Predictors of needle-sharing behavior among IDUs entering treatment

Abstract

Public funded treatment intake data from 3905 injection drug users were analyzed to identify correlates of reported needle sharing. Respondents included all first admissions to treatment from July 1, 1988 to June 30, 1989 in the city and county of San Francisco. More previous experience in drug treatment predicted lower rates of needle sharing (OR = 0.85, 95% C.I.= 0.79 - 0.92). Young age, cocaine use and white or Hispanic ethnicity predicted higher rates of needle sharing. The finding that drug treatment reduces the frequency of needle sharing in this population has important policy implications; these data support the role of treatment availability in reducing the spread of HIV among injection drug users.     

Choice behavior in a discrete-trial concurrent VI-VR: A test of maximizing theories of matching

Rats were trained on a discrete-trial procedure in which one alternative (VR) was correlated with a constant probability of reinforcement while the other was correlated with a VI schedule which ran during the intertrial intervals and held the scheduled reinforcer until they were obtained by the next VI response. Relative reinforcement rate was varied in series of conditions in which the VR schedule was varied and in series in which the VI was varied. Choice behavior was described well by the generalized matching law, although moderate undermatching occurred for all subjects. Contrary to the predictions of molar maximizing (optimality) theories, there was no consistent bias in favor of the ratio alternative, and the sensitivity to reinforcement allocation was not systematically affected by whether the ratio or interval schedule was varied. The results were also contrary to momentary maximizing accounts, as there was no correspondence between the probability of a changeover to the VI behavior and the time since the last response to the VI alternative. Neither variety of maximizing theory appears to provide a general explanation of matching in concurrent schedules.     

The development of spatial and class relations in four young children with right-cerebral-hemisphere damage: Evidence for an early spatial constructive deficit

This study followed the development of four children with right-hemisphere injury on a series of manipulative classification tasks to determine whether and how early brain injury affects the development of spatial and class relations. The children were first tested at about 2 years of age. Their data were compared with previously collected data from 18- to 42-month-old normal children, and with data from four young children with left-hemisphere injury. The results showed the children with right-hemisphere injury do not generate a particular spatial relation (next to) in their spatial groupings with the same frequency as normal or left-hemisphere damaged children, although they do generate in and on relations with normal frequency. An apparent deficit in the development of class relations is shown to be secondary to the spatial deficit, in that it is evident only in tasks that require spatial grouping.     

An alternative scaling method for priorities in hierarchical structures

The early contributions of Saaty have spawned a multitude of applications of principal right (PR) eigenvector “scaling” of a dominance matrix [R]. Prior to Saaty's work (1977–1984) scaling of dominance matrices received little attention in multidimensional scaling, e.g., see Shepard (1972, pp. 26–27). This eigenvector method (EM) of scaling [R] yields u_i scores (weights) popularly used at each branching of the Analytic Hierarchy Process (AHP) technique that has been increasingly applied in multiple criterion analysis of utility, preference, probability, and performance. In this paper, it is proposed that an alternate least squares method (LSM) scaling technique yielding least squares optimal scores (weights) provides $\text{w}{}_{\mathrm{i}}{}^1$ values having a number of important advantages over u_i scores popularly utilized to date.     

On data-limited and resource-limited processes

This paper analyzes the effect on performance when several active processes compete for limited processing resources. The principles discussed show that conclusions about the interactions among psychological processes must be made with caution, and some existing assumptions may be unwarranted. When two (or more) processes use the same resources at the same time, they may both interfere with one another, neither may interfere with the other, or one may interfere with a second without any interference from the second process to the first. The important principles are that a process can be limited in its performance either by limits in the amount of available processing resources (such as memory or processing effort) or by limits in the quality of the data available to it. Competition among processes can affect a resource-limited process, but not a data-limited one. If a process continually makes preliminary results available even before it has completed all its operations, then it is possible to compute performance-resource operating characteristics that show how processes interact. A number of experiments from the psychological literature are examined according to these processing principles, resulting in some new interpretations of interactions among competing psychological processes.     

Expressed vs inventoried interests as predictors of paramedical effectiveness

Two interest measures, a composite of six items which provide a direct assessment of an individual's preferences for Navy health care work and a Navy Vocational Interest Inventory (NVII) scale which assessed the degree of similarity between an individual's activity preferences and those of hospital corpsmen (HMs), were considered along with aptitude test scores as potential predictors of effectiveness among 2429 Navy enlisted personnel assigned to training for HM jobs. Effectiveness was defined as completion of HM training and remaining on the job for at least 2 years. The six-item composite and NVII HM scale scores were correlated .51 with each other and were correlated .27 and .28, respectively, with the effectiveness criterion. When these measures were added to the aptitude measure by using multiple regression procedures, the validity for predicting effectiveness was increased significantly from .36 to .42 with a cross-validity of .42 for the three-variable equation. These findings provide support for the contention that interest measures can be useful predictors of occupational success as well as occupational entry. Furthermore, since most of the interest-related attrition that was found in this study occurred during HM training, these findings suggest that job withdrawal attributable to mismatches in vocational interests may tend to occur very soon after the individual enters the occupational field.     

Correlates of career progression among Mexican-American college graduates

Individual and structural correlates of career progression were studied among 111 Mexican-American college graduates. Results of the study were that career progression was correlated to (1) high school grades, (2) tolerance for ambiguity, (3) work ethic, (4) psychological success, and (5) need for achievement. Career progression was related to both the extent of career development programs available and the industry in which the employing organization was located.     

The precision fluency shaping program: Replication and evaluation

The purpose of this article is to present the results of a two-year project to evaluate the Precision Fluency Shaping Program (Webster, 1980) in a community speech and hearing center. Fifty stutterers participated in therapy. Results indicated that Precision Fluency Shaping was an effective therapy for the treatment of stuttering. In addition, stutterer's perception of their speech changed from pre to post therapy. Follow-up data are presented on 28 clients. Advantages of conducting Precision Fluency Shaping, meeting accountability standards, and procedures for collecting follow-up data are discussed.     

Self-punitive behavior in humans: Effects of a self-fulfilling prophecy

Human subjects were exposed to contingencies which programmed aversive tones (100 db). Two types of contingencies were employed: self-confirming (i.e., self-fulfilling prophecies), in which the aversive tone was occasioned by the prediction it was about to occur; and self-disconfirming, in which the tone was probable when subjects predicted it would not occur. Experiments 1 and 2 used a modified classical conditioning paradigm, and demonstrated that a self-confirming contingency maintained reliable self-punitive responding, i.e., subjects consistently predicted and therefore obtained tones on every trial. Subjects in Experiment 3 were instructed to express predictions continuously throughout four sessions to ensure adequate sampling of the various predictions. Subjects exposed to a self-disconfirming contnngency reliably evidenced awareness of the contingency in effect (judged by answers on a postexperimental questionnaire), whereas subjects exposed to a self-confirming contingency failed to show effective avoidance behavior or contingency awareness. Experiment 4 investigated free-operant self-punitive behavior, utilizing a single prediction response button, which subjects depressed repeatedly. Subjects were exposed to either periodic or aperiodic punishment schedules over as many as four sessions. In general, more persistent self-punitive responding was found in the groups receiving periodic punishment. The results from the four experiments show that self-confirming contingencies can effectively prolong self-punitive responding in human subjects. The findings are consistent with a blocking interpretation of self-punitive behavior, which asserts that when an aversive event is already predicted by stimuli in the situation (including temporal cues), the association between a response and punishment is impaired, and self-punitive responding is likely to be maintained. An integration of human and animal self-punitive research is proposed.