The effects of the stimulus-reinforcer correlation in a discrete-trials IRT>t procedure

The correlation between a keylight and food in a discrete-trials, interresponse-time-greater-than 6-sec (IRT>6-sec) procedure was varied by manipulating the rate of response-independent food presentation in the intertrial interval. When the correlation was positive, the rates of pecking in the IRT>6-sec condition were high and food was obtained on only about 5% of the trials. Likewise, responding was maintained at a high rate in yoked birds that received the same presentations of the light and food as the birds in the IRT>6-sec condition. When the rate of reinforcement between trials was equated to or made greater than the rate of reinforcement within trials, the response rate decreased for all birds, and those decreases were considerably larger for the yoked birds. However, the percentage of trials in which reinforced responses occurred under the IRT>6-sec procedure did not increase substantially when the light and food were either uncorrelated or negatively correlated. The percentage of trials in which a reinforcer was obtained increased when the keylight was left on continuously and the discriminative stimulus was not presented on the key. The results show that the stimulus-reinforcer correlation affects responding in the discrete-trials IRT>6-sec procedure, but that the effects of the stimulus-reinforcer correlation vary as a function of whether reinforcement is response-dependent or response-independent. The differences between the effects of response-independent and response-dependent pairings and nonpairings of the light and food are best accounted for in terms of differences in the control of responding by background stimuli.     

Applications of social cognitive theory to the career development of women of color

This article provides a review of the literature on the educational and career development of women of color within the context of social cognitive career theory (Lent, et al, 1994 and Lent, et al, 1996). Specifically, possible gender, ethnic, racial, and cultural influences on career self-efficacy and outcome expectations are explored to delinate the potential mechanisms whereby ethnicity, culture, and ethnic and racial identity development, in interaction with gender, affect career choice and adjustment. Suggestions for future research on social cognitive career theory and the career development of women of color are presented.     

Increasing and signaling background reinforcement: effect on the foreground response-reinforcer relation.

Herrnstein's (1970) hyperbolic matching equation describes the relationship between response rate and reinforcement rate. It has two estimated parameters, k and Re. According to one interpretation, k measures motor performance and Re measures the efficacy of the reinforcer maintaining responding relative to background sources of reinforcement. Experiment 1 tested this interpretation of the Re parameter by observing the effect of adding and removing an additional source of reinforcement to the context. Using a within-session procedure, estimates of Re were obtained from the response-reinforcer relation over a series of seven variable-interval schedules. A second, concurrently available variable-interval schedule of reinforcement was added and then removed from the context. Results showed that when the alternative was added to the context, the value of Re increased by 107 reinforcers per hour; this approximated the 91 reinforcers per hour obtained from this schedule. Experiment 2 investigated the effects of signaling background reinforcement on k and Re. The signal decreased Re, but did not have a systematic effect on k. In general, the results supported Herrnstein's interpretation that in settings with one experimenter-controlled reinforcement source, Re indexes the strength of the reinforcer maintaining responding relative to uncontrolled background sources of reinforcement.     

目标－背景色的配合对彩色CRT显示工效的影响

以通道容量为作业效标,用实验方法对ＣＲＴ显示屏上黑、深蓝、绿、浅蓝、红、紫、黄、白等８种颜色组成的５６种目标－背景色配合方式与显示工效的关系作了比较研究。结果表明：从工效学考虑,彩色ＣＲＴ显示屏的背景色有以深色为好的趋势,目标色有以浅色为好的趋势。目标与背景色彩的恰当配合能显著提高信息的传递绩效。白目标黑背景、黄目标黑背景、绿目标黑背景等对比度较大的目标－背景配合显示工效最佳。     

右视野颜色范畴知觉是长期习得语言范畴还是即时分类颜色的结果?

