语义联系类型和强度对预期推理生成的制约作用

首先采用开放式问卷实验方法,由被试生成日常生活中的事件以及组成这些事件的各种活动和活动的参加者。然后,对这些事件熟悉性、对活动的典型性和可区分性三个维度进行主观评价,形成事件以及每个事件活动序列,并据此编制实验材料。实验主要考察活动的典型性和可区分性对于熟悉性高的事件的预期推理的影响,以及不同工作记忆能力的被试进行事件预期推理时的加工模式。实验结果表明：（１）高工艺记忆能力的被试对事件的预期量小于     

The psychologist's role in assessing and facilitating patients' knowledge of advance directives in medical settings: A preliminary investigation

In a time of budgetary shortfalls in the medical industry, an aging population, and an increased emphasis on health care choices, psychologists are being called upon to administer advance medical directive programs to patients. This study reports preliminary findings from a program to assess and facilitate patients' knowledge of advance directives (ADs) by the Psychology Service at the Ann Arbor VA Medical Center. The participant pool included 243 male veteran patients admitted to medical and surgical wards at the hospital. The intervention included the use of a computer-generated prompt for consultation, which was sent to the psychology staff in response to a patient inquiry regarding ADs. It also involved an increased emphasis on the delivery of written material on ADs by the admissions clerks. The intervention appeared to result in a modest increase in patients' knowledge of advance directives. Suggestions are offered for areas that should be emphasized in future attempts to increase patients' knowledge and utilization of advance directives.     

Effects of component length and of the transitions among components in multiple schedules

Pigeons received equal variable-interval reinforcement during presentations of two line-orientation stimuli while five other orientations appeared in extinction. Component duration was 30 seconds for all orientations and the sequence was arranged so that each orientation preceded itself and each other orientation equally often. The duration of one component (0°) was shortened to 10 seconds and the other (90°) was lengthened to 50 seconds. All animals showed large increases in response rate in the shortened component and this increase was recoverable after an interpolated condition in which all components were again 30 seconds in duration. This effect was replicated in a second experiment in which component duration was changed from 150 seconds to 50 seconds and 250 seconds. An examination of local contrast effects during the first experiment showed that the shortened component produced local contrast during subsequent presentations of the lengthened component, just as would a component associated with more frequent reinforcement. When the presentation sequence was changed so that the lengthened component was always followed by the shortened component, response rates generally increased during the lengthened component. When the sequence was arranged so that the shortened component always preceded the longer component, response rate decreased in the former. These effects, as well as the increases in response rate following change in component length, seem not to be the product of local contrast effects among components.     

Local contrast and maintained generalization.

Pigeons received variable-interval reinforcement for key pecking during presentations of horizontal and vertical line-orientation stimuli, while pecks during five intermediate orientations were extinguished. Lowest peck rates were observed during presentations of negative stimuli adjacent to the positive orientations while peck rate during 45 degrees (the intermediate negative orientation) was relatively high, i.e., there were negative contrast shoulders. When peck rates were manipulated in the positive orientations, peck rate in neithboring orientations changed in the opposite direction. Contrast shoulders faded after prolonged training. A second type of contrast, local contrast, was correlated with similarity of preceding stimulus and different average peck rates during different stages of the discrimination process. The data suggest that sequential local contrast accompanying the formation of a discrimination contributes to the form of generalization gradients. Blough's model of stimulus control predicts the changes in gradient form described here, but may not accurately depict the underlying process responsible for gradient form.     

Choice as a function of local versus molar reinforcement contingencies.

