The Effect of Interactivity on Learning Physical Actions in Virtual Reality

Virtual reality (VR) offers new possibilities for learning, specifically for training individuals to perform physical movements such as physical therapy and exercise. The current article examines two aspects of VR that uniquely contribute to media interactivity: the ability to capture and review physical behavior and the ability to see one's avatar rendered in real time from third person points of view. In two studies, we utilized a state-of-the-art, image-based tele-immersive system, capable of tracking and rendering many degrees of freedom of human motion in real time. In Experiment 1, participants learned better in VR than in a video learning condition according to self-report measures, and the cause of the advantage was seeing one's avatar stereoscopically in the third person. In Experiment 2, we added a virtual mirror in the learning environment to further leverage the ability to see oneself from novel angles in real time. Participants learned better in VR than in video according to objective performance measures. Implications for learning via interactive digital media are discussed.     

A real-time control system for CAI and prothesis

An integrated hardware and software system was used for the real-time control of text display in a CAI environment. Reliability and cost considerations led to the development of a digital EOG transducer, which was used in conjunction with a KIM-1 microcomputer. This paper traces the development of that system from a complex and expensive PDP-11-based system to a microcomputer firmware approach. Such a system could, in real time, accomplish a similar display task for severely handicapped nonvocal individuals.     

Simultaneous effects and aftereffects of the intensity and success aspect in coping with stresses

Intensity and success of coping processes in achievement-related situations are very often tightly connected. Therefore, the specific empirical status of each of the two aspects is unclear. In the current study a technique is introduced which allows orthogonal variation of both components. 64 subjects were confronted with a simple perceptual-speed task in which objective success rate was held constant by a computer-based adaptive process. Graphic feedback was provided about the objective success rate in relation to one of two different success criteria. For half of the subjects the criterion was above (failure condition) and for the other half it was below (success condition) the adaptively controlled success rate. Intensity, the second between-subjects factor, was manipulated by presenting either a high or a low number of items per time unit. As an additional quasi-experimental factor, the degree of action- vs. state-orientation (Kuhl, 1983) was included. The results showed highly specific effects for both the intensity and the failure/success dimension: High intensity resulted in an increase of electrodermal activity which could be observed throughout a one hour post-stressor phase. The failure/success variation had effects mainly on subjective variables representing appraisal of controllability and produced no after-effects. Especially strong effects on subjective variables could be observed when state-oriented subjects were confronted with both failure and high intensity.     

Lateral masking in cycling displays: the relative importance of separation, flanker duration, and interstimulus interval for object-mediated updating

A central bar repeatedly presented in alternation with two flanking bars can lead to the disappearance of the central bar. Recently it has been suggested that this masking effect could be explained by object-mediated updating: the information from the central bar is integrated into the representation of the flankers, leading not only to the disappearance of the central bar as a separate object, but also to the perception of the flankers in apparent motion between their real position and the position of the central bar. This account suggests that the visibility of the central bar should depend on the same factors as those that influence the construction and maintenance of object representations. Therefore separation between central bar and flankers should not influence visibility as long as the time interval between them is adequate to make an interpretation of the scene in terms of one object moving from one location to the other possible location. We found that if the time interval between the central bar and the flankers is neither too short nor too long, the central bar becomes invisible even at large separations. These findings are inconsistent with traditional accounts of the cycling lateral masking displays in terms of local inhibitory mechanisms.     

马克思主义理论整体性的创生大纲——论《巴黎手稿》和异化劳动理论的性质与地位

我国学术界新近出现的试图从不同角度说明《巴黎手稿》和异化劳动理论本身是不成熟的或混乱的,从而否定它们的重要历史地位的倾向,是对"手稿"和异化劳动理论的曲解。"手稿"和异化劳动理论是马克思主义的真正诞生地和秘密,是系统构建马克思主义理论体系的逻辑大纲,是马克思主义全部丰富内容的理论起点和立论基础。这可以从"手稿"本身所完成的理论任务或在欧洲思想史上实现的创造性变革、"手稿"的内容及其逻辑结构与马克思主义理论体系的对应关系以及异化劳动理论的解密中得到充分的证明。     

