The microcrystalline state of slowly solidified decaprismatic Al-Co-Cu(-Si) needles

Abstract

We show that samples of the decagonal Al-Co-Cu(-Si) phase produced by different slow solidification methods are in the microcrystalline and not in the quasicrystalline state. Parameters for the underlying unit cell are a = b ≈ 51.3 Å, c ≈ 4.1 Å and γ = 108°. Experiments on differently produced samples show the same microcrystalline state and that the (5,7) approximant seems to be highly favoured, compared with the set of possible high-order approximant states.     

Effects of Visual Tasks and Conversational Partner on Personal and Interpersonal Postural Activity

The control of stance is influenced by activities that are engaged in during stance. We investigated simultaneous constraints imposed by individual-specific factors (such as the distance of visual targets) and of interpersonal factors arising from dyadic conversation. Each member of participant pairs looked at targets (drawings) that were similar to, but differed from, that of a conversational partner. Conversational partners conversed to identify the differing elements. In Experiments 1 and 2, members of each dyad conversed with each other or separately conversed with a confederate (an experimenter). We varied the distance of targets (Experiment 1) and their size (Experiment 2). In Experiment 3, target size could be the same for both members of a dyad (i.e., small-small, large-large) or could differ (i.e., small-large, large-small). Interpersonal postural coordination was stronger when members of dyads conversed with each other, replicating earlier studies, but this manipulation also influenced parameters of individual sway. In Experiment 3, interpersonal postural coordination also was influenced by variation in the size of the partner's target. Analysis of the sway of individuals revealed influences of target distance and size, replicating previous effects; however, these manipulations also influenced interpersonal postural coordination. Overall, the results indicate that postural activity was modulated simultaneously with respect to individual and dyadic parameters of the task situation. We argue that it may be useful, both theoretically and empirically, to interpret the effects of conversation on postural activity within the broader context of relations between postural control and the performance of suprapostural tasks.     

A status-enhancement account of overconfidence

In explaining the prevalence of the overconfident belief that one is better than others, prior work has focused on the motive to maintain high self-esteem, abetted by biases in attention, memory, and cognition. An additional possibility is that overconfidence enhances the person's social status. We tested this status-enhancing account of overconfidence in 6 studies. Studies 1-3 found that overconfidence leads to higher social status in both short- and longer-term groups, using naturalistic and experimental designs. Study 4 applied a Brunswikian lens analysis (Brunswik, 1956) and found that overconfidence leads to a behavioral signature that makes the individual appear competent to others. Studies 5 and 6 measured and experimentally manipulated the desire for status and found that the status motive promotes overconfidence. Together, these studies suggest that people might so often believe they are better than others because it helps them achieve higher social status. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Learning and transfer of category knowledge in an indirect categorization task

Knowledge representations acquired during category learning experiments are ‘tuned’ to the task goal. A useful paradigm to study category representations is indirect category learning. In the present article, we propose a new indirect categorization task called the “same”–“different” categorization task. The same–different categorization task is a regular same–different task, but the question asked to the participants is about the stimulus category membership instead of stimulus identity. Experiment 1 explores the possibility of indirectly learning rule-based and information-integration category structures using the new paradigm. The results suggest that there is little learning about the category structures resulting from an indirect categorization task unless the categories can be separated by a one-dimensional rule. Experiment 2 explores whether a category representation learned indirectly can be used in a direct classification task (and vice versa). The results suggest that previous categorical knowledge acquired during a direct classification task can be expressed in the same–different categorization task only when the categories can be separated by a rule that is easily verbalized. Implications of these results for categorization research are discussed.