Reaction times of younger and older men and temporal contingencies of reinforcement

Influences of extended training and temporal contingencies on reaction time were studied in relation to developmental differences. Older and younger men were trained on a chained schedule in which completion of a variable interval produced a terminal link in which reaction time was measured. The reaction-time procedure involved a conditional discrimination with matching to sample in one component and oddity matching in the other. During baseline training, no time limit was placed on the response to the discrimination choice stimuli. Subsequently, increasingly severe time limits were imposed over a series of sessions. Older and younger men showed increased speeds (decreased reaction times) when temporal contingencies were imposed, and these changes were maintained during post-training baseline sessions when there was unlimited time in which to respond. The younger men generally responded faster than the older ones, and age differences were not appreciably reduced during the course of the experiment. The results indicated the feasibility of studying reaction time in human subjects using operant procedures analogous to those developed for the study of nonverbal organisms.     

EFFECTS OF CONTEXTUAL COMPETENCE ON SOCIAL INITIATIONS

The frequency of social initiations and satisfaction with interactions in three dyads, each consisting of 1 student with disabilities and 1 nondisabled peer, were assessed under two alternating conditions: Condition 1 assessed the interactions around a set of four trained computer games, and Condition 2 assessed interactions when students were playing a set of four untrained computer games. Training was conducted with a multiple baseline design across participants and was followed by social interaction probes using an alternating treatments design. The results indicated greater frequencies of social initiations by 5 of 6 participants, higher degrees of game satisfaction by all participants, and equal or higher degrees of peer satisfaction by 5 of 6 participants when playing trained games in comparison to untrained games.     

Sensory superstition on multiple interval schedules.

Pigeons were exposed to multiple schedules in which an irregular repeating sequence of five stimulus components was correlated with the same reinforcement schedule throughout. Stable, idiosyncratic, response-rate differences developed across components. Components were rank-ordered by response rate; an approximately linear relation was found between rank order and the deviation of mean response rate from the overall mean rate. Nonzero slopes of this line were found for multiple fixed-interval and variable-time schedules and for multiple variable-interval schedules both when number of reinforcements was the same in all components and when it varied. The steepest function slopes were found in the variable schedules with relatively long interfood intervals and relatively short component durations. When just one stimulus was correlated with all components of a multiple variable-interval schedule, the slope of the line was close to zero. The results suggest that food-rate differences may be induced initially by different reactions to the stimuli and subsequently maintained by food.     

Human performance on conjunctive fixed-interval fixed-ratio schedules

Eighteen young adults performed a lever-pulling task for money. Subjects were initially exposed to a fixed-interval 80-second schedule and subsequently to one of three conjunctive schedules in which the added fixed-ratio requirement was set at either 10, 80, or 120 responses. Three fixed-interval response patterns emerged: high constant rate, intermediate rate, or low rate, with most subjects displaying the last. Conjunctive performance was related to the subjects' prior fixed-interval patterns and the conjunctive ratio requirements. Low-rate subjects tended to optimize reinforcement (maximum reinforcers for minimum responses) on conjunctive schedules. Response rate was directly related to ratio requirements. Subjects' performance closely corresponded to their verbal statements of the contingencies.     

SHORT- AND LONG-TERM EFFECTS OF CONTINGENCY MANAGED INSTRUCTION ON LOW,MEDIUM, AND HIGH GPA STUDENTS1

Undergraduate students had been assigned to a contingency managed course or a conventional lecture course (Du Nann and Fernald, Journal of Applied Behavior Analysis, 1976, 9 , 373–374). Two years later, some 35% (N = 86) of the original classes responded to a letter offering them $2.00 to participate in a study of their educational experiences. These students completed a multiple-choice test on material from the course, and answered questions about activities and attitudes that might have been affected by the experience in Introductory Psychology. In the contingency management course 2 yr past, students were tested each week on a chapter of textbook material with 10-item multiple-choice quizzes. The course employed a modified “Doomsday Contingency”, requiring each student to achieve 80% mastery on one of the four weekly quizzes or drop the course. Quizzes were given in small groups and scored individually, while the student stood near, by an undergraduate proctor assigned to that group. The proctor was asked to show interest in the students' quiz performances, help clear up difficult areas, and develop a friendly working relationship with each student. While many students passed the quiz on the first attempt, others were given individual tutoring, so that no one was in fact forced to drop the course. In addition to the weekly quiz assignment, students in the contingency managed group were asked to attend one lecture each week. While the contingency management course procedures had much in common with PSI (Keller, Journal of Applied Behavior Analysis, 1968, 1 , 79–89), several departures made them unique. First, self-pacing was curtailed because students were required to master one unit per week or drop the course. Second, proctors met with students in small groups, usually giving individual tutoring only to those students who did not pass the quiz on the first attempt. Finally, students were asked to attend one lecture per week. Students in the conventional lecture group were not asked to pass weekly quizzes, but instead attended three 50-min lectures each week. Two of these lectures followed the textbook material closely, while the third, which was also attended by students from the contingency management course, covered material only indirectly related to the text. This partition of lecture content allowed material to be similar across the two instructional groups. Although students in the lecture condition were told they could obtain copies of the quizzes, few of them did so. Course grades were determined by scores on two 45-item multiple-choice hourly exams, each covering half the semester material (each worth 25%), and by a 90-item final exam, which served as a measure of short-term retention. Before analyzing the follow-up data, several characteristics of the returning students were compared to determine the comparability of the sample from the two original classes. Most important, both attrition and the current mean GPAs of students from the two classes were very similar. These considerations, and others, suggested there was no systematic sampling bias to confound comparisons of student performance. A 2 (contingency management versus traditional lecture) by 3 (high, medium, and low GPA) analysis of variance was computed on the course final-exam scores and the follow-up measures. Instructional procedure and GPA interacted on the final exam such that low and medium GPA students performed significantly better under contingency management, but there was no significant effect of instructional procedure with high GPA students. On the 2-yr retention measures, students from the contingency management course performed significantly (p < 0.01) better on items drawn from quizzes used in their original course, and marginally better (p < 0.10) on items drawn from the final exams, but no interactions with GPA appeared. Furthermore, instructional method produced no significant main effects or interaction with how many students became majors or minors in psychology, how many psychology courses were later taken, how many books in psychology were reported to have been read, or on students' evaluation of the interest and importance of psychology.     