调强适形放射治疗的多学科整合

调强适形放射治疗是放射治疗100余年历史中的一个革命性进步,能使高剂量的立体分布适合外形非常不规则甚至怪异的肿瘤,调整靶区内诸点的输出剂量率,显著提高肿瘤放疗的疗效。近年计算机技术、放射物理学、放射生物学、分子生物学、影像学特别是功能性影像学的快速发展以及多门边缘学科之间的有机结合,为调强适形放射治疗提供在靶区三维精确模拟定位、立体定向定位摆位框架、逆向治疗计划系统、调强治疗机等方面的发展基础。调强适形放射治疗——多元化医学理论下的医疗方法将在学科交叉、综合发展中进一步巩固。     

Constant errors occur in matched reproduction of angles even when likely biases are eliminated

The literature on the reproduction of visually perceived angles often seems to contain an explicit or implicit assumption that systematic errors are caused by misperception of the sizes of the angles. We argue that in the absence of procedural artifacts no consistent error should arise from purely perceptual causes. Accordingly, an experimental procedure was designed to eliminate or evaluate a number of artifacts that probably affected earlier experiments. A computer-controlled display generated both a standard angle and a variable one that could be adjusted by a subject to match the standard. The data analysis followed Cox’s (1970) procedure for the analysis of binary data to focus on the numbers of positive and negative errors rather than on their magnitudes and so eliminate the numerically distorting effects of asymmetrical error distributions. Nevertheless, the results showed what has usually been reported before: acute angles were matched with too large a comparison angle, and obtuse ones with too small an angle. Thus, there is a real effect to be explained, although the explanation must invoke response processes.     

LKB1蛋白在食管鳞癌组织中的表达及意义

为了探讨肝激酶B1（LKB1）蛋白在食管鳞癌组织中的表达水平及其与食管鳞癌临床特征及生存期的关系,应用免疫组化方法检测120例食管鳞癌患者组织中LKB1蛋白表达情况并对诸多临床特征进行相关性分析研究,发现LKB1蛋白在食管癌旁正常组织的阳性表达率高于癌组织;LKB1蛋白表达与患者年龄、性别、肿瘤部位、病变长度及浸润深度无关而与分化程度、淋巴结转移及临床分期（TNM）相关,且LKB1蛋白阴性组预后较阳性组差.可见LKB1视为抑癌基因影响食管鳞癌的预后,可能成为食管鳞癌新型的临床预后指标之一.     

How Digital Computer Simulations Explain Real‐World Processes

Scientists of many disciplines use theoretical models to explain and predict the dynamics of the world. They often have to rely on digital computer simulations to draw predictions fromthe model. But to deliver phenomenologically adequate results, simulations deviate from the assumptions of the theoretical model. Therefore the role of simulations in scientific explanation demands itself an explanation. This paper analyzes the relation between real‐world system, theoretical model, and simulation. It is argued that simulations do not explain processes in the real world directly. The way in which simulations help explaining real‐world processes is conceived as indirect, mediated by the theoretical model. Simulacra are characterized further, and turn out to be a priori measurable. This gives a clue to a better understanding of the epistemic role of computer simulations in scientific research.     

Living in a Digital Culture

Today our lives are filled with technology through which we communicate, work, play, and even engage with for making meaning. This implies the pervasive presence of digital media as an integral part of our everyday life. Although studies on media are mostly done by sociology and communication students, living in a digital age has significant implications for theological reflections. Despite this being the case, there is a gap in terms of a religious response to technology. In response to this, the aim of this article is to stimulate theological reflections with regard to living in a digital culture. This is achieved by raising theological questions in the hope that theology could take a proactive role in these discussions. The implications of living in a digital culture are quite vast; therefore, the focus will be limited to how a community is formed and sustained, and the possible implications for the church as community.     

Apparatus for measuring and recording path velocity and direction characteristics of human locomotion

A measuring system using electromechanical transducers and optional computer or electronic signal processing has been developed to determine characteristics of human mobility. The apparatus measures body position over a laboratory area of 80 m2 with a position error less than 2.5 cm. The basic measuring system provides plots of path, and when used with a computer allows higher order measures based on velocity and acceleration.     

