A Radical Notion of EmbeddednessA Logically Necessary Precondition for Agency and Self-Awareness

The aim of this essay is to establish the logically necessary preconditions for the existence of self-awareness in an artificial or a natural agent. It examines the terms agent , situated , embodied , embedded , and representation as employed ubiquitously in cognitive science, attempting to clarify their meaning and the limits of their use. It discusses the minimal conditions for an agent's environment constituting a 'world' and rejects most, though not all, types of virtual world. It argues that to qualify as genuinely situated an agent should function in real time within the dynamic world we inhabit, or some close simulacrum of it. It shows that embodied agents will possess or evolve local coordinate systems, or points of view, locating, identifying, and interacting with objects relative to their current position in space-time, and it discusses various types of embodiment, arguing that most current situated and embodied systems are too limited to be candidates for even the most minimal claim to self-identity. It argues that a truly autonomous agent has to be active in its participation with the world, able to synthesize and order its internal representations from its own point of view, and that to do this effectively the agent will have to be embedded. To this end it proposes a six-point definition of embeddedness. Ultimately it argues for a philosophical-cum-cognitive-science model of the self that satisfies essential elements of both sets of definitions of the term.     

Connecting the Many Levels and Facets of Cognitive Aging

Basic cognitive mechanisms, such as the abilities to briefly maintain, focus, and process information, decline with age. Related fields of cognitive aging research have been advancing rapidly, but mostly independently, at the biological, information processing, and behavioral levels. To facilitate integration, this article reviews research on cognitive aging at the different levels, and describes a recent integrative theory postulating that aging-related deficiencies in neurotransmission cause increased noise in information processing and less distinctive cortical representation, which in turn lead to cognitive deficits. Aging-related attenuation of catecholaminergic modulation can be modeled by lowering a neural network parameter to reduce the signal-to-noise ratio of information processing. The performance of such models is consistent with benchmark phenomena observed in humans, ranging from age differences in learning rate, asymptotic performance, and interference susceptibility to intra- and interindividual variability and ability dedifferentiation. Although the details of the conjectured sequence of effects linking neuromodulation to cognitive aging deficits await further empirical validation, cross-level theorizing of the kind illustrated here could foster the coevolution of related fields through cross-level data synthesis and hypothesis testing.     

知觉或记忆条件下对连续变化刺激的相似判断

控制不同材料(图形和字母)的大小、位置和长宽比连续变化,在标准和待判断刺激同时(知觉任务)或相继呈现(记忆任务)两种条件下进行相似判断的实验研究。结论为(1)任务方式对图形的相似判断有非常显著的影响;(2)知觉任务中相似判断的反应时非常显著地长于记忆任务中的反应时;(3)对材料各种特征的相似判断和加工速度差异非常显著．某些特征在相似表征中有较重要的作用。     

语篇主题表征在大脑两半球的存贮

使用半视野速示技术和启动—再认探测方法,采用包含两个句子的短语篇作为前行信息、通过主题启动、歧义词启动探测语段阅读时主题表征在大脑两半球的存贮情况,结果发现,无论是主题启动还是歧义词启动,左视野／右半脑和右视野／左半脑对语境相关的目标词反应时间都比不一致目标词更长,说明语段阅读后两半脑对主题表征都有存贮。     

米契尔关于满足延宕的研究

满足延宕是非常重要的自我控制行为,本文主要介绍米契尔在这方面的研究,涉及到了满足延宕的研究模式、影响个体做出延宕选择的因素、注意转移和认知表征对延宕过程的影响、儿童关于延宕的元认知发展、早期延宕行为与多年后个体的认知能力、社会应对技能的相关性研究、双重系统结构的理论,并分析了米契尔的研究对当今儿童教育的启示。     

Visual Technologies, Cosmographies, and Our Sense of Place in the Universe

The first part of this paper surveys the visual technologies that have transformed the modern visual environment and argues for the relevance of their study to an understanding of modernity in general and to the field of religion and science in particular. The term cosmography is adopted for the visual and spatial manifestation of a worldview, and the importance of analyzing and advancing modern cosmography is asserted. In the second part, the focus shifts to one particular challenge presented by modern cosmography: how to represent and find visual meaning in the new range of size scales that have been offered up by the modern scientific worldview. Six strategies for representing and finding meaning in this new expanded picture of the universe are explored.     

盲人的时间水平方向隐喻的通道特异性

通过2个实验, 考察了感觉通道对盲人的时间水平方向隐喻的影响。实验1发现, 盲人只在动作水平上存在同阅读方向一致的时间水平方向隐喻, 对表征过去的词或句子按左键反应和对表征将来的词或句子按右键反应时更快, 表明盲人用于隐喻时间的空间信息是知觉性的。实验2比较了明眼人可视组被试和明眼人遮眼组被试的时间空间隐喻, 发现明眼人可视组被试只在动作水平上存在时间水平方向隐喻, 明眼人遮眼组被试只在刺激在右侧时呈现才出现动作水平的时间水平方向隐喻。综合分析表明, 盲人和明眼人可视组被试的反应更为接近, 表明盲人的时间空间隐喻未受听觉信息的影响。盲人通过运动通道获得的空间认知代偿了视觉通道信息的缺失。     

数量表征的符号特异性和符号非特异性

数量表征(numerical representation)指与特定数量相联系的心理表征。长期以来抽象的数量表征假说占据主导地位, 但随着自动化加工范式和脑成像技术的发展, 数量表征存在符号特异性的证据已不断涌现。其中, 最近有两个理论认为数量表征可能同时存在符号特异性和符号非特异性。计算的模型假说提出非符号数量和符号数字在总和编码阶段具有符号特异性, 而在之后的位置编码阶段具有符号非特异性。双重编码的延伸假说则认为数量表征在自动编码阶段具有符号特异性, 然后在有意编码阶段, 受任务要求影响, 数量表征向实时的抽象表征过渡。已有大量行为和神经基础研究为以上假说提供了证据, 但数量表征动态变化的内在机制和脑区还有待探索, 未来应该在发展、跨文化、自动加工范式与神经成像相结合、单细胞记录技术等方向继续开展数量表征研究。     

Left to right: representational biases for numbers and the effect of visuomotor adaptation

Adaptation to right-shifting prisms improves left neglect for mental number line bisection. This study examined whether adaptation affects the mental number line in normal participants. Thirty-six participants completed a mental number line task before and after adaptation to either: left-shifting prisms, right-shifting prisms or control spectacles that did not shift the visual scene. Participants viewed number triplets (e.g. 16, 36, 55) and determined whether the numerical distance was greater on the left or right side of the inner number. Participants demonstrated a leftward bias (i.e. overestimated the length occupied by numbers located on the left side of the number line) that was consistent with the effect of pseudoneglect. The leftward bias was corrected by a short period of visuomotor adaptation to left-shifting prisms, but remained unaffected by adaptation to right-shifting prisms and control spectacles. The findings demonstrate that a simple visuomotor task alters the representation of space on the mental number line in normal participants.