Behavioral contrast as a function of the temporal location of reinforcement

Pigeons were trained on a multiple variable-interval variable-interval schedule of reinforcement. One component was then changed to a variation of a fixed-interval schedule in which the same rate of reinforcement was obtained as previously but the location of the reinforcer was fixed within the component. The effects of different temporal locations were compared. An increase in response rate for the unchanged variable-interval component (behavioral contrast) occurred when the reinforcer was located in the middle or at the end of the FI component, but response suppression occurred when it was located at the beginning of the component. The pattern of results cannot be explained by any previous theories of contrast. The overall response rates, and the pattern of local rates within the components, were consistent with the hypothesis that the major determinant of the contrast effect was the transition to a lower reinforcement rate following the unchanged component.     

不同加工与记忆编码关系的ERP研究

通过事件相关电位(ERPs)记录,探讨了深、浅2种加工与记忆编码的相互关系。研究结果表明,（1）在深、浅两种加工条件下,首次使用汉字材料,获得了ERP相继记忆效应（Dm),随后再认正确的ERPs比随后再认不正确的ERPs有更大的晚正成分。（2）深加工的Dm效应始于N2波的前支（230－280ms)和N2波之后（395－800ms);而浅加工的Dm效应发生在345－490ms之间。深、浅加工的Dm效 涉及不同的脑区,这一结果支持深、浅两种加工的Dm效应可能是分离的结论。     

The impact of L1 structural frequency and cognate status on the timing of L2 production

The present study investigates the impact of first language (L1) structural frequency and L1 lexical accessibility, manipulated via cognate status, on second language (L2) speech production. L1 German–L2 English speakers and L1 English speakers completed a production task containing pre- and post-modified possessive noun phrase (NP) constructions (e.g. The actress’s sofa vs. The sofa of the actress) in which the head nouns were English-German cognates (e.g. sofa) or noncognates. While English prefers pre-modified NPs, German has a strong frequency bias for post-modified NPs. L2 English speakers exhibited higher production accuracy than L1 English speakers on post-modified NP sentences. However, facilitative L1 effects in production latencies were restricted to post-modified NP sentences containing cognates and only developed cumulatively after repeated exposure to post-modified NP sentences. We discuss how cognate status and L1 structural frequency differentially influence the accuracy and timing of choosing between different structural alternatives during L2 production.     

Financial prospect relativity: context effects in financial decision‐making under risk

We report three studies in which methodologies from psychophysics are adapted to investigate context effects on individual financial decision‐making under risk. The aim was to determine how the range and the rank of the options offered as saving amounts and levels of investment risk influence people's decisions about these variables. In the range manipulation, participants were presented with either a full range of choice options or a limited subset, while in the rank manipulation they were presented with a skewed set of feasible options. The results showed that choices are affected by the position of each option in the range and the rank of presented options, which suggests that judgments and choices are relative. Copyright © 2006 John Wiley & Sons, Ltd.     

风险决策中动态框架效应研究

风险决策的框架效应一直是理论研究和实践应用的焦点。该研究利用计算机联网模拟团队分布式动态风险决策任务,从三个方面（过去绩效,启动资金和目标设置）研究决策者在动态条件下风险偏好的变化规律。研究发现“目标设置”因素框架效应具有抑制作用,“启动资金”因素对个体和团队有不同影响。研究结果表明,风险敏感性同样适用于解释动态情境下的风险偏好。