On-line brain stimulation: Measurement of threshold of reinforcement

This program and interface for a small computer (PDP8/e) performs the following operations: generates and delivers constant current stimulation to the brain of an animal, monitors electrical resistance at the stimulating electrode, and calculates the threshold of reinforcement based upon the frequency of characteristic pauses in the animal’s responding.     

The Munroe-Meyer Approach: Continuous Integration of Didactic Instruction,Research, and Clinical Practice

Increased demand for applied behavior analysis (ABA) services has increased the need for additional masters-level practitioners and doctoral-level academicians and clinical directors. Based on these needs, the University of Nebraska Medical Center’s (UNMC) Munroe-Meyer Institute has developed a PhD program. The academic structure at UNMC allowed us to create our PhD program in a relatively quick and efficient manner. Our PhD program has many unique features, including (a) close integration of didactic instruction with clinical and research training provided by leading experts in ABA in which students immediately apply concepts introduced in the classroom during coordinated clinical and research practica; (b) structured grant writing training in which students learn to write and submit an NIH-level grant; (c) financial support in the form of a stipend of $23,400 per year, free health benefits, and a full-tuition waiver for up to 12 credits per semester for UNMC courses (a benefits package worth approximately $50,000 per year for an out-of-state student); and (d) encouragement and financial support to present papers at local, regional, and national behavior analysis conferences.     

The Behavioral Dyscontrol Scale and Functional Status Among Elderly Medical and Surgical Rehabilitation Patients

This research was conducted in a sample of 150 older adults (mean age = 78.0) who were inpatients receiving rehabilitation services for a variety of medical and postsurgical conditions. The purpose of the study was to test the hypothesis that the Behavioral Dyscontrol Scale (BDS), a measure of the ability to use intentions to guide purposeful activity, would be strongly associated with concurrent functional status after controlling for age, sex, education, severity of pain, medical comorbidity, depression (Geriatric Depression Scale), and general mental status (Mini Mental State Exam [MMSE]). Functional status was assessed by rehabilitaion nurses' ratings of patients on 11 individual Activities of Daily Living (ADL) items and the Barthel Index. The hypothesis, tested by means of multiple regression analysis, was supported by the results. The BDS was the independent variable most strongly associated with all 11 ADL items and the Barthel Index. The MMSE contributed significantly to none of the models. Other covariates made minimal contributions to the variance shared with functional ability. Consistent with prior results in other samples, the ability to use intentions to guide purposeful behavior appears to be an important contributor to everyday functioning among older adults.     

The influence of musical distraction of varying complexity on the cognitive performance of extroverts and introverts

This study examined the effects of complexity in background music on the performance of four cognitive tasks by extroverts and introverts. In the presence of either ‘complex’ or ‘simple’ musical distraction or in silence, 24 introverts and 24 extroverts carried out a reading comprehension test, an observation test, and a memory test (in which recall was measured both immediately and after a six‐minute delay). An interaction was predicted such that increasing‐complexity musical distraction would result in the increase of extroverts', and the decrease of introverts', cognitive‐task performance. A significant interaction was obtained for three of the four tests: the observation test and both memory tests. These findings are discussed with regard to Eysenck's theory of personality. Copyright © 1999 John Wiley & Sons, Ltd.     

Effects of peripheral immune activation on social behavior and adrenocortical activity in aggressive mice: Genotype-environment interactions

To explore genetic-developmental differences in the biobehavioral effects of induced illness, males from two lines of mice selectively bred for high or low levels of aggressive behavior were injected with endotoxin (Escherichia coli, LPS: 0.25 mg/kg, 1.25 mg/kg, or 2.5 mg, i.p.) or saline. Body temperature, weight, and locomotor activity were monitored immediately before and 8 and 24 hr after injection. Twenty-four hours after injection, social behaviors were assessed in a 10-min dyadic test, and hypothalamus, spleen, and serum were collected. In both lines, endotoxin treatment increased behavioral immobility ("freezing") and decreased social exploration. Other effects showed line differences: Males from the high-aggressive line had a lower threshold to endotoxin-induced effects on body temperature, weight loss, spleen weight, and corticosterone. Social reactivity (startle response to mild social investigation) increased in the high-aggressive line and decreased in the low-aggressive line after treatment. In the high-aggressive line only, endotoxin decreased attack frequency and increased latency to attack. The interactions between selected line (genotype) and endotoxin treatment (environment) demonstrate that genetic-developmental differences in social and aggressive behavior may indicate the extent to which immune stimuli (e.g., bacteria, viruses, cytokines) function as "biobehavioral stressors." Aggr. Behav. 23:93–105, 1997.© 1997 Wiley-Liss, Inc.     

Custody evaluations: a survey of mental health professionals

Mental health professionals who conduct custody evaluations (N=165, 61% return rate) were surveyed about their practices and attitudes. These experts were primarily licensed psychologists, most with degrees in clinical and counseling. Few had specific training in child custody or forensic evaluation, and although they averaged 8·1 evaluations over the last year, most devoted a modest portion of their practice to custody work. They generally regarded custody evaluations as valuable to the courts, but were critical of the adversarial approach to determining custody. Procedures and priorities have changed little over the past decade, with most experts relying heavily on interviews and observation. Cautions are given regarding overstepping ethical guidelines and using procedures that presently lack established validity. © 1998 John Wiley & Sons, Ltd.     

Fostering Diversity in the Creative Arts by Addressing Students' Capacity to Aspire

Research on young people's aspirations and their capacity to aspire to higher education has proliferated in recent decades, however, very little attention has been paid to the creative arts. Diversity in the arts remains a persistent issue in many nations, and repeated attempts to promote diversity in the Australian arts community have had limited impact, suggesting the need for new approaches. Drawing on data from a 4‐year longitudinal study of students from ages 8 to 18 (n = 6,492) in government schools, we examine school students' aspirations for careers in the arts. Arts‐related careers were popular among students, yet we found a distinct lack of diversity among those aspiring to such careers. Using logistic regression analysis we found that being female, high achieving, from an English‐speaking background, possessing high cultural capital, and attending advantaged schools were significant predictors of interest in the arts, suggesting the likely reproduction of existing patterns of participation. We argue that initiatives within schools are essential to disrupting these patterns and building the capacity of a more diverse range of students to aspire to careers in the arts.     

The Impact of Item Misspecification and Dichotomization on Class and Parameter Recovery in LCA of Count Data

Mixture analysis of count data has become increasingly popular among researchers of substance use, behavioral analysis, and program evaluation. However, this increase in popularity seems to have occurred along with adoption of some conventions in model specification based on arbitrary heuristics that may impact the validity of results. Findings from a systematic review of recent drug and alcohol publications suggested count variables are often dichotomized or misspecified as continuous normal indicators in mixture analysis. Prior research suggests that misspecifying skewed distributions of continuous indicators in mixture analysis introduces bias, though the consequences of this practice when applied to count indicators has not been studied. The present work describes results from a simulation study examining bias in mixture recovery when count indicators are dichotomized (median split; presence vs. absence), ordinalized, or the distribution is misspecified (continuous normal; incorrect count distribution). All distributional misspecifications and methods of categorizing resulted in greater bias in parameter estimates and recovery of class membership relative to specifying the true distribution, though dichotomization appeared to improve class enumeration accuracy relative to all other specifications. Overall, results demonstrate the importance of accurately modeling count indicators in mixture analysis, as misspecification and categorizing data can distort study outcomes.