct their judgments for the influence of affect, although they were aware of the manipulation. The impact of fluency and affect was also generalized to intuitions of visual coherence and intuitions of grammaticality in an artificial grammar learning paradigm. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

When hunger finds no fault with moldy corn: Food deprivation reduces food-related disgust.

The main purpose of this study was to examine if disgust toward unpalatable foods would be reduced among food-deprived subjects and if this attenuation would occur automatically even under moderate levels of food deprivation. Subjects were either satiated or food deprived for 15 hours and electromyographic activity was recorded at the levator muscle region while they were watching pictures of palatable versus unpalatable foods, and pictures of positive versus disgust-related control pictures. For control purposes, subjects' activity of the zygomaticus and corrugator muscles was also recorded. As compared with satiated subjects, food-deprived subjects exhibited stronger activity in the zygomaticus muscle region when watching pictures of palatable foods (but not when watching positive control pictures). More important, hungry subjects exhibited weaker activity in the levator muscle region when watching pictures of unpalatable foods (but not when watching disgusting control pictures). Thus, this is the first study ever to show that specific emotions (disgust) are moderated by homeostatic dysregulation automatically. Results indicate that the modulation of facial expressions might play an important role in lowering the threshold for food intake. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Planung für das Schiffshebewerk am Drei‐Schluchten‐Staudamm in China

Design of the ship lift at the Three Gorges Dam in China. A vertical ship lift based on the counterweight principle is to be built to allow passenger ships passing the Three Gorges Dam at the Yangtze River near Yichang. This project is realized by the China Yangtze Three Gorges Project Corporation, building and operating company of the Three Gorges Dam. The German joint venture, “German Design Group”, incorporating the two companies Krebs und Kiefer International and Lahmeyer International has been entrusted with the general layout, intermediate and final design. As part of the “Panel of Experts” the German Bundesanstalt für Wasserbau (Federal Waterways Engineering and Research Institute) provides consulting support to the building company.     

The "relative self": Informational and judgmental consequences of comparative self-evaluation.

Results of 5 studies demonstrated that self-evaluative comparisons have 2 distinct informational consequences with opposing judgmental effects: They selectively increase the accessibility of standard-consistent self-knowledge and provide an evaluative reference point. The first informational consequence produces assimilation in self-evaluative judgments, whereas the latter yields contrast. Using a lexical decision task, Study 1 demonstrated that a social comparison selectively increases the accessibility of standard-consistent self-knowledge. Study 2 showed that this effect also holds for comparisons with objective standards. Studies 3 and 4 revealed that the same comparison may lead to assimilation on objective and contrast on subjective self-judgments. Finally, Study 5 demonstrated that assimilation results for comparisons with relevant and irrelevant standards, whereas contrast occurs only for relevant standards. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Approach and avoidance: The influence of proprioceptive and exteroceptive cues on encoding of affective information.

In 3 experiments, the authors tested the assumption that perceived movements toward a person trigger the approach system and thereby facilitate the processing of positive affective concepts, whereas perceived movements away from a person trigger the avoidance system and thereby facilitate the processing of negative affective concepts. In the 1st study, participants categorized positive words more quickly than negative words while flexing the arm and negative words more quickly than positive words while extending the arm. The 2nd study revealed that positive words were categorized more rapidly than negative words if viewers had the impression that they were moving toward the computer screen, whereas negative words were categorized faster if viewers had the impression that they were moving away from the screen. These findings were replicated in Experiment 3 using a lexical decision task instead of an adjective evaluation task. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Proprioceptive determinants of emotional and nonemotional feelings.

Reports 2 experiments that test whether both emotional and nonemotional feelings may be influenced by uninterpreted proprioceptive input. The logic of the procedure was adopted from studies by F. Strack et al (1988), who unobtrusively manipulated people's facial expressions. In the 1st experiment, a functionally equivalent technique was used to vary the posture of the body. Study 1 results revealed that success at an achievement task led to greater feelings of pride if the outcome was received in an upright position rather than in a slumped posture. Study 2 results revealed that nonemotional feelings of effort were influenced by contraction of the forehead muscle (corrugator), and Ss' self-ratings on a trait dimension reflected this experience when the facial contraction was maintained during the recall of behavioral episodes exemplifying this trait. To account for these results, a framework is proposed that draws on a distinction between noetic and experiential representations. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Explaining the enigmatic anchoring effect: Mechanisms of selective accessibility.

Results of 3 studies support the notion that anchoring is a special case of semantic priming; specifically, information that is activated to solve a comparative anchoring task will subsequently be more accessible when participants make absolute judgments. By using the logic of priming research, in Study 1 the authors showed that the strength of the anchor effect depends on the applicability of activated information. Study 2 revealed a contrast effect when the activated information was not representative for the absolute judgment and the targets of the 2 judgment tasks were sufficiently different. Study 3 demonstrated that generating absolute judgments requires more time when comparative judgments include an implausible anchor and can therefore be made without relevant target information that would otherwise be accessible. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Decreased plasma insulin but normal glucagon in rats fed low protein diets

Plasma glucagon and insulin were determined in rats fed three diets, one control and two low protein (LP 1 & LP 2). In LP 1, the protein omitted was replaced by carbohydrate while in LP 2, fat and alpha-cellulose replaced the omitted protein. Among rats fed LP diets ad libitum, food consumption decreased and body weight loss occurred. In order to separate the effects of reduced food intake and weight loss from the effects of LP diet alone, paired feeding and paired weight experiments were conducted. In another experiment, ingestion of a LP diet for 8 to 10 days was followed by refeeding the control diet for 5 days. The results demonstrate that plasma insulin was reduced in LP rats compared to the full-fed controls and pair-fed controls, the lowest levels being observed in rats fed LP 2 diet. Furthermore, the paired feeding experiment revealed that the diminished food consumption plays no significant role in lowering plasma insulin in LP rats. The refeeding experiment showed that the decline in plasma insulin in LP rats is a transient phenomenon and the plasma insulin promptly reverts to normal upon resumption of feeding the control diet. Plasma glucagon was unaltered throughout these dietary manipulations.     

Attractiveness of the underling: An automatic power?→?sex association and its consequences for sexual harassment and aggression.

One characteristic of men who sexually harass is that they are not aware that their actions are inappropriate or a misuse of their power (L. F Fitzgerald, 1993a). We investigated the existence and automaticity of a mental association between the concepts of power and sex, and its consequences for sexual harassment tendencies. Using a subliminal priming paradigm, Experiment 1 demonstrated an automatic link between power and sex, and only for men high in the likelihood to sexually harass or aggress. In Experiment 2, male participants were unobtrusively primed with either power related or neutral stimuli. For men likely to sexually aggress, but not other participants, attraction ratings of a female confederate were significantly higher in the power priming than the neutral priming condition. (PsycINFO Database Record (c) 2010 APA, all rights reserved)