Local contrast in multiple schedules: the effect of stimulus discriminability.

A three-ply multiple schedule assessed responding in a standard component as a function of the just-preceding schedule. The principal experimental condition was the difference among the wavelengths signaling the schedule components. Only the pigeons working in a narrow wavelength range showed persistent positive local contrast; that is, response rate during the standard component was higher when that component followed extinction than when it followed itself. Birds in both narrow- and medium-range groups showed persistent negative local contrast; that is, rate was lower following a relatively rich component. The dissipation of positive contrast appeared to be most clearly related to the establishment of differential responding. Negative contrast was inversely related to wavelength differences. Theories pertaining to contrast must account for the role of discrimination in both positive and negative types.     

Choice for aperiodic versus periodic ratio schedules: A comparison of concurrent and concurrent-chain procedures

Choice between mixed-ratio schedules, consisting of equiprobable ratios of 1 and 99 responses per reinforcement, and fixed-ratio schedules of food reinforcement was assessed by two commonly used procedures: concurrent schedules and concurrent-chains schedules. Rats were trained under concurrent fixed-ratio mixed-ratio schedules, in which both ratio schedules were simultaneously available, and under a concurrent-chains schedule, in which access to one of the mutually exclusive ratio schedules comprising the terminal links was contingent on a single “choice” response. The distribution of responses between the two ratio schedules was taken as the choice proportion under the concurrent procedure, and the distribution of “choice” responses was taken as the choice proportion under the concurrent-chains procedure. Seven of eight rats displayed systematic choice; of those, each displayed nearly exclusive choice for fixed-ratio 35 to the mixed-ratio schedule under the concurrent procedure, but each displayed nearly exclusive choice for the mixed-ratio schedule to fixed-ratio 35 under the concurrent-chains procedure. Thus, preference for a fixed or a mixed schedule of reinforcement depended on the procedure used to assess preference.     

Contrast and autoshaping in multiple schedules varying reinforcer rate and duration

Thirteen master pigeons were exposed to multiple schedules in which reinforcement frequency (Experiment I) or duration (Experiment II) was varied. In Phases 1 and 3 of Experiment I, the values of the first and second components' random-interval schedules were 33 and 99 seconds, respectively. In Phase 2, these values were 99 seconds for both components. In Experiment II, a random-interval 33-second schedule was associated with each component. During Phases 1 and 3, the first and second components had hopper durations of 7.5 and 2.5 seconds respectively. During Phase 2, both components' hopper durations were 2.5 seconds. In each experiment, positive contrast obtained for about half the master subjects. The rest showed a rate increase in both components (positive induction). Each master subject's key colors and reinforcers were synchronously presented on a response-independent basis to a yoked control. Richer component key-pecking occurred during each experiment's Phases 1 and 3 among half these subjects. However, none responded during the contrast condition (unchanged component of each experiment's Phase 2). From this it is inferred that autoshaping did not contribute to the contrast and induction findings among master birds. Little evidence of local contrast (highest rate at beginning of richer component) was found in any subject. These data show that (a) contrast can occur independently from autoshaping, (b) contrast assays during equal-valued components may produce induction, (c) local contrast in multiple schedules often does not occur, and (d) differential hopper durations can produce autoshaping and contrast.     

篇章阅读理解中句子边界对整体连贯性的影响

通过四个实验考察句子边界对整体连贯性的影响。实验运用不一致程序(inconsistent paradigm)进行。实验一结果发现,当目标行1(target line)不是一个完整句子时,被试阅读完目标行2(post-target line)后才会意识到目标行1中的不一致。实验二结果发现,当目标行1是一个完整句子时,被试阅读完目标行1后就可立刻意识到其中的不一致,但探测词的反应时在两种条件下则并没有明显差异。这两个实验的结果表明,句子边界作为一种信号,提示读者在阅读下一句子前要完成当前句子的整合加工。实验三结果发现,目标行1以一个无关词(如然后)结束时,被试阅读完目标行1后也可立刻注意到其中的不一致,这表明句号对背景信息的整合不是必需的。实验四考察了分号的作用,结果显示:被试阅读完目标行1后并没有意识到其中的冲突。根据本研究的结果,可以推测句号在理解过程中起着重要影响,而其它句子边界(如:分号)的作用则并不明显。     

视觉特征提取加工中的认知可塑性

本研究采用“加因素法”研究范式,通过两个实验分别检测20名飞行员和lO名老年被试及其相应控制组在视觉特征提取任务上的认知加工水平,旨在探讨视觉特征提取这一高水平视觉表象加工上的认知可塑性水平。研究结果表明,视觉特征提取加工既表现出了随外界系统训练而发生功能增强的练习效应,也表现出了随年老化过程而发生相应功能显著改变的年龄效应。研究提示,由于受大脑神经细胞活动特性改变的影响,视觉特征提取加工更多地表现出了可塑性或易变性相对较高的认知特性。结合相关的工作基础,研究结果还进一步证实高水平视觉认知加工所表现出的练习效应和年龄效应在大脑神经网络上的分布是不平衡的。本研究不仅对于揭示高水平视觉表象加工的认知特性具有重要的理论意义,而且在实践中对于建立飞行员、宇航员等特殊职业人员的选拔模型以及揭示飞行空间定向障碍的认知机制也具有重要的应用价值。     

语篇阅读理解中人物性格模型的建构

采用实时窗口阅读技术,通过操纵特征段落性质和屏蔽段落长度两个变量,探讨人物性格模型在语篇阅读中的建构和影响因素。在研究所用材料中,特征段落描述能反映主人公性格的典型行为或不能反映其性格的一般行为,使其与目标句分别形成冲突或无关关系,考察读者能否利用这些内隐式的行为描述建构人物的性格模型。同时,改变屏蔽段落长度,形成局部或整体联贯两种条件,考察不同联贯类型的影响作用。结果发现：在不论整体还是局部联贯条件下,读者均能利用内隐的行为描述建构人物性格模型,并能应用该模型预期人物的后续行为。     

西方童话与中国神话中人物的人格特征研究

童话和神话中人物的人格特征影响着个体早期的社会化。本文选择了24篇著名的西方童话和中国神话,采用人格形容词评定法,对其中人物的人格特征进行对比研究发现,这些人物既具有人类追求真善美的共性,也表现出不同民族所特有的民族精神和价值观的差异性。分析了这些共性和差异性的表现及其产生原因,阐述了这些人物的人格特征对儿童形成其个性品质、行为模式、道德品质、社会角色等方面的作用和意义。     

论道德现象的特点

从道德存在论看 ,道德是普遍性与特殊性的统一 ;地域性与历史性的统一。从道德价值论看 ,道德是相对性与绝对性的统一 ;多元性与一元性的统一。从道德认识论看 ,道德是客观性与主观性的统一 ;群体性与个体性的统一。从道德实现论看 ,道德是他律性与自律性的统一 ;现实性与理想性的统一。     

论道德意识的认知特征

道德作为一种实践意识 ,其认知特征主要有三 :一是人道为本 ,自觉觉他 ;二是“是”“应”同辙 ,智仁并举 ;三是情理交融 ,知行合一。     

Some Aspects of Product Shape in Mechanical Engineering

The paper examines some of the many factors that influence the shape of designed products in the mechanical engineering industries. It is shown that, once the detailed shape of a product has been determined, the analysis of that shape from the viewpoints of various engineering activities downstream of design leads to a range of inherently different perceptions of it.