Optimized many body potential for fcc metals

A formalism for optimized many body (OMB) potentials to describe the interatomic interactions in fcc metals is described. The OMB approach is based on the Tersoff potential, widely used to describe covalently bonded materials, and is closely related to the charge optimized many body (COMB) potential formalism for oxides. OMB extends to first nearest neighbors only, and employs a third-order Legendre polynomial to distinguish fcc and hcp structures, the strength of which can be adjusted to match the intrinsic stacking fault energy to arbitrary precision. The potential also predicts generalized stacking fault energy curves that are in very close agreement to the values determined from electronic-structure calculations. This potential is thus well-suited to investigating mechanical properties such as plastic deformation at the atomic scale.     

The computerized scoring algorithm for the autobiographical memory test: updates and extensions for analyzing memories of English-speaking adults

ABSTRACT

The Autobiographical Memory Test (AMT) has been central in psychopathological studies of memory dysfunctions, as reduced memory specificity or overgeneralised autobiographical memory has been recognised as a hallmark vulnerability for depression. In the AMT, participants are asked to generate specific memories in response to emotional cue words, and their responses are scored by human experts. Because the manual coding takes some time, particularly when analysing a large dataset, recent studies have proposed computerised scoring algorithms. These algorithms have been shown to reliably discriminate between specific and non-specific memories of English-speaking children and Dutch- and Japanese-speaking adults. The key limitation is that the algorithm is not developed for English-speaking adult memories, which may cover a wider range of vocabulary that the existing algorithm for English-speaking child memories cannot process correctly. In the present study, we trained a new support vector machine to score memories of English-speaking adults. In a performance test (predicting memory specificity against human expert coding), the adult-memory algorithm outperformed the child-memory variant. In another independent performance test, the adult-memory algorithm showed robust performances to score memories that were generated in response to a different set of cues. These results suggest that the adult-memory algorithm reliably scores memory specificity.     

Effects of 7.5% CO2-Induced Anxiety on Individual Performance During a Group Computer Combat Game

The inhalation of 7.5% CO₂ has been shown to induce cognitive effects similar to anxiety. Sixteen healthy participants (14 male; mean age 25.6 years) inhaled either a mixture of 7.5% CO₂ gas or air while playing a group combat computer game. Participants reported greater feelings of anxiety and fired fewer bullets when inhaling CO₂ compared with air, indicating CO₂-induced anxiety may improve efficiency without task-related decrements. Being able to induce controlled and measured anxiety in group situations by CO₂ inhalation may be a useful technique when evaluating response to stressful situations, such as combat, in simulators or real-life scenarios.     

Structural and functional information—an evolutionary approach to pragmatic information

The paper starts with a critics of the potential information which is related to the statistical entropy. In order to include the syntactic and semantic aspects of information, we propose a distinction between structural and functional information, instead. Structural information represents the structural determination of a system state, it measures the content of information, as given by the material structure. Functional information, on the other hand, represents the operational closure of the system, it could be e.g. an algorithm which activates and interprets the existing structural information.

From an evolutionary point of view, pragmatic information is generated by an interplay of structural and functional information. This leads to a new insight into the concept of pragmatic information, which is not an invariant of evolution, but must be steadily re‐generated.

The active role of information in a self‐organization process is demonstrated in a model of artificial agents. It is shown by means of computer simulations that the feedback of already existing information on the generation of new information performs analogies to the creation of a collective memory.     

Shyness,sociability, and the role of media synchronicity in the use of computer‐mediated communication for interpersonal communication

This study analysed how university students in Hong Kong with varying degrees of shyness and sociability utilized computer‐mediated communication (CMC) technologies for interpersonal communication. As spontaneous communication can increase the workload on working memory and accentuate feelings of social anxiety, it was hypothesized that shy students were more likely to use email and social network sites (asynchronous CMC) more frequently, and instant messaging and chat less (synchronous CMC). Results from an online questionnaire provided partial support for the hypotheses and suggested distinctive usage patterns separated by media synchronicity. Moreover, the analyses revealed a significant interaction between shyness and sociability on asynchronous CMC use.     

