Substance use and violent behavior in adolescence

The relation between substance use and violent behavior in adolescence is reviewed, and each of five competing models of this relation is examined. I begin by presenting background material on adolescent substance use and adolescent violence. I then describe five different models that have been proposed to explain the association between substance use and violent behavior. Next, I review the adolescent literature concerning substance use and violence, noting methodological weaknesses that have plagued this research. I conclude with an evaluation of the five models and suggestions for future research.     

Differentiation of brain damage among low IQ subjects with three projective techniques.

Using a battery of three projective techniques (Rorschach, Hand Test, Bender-Gestalt) only slight discrimination was found between low IQ subjects classified according to the presence or absence of brain trauma (exogenous vs endogenous), while substantial discrimination was obtained between the same subjects categorized in terms of "lower" (60-74) and "higher" (75-89) FS WAIS IQ. All four groups used in this study had been first equated on sex and age. Results were interpreted as supporting the position that some sort of brain impairment underlies most or all retardation. Question was raised concerning the efficacy of projective techniques for diagnosing organicity in subjects of average or better intelligence.     

Goodness of fit tests for probabilistic measurement models

General goodness of fit tests for probabilistic response models are developed. The tests are applicable in psychophysics, in the theory of choice behavior and in mathematical learning theories. The necessary and sufficient constraints that a measurement model puts on the response probabilities are used for testing this model. In addition, representation theorems for some models are proved and the goodness of fit to experimental data is considered.     

Hemispheric asymmetries in faculty and student musicians and nonmusicians during melody recognition tasks

Current research has suggested that musical stimuli are processed in the right hemisphere except in musicians, in whom there is an increased involvement of the left hemisphere. The present study hypothesized that the more musical training persons receive, the more they will rely on an analytic/left-hemispheric processing strategy. The subjects were 10 faculty and 10 student musicians, and 10 faculty and 10 student nonmusicians. All subjects listened to a series of melodies (some recurring and some not) and excerpts (some actual and some not) in one ear and, after a rest, to a different series of melodies in the other ear. The task was to identify recurring vs. nonrecurring melodies and actual vs. nonactual excerpts. For student musicians, there was a right-ear/left-hemispheric advantage for melody recognition, while for student nonmusicians, the situation was the reverse. Neither faculty group showed any ear preference. There were no significant differences for excerpt recognition. Two possible explanations of the faculty performance were discussed in terms of physical maturation and a functionally more integrated hemispheric approach to the task.     

A review of projective test findings with older adults

The projective test literature on aging is reviewed. It was concluded that, while much critical research remains to be done and many of the studies are flawed, projective testing has contributed a great deal to the understanding of the aging process and has yielded a core of consistent findings. Suggestions for future research which would help resolve some current ambiguities were made.     

Logistic latent trait models with linear constraints

Two linearly constrained logistic models which are based on the well-known dichotomous Rasch model, the ‘linear logistic test model’ (LLTM) and the ‘linear logistic model with relaxed assumptions’ (LLRA), are discussed. Necessary and sufficient conditions for the existence of unique conditional maximum likelihood estimates of the structural model parameters are derived. Methods for testing composite hypotheses within the framework of these models and a number of typical applications to real data are mentioned.     

Social influences on remembering: Intellectual,interpersonal and intergroup components

When people recall an event collaboratively we may expect the product to be influenced by the combined cognitive resources of the group, interpersonal acquaintance of the members, and social competition engendered by salient intergroup considerations. Using undergraduate students and serving police officers as subjects, a range of experimental conditions was established which varied on the three factors of cognitive resources of the participants (Cognitive Resources), interpersonal acquaintance of the participants (Interpersonal Acquaintance) and professional salience (Professional Salience) of the recall material. Participants answered a questionnaire concerning a police interrogation they had witnessed, and rated how much confidence they had in their answers. Multiple regression revealed statistically significant associations between (i) Cognitive Resources and number of correct answers, (ii) Interpersonal Acquaintance and confidence for implicational errors, and (iii) Professional Salience and (a) number of implicational errors and (b) confidence in confusional errors. The theoretical implications for our understanding of memory as a social process are discussed, and the practical implications for courtroom testimony briefly described.     

The specificity of the effects of stimulant medication on classroom learning-related measures of cognitive processing for Attention Deficit Disorder children

There appear to be beneficial effects of stimulant medication on daily classroom measures of cognitive functioning for Attention Deficit Disorder (ADD) children, but the specificity and origin of such effects is unclear. Consistent with previous results, 0.3 mg/kg methylphenidate improved ADD children's performance on a classroom reading comprehension measure. Using the Posner letting-matching task and four additional measures of phonological processing, we attempted to isolate the effects of methylphenidate to parameter estimates of (a) selective attention, (b) the basic cognitive process of retrieving name codes from permanent memory, and (c) a constant term that represented nonspecific aspects of information processing. Responses to the letter-matching stimuli were faster and more accurate with medication compared to placebo. The improvement in performance was isolated to the parameter estimate that reflected nonspecific aspects of information processing. A lack of medication effect on the other measures of phonological processing supported the Posner task findings in indicating that methylphenidate appears to exert beneficial effects on academic processing through general rather than specific aspects of information processing.