Combining effect size estimates in meta-analysis with repeated measures and independent-groups designs

When a meta-analysis on results from experimental studies is conducted, differences in the study design must be taken into consideration. A method for combining results across independent-groups and repeated measures designs is described, and the conditions under which such an analysis is appropriate are discussed. Combining results across designs requires that (a) all effect sizes be transformed into a common metric, (b) effect sizes from each design estimate the same treatment effect, and (c) meta-analysis procedures use design-specific estimates of sampling variance to reflect the precision of the effect size estimates.     

Concordance of self- and informant ratings of adults' current and childhood attention-deficit/hyperactivity disorder symptoms

Self-informant rating concordance for attention-deficit/hyperactivity disorder (ADHD) symptoms was assessed in 281 adults at the subscale (Inattention, Hyperactivity-Impulsivity) and individual symptom levels. Potential demographic, diagnostic, and informant identity moderators were also investigated. Concordance levels were similar for current and childhood symptoms. Although moderate positive correlations were found between self- and informant ratings on both subscales, informants endorsed more significant inattentive symptom severity. Kappa coefficients were variable, suggesting low concordance for certain symptoms. Sex and ADHD diagnosis moderated concordance, although effect sizes were small. These results have implications for the use of behavior rating scales in diagnosing ADHD, raise questions about the validity of self- and informant ratings, and support the need to investigate individual-differences variables that may impact concordance.     

Treating Childhood Shyness and Related Behavior: Empirically Evaluated Approaches to Promote Positive Social Interactions

Behavioral and cognitive–behavioral strategies, including exposure, social skills training, and peer-mediated approaches, used to treat childhood shyness and related impairments are described. In addition, relevant outcome studies published within the past 20 years are evaluated, and limitations regarding the generalization, maintenance, and social validity of the reported treatment gains are addressed. Although the interventions reviewed have demonstrated short-term merit in ameliorating social and emotional impairments, such as problematic peer relations and internalizing difficulties, there currently is a lack of evidence to support the social validity and long-term generalization and maintenance of such behavioral gains. Thus, recommendations for future research are made, including the need to (a) assess the social validity of treatment outcomes, (b) utilize important socialization agents (e.g., parents, teachers, peers), and (c) conduct prevention research and longitudinal outcome studies.     

Identity and similarity in repetition blindness: no cross-over interaction

The difficulty in reporting both occurrences of a repeated item is a phenomenon referred to as repetition blindness (RB). RB has been proposed to result from temporal limitations in creating separate episodic tokens for a twice-activated type. Recently, Chialant and Caramazza (Cognition 63 (1997) 79-119) disputed the conventional view that RB for non-identical words (orthographic RB, as in lice and lick) results from the same mechanism as identity RB, and proposed that orthographic RB arises from competition for lexical selection. Supporting evidence was that identical and merely similar words showed different amounts of RB as a function of stimulus onset asynchrony (lag). Four experiments failed to replicate Chialant and Caramazza's finding that identity RB decreases, but orthographic RB increases, as a function of lag. Instead, RB for all stimuli, including homonym pairs, declined monotonically with lag. These results are consistent with a common mechanism underlying RB for identical and orthographically similar words and with prior research suggesting that RB in similar words occurs at a sublexical level.     

Some reflections on 25 years of the association for behavior analysis: Past, present, and future

This paper offers some reflections on the discipline and profession of behavior analysis, as well as on the Association for Behavior Analysis (ABA), on the occasion of the association's 25th anniversary. It is based on a panel session conducted at the 1999 convention that included six past presidents of ABA (Donald M. Baer, Judith E. Favell, Sigrid S. Glenn, Philip N. Hineline, Jack Michael, and Edward K. Morris) and its current Executive Director and Secretary-Treasurer (Maria E. Malott). Among the topics addressed were (a) the survival of behavior analysis in university and cultural contexts, (b) the training of behavior-analytic researchers and practitioners, (c) relations between basic and applied research, (d) convergences between behavior analysis and other disciplines, (e) the structure and function of ABA, and (f) the importance of students for the future of the association, the discipline, and the profession. Questions from the audience raised issues concerning the relevance of major behavior-analytic journals, advances in behavior analysis since the death of B. F. Skinner, and the availability of accessible, popular material on applied behavior analysis.     

