Rule abstraction, item memory, and chunking in rat serial-pattern tracking

Two studies used a stimulus tracking paradigm to test whether rats are sensitive to the rule-based formal properties of structured serial patterns. Hooded rats tracked 16-element patterns of flashing lights by pressing levers under an array of 6 indicator lights. In Experiment 1, rats tracked a pattern similar to one previously used with human subjects and yielded remarkably similar results. More errors and response omissions occurred at boundaries of structural "chunks" than within chunks, and errors often reflected anticipation of the next chunk or extrapolation of the preceding chunk. In Experiment 2, temporal "phrasing" cues encouraged different groups to encode a pattern as a series of either "runs" or "trills." Differential placement of pauses induced rats to encode different rule-based representations of the pattern. Results indicate that under appropriate conditions rats may encode a representation of formal structure when they learn organized response patterns.     

Sex-role stereotyping in school superintendents' personnel decisions

In this study, school district superintendents were asked to make personnel decisions that involved potential domestic conflicts. Sex-role stereotypes or sex bias were reflected in the respondents' choices in the following situations: (1) A male was more likely than a female to be selected for a job requiring travel; (2) when an employee's spouse's job required a move, the superintendents were less likely to attempt to influence a female employee to remain and more likely to try to find a female spouse a local job; (3) a female who expressed family priorities over job responsibilities was less likely to be promoted than a male who expressed an identical commitment; (4) a male's request for a leave of absence for child care was considered more appropriate and was more likely to be approved with pay than a female's identical request. Lack of sex-role stereotyping was evidenced by the responses to a case involving the social support of an administrator's spouse and in the tendency to base an administrator's promotion on past performance.     

What is learned in sequential learning? An associative model of reward magnitude serial-pattern learning

A computational model of sequence learning is described that is based on pairwise associations and generalization. Simulations by the model predicted that rats should learn a long monotonic pattern of food quantities better than a nonmonotonic pattern, as predicted by rule-learning theory, and that they should learn a short nonmonotonic pattern with highly discriminable elements better than 1 with less discriminable elements, as predicted by interitem association theory. In 2 other studies, the model also simulated behavioral "rule generalization," "extrapolation," and associative transfer data motivated by both rule-learning and associative perspectives. Although these simulations do not rule out the possibility that rats can use rule induction to learn serial patterns, they show that a simple associative model can account for the classical behavioral studies implicating rule learning in reward magnitude serial-pattern learning.     

Concurrent Cognitive Processes in Rat Serial Pattern Learning: Item Memory, Serial Position, and Pattern Structure

Three experiments examined the processes mediating rat serial pattern learning for rule-consistent versus rule-violating pattern elements (“violation elements”). In all three experiments, rats were trained to press retractable levers in a circular array in a specific sequence for brain-stimulation reward (BSR). Experiment 1 examined the role of lever location (L) and element serial position (SP) cues in rats’ ability to learn to anticipate a violation element positioned at the end of a 24-element serial pattern. Rats with L cues either alone or in combination with SP cues learned to anticipate the violation element, whereas those with SP cues alone did not. Rats in groups L and L + SP underwent a series of transfers designed to remove various cues that might have controlled their performance on the violation element. Results indicated that intra-chamber lever location cues mediated performance on the violation element whereas performance on rule-consistent elements within pattern chunks was mediated by an internal mnemonic representation that was insensitive to changes in lever location cues. Experiment 2 examined whether rats could learn to use SP cues alone to anticipate a violation element if it was positioned earlier in a serial pattern. Rats learned to anticipate the violation element based on SP cues alone when it was located in SP6 in a 24-element pattern, but not when it was in SP12. Experiment 3 examined whether or not rats spontaneously encode information about chunk length and the serial position of phrasing cues in serial patterns. Rats were trained to a high criterion on the serial pattern used in Experiment 1, then were challenged with three probe patterns that manipulated both chunk length and overall pattern length. Results indicated that rats spontaneously encoded information regarding the serial position of phrasing cues in relation to chunk length. Thus, rats appear to use at least three cognitive processes concurrently in serial pattern learning tasks, namely, item memory involving external discriminative cues, counting- or timing-like processes for encoding serial position, and rule abstraction for encoding an internal representation of pattern structure.     

Influence of Time in Treatment and Follow-Up Duration on Methadone Treatment Outcomes

Data for 422 methadone treatment clients in the National Treatment Improvement Evaluation Study (NTIES) were analyzed. Clients maintained continuously in methadone treatment for longer than 12 months and clients who leftbetween 3–12 months were compared with clients treated for less than 3 months. Additionally, clients treated for 3–12 months who had short follow-up periods (6-month average) were compared with 3–12-month clients with long follow-up periods (11-month average). Positive treatment outcomes includinglower drug use, reduced risk of viral infectionand sexually transmitted disease (through needle sharing and multiple sex partners), and less criminality wereassociated with both longer duration treatment and shorter follow-up periods. The findings suggested that continuous methadone treatment of 12 or more months is optimal, whereas stays of less than3 months may be ineffective. Furthermore, stays of 3–12 months are likelyto be beneficial over a relatively short time span, for example 6 months.     

Who uses services for homeless people? An investigation amongst people sleeping rough in London

From a sample of 389 homeless people in London, the characteristics of those who used services for homeless people are presented and the implications for service planning and delivery explored. Staff providing services for this client group need knowledge about drug use and the confidence to work effectively with homeless drug users. Copyright © 2002 John Wiley & Sons, Ltd.     

Exploring self-forgiveness

This article presents the results of a phenomenological study of the experience of self-forgiveness. On the basis of in-depth interviews with seven subjects, self-forgiveness is described not as an achievement but rather as a gift where one moves from estrangement and brokenness to a sense of at-homeness.This article is based in part on a paper presented at the Eighth International Human Science Research Conference at the University of Aarhus, Denmark, in August 1989. The authors thank their colleagues Carolyn Grissom and Jodi Kelly for their helpful suggestions.     

A portable,unobtrusive device for videorecording clinical interactions

Recording and analyzing real-time interactions in clinical settings is important for basic and applied research in psychology and other disciplines. Investigators frequently have used simple audiotaping procedures to record these encounters (e.g., Roter, Geller, Bernhardt, Larson, & Doksum, 1999), but videorecording is increasingly viewed as more reliable and valid, because it captures the full range of complex and interdependent verbal and nonverbal behaviors that occur in an interaction. This article describes a system designed to videotape clinical interactions in a manner that can be moved in and out of different clinical rooms to preserve flexibility in its use. Data are presented to demonstrate that the system is unobtrusive during the interaction, yet fully compatible with institutional review board guidelines to protect human participants’ privacy and freedom to control the recording process.