语言表征在颜色类别知觉中的作用

采用同时和继时实验任务,探讨语言表征在颜色类别知觉中的作用.实验一刺激同时呈现,被试表现出类别知觉效应,但效应不受语言干扰影响.实验二刺激间隔呈现,被试表现出类别知觉效应,效应在语言干扰时消失.实验三采用继时任务,没有语言干扰,在刺激呈现间隔(SOA)小于300ms时效应不显著,大于等于300ms时效应显著.研究提示类别知觉效应的机制取决于任务要求和被试无意识的认知策略.在同时任务中效应来自知觉过程本身,在继时任务中效应来自语言编码.继时任务中效应量随SOA变化,说明语言表征由上至下地影响知觉加工,类别知觉是一个动态过程.     

类别特征的相似性与竞争性对归类的影响

探讨新项目特征的性质对归类的影响。共包括两个实验,被试是华南师范大学180名二年级本科生。研究材料分两部分,学习材料是两类昆虫的若干类别成员,每类昆虫有6种特征;测试材料则是与学习材料的类别成员有不同相似性或竞争性的新项目,要求被试经过学习之后对新项目进行归类,然后对被试归类的一致性或确信度进行分析。实验1主要探讨新项目与类别成员相似性对归类的影响;实验2主要探讨新项目特征的竞争性对归类的影响。结果表明,匹配特征数量及其概率是相似性的两个构成因素,它们与新项目的归类概率成正比,而对立特征数量及其概率则是竞争性的两个构成因素,它们均与新项目的归类概率成反比。     

归纳推理中相似性和类别标签的作用

该文采用“篇章阅读”实验范式探索了归纳推理中前提类别和结论类别间相似性、结论类别标签属性对归纳推理的作用。90名大学生被试参加了3个实验。实验1结果表明,归纳推理受前提类别和结论类别之间相似性的影响,相似性越高归纳推理力度越强;实验2结果表明,归纳推理还受结论类别上位类别知识的影响,当类别属性和相似性冲突情况下,被试更倾向按照类别属性进行推理;实验3结果表明,归纳推理通达上位类别知识是一个主动建构的过程,即使是在类别标签不确定的情况下,被试仍然依赖类别标签进行推理。并初步提出了“归纳推理力度=两事物相似性×归类概率”模型设想。     

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     

材料的呈现方式对大学生分类活动影响的研究

以60名视力、智力均正常的大学生为被试,采用维度特征互不相同的三套图片材料和三种材料呈现方式,以被试分类的结果和解释的理由为依据,用一维特征分类、整体相似性分类、两阶段策略分类和其他分类等作为因变量指标,采用不完全被试内设计进行实验。用SPSS 8．0 for windows对实验结果进行处理。结果：在A方式下,被试倾向于按材料的一维特征分类;在B方式下,被试倾向于按材料的整体相似性分类;在C方式下,被试倾向于按两阶段策略分类。     

学习方式对关系类别间接性学习的影响

以96名大学生为被试,以4特征虚拟外星生物为实验材料,通过类别的间接性学习,探讨学习方式对关系类别间接性学习的影响,结果发现：类别的间接性学习条件下,限定分类任务中,被试更倾向于选择关系作为类标准;参照条件下被试限定分类结果与标准的关系类别的分类结果的杰卡德相似性显著高于个人条件;被试分类结果的简单关系类别的杰卡德相似性显著高于复杂关系类别的杰卡德相似性,4特征关系类别的间接性学习中存在单一性效应。     

非监控类别学习的分类策略与表征

类别学习是人类对不同类别加以归类的过程。类别信息的表征、分类策略运用的特点一直是类别学习研究的重点。非监控类别学习可分为直接的非监控类别学习和间接的非监控类别学习。直接的非监控类别学习(非限制任务, 限制任务)中被试的分类策略具有分类“单维度倾向”策略特点,类别变异程度会影响类别表征; 间接的非监控类别学习更倾向形成相似性表征, 直接的非监控类别学习则为基于规则表征。现有的非监控类别学习的理论对分类策略和表征的解释仍显薄弱, 不同学习任务下类别迁移和知识效应的研究还存在不足, 未来研究还需要进一步验证知识效应对非监控类别学习的认知加工过程的影响、探索影响类别表征形成的因素等问题。     