The relation between preparatory stance and trunk rotation movements

The influence of preparatory stance on rotation movement reaction time of the trunk by bending of the knee and hip joint(s) was examined in 12 subjects. Four preparatory stances were examined: straight knee and hip extension (STAND), slight flexion of knee joints and hip joint (LIGHT), deep flexion (DEEP), and free initial position, i.e. that felt to be the most comfortable and effective (FREE). There was no significant influence of the preparatory stance on hip latency, but there were significant differences between the preparatory stances on response time (RT) and movement time (MT). Furthermore, using a quadratic curve fitting technique, knee joint angles of 24.8 degrees and a hip joint angle of 23.3 degrees were shown to be the optimum flexion angles in the preparatory stance for the initiation of quick trunk rotation movements. It is proposed that mechanical factors have considerably more effects on trunk rotation movements than does the nervous system.     

Pre-driving adolescent attitudes: Can they change?

The problem of reducing young drivers’ high accident rates has been approached from many different angles but a primary focus has been to try and find ways of changing the attitudes and behaviours of young people who are already drivers. It is hypothesised that there is a link between pre-driver attitudes, intentions and their future driving behaviour. By changing pre-driver attitudes and/or intentions, individuals may mature into safer drivers. This study approaches this young driver problem by looking at pre-drivers’ attitudes to driving to see how they change over time. The results from two questionnaires indicated significant gender differences and changes in responses (both long-term and short-term) over a 6-month period. It is concluded that adolescent attitudes and intentions towards driving remain fluid such that they may be positively influenced through pre-driver interventions, even if only temporarily. Regular pre-driver interventions could thus reinforce safe driving messages and create safety-conscious driving attitudes in the next generation of drivers.     

Constant errors donot occur in the matched reproduction of angles

MacRae and Loh (1981) reported that when observers attempt to match angles, whether simultaneously or successively, and regardless of whether the angles have the same orientation or not, acute angles generally are set too large and obtuse angles, too small. Without presenting data, they argued indirectly that starting-position effects in their adjustment procedure could not have accounted for the errors. In four experiments, we have demonstrated that effects similar to MacRae and Loh’s do occur when their starting positions are used and that no such effects occur when psychophysical methods that minimize or eradicate starting position effects are used.     

When Possibility Informs Reality: Counterfactual Thinking as a Cue to Causality

People often engage in counterfactual thinking, that is, imagining alternatives to the real world and mentally playing out the consequences. Yet the counterfactuals people tend to imagine are a small subset of those that could possibly be imagined. There is some debate as to the relation between counterfactual thinking and causal beliefs. Some researchers argue that counterfactual thinking is the key to causal judgments; current research suggests, however, that the relation is rather complex. When people think about counterfactuals, they focus on ways to prevent bad or uncommon outcomes; when people think about causes, they focus on things that covary with outcomes. Counterfactual thinking may affect causality judgments by changing beliefs about the probabilities of possible alternatives to what actually happened, thereby changing beliefs as to whether a cause and effect actually covary. The way in which counterfactual thinking affects causal attributions may have practical consequences for mental health and the legal system.     

微创医学中的介入性超声

超声检查具有实时、动态、灵活、方便等优点,在临床上有重要作用。介入性超声是在超声显像的基础上,为进一步满足临床诊断和治疗的需要而发展起来的一门新技术,在微创医学体系中占有非常重要的地位,但只有与其它微创技术联合应用才更有活力和生机。     

Screens across the pond: Findings from longitudinal screen time research in the US and UK

