Immediate and long-term retention of basic-level categories in 24-month-olds

This study assessed the effect of presenting single versus multiple exemplars of basic-level categories on 24-month-olds' long-term memory for categorical information. Sixty-four infants were tested in a paired-comparison recognition memory paradigm immediately and one week after familiarization with basic-level categories. Infants were randomly assigned to one of two familiarization conditions and one of two test conditions. In one familiarization condition (Varied Exemplar), they briefly viewed four different exemplars of each of 16 basic-level categories. In the other familiarization condition (Single Exemplar), they viewed only one instance of each category on four different trials. Test trials consisted of either an exemplar seen during familiarization (Familiar-Exemplar Test) or novel intracategory exemplar (Unfamiliar-Exemplar Test) paired with a stimulus from a novel category. Both immediately following familiarization and one week later, infants looked longer at test stimuli from the novel category irrespective of familiarization or test condition.     

Electrode placement,EMG feedback,and relaxation for tension headaches

Fifteen tension headache subjects were allocated to one of three groups: direct EMG feedback (from a site corresponding to the source of pain), indirect EMG feedback (from a site not corresponding to the source of the pain) and relaxation instructions. There were two base-line, six treatment and one post-treatment sessions. No significant differences were found between base-line and post-treatment EMG levels, for any of the groups; however, some significant reductions in levels were obtained within sessions. EMG levels recorded during headache attacks did not differ significantly from levels recorded during base-line. Frequency and intensity of headaches were significantly reduced, particularly in the relaxation group. At follow-up this improvement was maintained for subjects with forehead pain, but differences between the groups had disappeared.     

On knowing how well one is remembering: The persistence of strategy use during transfer

A potential cause for children's failure to transfer learning strategies was explored in the present study. A self-monitoring process was suggested to be essential for evaluating one's own level of performance and the effectiveness of various mnemonic strategies. Matched on free recall scores in this study's first sort-and-recall phase, first, third, and fifth graders (ages 7, 9, and 11 years, respectively) were assigned to one of three treatment groups or a control group. During Phase II, the treatment groups received instruction in sorting pictures according to semantic similarities in preparation for future recall. In addition, Groups 3 and 4 later received feedback indicating their Phase II improvement in performance. A cause-and-effect relationship between strategy use and enhanced recall was further suggested to Group 4. Among third graders, only those provided with feedback and strategy instruction continued to rely upon the input organization strategy when faced with transfer tasks in Phase III. Both enhanced recall and improved sorting styles were observed for these subjects in Phase III. Some first graders also showed improved sorting styles and improved recall following feedback, while fifth graders showed enhanced recall even without experimenter-provided feedback. Subject's responses to a metamemory interview provided additional support for the hypothesis that the self-monitoring of memory performance is more likely to be part of fifth graders' (than first graders') memory abilities.     

Stimulus control of delayed matching in pigeons: Directed forgetting

Pigeons were trained in delayed matching-to-sample with two postsample stimuli. A postsample R-cue signaled that a matching choice phase would follow. A postsample F-cue signaled that a matching choice phase would not follow. Previous research found reduced matching accuracy on F-cued probe trials when comparison stimuli were presented in the choice phase. The present four experiments systematically varied the events following an F-cue to determine the conditions under which the F-cue reduces delayed-matching accuracy. When F-cues and R-cues controlled different behavior, matching on probe trials was poor. When both cues controlled the same behavior, matching on probe trials was good. This result is best explained by the theory that comparison stimuli retrieve the sample representation, but only in the behavioral context established by the R-cue. The present research supports the view that response-produced stimuli serve a contextual role in animal short-term memory.     

The interaction between stimulus and reinforcer control on remembering.

In a symbolic matching-to-sample task, 6 pigeons obtained food by pecking a red side key when the brighter of two white lights had been presented on the center key and by pecking a green side key when the dimmer of two white lights had been presented on the center key. Across Part 1 and Parts 6 to 10, the delay between sample-stimulus presentation and the availability of the choice keys was varied between 0 s and 25 s. Across Parts 1 to 5, the delay between the emission of a correct choice and the delivery of a reinforcer was varied between 0 s and 30 s. Although increasing both types of delay decreased stimulus discriminability, lengthening the stimulus-choice delay produced a greater decrement in choice accuracy than did lengthening the choice-reinforcer delay. Additionally, the relative reinforcer rate for correct choice was varied across both types of delay. The sensitivity of behavior to the distribution of reinforcers decreased as discriminability decreased under both procedures. These data are consistent with the view, based on the generalized matching law, that sample stimuli and reinforcers interact in their control over remembering.     

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.     

Decomposing the encoding of action events: A dual conception

Two experiments are reported in which we tested the hypothesis that encoding of verbal features of subject-performed tasks or SPTs (e.g., bounce the ball, lift the spoon) is attention-demanding and effortful, whereas physical features of this memory task (e.g., color, weight) are acquired with little effort, and without deliberate encoding strategies. In Experiment 1, subjects were asked to perform a series of SPTs and were examined on recall of verbal instructions and colors of objects involved under conditions of focused or divided attention. In Experiment 2, performance of a series of SPTs was followed by recall of verbal instructions and recall of weights of objects involved. Results of both experiments indicated that recall of the verbal task component was negatively affected by requirements of dual-task performance, whereas recall of both physical task features was equally good in both encoding conditions. The obtained pattern of outcome is interpreted as supportive of the dual conception hypothesis of the nature of the encoding of action events.     

The life and times of PSI

This paper describes the essential features of the personalized system of instruction (PSI). Results from outcome research examining the effectiveness of PSI-based courses relative to traditional methods provide unequivocal support for the superiority of PSI. Parametric studies, or component analyses, show that the mastery requirement, immediate performance feedback, and review units are the key features underlying high quality student performances in PSI courses. The use of student proctors as peer-tutors, optional lectures, and selfpacing do not, in and of themselves, appear to be vital to student success in PSI courses. Despite its superiority, PSI has not supplanted traditional methods as the dominant pedagogical system in higher education. Difficulties inherent in overcoming the inertia of the lecture within our established instructional system, the implications of PSI for that system, and the Zeitgeist that permeates educational reform are the major obstacles to widespread adoption of PSI.     

The cognitive interview: Its origins,empirical support,evaluation and practical implications

This paper provides a background to current research on the cognitive interview (CI), which is a set of cognitive retrieval techniques designed to facilitate memory search (for example, via reinstatement of contextual cues). One of the principal aims of this research is to identify and develop techniques which police investigators can themselves use. A series of studies were conducted at the University of California, Los Angeles, using police officers as interviewers and students, non-students and children as witnesses to realistic crimes. In all studies the CI elicited significantly more correct information with no apparent increase in errors or confabulations. The CI has been tested in a field study involving police officers in Florida. This paper will critically review this research, as well as more recent unpublished work including CI studies conducted in Germany and the UK. Some important modifications of the original CI procedure are described, and there is a theoretical discussion and explanation of the various components of the CI procedure. Finally, we will consider applications of the CI in clinical and organizational settings.