继时呈现条件下类别归纳过程的ERPs研究

采用ERP技术对继时呈现条件下类别归纳过程进行了实验研究.使用几何图形为材料,18名被试在单维属性不告知、单维属性告知、双维属性不告知三种条件下完成类别归纳任务.通过对相关ERP成分的分析得出以下结论:(1)在继时呈现归纳材料的情况下,对刺激的加工是在已有背景基础上对后来呈现的刺激进行选择性加工,从而形成类别;(2)成年人与儿童在类别归纳中认知加工方式可能存在不同,当类别归纳的复杂程度增加时,即在需要归纳的属性从一个变为两个的时候,成年人仍然倾向于通过归纳出类别判断规则用于分类任务,而非通过相似性进行判断;(3)继时呈现材料条件下类别归纳任务中出现的P400可能是标志类别归纳过程完成的ERP成分,而且与对刺激属性加工具体过程无关.     

初中学生类别建构中的知识效应研究

采用类别建构的实验范式,选取具有家族相似性结构的人工类别材料,考察了已有知识对初中学生类别建构的影响。实验结果表明,当类别特征能够在已有知识的基础上形成主题时,初中学生倾向于按主题建构类别,而且在主题愈突出时这种趋势愈为明显;并且,主题性质对不同领域材料的类别建构的影响是一致的。     

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.     

Induction and category coherence

In studies of category formation, subjects rarely construct family resemblance categories. Instead, they divide objects into categories using a single dimension. This is a puzzling result given the widely accepted view that natural categories are organized in terms of a family resemblance principle. The observation that natural categories support inductive inferences is used here to test the hypothesis that family resemblance categories would be constructed if stimuli were first used to generate inductive inferences. In two experiments, subjects answered either induction questions, which made interproperty relationships more salient, or frequency questions, which required information only about individual properties, before they performed a sorting task. Subjects were likely to produce family resemblance sorts if they had first answered induction questions but not if they had answered frequency questions.     

The influence of stimulus properties on category construction

It has been demonstrated that when people free classify stimuli presented simultaneously in an array, they have a preference to categorize by a single dimension. However, when people are encouraged to categorize items sequentially, they sort by "family resemblance," grouping by overall similarity. The present studies extended this research, producing 3 main findings. First, the sequential procedure introduced by G. Regehr and L. R. Brooks (1995) does not always produce a preference for family resemblance sorts. Second, sort strategy in a sequential procedure is sensitive to subtle variations in stimulus properties. Third, spatially separable stimuli evoked more family resemblance sons than stimuli of greater spatial integration. It is suggested that the family resemblance sorting observed is due to an analytic strategy.     

Sorting out categories: Incremental learning of category structure

Two experiments examine how inferences might promote unsupervised and incremental category learning. Many categories have members related through overall similarity (e.g., a family resemblance structure) rather than by a defining feature. However, when people are asked to sort category members in a category construction task, they often do so by partitioning on a single feature. Starting from an earlier result showing that pairwise inferences increase family resemblance sorting (Lassaline & Murphy, 1996), we examine how these inferences lead to learning the family resemblance structure. Results show that the category structure is learned incrementally. The pairwise inferences influence participants’ weightings of feature pairs that were specifically asked about, which in turn affects their sorting. The sorting then allows further learning of the categorical structure. Thus, the inferences do not directly lead learners to the family resemblance structure, but they do provide a foundation to build on as the participants make additional judgments.     

Diversion of attention in everyday concept learning: Identification in the service of use

Many people tend to believe that natural categories have perfectly predictive defining features. They do not easily accept the family resemblance view that the features characteristic of a category are not individually sufficient to predict the category. However, common category-learning tasks do not produce this simpler-than-it-is belief. If there is no simple classification principle in a task, the participants know that fact and can report it. We argue that most category-learning tasks in which family resemblance categories are used fail to produce the everyday simpler-than-it-is belief because they encourage analysis of identification criteria during training. To simulate the learning occurring in many natural circumstances, we developed a procedure in which participants' analytic activity is diverted from the way in which the stimuli are identified to the use to which the stimuli will be put. Finally, we discuss the prevalence of this diverted analysis in everyday categorization.     

Are rating-based procedures reliable for derivation of typicality judgments from children?

