Coordination dynamics of rhythmical and discrete prehension movements: Implications of the scanning procedure and individual differences

The aim of this study was to compare the coordination dynamics of discrete and rhythmical reaching and grasping movements from a dynamical systems perspective. Previous research from this theoretical perspective had focused on rhythmical actions and it is unclear to what extent discrete movements are amenable to a similar dynamical systems analysis. Six adult subjects performed prehension in two conditions: a discrete, non-continuous mode and a rhythmical, continuous mode. A `scanning procedure' was implemented between pre- and post-tests in which the required time of final relative hand closure (T_rfc) was systematically varied. It was shown that the error in the reaching and grasping pattern was least at an attractor region and systematically increased with deviation from the attractor. Results also indicated that there were no differences between condition or trial block for the group. However, there were several within-subject effects of interest. The validity of the scanning procedure was found to be questionable in the discrete condition, where four subjects showed differences in T_rfc between pre- or post-test and the predicted T_rfc of the scanning procedure. Four out of six subjects also had different preferred T_rfc values for discrete and rhythmical movement, indicating that individual specific models might need to be constructed for future dynamical modelling of discrete movement.PsycINFO classification: 2330     

汉字内隐记忆的实验研究(Ⅲ):检验加工分离说的修正模型

实验1和实验2依据目标字和非目标字两种条件,比较了再认、整字偏好、包含、排除四类测验。在“过程不纯净”假设的前提下．检验了加工分离说（PDP）的修正模型并得到以下结果：（1）PDP修正馍型的结论与匹配比较法的结果吻合。本实验条件下,偏好测验是“纯净”的．但无意识影响参与了再认测验。（2）PDP修正模型关于R＞R。的理论结果得到了目标字与非目标字两种条件下的实验的证实。另外．关于无意识影响遵循的规律与指导语无关的理论推测也得到了证实。（3）再认与偏好测验出现了功能分离。PDP修正模型可以解释其本质。（4）750ms呈现刺激时,反应倾向的规津是：外显过程比内隐过程严格;两过程均不受注意程度的作用而发生波动。     

A new procedure for detection of crossing DIF

The purpose of this paper is to present a hypothesis testing and estimation procedure, Crossing SIBTEST, for detecting crossing DIF. Crossing DIF exists when the difference in the probabilities of a correct answer for the two examinee groups changes signs as ability level is varied. In item response theory terms, crossing DIF is indicated by two crossing item characteristic curves. Our new procedure, denoted as Crossing SIBTEST, first estimates the matching subtest score at which crossing occurs using least squares regression analysis. A Crossing SIBTEST statistic then is used to test the hypothesis of crossing DIF. The performance of Crossing SIBTEST is evaluated in this study.This research was partially supported by a grant from the Law School Admission Council and by National Science Foundation Mathematics Grant NSF-DMS-94-04327. The research reported here is collaborative in every respect and the order of authorship is alphabetical. The authors thank Jeff Douglas and Louis Roussos for their useful comments and discussions.     

Punishment of autoshaped key-peck responses of pigeons

The effects of different voltages of response-dependent and response-independent electric shock on the frequency of key-peck responses engendered by an autoshaping procedure were studied. In Experiments I and II, each response produced a brief electric shock, and response frequency generally decreased more with higher-voltage shock. Preshock frequencies of responding were generally recovered across successive sessions of relatively low-voltage shock delivery but not at higher shock voltages. The effects of response-dependent and response-independent shock were compared in Experiment III by using a yoked-control procedure in which each pigeon received each type of shock delivery at different times. Response-dependent shock generally produced greater decreases in response frequency. In the final experiment, one response-independent shock per autoshaping trial was scheduled. The number of autoshaped responses per trial was related to shock voltages. These results suggest that response-dependent and response-independent electric shock effectively decrease frequency of autoshaped responses.     

Choice in the time-left procedure and in concurrent chains with a time-left terminal link.

In two experiments, rats chose between a standard fixed-duration food-associated stimulus and a stimulus whose duration was the time remaining to reinforcement in an elapsing comparison interval. In Experiment 1, 4 rats responded in a time-left procedure wherein a single initial-link variable-interval schedule set up two potential terminal links simultaneously. As time elapsed in the initial-link schedule, the choice was between a standard fixed-interval 30-s terminal link and a time-left terminal link whose programmed interval requirement equaled 90 s minus the elapsed time in the initial link. Rats generally responded more on the lever with the shortest programmed terminal-link duration, but the temporal parameters of the procedure were found to vary with response distributions. Contrary to previous reports, therefore, time-left data were well predicted by choice models that make no assumptions about animal timing. In Experiment 2, 8 rats responded on a concurrent-chains schedule with independent variable-interval initial links and a time-left terminal link in one of the choice schedules. On the time-left lever, the programmed terminal-link delay equaled 90 s minus the elapsed time in the time-left initial link. On the standard lever, terminal-link responses were reinforced according to a variable-interval schedule whose average value varied over four conditions. Relative time-left initial-link responses increased in the elapsing time-left initial-link schedule as the time-left terminal link became shorter relative to the standard terminal link. Scalar expectancy theory failed to predict the resultant data, but a modified version of the delay-reduction model made good predictions. An analysis of the elaboration of scalar expectancy theory for variable delays demonstrated that the model is poorly formulated for arithmetically distributed delays.     