A comparison of African American and White American veteran MMPI-2 profiles

The present study compared a matched sample of 180 African American and 180 White American veterans who completed the MMPI-2 as a part of their evaluation while receiving inpatient psychiatric treatment. Findings indicated no significant multivariate or univariate effects associated with race on the basic validity and clinical scales, a significant multivariate effect but no significant univariate effects associated with race across the supplementary scales. Overall the two groups had very similar mean profiles across the basic validity, clinical, and supplementary scales. Comparison of the two groups on the content scales yielded a significant multivariate and significant univariate effects with African Americans scoring higher on the FRS, BIZ, CYN, and ASP scales. Because the two groups differed in terms of frequency and type of drug abuse, follow-up 2 x 2 univariate analyses of variance were conducted for the FRS, BIZ, CYN, and ASP content scales comparing participants classified in terms of presence or absence of a primary or secondary drug abuse diagnosis by race. A significant main effect associated with drug abuse was obtained for ASP. Results are discussed and considered in light of earlier research on the MMPI-2 and race. Content scale differences are also discussed in terms of possible differences in worldview.     

Regional variation of cloze probabilities for sentence contexts

In 1980, Bloom and Fischler published a paper describing a set of sentence contexts (SCs) and their cloze probabilities (CPs). This material has subsequently been employed in numerous studies of linguistic processing. We sought to define the completion words and their CPs for Bloom and Fischler’s sentences in an inner-city British population in order to establish reliable norms for subsequent studies in the U.K. One hundred and fifty incomplete SCs were presented to 73 volunteers. The CPs for each of the words used to complete the SCs were computed. We then compared the CPs from our sample with those from Bloom and Fischler. There were significant differences between CPs from each sample in 14% of the SCs analyzed (p < .01). Our data suggest that studies employing SCs and CPs may require locally defined norms if the test population differs substantially from the original one. The consequences of employing SCs and CPs to study linguistic processing without normalization are discussed.     

Using proton magnetic resonance imaging and spectroscopy to understand brain "activation"

Upon stimulation, areas of the brain associated with specific cognitive processing tasks may undergo observable physiological changes, and measures of such changes have been used to create brain maps for visualization of stimulated areas in task-related brain "activation" studies. These perturbations usually continue throughout the period of the stimulating event, and then subside when the event is terminated. In this communication, we consider the nature and meaning of these task-related brain activations. Since stimulation usually results in an increase in the frequency of neuron depolarizations or "spikes", an energy expensive activity that requires ATP for restoration of ionic gradients, additional energy supplies must be rapidly deployed to the stimulated areas or rates of re-polarization could be decreased, and refractory periods between spikes increased. As a result, maximum spiking rates may be decreased and some frequency-encoded information lost. The energy available to brain cells to re-synthesize ATP from ADP is a function of levels of glucose and oxygen in blood, and their availability to stimulated neurons is a function of the rate at which focal blood supplies can be increased (hyperemia). In this review we explore how neurons transmit meaningful encoded information; how the integrity of that information is dependent on a continuous supply of energy, and how proton magnetic imaging and spectroscopy may aid in understanding the process. Finally, evidence is presented that the neuropeptide, N-acetylaspartylglutamate, is a neuronal astrocyte-vascular feedback signal that regulates activation induced focal hyperemic responses.     

Non-pharmacologic Interventions for CFS: A Randomized Trial

Non-pharmacological behavioral treatments for CFS have been suggested as promising. These trials have tested protocols composed of behavioral, cognitive and cognitive–behavioral interventions but there have been few efforts to differentially evaluate their outcomes. The primary purpose of the current study was to evaluate the effectiveness of nurse delivered non-pharmacologic interventions. In the present study, 114 participants diagnosed with CFS were randomly assigned to four 6-month interventions. The interventions were: cognitive–behavior therapy, cognitive therapy, anaerobic activity, and a relaxation control group. The study found that these interventions led to increases in several areas of functioning, with more consistent changes occurring among those participants in the cognitive condition. For the 25 variables in this study, significant change occurred for 28%, 20%, 16%, and 12% of the variables for the cognitive, cognitive behavior therapy, anaerobic activity, and relaxation conditions, respectively. However, the majority of participants continued to be diagnosed with CFS following the treatment trial. Implications of these findings are discussed.