Personal computer software for teaching differential psychodiagnostics

The third edition of theDiagnostic and Statistical Manual of Mental Disorders (American Psychiatric Association, 1980), outlines for the student what symptoms to consider when attempting to arrive at an accurate differential diagnosis of eight broad psychiatric categories. This paper describes a program developed to instruct a medical or graduate student in the science of such decision making.     

A nonparametric approach for assessing latent trait unidimensionality

Assuming a nonparametric family of item response theory models, a theory-based procedure for testing the hypothesis of unidimensionality of the latent space is proposed. The asymptotic distribution of the test statistic is derived assuming unidimensionality, thereby establishing an asymptotically valid statistical test of the unidimensionality of the latent trait. Based upon a new notion of dimensionality, the test is shown to have asymptotic power 1. A 6300 trial Monte Carlo study using published item parameter estimates of widely used standardized tests indicates conservative adherence to the nominal level of significance and statistical power averaging 81 out of 100 rejections for examinee sample sizes and psychological test lengths often incurred in practice.The referees' comments were remarkably detailed and greatly enhanced the writeup and sensitized the author to certain pertinent issues. Discussions with Fritz Drasgow, Lloyd Humphreys, Dennis Jennings, Brian Junker, Robert Linn, Ratna Nandakumar, and Robin Shealy were also very useful.This research was supported by the Office of Naval Research under grant N00014-84-K-0186; NR 150-533, and by the National Science Foundation under grant DMS 85-03321.     

AN ALTERNATING TREATMENTS COMPARISON OF ORAL AND TOTAL COMMUNICATION TRAINING WITH MINIMALLY VERBAL RETARDED CHILDREN

This study was a comparison of the effects of oral speech with total communication (speech plus sign language) training on the ability of mentally retarded children to repeat 4-word sentences. Three children were chosen who used single words to communicate but who did not combine words into complete sentences. Three sentence pairs were trained, with each pair having one sentence trained using oral methods and an equivalent one trained using the total communication approach. Both training procedures involved chaining sentence parts, reinforcement, and prompting. Oral methods involved presenting vocal stimuli and requiring vocal responses whereas total communication methods involved presenting vocal and signed stimuli and requiring vocal and signed responses. For the initial sentence pair with each child, an alternating treatments design was used to determine the relative efficacy of the two language training approaches. This was repeated with a second and third sentence pair using a multiprobe technique within a multiple baseline design. Results pointed to the superiority of the total communication approach in facilitating sentence repetition. Possible explanations of these results are offered and the utility of the alternating treatments experimental design is discussed.     

Cortical steady-potential shifts in conditioning

Cortical steady-potential shifts obtained from nonpolarizing electrodes chronically implanted in freely moving cats and rats reveal cortical activation related to urgency of response to unconditional and conditional stimuli. Such shifts appear relatively independent of activation in the rhythmic electrocorticogram and are related to higher levels of activation. Shifting is found to be modulated by drive and level of learning, suggesting a correlation with the proposed reaction potential of Hull. Both approach and avoidance “urgency” are reflected in the onset slope and amplitude of SP shifts in a manner suggesting modulation of cortical activation by the effects of behavioral regulation of stimulus conditions.     

The asymptotic posterior normality of the latent trait in an IRT model

It has long been part of the item response theory (IRT) folklore that under the usual empirical Bayes unidimensional IRT modeling approach, the posterior distribution of examinee ability given test response is approximately normal for a long test. Under very general and nonrestrictive nonparametric assumptions, we make this claim rigorous for a broad class of latent models.This research was partially supported by Office of Naval Research Cognitive and Neural Sciences Grant N0014-J-90-1940, 442-1548, National Science Foundation Mathematics Grant NSF-DMS-91-01436, and the National Center for Supercomputing Applications. We wish to thank Kumar Joag-dev and Zhiliang Ying for enlightening suggestions concerning the proof of the basic result.The authors wish to thank Kumar Joag-Dev, Brian Junker, Bert Green, Paul Holland, Robert Mislevy, and especially Zhiliang Ying for their useful comments and discussions.     

On the Nature of Embarrassabllity: Shyness, Social Evaluation, and Social Skill

In this study, the correlates of embarrassability, or chronic susceptibility to embarrassment, were examined. Competing theoretical models suggest either that embarrassable people should be especially concerned about others' evaluations of them or that they should lack social skills. Further, shyness and embarrassment are typically considered to be closely related states. To test these propositions, 310 participants provided extensive self-reports of social skill, fear of negative evaluation, self-esteem, self-consciousness, and negative affectivity. Regression and factor analyses indicated that, compared to those of low embarrassability, highly embarrassable people are particularly concerned with the normative appropriateness of behavior and are more motivated to avoid rejection from others. In contrast, shyness was best predicted by low social self-confidence and low social skill. The data best support a social-evaluation model of embarrassment and argue that embarrassability is linked to the appropriateness of social behavior, and shyness to its effectiveness.     

Psychopathic personality traits and temporal perspective: A test of the short time horizon hypothesis

A number of authors have proposed that psychopathic individuals possess an abnormally constricted time horizon (i.e., foreshortened sense of the future). This hypothesis was tested among 101 undergraduates, who were administered a battery of (1) self-report indices of psychopathic personality traits, antisocial behavior, and normal-range personality traits; (2) self-report indices of time perspective; (3) projective tests of time perspective; and (4) laboratory tasks assessing time estimation and capacity for foresight and impulse control. Measures of psychopathy/antisocial behavior tended to be negatively correlated with several self-report indices assessing preoccupation with the future and with a projective task assessing the frequency of thoughts concerning future events, although only one of the correlations with this latter task was significant. In most cases these correlations were not attributable to the variance shared by measures of psychopathy/antisocial behavior and measures of (low) anxiety-proneness, although several correlations decreased substantially after levels of harmavoidance were controlled. In contrast, measures of psychopathy/antisocial behavior were negligibly correlated with laboratory tasks. These results provide mixed support for the short time horizon hypothesis and suggest that further attention to the role of method factors in investigations of future time perspective is warranted.     

Sensation-seeking and selection of entertainment

The relationship between entertainment activity preference and sensation-seeking was investigated by survey and actual movie selection and viewing. Cardiac rate and rate change was monitored during movie selection and viewing. High sensation-seeking (HSS) females reported preferences for activities centered about alcohol, sexually-explicit materials and ‘rock’ music. HSS males reported preferences for sexually-explicit materials and news/documentary reports. Low sensation-seeking (LSS) males and females reported preferences for the musical stage, theatrical drama and comedy, and romantic/dramatic novels. HSS males and HSS females allotted high proportions of viewing time to an ‘action’ movie, and changed channels more frequently than LSS. The indices of cardiac response utilized in this study were unrelated to movie viewing activities, a result which does not support the ‘optimal level of arousal’ view of sensation-seeking proposed by Zuckerman (1979).