内隐记忆的证明逻辑与加工分离说（PDP）的修正模型

讨论了内隐记忆的证明逻辑和内隐与外显测验中的意识和无意识影响问题。间接证明内隐记忆的逻辑应用在功能分离实验中。它的前提假设是记忆测验都是＂纯净＂的。直接证明逻辑应用在匹配比较实验中。它认为测验中的意识和无意识影响是并存的,Ｊａｃｏｂｙ等人近期提出的加工分离说（ＰＤＰ）在匹配比较法的基础上,将测验中的意识和无意识影响进行了分离,并借用经典测验理论的公式计算这两种影响。作者认为,按照概率论关于两个随机独立事件之和与积的运算法则,必须把包含测验（ｉｎｃｌｕｓｉｏｎｔｅｓｔ）的公式修正为Ｉｎｃｌｕｓｉｏｎ＝Ｒ（１－ａ）＋Ａ（１－Ｒ）。修正过的ＰＤＰ由四个方程组成。它不仅考虑了原ＰＤＰ忽视的外显条件下的无意识缺失（１－ａ）,而且可以更加确切地估计回忆概率（Ｒ）。这在数学理论上已找到了证据。     

错误归因的叠加效应：发生于情感还是语义过程？

错误归因是指将某个效应的来源错认为是其它来源。研究采用修改的、双启动词的情感错误归因程序（AMP）范式,考察了错误归因的叠加效应以及该效应发生于情感还是语义过程。结果表明：(1)经典的AMP范式下,不论是情感启动词还是语义启动词都可以引发错误归因反应。(2)双启动词AMP范式下,先后出现的情感启动词产生了错误归因的叠加效应。（3）双语义启动词AMP范式下,没有发现错误归因的叠加效应。说明双启动词AMP范式下错误归因的叠加效应只发生于情感过程。     

认知资源和信息类型对大学生职业印象形成的影响

采用加工分离程序,探讨了认知资源和信息类型对大学生职业印象形成的影响及其心理加工机制。结果表明：(1)印象形成受到包括认知资源的限制、刻板化信息和个体化信息的典型性等多种因素的影响。刻板化信息间接地对印象形成起作用。个体化信息的作用远大于认知资源。(2)在印象形成过程中,控制性加工和自动化加工是并行的。(3)刻板化信息以内隐的自动化加工为主,个体化信息加工则存在外显与内隐两种方式。     

Varying Problem Effort and Choice: Using the Interspersal Technique to Influence Choice Towards More Effortful Assignments

College students were exposed to two pairs of mathematics assignments. Assignment Pair A included a high-effort assignment containing 18 long three-digit × two-digit (3×2) multiplication problems with all numerals in each problem being equal to or greater than four and a moderate-effort assignment that contained nine long problems and nine interspersed moderate 3×2 problems with numerals less than four. Assignment Pair B contained similar assignment sheets, the exception being that the high-effort assignment contained six additional one-digit × one-digit (1×1) problems interspersed following every third 3×2 problem. After working on each assignment pair, students ranked assignments and chose a new assignment for homework. Analysis of Assignment Pair A revealed that students overwhelmingly preferred the moderate-effort assignment. Analysis of interaction effects showed that when additional brief problems were added to the high-effort assignments, the proportion of students who chose the high-effort assignment for homework and ranked it as being less difficult, time consuming, and effortful increased significantly. Results support previous research on effort and choice and the hypothesis that a completed discrete problem may serve a reinforcing stimulus.     

语篇主题表征在大脑两半球的存贮

使用半视野速示技术和启动—再认探测方法,采用包含两个句子的短语篇作为前行信息、通过主题启动、歧义词启动探测语段阅读时主题表征在大脑两半球的存贮情况,结果发现,无论是主题启动还是歧义词启动,左视野／右半脑和右视野／左半脑对语境相关的目标词反应时间都比不一致目标词更长,说明语段阅读后两半脑对主题表征都有存贮。