Rats were trained on a discrete-trial probability learning task. In Experiment 1, the molar reinforcement probabilities for the two response alternatives were equal, and the local contingencies of reinforcement differentially reinforced a win-stay, lose-shift response pattern. The win-stay portion was learned substantially more easily and appeared from the outset of training, suggesting that its occurrence did not depend upon discrimination of the local contingencies but rather only upon simple strengthening effects of individual reinforcements. Control by both types of local contingencies decreased with increases in the intertrial interval, although some control remained with intertrial intervals as long as 30 s. In Experiment 2, the local contingencies always favored win-shift and lose-shift response patterns but were asymmetrical for the two responses, causing the molar reinforcement rates for the two responses to differ. Some learning of the alternation pattern occurred with short intertrial intervals, although win-stay behavior occurred for some subjects. The local reinforcement contingencies were discriminated poorly with longer intertrial intervals. In the absence of control by the local contingencies, choice proportion was determined by the molar contingencies, as indicated by high exponent values for the generalized matching law with long intertrial intervals, and lower values with short intertrial intervals. The results show that when molar contingencies of reinforcement and local contingencies are in opposition, both may have independent roles. Control by molar contingencies cannot generally be explained by local contingencies.     

Essential independence and likelihood-based ability estimation for polytomous items

A definition ofessential independence is proposed for sequences of polytomous items. For items satisfying the reasonable assumption that the expected amount of credit awarded increases with examinee ability, we develop a theory ofessential unidimensionality which closely parallels that of Stout. Essentially unidimensional item sequences can be shown to have a unique (up to change-of-scale) dominant underlying trait, which can be consistently estimated by a monotone transformation of the sum of the item scores. In more general polytomous-response latent trait models (with or without ordered responses), anM-estimator based upon maximum likelihood may be shown to be consistent for under essentially unidimensional violations of local independence and a variety of monotonicity/identifiability conditions. A rigorous proof of this fact is given, and the standard error of the estimator is explored. These results suggest that ability estimation methods that rely on the summation form of the log likelihood under local independence should generally be robust under essential independence, but standard errors may vary greatly from what is usually expected, depending on the degree of departure from local independence. An index of departure from local independence is also proposed.This work was supported in part by Office of Naval Research Grant N00014-87-K-0277 and National Science Foundation Grant NSF-DMS-88-02556. The author is grateful to William F. Stout for many helpful comments, and to an anonymous reviewer for raising the questions addressed in section 2. A preliminary version of section 6 appeared in the author's Ph.D. thesis.     

Mood and realism of confidence judgements of one''s own answers to general knowledge questions

This study examines the effect of a depressed mood on the realism of subjects' confidence judgements of the correctness of answers to general knowledge questions. Research conducted on how mood influences cognitive processes gives reason to expect that a depressed mood might increase the realism of individuals' confidence ratings. Sixty subjects were divided into three conditions, two of which were given mood induction, one condition into an elated-happy mood and one condition into a depressed-sad mood. As evidenced by subjects' responses to mood scales only the depressed condition was affected by the mood induction. All subjects answered 93 general knowledge questions and rated their confidence in the correctness of the answer given. Subjects were instructed to think aloud when answering the last 31 questions. The conditions did not differ with respect to the proportion of questions answered correctly, mean level of confidence, nor with respect to three measures of the realism in subjects' confidence ratings (calibration, over/underconfidence and resolution). The results were the same when questions answered with and without think aloud instructions were analysed separately.     

A note on the investigation of local and global identifiability

In general, nonlinear models such as those commonly employed for the analysis of covariance structures, are not globally identifiable. Any investigation of local identifiability must either yield a mapping of identifiability onto the entire parameter space, which will rarely be feasible in any applications of interest, or confine itself to the neighbourhood of such points of special interest as the maximum likelihood point.The author would like to thank J. Jack McArdle and Colin Fraser for their comments on this paper.     

Eye tracking provides no evidence that young infants understand path obstruction

In two experiments with 47 4-month-olds, we investigated attention to key aspects of events in which an object moved along a partly occluded path that contained an obstruction. Infants were familiarized with a ball rolling behind an occluder to be revealed resting on an end wall, and on test trials an obstruction wall was placed in the ball's path. In Experiment 1, we did not find longer looking when the object appeared in an impossible location beyond the obstruction, and infants did not selectively fixate the object in this location. In Experiment 2, after rolling one or two balls, we measured infants' fixations of a two-object outcome with one ball in a novel but possible resting position and the other in a familiar but impossible location beyond the obstruction. Infants looked longer at the ball in the possible but novel location, likely reflecting a looking preference for location novelty. Thus we obtained no evidence that infants reasoned about obstruction and identified a violation on that basis.