The aim of the present study was to examine whether a rating-based procedure that has already been used by other investigators can be used for derivation of typicality ratings from children. The evidence reported in the study establishes that such a procedure cannot be reliably used for this purpose. The results show that children rated category items in terms of personal preferences rather than as a function of how representative they considered the items to be of their superordinate category. On the basis of these findings, an alternative method based on the family resemblance scores of the category members was proposed in order to derive typicality ratings from young children. This family resemblance method of obtaining typicality judgments may be useful to investigators interested in assessing how children process categorical information.     

Domains and knowledge effects: strategies in object and social classification

This research examined differences in classification strategies in object and social domains. Wattenmaker (1995) found that additive classification rules were more compatible with the social than the object domain. The present experiments examined the generality of these results by using fundamentally different types of social and object categories. A sorting paradigm was used to evaluate the frequency with which subjects used additive strategies. In Experiment 1, the social domain was represented by social events that possess very different properties than core social concepts such as traits or occupations. Even with these types of social materials, however, many more additive strategies and family resemblance sorts occurred with social than object materials. In Experiment 2, the object domain was represented by abstract object categories that were designed to possess properties of core social concepts such as traits. Again, however, more additive strategies and family resemblance sorts occurred with social than object materials. The results indicate that differences in the compatibility between additive strategies and object and social domains are not limited to subsets of categories in these domains but rather extend to many types of object and social categories.     

Classification of exemplars with single- and multiple-feature manifestations: the effects of relevant dimension variation and category structure

Most classification research focuses on cases in which each abstract feature has the same surface manifestation whenever it is presented. Previous research finds that people have difficulty learning to classify when each abstract feature has multiple surface manifestations. These studies created multiple manifestations by varying aspects of the stimuli irrelevant to the abstract feature dimension. In this article, multiple manifestations were created by varying aspects of the stimuli relevant to the abstract feature dimension. People given categories with the family resemblance category structure often used in psychology experiments had difficulty learning to classify when multiple manifestations were present, even though the variation was relevant. This effect was reversed when a family resemblance structure with nondiagnostic values was used.     

The inference of covert hypotheses by verbal reports in concept-learning research

A paradigm designed to examine the degree to which verbal reports represent the subject's learning was evaluated using a concept-acquisition task. Specifically, the degree to which hypotheses verbalized during the concept-acquisition procedure represent the covert hypotheses controlling category responding was examined. Subjects were required to make category responses, verbal reports, and sorts and re-sorts (blank-trial probes) of the stimuli at intervals in a reception paradigm. By comparing the sorts made during the acquisition procedure, the re-sorts after a 1-week delay, and the sorts made by subjects who had not participated in the acquisition procedure, it was determined that the verbal reports do not accurately represent the underlying hypothesis-testing process under all conditions. Verbal reports elicited at the beginning of the acquisition procedure and at criterion accurately represented the underlying hypotheses; those elicited at intervening points did not. The ambiguity of the verbal reports was a similar function of acquisition trials.     

The influence of attention on holistic face encoding

We examined the influence of attention on the formation of holistic face representations using the composite effect (Perception 16 (1987) 747). In Experiment 1, stimuli composed of a face superimposed on a house were shown during encoding. Subjects delineated either the face or the house, thus manipulating attention away or toward the face. In Experiment 2, an intact face image was presented with letters scrolling from top to bottom. Subjects were asked to either ignore the letters or read them and decipher the words that they formed. Aligned and misaligned composites were shown at testing. Recognition performance was consistently better for misaligned than aligned stimuli, regardless of the allocation of attention during encoding. In Experiment 3, we show that the composite effect can be eliminated by a disruption in holistic processing at the time of encoding. We conclude that holistic encoding is one aspect of face analysis that occurs equally well with or without attention.     

Making Probabilistic Relational Categories Learnable

Theories of relational concept acquisition (e.g., schema induction) based on structured intersection discovery predict that relational concepts with a probabilistic (i.e., family resemblance) structure ought to be extremely difficult to learn. We report four experiments testing this prediction by investigating conditions hypothesized to facilitate the learning of such categories. Experiment 1 showed that changing the task from a category‐learning task to choosing the “winning” object in each stimulus greatly facilitated participants' ability to learn probabilistic relational categories. Experiments 2 and 3 further investigated the mechanisms underlying this “who's winning” effect. Experiment 4 replicated and generalized the “who's winning” effect with more natural stimuli. Together, our findings suggest that people learn relational concepts by a process of intersection discovery akin to schema induction, and that any task that encourages people to discover a higher order relation that remains invariant over members of a category will facilitate the learning of putatively probabilistic relational concepts.