Measuring category intuitiveness in unconstrained categorization tasks

What makes a category seem natural or intuitive? In this paper, an unsupervised categorization task was employed to examine observer agreement concerning the categorization of nine different stimulus sets. The stimulus sets were designed to capture different intuitions about classification structure. The main empirical index of category intuitiveness was the frequency of the preferred classification, for different stimulus sets. With 169 participants, and a within participants design, with some stimulus sets the most frequent classification was produced over 50 times and with others not more than two or three times. The main empirical finding was that cluster tightness was more important in determining category intuitiveness, than cluster separation. The results were considered in relation to the following models of unsupervised categorization: DIVA, the rational model, the simplicity model, SUSTAIN, an Unsupervised version of the Generalized Context Model (UGCM), and a simple geometric model based on similarity. DIVA, the geometric approach, SUSTAIN, and the UGCM provided good, though not perfect, fits. Overall, the present work highlights several theoretical and practical issues regarding unsupervised categorization and reveals weaknesses in some of the corresponding formal models.     

One or two dimensions in spontaneous classification: a simplicity approach

When participants are asked to spontaneously categorize a set of items, they typically produce unidimensional classifications, i.e., categorize the items on the basis of only one of their dimensions of variation. We examine whether it is possible to predict unidimensional vs. two-dimensional classification on the basis of the abstract stimulus structure, by employing Pothos and Chater's simplicity model of spontaneous categorization [Pothos, E. M., & Chater, N. (2002). A simplicity principle in unsupervised human categorization. Cognitive Science, 26, 303-343]. The simplicity model provides a quantitative measure of how intuitive a particular classification is. With objects represented in two dimensions, we propose that a unidimensional classification will be preferred if it is more intuitive than all possible two-dimensional ones, and vice versa. Empirical results supporting this proposal are reported. Implications for Goodman's paradox are discussed.     

The strength and generality of stimulus over-selectivity in simultaneous discrimination procedures

Stimulus over-selectivity refers to behavior being controlled by one element of the environment at the expense of other equally salient aspects of the environment. This is a common problem for many individuals, including those with autism spectrum disorders, and learning difficulties, and presents a considerable problem for information processing in many important situations involving complex cues and environments. Three experiments explored the strength and generality of the over-selectivity effect in non-clinical adults undertaking a cognitively demanding task, by training and testing participants on a two-component trial-and-error discrimination learning task. The over-selectivity effect was found in a variety of test conditions, including when the comparison test stimulus was neutral (Experiment 1), novel (Experiment 2), neutral with no conditioning history (Experiment 3), or when punished during training (Experiments 1, 2 and 3). Such results provide ubiquity to the phenomenon, making it important to investigate further.     

When do ratings implicate perception versus judgment? The “overgeneralization test” for top-down effects

ABSTRACT

When looking at an object—say, a banana—we can both directly perceive its visual qualities (e.g., its size) and also make higher-level judgments about its visual and non-visual properties (e.g., not only its size, but also its cost). Suppose you obtain a rating of a property such as size. Does that rating implicate seeing or merely higher-level judgment? The answer often matters a great deal -- e.g., determining whether such ratings imply “top-down” effects of cognition on perception. Too often, however, this distinction is ignored in empirical investigations of such effects. Here we suggest a simple test for when such ratings can be used to implicate perception: whenever the very same experiment “overgeneralizes” to an unambiguously non-perceptual factor, the results cannot be used to draw implications about perception, per se. As a case study, we investigate an empirical report alleging that conservatives perceive Barack Obama as darker skinned than liberals do. Two simple experiments show that the very same effects, measured via the same “representativeness” ratings, obtain with unambiguously non-perceptual and even silly factors (involving bright red horns vs. halos, rather than brightness differences). We suggest that this renders such methods unable to implicate visual processing and we recommend that “overgeneralization tests” of this type always be conducted in such contexts.     

Hume and cognitive science: The current status of the controversy over abstract ideas

In Book I, Part I, Section VII of the Treatise, Hume sets out to settle, once and for all, the early modern controversy over abstract ideas. In order to do so, he tries to accomplish two tasks: (1) he attempts to defend an exemplar-based theory of general language and thought, and (2) he sets out to refute the rival abstraction-based account. This paper examines the successes and failures of these two projects. I argue that Hume manages to articulate a plausible theory of general ideas; indeed, a version of his account has defenders in contemporary cognitive science. But Hume fails to refute the abstraction-based account, and as a result, the early modern controversy ends in a stalemate, with both sides able to explain how we manage to speak and think in general terms. Although Hume fails to settle the controversy, he nevertheless advances it to a point from which we have yet to progress: the contemporary debate over abstract ideas in cognitive science has stalled on precisely this point.     

人工类别学习的认知神经研究

基于类别学习包含类别归纳、分类和认知控制3个子过程的假设, 设计了人工类别学习的新任务, 利用高密度ERP技术并结合偶极子源分析, 从纵向和横向两个方面研究了人工类别学习的神经基础与机制。结果表明, 人工类别学习涉及前扣带回、前额叶皮质和内侧颞叶等关键脑区, 并在时间序列上显示了这些脑区扮演的不同作用。基于当前发现, 我们从时-空水平上讨论了的人工类别学习的认知神经机制。     

发展的认知神经科学--神经科学与认知发展研究的融合点

本文介绍了发展的神经科学自 2 0世纪 80年代以来在早期突触形成、关键期及丰富环境对脑发育的影响等领域的一些突出成就 ,阐述了从神经科学与认知发展共同研究的主题来考察两个学科的整合的意义 ,并对发展的认知神经科学研究的未来趋势作了展望。     

主题还是分类学? 对事物分类倾向的发展研究

研究旨在探讨个体分类倾向的发展趋势与影响因素.实验一采用图片、文字两种方式呈现实验材料,并使用不同指导语.要求被试选择三个事物中关系更近的两个.结果表明,成人比儿童具有更显著的按照主题分类的倾向,实验材料的呈现方式对于被试分类倾向没有显著影响.实验二进一步考察了分类倾向的发展轨迹,随着年龄增长,个体按照主题划分事物的倾向增强,由倾向于按照分类学规则向按照主题分类的转变可能发生在小学低中年级之间.     