Role of face‐to‐face and computer‐mediated communication time in the cohesion and performance of mixed‐mode groups

Although the rapid development of information technology has led to the increasing use of computer‐mediated communication (CMC), few studies have examined the relational aspect of mixed‐mode groups that use both face‐to‐face (FTF) communication and CMC. A field study comprising 42 student groups was conducted to assess the relationships among communication time, cohesion, and performance in mixed‐mode groups. The findings suggest that time spent in FTF communication significantly predicted group social cohesion, but time spent in CMC did not. In contrast, group task cohesion was predicted by time spent in CMC but not by time spent in FTF communication. Time spent in CMC was also a strong predictor of group task performance. These results suggest that FTF communication contributes to the social aspect of mixed‐mode groups and that CMC is beneficial to their task‐related aspect. The findings of mediation analyses showed a significant indirect effect among time spent in FTF communication, group social cohesion, and group contextual performance. In other words, time spent in FTF communication had a positive effect on group social cohesion, which in turn positively affected group contextual performance. However, no mediating effect was found among time spent in CMC, group task cohesion, and group task performance. Theoretical and practical implications of these findings are discussed.     

Investigation of the relationship between social isolation, self-esteem, aggression and computer game play in Japanese adolescents

Some support for expressed concern over the negative consequences of computer game play was obtained by Colwell and Payne (2000) in a questionnaire survey of UK adolescents. A second study was carried out in Tokyo, Japan, to test for generality of findings. There was strong evidence of similarity in relation to play patterns, but in contrast to the UK sample, number of good friends and self-esteem did not relate to game play. A principal components analysis of a scale to measure needs met by game play resulted in the same two previously obtained factors; 'companionship' and 'prefer to friends'. However, in contrast to the UK sample, 'companionship' did not relate to play. A positive relation between the 'prefer to friends' factor and play was obtained for both boys and girls (boys only in the UK), thus providing support for the 'electronic friendship' hypothesis. There was evidence of a positive relation between play and aggression, but a preference for aggressive games was associated with lower aggression scores, and this raises questions for the 'causal hypothesis'.     

Synthetic Neuroethology

Computation and philosophy intersect three times in this essay. Computation is considered as an object, as a method, and as a model used in a certain line of philosophical inquiry concerning the relation of mind to matter. As object, the question considered is whether computation and related notions of mental representation constitute the best ways to conceive of how physical systems give rise to mental properties. As method and model, the computational techniques of artificial life and embodied evolutionary connectionism are used to conduct prosthetically enhanced thought experiments concerning the evolvability of mental representations. Central to this essay is a discussion of the computer simulation and evolution of three-dimensional synthetic animals with neural network controllers. The minimally cognitive behavior of finding food by exhibiting positive chemotaxis is simulated with swimming and walking creatures. These simulations form the basis of a discussion of the evolutionary and neurocomputational bases of the incremental emergence of more complex forms of cognition. Other related work has been used to attack computational and representational theories of cognition. In contrast, I argue that the proper understanding of the evolutionary emergence of minimally cognitive behaviors is computational and representational through and through.     

Learning a second language by playing a game

Game‐like educational apps are intended to boost learner motivation leading to better learning outcomes. To test this idea about the value of gamification, college students (n = 64) learned Italian by playing the online language learning game, Duolingo at home for seven sessions, or learned the same material through watching an online slideshow for seven sessions. Although the groups did not differ significantly on achievement posttests, the Duolingo group rated their learning experience as significantly more enjoyable (d = 0.77), more appealing (d = 1.17), and less difficult (d = 0.51), and was significantly more willing to continue with similar learning experiences (d = 1.39). Overall, these results point to the motivational and affective benefits of Duolingo as a promising alternative to more traditional methods for students who may require additional motivation not to disengage from the material.     

Teaching ethics and technology with <Emphasis Type="Italic">Agora</Emphasis>, an electronic tool

Courses on ethics and technology have become compulsory for many students at the three Dutch technical universities during the past few years. During this time, teachers have faced a number of didactic problems, which are partly due to a growing number of students. In order to deal with these challenges, teachers in ethics at the three technical universities in the Netherlands — in Delft, Eindhoven and Twente — have developed a web-based computer program called Agora (see www.ethicsandtechnology.com). This program enables students to exercise their ethical understanding and skills extensively. The program makes it possible for students to participate actively in moral reflection and reasoning, and to develop the moral competencies that are needed in their later professional practice. The developers of the program have tried to avoid two traps. Firstly, they rejected, from the outset, a cookbook style of dealing with ethical problems that applied ethics is often taken to be and, secondly, they wanted to design a flexible program that respects the student’s as well as the teacher’s creativity, and that tries to engage students in moral reflection. Agora meets these requirements. The program offers possibilities that extend beyond the requirements that are usually accepted for case-exercises in applied ethics, and that have been realised in several other computer models for teaching ethics. In this article, we describe the main considerations in the development of Agora and the features of the resulting program.