Digital media are increasingly pervasive in the lives of young children. This increase in the availability of digital media might have long-run implications for child development; however, it is too soon to definitively conclude the direction of effects. In part due to this lack of certainty, leading health organizations have chosen to make different recommendations to parents of young children: Many international health organizations (e.g., the American Academy of Pediatrics, World Health Organization) recommend very young children be limited to under one hour of screen time daily, whereas others (e.g., Royal College of Paediatrics and Child Health) have intentionally opted not to make recommendations about specific limits. These guidelines might contribute to parents in different countries making meaningfully different choices about children’s use of digital media. Using a sample of N = 303 families recruited in Cambridgeshire, England and New York City prior to the birth of couples’ first child, we explore predictors of digital media use across the first two years of life. Data were collected when children were 4, 14, and 24 months of age. Results of latent growth curve analyses show that generally, children spend more time engaging with digital media as they grow older; however, growth mixture models reveal most children fit into one of two classes: One group of children (High Media Users; 52.2 %) engages with a substantial amount of digital media, whereas the other (Low Media Users; 48.8 %) engages with relatively little. Children in the US were approximately 30 % more likely to be in the Low Media Users group and there were no differences in group membership on the basis of parents’ psychosocial wellbeing. While these differences could be due to a number of factors, these findings may reflect the power of pediatric recommendations.     

Personal attitudes toward time: The relationship between temporal focus,space‐time mappings and real life experiences

What influences how people implicitly associate “past” and “future” with “front” and “back?” Whereas previous research has shown that cultural attitudes toward time play a role in modulating space‐time mappings in people's mental models (de la Fuente, Santiago, Román, Dumitrache & Casasanto, 2014), we investigated real life experiences as potential additional influences on these implicit associations. Participants within the same single culture, who are engaged in different intermediate‐term educational experiences (Study 1), long‐term living experiences (Study 2), and short‐term visiting experiences (Study 3), showed their distinct differences in temporal focus, thereby influencing their implicit spatializations of time. Results across samples suggest that personal attitudes toward time related to real life experiences may influence people's space‐time mappings. The findings we report on shed further light on the high flexibility of human conceptualization system. While culture may exert an important influence on temporal focus, a person's conceptualization of time may be attributed to a culmination of factors.     

Dynamics of the dyad: How mothers and infants co-construct interaction spaces during object play

Studies of dyadic interaction often examine infants’ social exchanges with their caregivers in settings that constrain their physical properties (e.g., infant posture, fixed seating location for infants and adults). Methodological decisions about the physical arrangements of interaction, however, may limit our ability to understand how posture and position shape them. Here we focused on these embodied properties of dyadic interaction in the context of object play. We followed 30 mother–infant dyads across the first year of life (at 3, 6, 9, and 12 months) and observed them during 5 min of play with a standard set of toys. Using an interval-based coding system, we measured developmental change in infant posture, how mothers and infants positioned themselves relative to one another, and how they populated interaction spaces with objects. Results showed that mother–infant dyads co-constructed interaction spaces and that the contributions of each partner changed across development. Dyads progressively adopted a broader spatial co-orientation during play (e.g., positioned at right angles) across the first year. Moreover, advances in infants’ postural skills, particularly increases in the use of independent sitting in real time, uniquely predicted change in dyadic co-orientation and infants’ actions with objects, independent of age. Taken together, we show that the embodied properties of dyadic object play help determine how interactions are physically organized and unfold, both in real time and across the first year of life.     

Development of the Correspondence Between Real and Imagined Fine and Gross Motor Actions

The development of the correspondence between real and imagined motor actions was investigated in 2 experiments. Experiment 1 evaluated whether children imagine body position judgments of fine motor actions in the same way as they perform them. Thirty-two 8-year-old children completed a task in which an object was presented in different orientations, and children were asked to indicate the position of their hand as they grasped and imagined grasping the object. Children’s hand position was almost identical for the imagined- and real-grasping trials. Experiment 2 replicated this result with 8-year-olds as well as 6-year-olds and also assessed the development of the correspondence of the chronometry of real and imagined gross motor actions. Sixteen 6-year-old children and seventeen 8-year-old children participated in the fine motor grasping task from Experiment 1 and a gross motor task that measured the time it took for children to walk and imagine walking different distances. Six-year-olds showed more of a difference between real and imagined walking than did 8-year-olds. However, there were strong correlations between real and imagined grasping and walking for both 6- and 8-year-old children, suggesting that by at least 6 years of age, motor imagery and real action may involve common internal representations and that motor imagery is important for motor control and planning.