Infants' comprehension of toy replicas as symbols for real objects

Infants' understanding of toy model-real exemplar relations was assessed through preferential looking and habituation tasks. Results from the preferential looking task suggest that 18-month toddlers are just beginning to demonstrate comprehension of symbolic relations between iconic models and their real object counterparts. Performance of 10- and 14-month-old infants in the preferential looking task did not improve when across-domain pairs of videos were used in place of within-domain pairs. Habituation task results indicated that 10-month-olds do not comprehend symbolic relations between miniature toy replicas and their "real" counterparts, but that such understanding begins to emerge by age 14 months. Interactions between symbolic processing and early lexical development are considered, as are methodological implications for the study of infant categorization.     

语法性别对认知的影响及其机制

语法性是许多语言中普遍存在的现象。它本质上属于句法属性,但是一定程度上关联着语义,而且会影响个体对物体的分类、知觉、认知加工,以及对二语的学习等认知活动,其对认知的影响程度受任务、语言、语法性透明度等因素调节。语法性影响认知的机制主要有概念水平上的相似性假设;生物性假设;词汇水平上的双选择模型。未来的研究要进一步探究语法性的认知机制、二语学习中语法性习得的认知过程、语法性不同形式性别差异影响的机制。     

认知风格影响归类过程中的神经活动-来自fMRI研究的证据

行为学研究表明归类过程中的反应具有认知风格上的不同,但未有研究明确探讨归类过程的神经活动是否也受认知风格的影响。本研究通过双重认知风格分型任务筛选出分析型和整体型被试,以探讨归类过程中二者之间是否表现出神经活动的差异。实验任务要求被试从两个待选物中选出与目标物属于同一类别的一个。同时,采用fMRI技术扫描并记录他们完成任务时的BOLD信号。结果发现,与基线任务相比,整体型和分析型个体均激活了额-枕网络的一些脑区,包括额下回、楔前叶、枕中回等,表明不同认知风格个体在任务中可能共享与工作记忆等相关的脑区。另外,与分析型个体相比,整体型个体在右额下回、右旁海马回呈现更广泛的特异性激活,提示,认知风格可以影响归类过程中的脑活动,而整体型个体大脑右半球更强烈的活动表明这一类型认知风格个体在归类时更依赖于远距离的语义联结。     

规则策略和样例策略在归类过程中的运

探讨人们在归类过程中对规则策略和样例策略的运用。包括3个实验,被试为华南师范大学110名本科生。用计算机呈现类别学习材料,被试学习后立即进行归类迁移测试,考察被试的归类策略倾向。实验1提高了Erickson和Kruchke研究中例外类别规则的清晰性,考察当学习材料中潜在规则易于掌握时,被试是否会倾向于运用规则策略进行归类;实验2探讨当学习材料中的潜在规则较难掌握时,被试是否会倾向于运用样例策略进行归类;实验3探讨人们在运用规则进行归类时对不同规则选用的特点。结果表明：当学习情境中潜在规则易于掌握时,被试倾向于运用规则策略进行归类;当潜在规则难以掌握时,被试则倾向于运用样例策略进行归类;当同时可以运用不同规则时,被试会选用更概括、更有普遍性的规则而弃用较具体、适用范围较限定的规则。据此,研究初步认为,人们在归类中首选的是规则策略,只有当学习情境中潜在规则难以掌握时,才转而采用样例策略;当有多种规则可以选择时,则倾向于选择更概括、更有普遍意义的规则     

指向性遗忘中认知抑制能力的发展

采用组块提示法,以小学二年级、五年级学生和大学生共104名为被试,考察语词记忆指向性遗忘效应的机制及其发展.结果表明:(1)各年龄段被试都明显存在着指向性遗忘效应;(2)指向性遗忘效应是提取抑制和选择性编码两种机制共同作用的结果,且年幼儿童与年长儿童、成人之间作用情况可能存在差异;(3)小学二年级、五年级学生和大学生之间认知抑制能力差异显著,随年龄增长,认知抑制能力不断增长.     

Thinking Styles and Cognitive Development

Using R. J. Sternberg's (1988, 1997) theory of thinking styles and W. G. Perry's (1970) theory of cognitive development, the author investigated the nature of thinking styles as they relate to cognitive development. Eighty-two Hong Kong university students (44 male, 38 female) responded to the Thinking Styles Inventory (R. J. Sternberg & R. K. Wagner, 1992) and the Zhang Cognitive Development Inventory (L. F. Zhang, 1997). Statistical analyses provided varying degrees of support for the prediction of an overlap between the thinking style and cognitive development constructs. In general, students who reasoned at a higher cognitive developmental level tended to use a wider range of thinking styles than students who reasoned at a lower cognitive developmental level. Implications of results are discussed in relation to education and research.