Parallel distributed processing and neuropsychology: A neural network model of Wisconsin card sorting and verbal fluency

Neural networks can be used as a tool in the explanation of neuropsychological data. Using the Hebbian Learning Rule and other such principles as competition and modifiable interlevel feedback, researchers have successfully modeled a widely used neuropsychological test, the Wisconsin Card Sorting Test. One of these models is reviewed here and extended to a qualitative analysis of how verbal fluency might be modeled, which demonstrates the importance of accounting for the attentional components of both tests. Difficulties remain in programming sequential cognitive processes within a parallel distributed processing (PDP) framework and integrating exceedingly complex neuropsychological tests such as Proverbs. PDP neural network methodology offers neuropsychologists co-validation procedures within narrowly defined areas of reliability and validity.     

Parent-tutoring procedures: Experimental analysis and validation of generalization in oral reading across passages,settings, and time

A study that involved parents as reading tutors was carried out at home during the summer with four elementary children, three with learning disabilities. One purpose was to determine the effects of tutoring in the basal reader on reading rates at home. Another purpose was to determine potential generalization effects as a result of parent tutoring on different academic tasks at home and, later at school, on different and similar tasks. A combination multiple-baseline and reversal design tested for replication and generalization effects. Increases in correct rates were noted for the targeted variables across conditions. The results indicated that parents tutoring with school basal texts during the summer produced marked increases in reading rates that generalized at home to different academic tasks and at school to different and similar tasks. This suggests that parents, when using specific tutoring procedures, can increase their children's academic skills.     

Case vignette: premature surrender

Three commentaries are offered on the following case: George, age 57, is a previously healthy man who recently underwent surgery for removal of a low-grade malignant thymoma. At the time of admission to the hospital, George stressed to the staff that he had long ago signed a "living will," which he renewed immediately after he learned of his cancer diagnosis. At the time of surgery, the tumor was found to extend into his mediastinum; although it was removable, this required revision of part of the sternum and grafting of the vessels feeding the heart chambers. Because of the resultant tissue damage and neuronal hyperactivity, George experienced postoperative episodes of cardiac arrhythmia and bronchospasm. Unanimous medical opinion was that this situation was a temporary problem that would resolve itself as the tissues healed. Until that time, however, it will be difficult to wean him from ventilatory support. When his stay in the intensive care unit became prolonged, George and his family began to insist that his status be changed to "do not resuscitate" and reminded the staff about his longstanding living will. All of this is happening despite the fact that the patient and family seemingly comprehend that although the short-term interventions are invasive, there is a high probability of a successful outcome. George's cancer prognosis is excellent, and, although he may well have an episode of life-threatening arrhythmia, he is likely to respond to resuscitation interventions. Once the immediate postoperative period is over, his potential for a long and productive life with full capacities is excellent. Consider the following questions: (a) Should George's expressed wishes be respected, or should the staff take additional steps to help him survive the postoperative period, even if that means violating his stated wishes? and (b) What steps might the staff follow in sorting through this problem?     

Why the Principle of the Identity of Indiscernibles is not contingently true either

Faced with strong arguments to the effect that Leibniz'sPrinciple of the Identity of Indiscernibles (PII) is not a necessary truth, many supporters of the Principle have staged a strategic retreat to the claim that it is contingently true in this, the actual, world. The purpose of this paper is to examine the status of the various forms of PII in both classical and quantum physics, and it is concluded that this latter view is at best doubtful, at worst, simply wrong.I would like to thank Michael Redhead and an anonymous referee for several useful suggestions and criticisms relating to the earlier version of this paper. I must also acknowledge the support given by the Centre of Logic, Epistemology and History of Science of the University of Campinas and the Brazilian National Council for Scientific and Technological Development in the later stages of the preparation of this work.     

Mental health expert witnesses: Of science and crystal balls

This article reviews the history of and basis for mental health testimony. It surveys the roles of such experts in the legal system and the concomitant problems with current approaches. Finally, it suggests specific reforms that may improve the use of mental health experts in legal proceedings.     

Automated data collection using bar code

Using bar code technology to automate data collection provides a rapid and reliable alternative to paper-and-pencil tracking or keyboard entry into pocket or laptop computer. An array of bar code symbols is printed on a data menu, with a unique symbol corresponding to each possible observation. Bar code symbols are scanned using hand-held readers, which record the event, log the observation time, and store data for transfer to a personal computer. Advantages of the bar code monitoring system include: (1) ease of use by staff with minimal technical training, (2) reduced data entry errors and increased entry speed, (3) reliable portable operation, and (4) low-cost hardware. While the bar code system described here is used for behavioral monitoring in a residential treatment setting for the developmentally disabled, with minimal modification this system can be adapted for use in a wide variety of research and clinical applications.     

Conversational skills for autistic adolescents: An autistic peer as prompter

In this study, an autistic youth served as peer prompter for three other autistic adolescents. The peer prompter encouraged the other boys to talk about sports, a topic frequently discussed by typical teenagers. A multiple-baseline design across participants was used to assess the effectiveness of the peer-prompting procedure. During baseline, the youth rarely talked about sports, although all three had previously completed a sports-appreciation class and had displayed large pre-to-post gains on a paper-and-pencil test. During intervention, when a peer prompted sports discussions, all three youth engaged in much more sports-related conversation. Generalization measures indicated that: (1) the youth engaged in sports discussions in groups, as well as in the dyads that characterized the training situation; (2) they talked about sports in a setting other than the training setting; (3) they discussed sports with their peers when an unfamiliar teacher was present; and (4) they continued to discuss sports when training tapes and behavioral contracts between the teacher and the peer prompter were withdrawn. Previously, it has been common to use nonhandicapped or less-handicapped peers as tutors; this study demonstrates that an autistic youth may also effectively serve as a prompter who assists his schoolmates in acquiring conversational skills that contribute to their normalization.