本研究探讨了右视野颜色范畴知觉是由长期习得语言范畴还是即时分类颜色引起的。实验1让被试先将深绿、浅绿、浅蓝和深蓝四种颜色分为四种范畴,再接受视觉搜索任务。结果发现,视觉搜索任务中出现了与颜色分类相应的右视野颜色范畴知觉,且这一效应在任务的早段就表现出来,提示右视野颜色范畴知觉并非由分类颜色所引起。实验2让被试将四种渐进的蓝色分为两种范畴,并在之前与后接受视觉搜索任务。结果表明,分类后的视觉搜索中并未出现右视野颜色范畴知觉。先前研究表明,习得语言范畴使四种颜色为两种范畴后,颜色辨别会出现右视野范畴效应。因此,这一结果提示右视野颜色范畴知觉并非由分类颜色,而是由习得语言范畴所引起的。总体上,本研究提示右视野颜色范畴知觉是由长期习得语言范畴,而非即时分类颜色引起的,进一步揭示了语言与颜色知觉的关系。     

习得的语言范畴影响颜色知觉的机制:来自ERP的证据

本研究以两个实验探讨了习得的语言范畴影响颜色知觉的机制.实验1让被试接受短期“色-词”重组训练,使原先范畴内的两种颜色变为范畴间的颜色,训练前后完成视觉搜索任务.反应时结果显示,在训练后,与训练的两种颜色近似的另外两种颜色的知觉表现出边缘显著的偏侧化颜色范畴效应.实验2让被试接受与实验1相同的训练后,完成视觉Oddball任务.ERP结果显示,在训练后,与训练的两种颜色近似的另外两种颜色的偏差刺激在早期知觉阶段就表现出偏侧化vMMN效应.这些结果表明:习得的语言范畴能影响早期的、注意前的颜色知觉机能,且这一影响过程可以在短期内完成;习得的语言范畴会影响颜色知觉范畴,而非仅影响特定颜色点的知觉机能.     

动态情景中颜色特征和身份特征在返回抑制中的作用

在动态的“线索-靶子”范式中引入隧道刺激, 以靶子与线索的非空间特征相同时的反应延迟测量返回抑制效应。实验1利用单向隧道创设客体的空间位置信息明确且可靠的条件, 考察客体的颜色特征在返回抑制中的作用。实验2利用双向隧道创设客体的空间位置信息不明确的条件, 考察客体的颜色特征在返回抑制中的独立作用。实验3、4分别采用与实验1、2类似的方法, 在动态任务情景中考察客体的身份特征在返回抑制中的作用。结果显示, 线索呈现与靶子呈现的时间间隔较长时, 4个实验中均存在显著的返回抑制效应。这表明, 动态情景中, 客体的空间位置信息明确且可靠时, 颜色特征和身份特征在返回抑制中都发挥着重要作用; 客体的空间位置信息不明确时, 颜色特征和身份特征在返回抑制中也都具有相对独立的作用。     

多目标视觉追踪中物体属性加工的眼动研究*

采用多目标视觉追踪任务(MOT),探讨物体颜色特征对视觉追踪的影响,同时记录被试的眼动情况,探讨追踪过程中颜色特征对眼动模式的影响。结果发现,视觉追踪机制能够对物体的颜色特征进行加工,但加工程度受制于目标物与分心物之间的特征竞争关系。在物体颜色特征条件下,视觉系统采用知觉组织加工策略,以被追踪目标构成的多边形中心为注意中心。在对物体颜色特征的加工中,内源性注意与外源性注意相互影响。     

4～6岁幼儿颜色偏好实验研究

本实验采用对偶比较法．对4—6岁幼儿进行颜色偏好实验研究,结果表明：在4—6岁的年龄段中,幼儿颜色偏好顺序依次为：红、黄、橙、蓝、紫、绿;男女幼儿的颜色偏好有明显差异;不同年龄之间的幼儿颜色偏好没有明显差异。     

大学生颜色词分类的研究

运用自然分类和多维标度法．对279名大学生进行了11种基本颜色词的分类研究、结果表明,大学生将11种基本颜色词分成三类：(1)非彩色,包括黑、白、灰,也包括色彩暗淡的棕色;(2)暖色,包括红、橙、黄和粉红色;(3)冷色．包括绿、蓝和紫。基本颜色词的语义空间有两个纬度：(1)彩色／非彩色;(2)冷色／暖色。不同专业大学生对颜色词分类基本一致,但也具有专业特点。