人工神经网络在临床应用中的伦理思考

现代临床医学中的海量信息具有非线性特质,人工神经网络的自我学习、记忆和归纳功能,刚好适应了医学的新发展,在医学领域有良好的应用前景。事实上,人工神经网络临床应用的理论研究成果丰富,但商业应用并不多见。本文探讨人工神经网络在临床应用中可能引发的社会伦理争议,对其临床适用范围进行初步的论述。     

It’s not just what you know, it’s who you know: Testing a model of the relative importance of social networks to academic performance

Applying three mathematical modeling techniques, this study proposes and tests the fit of an academic performance model, and then estimates the relative importance of four performance predictors: academic ability, performance goal orientation, educational technology use, and social network density. Drawing on social network theory, findings from this study show that social network density is a statistically important and unique predictor of academic performance, suggesting that “who you know” matters in large classroom settings. However, this study also indicates that academic ability is the most dominant factor in the explanation of academic performance. Practical and theoretical implications for enhancing academic performance through social networks are discussed.

Abductive reasoning in neural-symbolic systems

Abduction is or subsumes a process of inference. It entertains possible hypotheses and it chooses hypotheses for further scrutiny. There is a large literature on various aspects of non-symbolic, subconscious abduction. There is also a very active research community working on the symbolic (logical) characterisation of abduction, which typically treats it as a form of hypothetico-deductive reasoning. In this paper we start to bridge the gap between the symbolic and sub-symbolic approaches to abduction. We are interested in benefiting from developments made by each community. In particular, we are interested in the ability of non-symbolic systems (neural networks) to learn from experience using efficient algorithms and to perform massively parallel computations of alternative abductive explanations. At the same time, we would like to benefit from the rigour and semantic clarity of symbolic logic. We present two approaches to dealing with abduction in neural networks. One of them uses Connectionist Modal Logic and a translation of Horn clauses into modal clauses to come up with a neural network ensemble that computes abductive explanations in a top-down fashion. The other combines neural-symbolic systems and abductive logic programming and proposes a neural architecture which performs a more systematic, bottom-up computation of alternative abductive explanations. Both approaches employ standard neural network architectures which are already known to be highly effective in practical learning applications. Differently from previous work in the area, our aim is to promote the integration of reasoning and learning in a way that the neural network provides the machinery for cognitive computation, inductive learning and hypothetical reasoning, while logic provides the rigour and explanation capability to the systems, facilitating the interaction with the outside world. Although it is left as future work to determine whether the structure of one of the proposed approaches is more amenable to learning than the other, we hope to have contributed to the development of the area by approaching it from the perspective of symbolic and sub-symbolic integration.

睡眠影响记忆巩固的同步EEG-fMRI研究

默认网络是静息状态活动较强的大脑结构, 它包含的海马和内侧前额叶两个脑区是记忆巩固的关键部位, 同时静息态也被证明伴随有记忆巩固现象, 我们推测默认网络是睡眠依赖记忆巩固的核心结构。本研究拟借助同步EEG-fMRI在时空分辨率上的优势, 研究默认网络参与睡眠依赖记忆巩固的神经机制。包括：1)发掘默认网络活动的电生理指标, 应用EEG源定位和跨频段耦合分析, 揭示记忆巩固的动态过程; 2)应用滑动时间窗和模块分析, 研究默认网络参与静息态和睡眠过程记忆巩固的异同, 揭示记忆在昼夜更迭中得以强化的神经机制; 3)通过多模态信息融合, 揭示记忆类型和睡眠阶段等因素对睡眠依赖记忆巩固的影响。本研究的开展对阐明睡眠依赖记忆巩固的神经机制具有深刻的理论意义, 并最终可能为治疗学习记忆相关障碍提供全新的思路。     

动态面孔表情优势效应的心理机制及神经基础

动态面孔表情优势效应是指较静态面孔表情而言, 个体在识别动态的面孔表情时表现出较好的识别能力。动态面孔表情优势效应的心理机制主要涉及增强的构形加工、补偿角色和面孔模仿能力。此外, 该优势效应的神经网络则由核心的神经网络和扩展的神经网络组成, 前者主要负责早期的知觉编码和刺激的运动加工, 而后者与个体的面孔模仿能力、刺激的动态表征等有关。今后的研究应集中在完善延伸的神经网络、拓展其心理机制; 开展动态面孔表情优势效应的发展性研究; 考察面孔表情的刚性运动特征; 注重在虚拟现实环境下研究动态面孔表情的优势效应。     

