Preliminary Evidence for Associations of CHRM2 with Substance Use and Disinhibition in Adolescence

Evidence for shared heritable influences across domains of substance use suggests that some genetic variants influence broad risk for externalizing behaviors. Theories of externalizing psychopathology also suggest that genetic liability for substance use manifests as temperamental risk factors, particularly those related to behavioral disinhibition, during adolescence. The cholinergic muscarinic receptor 2 gene (CHRM2) is a promising candidate for studying genetic influences on broad-based risk for externalizing traits. This study examined a candidate CHRM2 polymorphism (rs1455858) in relation to substance use and personality measures of disinhibition in a sample of high-risk adolescents (n?=?124). Bivariate analyses and structural equation modeling (SEM) evaluated associations of rs1455858 with measures of drug involvement (alcohol, tobacco and marijuana) and disinhibition (indexed by impulsivity and sensation seeking scores). Bivariate analyses showed significant associations of CHRM2 with several behavioral phenotypes. In SEM analyses CHRM2 related significantly to latent measures of substance use and disinhibition; additionally, disinhibition mediated the association of CHRM2 with substance use. These results suggest that CHRM2 variants are potentially relevant for adolescent substance use and that temperamental risk factors could contribute to these associations.     

Solving for two unknowns: an extension of vector-based models of landmark-based navigation

Vectors are mathematical representations of distance and direction information that take the form of line segments where length represents distance and orientation in space represents direction. Vector-based models have proven beneficial in understanding the spatial behavior of a variety of species in tasks that require landmark-based navigation via vector addition and vector averaging to determine a location. Extant research regarding vector-based representational and computational accounts of landmark-based navigation has involved tasks that required solving for one unknown (i.e., a location). Using a novel landmark-based navigation task, we provide evidence consistent with a form of vector algebra that involves solving two simultaneous equations with two unknowns in order to determine a location in space. Results extend vector-based accounts of landmark-based navigation and provide a novel methodological approach to the testing of mobile organisms.     

Capoeira as a Clinical Intervention: Addressing Adolescent Aggression With Brazilian Martial Arts

Aggression in adolescents is harmful and emotionally devastating to youth and surrounding communities. This article integrates martial arts and therapeutic principles into a culturally sensitive model that cultivates change in the aggressive behaviors of disenfranchised adolescents. The art form of Capoeira is proposed for promoting positive behavioral change. La agresión en los adolescentes es dañina y emocionalmente devastadora para los jóvenes y sus comunidades. Este artículo integra artes marciales y principios terapéuticos en un modelo culturalmente sensible que cultiva el cambio de los comportamientos agresivos de los adolescentes marginalizados. Se propone el arte de la Capoeira para promover un cambio positivo en el comportamiento.     

Causality and things in themselves

In this paper I examine Kant's use of causal language to characterize things in themselves. Following Nicholas Rescher, I contend that Kant's use of such causal language can only be understood by first coming to grips with the relation of things in themselves to appearances. Unlike Rescher, however, I argue that things in themselves and appearances are not numerically distinct entities. Rather, I claim that it is things in themselves that we are intentionally related to in veridical experience, though of course we know them only as they appear to us via our subjective experiential faculties. In light of this account of the role of things in themselves in Kant's account of experience, I argue that his use of causal locutions to describe things in themselves is simply his attempt to capture the fact that as the objects that we are related to in experience, the existence of things in themselves is presupposed by any account of the nature of our experienceof them.Substantial work on this paper was done while I attended the National Endowment for the Humanities 1986 Summer Seminar given by Hector-Neri Castañeda at Indiana University. I would like to thank the National Endowment for the Humanities for their support, and Professor Castañeda and the other members of the seminar for their many invaluable comments, suggestions, and criticisms.     

Selection of movement patterns during functional tasks in humans

These experiments examine the role of vision and step height in the selection of a simple binary choice of movement pattern by human subjects. The subjects selected a heel strike movement pattern (HS) (as used during level surface locomotion) or a toe strike movement pattern (TS) (as used during stair descent). The functional task involved descending a step of adjustable height followed by level surface walking under vision and nonvision conditions. Triceps surae and tibialis anterior electromyographic (EMG) activity, ankle angle position, and vertical force were examined. As step height was increased, there was an indistinct threshold at which subjects switched from landing with a HS movement pattern to a TS movement pattern. The tibialis anterior and triceps surae precontact EMG burst and subsequent ankle movement for HS and TS trials appear to be part of preprogrammed movement patterns, which are presumably of central origin. The particular mixture of voluntary, stereotypic, and reflex actions for any specified movement is based on the intent or functional outcome desired. The switching to the TS movement pattern as step height increased presumably results in the most efficient and stable movement.     

Testing specific cognitive abilities by telephone and mail

The two goals of this research were to develop a brief battery of tests of specific cognitive abilities that can be administered via telephone to adolescents and to assess the psychometric properties of the battery. In a sample of 212 adolescents from 10 to 15 years of age, factor analyses supported the hypothesized structure of verbal, spatial, perceptual speed, and memory abilities, with three tests intended to mark each factor. For a subsample of 62 subjects, retest correlations were .81, .73, .82, and .57, respectively, for the four specific cognitive abilities; scores from telephone testing and face-to-face testing correlated near the reliabilities of the telephone tests. Recommendations are made for shortening the 60-min battery to 35 min by using only two tests to mark each factor.     

Occupational Choice and Occupational Success in Slow-Learning School-Leavers

Educationally sub normal adolescents in special schools are compared with others of the same ability in the remedial groups of comprehensive schools, with regard to their choice of jobs and success in employment after leaving school. ESN pupils from special schools were found to be more realistic in their choice of occupation and to do better in their subsequent employment than those from comprehensive schools. Some possible reasons for this difference are proposed.     

Measuring the reliability of observational data: a reactive process

Reliability of observational data was measured simultaneously by two assessors under two experimental conditions. During overt assessment, observers were told that reliability would be measured by one of the two assessors, thus permitting computation of reliability with an identified and an unidentified assessor. During covert assessment, observers were not informed of the reliability measured. Throughout the study, each of the assessors employed a unique version of a standard observational code. In the overt assessment condition, reliability of observers with the identified assessor was consistently higher than reliability with the unidentified assessor, indicating that observers modified their observational criteria to approximate those of the identified assessor. In the covert assessment condition, reliability with the two assessors was substantially lower than during overt assessment. Further, observers consistently recorded lower frequencies of disruptive behavior than the two assessors during covert assessment.