Robert W. Holt

Looming vulnerability to spreading contamination in subclinical OCD

The present study examined the hypothesis, stimulated by the looming vulnerability model of anxiety (Riskind, in press, Behaviour Research and Therapy), that subclinical OCD is associated with a subjective sense of looming vulnerability. One-hundred and four undergraduates rated vignettes of common, everyday situations involving exposure to possible dirt, germs, or contamination. Participants in a subclinical obsessional group had a far higher sense of looming vulnerability to spreading contamination than did those in a control group. Results verified that the subjective sense of looming vulnerability still had separate, distinct and significant contributions to fear-of-contamination symptoms, with the effects of cognitive appraisals of other aspects of threat (such as probability of harm, or lack of control) removed. In contrast, these other cognitive appraisals had no significant associations with symptoms that proved to be independent of the subjective sense of looming vulnerability. A path analysis further explored the dependency of these other cognitive appraisals on looming vulnerability. This analysis found that part of the effects of the subjective sense of looming vulnerability on fears may be indirect and mediated via correlated effects of other cognitive appraisals.

Cognitive and Achievement Gains for Kindergartners Instructed in Piagetian Operations

ABSTRACT Unidimensional classification, unidimensional seriation, and number conservation were taught to kindergartners who were lagging in cognitive development. Significant gains on the Otis-Lennon School Ability Test and on Stanford Early School Achievement Test subscales resulted. The gains seemed to be the result of mastery of key cognitive operations at a stage shift in cognitive development by disadvantaged children who were ripe for progress.

Improving Rater Calibration in Aviation: A Case Study

The assessment of pilot performance relies on systematic observation and assessment by a single trained rater or instructor/evaluator (I/E). Because of the importance of aviation safety, it is imperative that the rating and evaluation processes used by these I/Es yield reliable and valid data. This article describes a case study focused on improving the reliability and validity of crew assessment at a commercial carrier. The process for improving reliability involved the evaluation of current training methods, the construction and evaluation of 5 metrics for assessing interrater reliability, and a standardized process for using these metrics to train I/Es. A separate set of interventions was developed and implemented to improve structural validity. Data collected from 2 fleets in this airline during a 3-year period indicate aspects of reliability and validity that should be the focal points of continuing I/E training.

Persistence of Gains From Instruction in Classification, Seriation, and Conservation

Abstract Children who received learning-set instruction on unidimensional classification, unidimensional seriation, and number conservation in the middle of kindergarten were retested at the end of 1st grade. The follow-up tests showed that a 17-percentile-point advantage conveyed by this instruction on the O-LSAT measure of school-related reasoning was essentially intact. It also appeared that a 10-percentile-point gain in mathematics, presumably an indirect effect of the increased competence in reasoning, was also intact. On the other hand, there was no longer any difference between experimental and control children in verbal comprehension. These results are discussed in terms of temporary, permanent, and self-propagating gains.

Strategy variability: How too much of a good thing can hurt performance

Recent research (e.g., Siegler, 1996) has discovered the important and vital role that variability plays among strategy use and development over time. However, as many researchers have pointed out (e.g., Miller, 1993), the majority of the research addressing this issue has focused on the outcomes, rather than on the potentially more informative aspects of variability, strategy development, and the process of adaptation. In this study, we examined the role of variability during strategy development, utilizing a longitudinal method. Thirteen participants were studied over 3 months as they coached a simulated football team. The results suggest that variability plays a major role in adaptive skill acquisition in a dynamic environment—in the direction, however, opposite to that predicted by previous research done with simple static tasks.

Model-Based Predictions of Interrupted Checklists

The improper completion of a cockpit checklist has contributed to a number of aviation accidents. In many of these cases, it can be shown that interruptions were a contributing factor in the failure to complete the checklist properly. Unfortunately, most studies of interruptions have provided only post-hoc explanations for these failures. Further, research has focused on whether or not tasks are resumed rather than on predictions of where people will resume a task after an interruption. This paper describes several generic models that were used to explore cognitive strategies for handling interruptions. One of these models was then modified to fit the specific real-world task of completing an aircraft checklist. This model produced detailed a priori predictions about where the interrupted checklist will be resumed. The implications of these predictions for task design and for the use of cognitive modeling as an approach to understanding interruptions are discussed.

Behavioral Validation of a Hazardous Thought Pattern Instrument

One approach to examining errors or potential errors in aviation has focused on measuring the hazardous thought patterns of pilots. Previous research identified five thought patterns and assumed that all pilots fall into one of these categories. The current research was designed to develop and behaviorally validate a new instrument to measure hazardous thought patterns. The research confirmed previous work in finding five hazardous thought patterns. However, the research also suggested the presence of a sixth factor related to confidence/competence. The validation suggested that the individual hazardous thought patterns differentially predicted accidents and incidents. The behavioral validation also identified relationships between particular hazardous thought patterns and specific driving behaviors that supported the validity and utility of the newly designed instrument.

Dopamine receptor subtype density as a function of age in Aplysia californica

The age-associated changes in dopamine subtype receptors were examined in Aplysia californica. The density of the subtype receptors D1, D2, D3 and D4 was examined in the ganglia from 4.5-, 6-, 8-, 9- and 12-month animals. Receptor analysis was performed by examining the binding of radiolabeled ligands to the individual subtypes. [3H]SCH23390 and [3H]Clozapine were used to analyze D1 and D4 specific binding. [3H]Quinpirole was used for determining D2 and D3 specific binding. Specific binding was found to be present for all four receptor subtypes. All receptor subtypes showed an increase in density from 4.5 to 6 months. From 6 to 8 months D2 and D3 decreased, while D1 and D4 increased. D4 showed the strongest increase. All four subtypes examined showed decreases from 8 to 12 months. ANOVA results indicated age was a significant factor in the subtype receptor density for all receptor types.

Age dependent changes in serotonin and dopamine receptors in Aplysia californica

Age related changes in dopaminergic and serotonergic receptors were examined in Aplysia californica. In this study dopamine (DA) and serotonin (5-HT) receptor levels were examined for animals belonging to 4-, 5-, 6-, 8-, 9- and 12-month age groups. Receptors analysis was performed using radio-labeled d-[3H] lysergic acid diethylamide (LSD) as the specific ligand. Specific binding for 5-HT was found to be significantly greater than that for DA in the young (4-month post-hatch) animals. The total DA and 5-HT receptor levels changed significantly with age. Dopamine levels increased from 5.34 fmol/mg of protein at 4 months to 19.11 fmol/mg at 12 months. Serotonin receptor levels increased from 7.35 fmol/mg at 4 months to 20.45 at 12 months.

Multilevel structured documentation

This research examined the effects of different types of documentation on the performance of users with different levels of experience on a word-processing program. Three forms of documentation (global overview, detailed step-by-step, and combined global and detailed) were presented to undergraduates with high, medium, and low levels of computer experience. Dependent measures were problem-solving behavior using a word-processing program, the amount of information retained by the participants about the program, and subjective reactions to the documentation. The results indicated that (a) combined global and detailed documentation was, in general, superior to either type of documentation alone; (b) more experienced users were superior in reading documentation more quickly and solving problems more quickly, but they did not have significantly better recall or recognition of components of the program; and (c) the effects of type of documentation did not interact with the level of users experience.