Differences in Friendship Networks and Experiences of Cyberbullying Among Korean and Australian Adolescents

ABSTRACT

Cyberbullying is one of the negative consequences of online social interaction. The digital environment enables adolescents to engage in online social interaction beyond the traditional physical boundaries of families, neighborhoods, and schools. The authors examined connections to friendship networks in both online and offline settings are related to their experiences as victims, perpetrators, and bystanders of cyberbullying. A comparative face-to-face survey of adolescents (12–15-year-olds) was conducted in Korea (n = 520) and Australia (n = 401). The results reveal that online networks are partially related to cyberbullying in both countries, showing the size of social network sites was significantly correlated with experience cyberbullying among adolescents in both countries. However there were cultural differences in the impact of friendship networks on cyberbullying. The size of the online and offline networks has a stronger impact on the cyberbullying experiences in Korea than it does in Australia. In particular, the number of friends in cliques was positively related to both bullying and victimization in Korea.     

Toward a Philosophy of Blockchain: A Symposium: Introduction

This article introduces the symposium “Toward a Philosophy of Blockchain,” which provides a philosophical contemplation of blockchain technology, the digital ledger software underlying cryptocurrencies such as bitcoin, for the secure transfer of money, assets, and information via the Internet without needing a third‐party intermediary. The symposium offers philosophical scholarship on a new topic, blockchain technology, from a variety of perspectives. The philosophical themes discussed include mathematical models of reality, signification, and the sociopolitical institutions that structure human life and interaction. The symposium also investigates the metaphilosophical theme of how to create a philosophy of anything, specifically a new topic such as blockchain technology. Repeated themes are identified, in all areas of philosophical inquiry (ontology, epistemology, and axiology), and conceptual resources are elaborated to contribute to a philosophical understanding of blockchain technology. Thus, philosophy as a metaphilosophical approach is shown to be able to provide an understanding of the conceptual, theoretical, and foundational dimensions of novelty and emergence in the world, with a particular focus on blockchain technology.     

Friendships Lost: The Social Consequences of Violent Victimization

Few studies have examined the impact of violent victimization on friendship networks. This study used 2 waves of data from the National Longitudinal Study of Adolescent to Adult Health (Add Health) to examine the effects of violent victimization on number of peer- and self-reported friendships. Guided by stigma theory (Goffman, 1963), fixed-effect regression models controlling for depression, delinquency, substance use, and school engagement were completed to predict changes in number of friends following victimization. Consistent with the theory, results indicate that experiencing violent victimization (e.g., jumped, stabbed, shot at) was associated with a decrease in number of friends. These effects were magnified for females and for individuals with a greater number of depressive symptoms. These results were consistent even when models were run separately for each individual type of victimization. Treatment and prevention implications are discussed.     

The Social Networks of Women Experiencing Domestic Violence

The research literature has demonstrated that battered women living in shelters experience impaired social support. This study examines this phenomenon among battered women living in the community. This study compared a group of pregnant battered women (n = 145) and a group of pregnant nonbattered women (n = 58) in terms of their structural [e.g., total number of supporters, network members in violent relationships with their partners (an index of homophily or nonhomophily) and functional (e.g., emotional)] social support. Four reasons for impaired support in battered women were proposed and examined, including social isolation, failure to disclose abuse, homophily, and low SES. Only homophily was related to impaired support among battered women. In addition, the relationship between structural and functional support and mental health outcomes (e.g., depression, self-esteem) was examined. Criticism, practical support, homophily, and disclosure were all significant predictors of mental health for battered women. Implications for community-based interventions are discussed in the context of current intervention strategies with battered women.     

Dissociable parietal systems for primacy and subsequent memory effects

The frequently observed superior memory for the first items on a list is referred to as primacy. The aetiology of this effect in terms of cognitive processes and their neural substrate is subject to an ongoing debate. However, the brain areas generally involved in successful encoding are well described by subsequent memory studies in which activity during encoding is correlated with memory performance. We employed an object-location association paradigm to differentiate the neural correlate of the primacy from the subsequent memory effect. Activity in the intraparietal sulcus predicted memory performance across all encoding positions. Increased activity in the inferior parietal lobe and angular gyrus resulted exclusively in a more efficient encoding of the first item presented. These areas are part of the ventral frontoparietal network involved in stimulus driven attention. Our results implicate the relatively elevated attention to the first item probably due to its contextual distinctiveness, as a major contributor to the primacy effect.