A linked muscular activation model for movement generation and control

A new model for movement control is presented which incorporates characteristics of impulse-variability and mass-spring models. Movements in the model were controlled with phasic torque impulses in agonist and antagonist muscles and a tonic agonist torque. Characteristics of the phasic agonist and antagonist torque profiles were based on observed properties of movement-related EMGs and muscle isometric torques. Variability of the phasic impulses depended on impulse magnitude as in impulse-variability models. The model therefore predicted a speed-accuracy tradeoff for limb movement. The time of onset and magnitude of the antagonist torque depended on the magnitude of the preceding agonist torque as indicated in studies of movement-related EMGs. This led to the new concept of linkage between the agonist and antagonist muscle forces which was shown to be important for reducing variability of fast movements. Progressive development of linkage during practice could explain the previous findings of decreased movement variability with practice coupled with increased variability of movement-related EMGs. It was concluded that an inherently variable motor system deals with the variability associated with generation of large muscle forces by linking the forces produced by opposing muscles. In this way, variability in net joint torques and in movements can be decreased without the need for the nervous system to closely regulate the individual torques.     

A comparison of inexpensive statistical packages for apple II microcomputers

The purpose of this paper is to describe and compare some inexpensive software packages that calculate a variety of statistics on the Apple II microcomputer. For each package, hardware requirements, program capacity, limitations, constraints, accuracy, editing, error handling, and other features were studied.     

Where gamma fails

A major question for the relevant logics has been, “Under what conditions is Ackermann's ruleγ from -A ∨B andA to inferB, admissible for one of these logics?” For a large number of logics and theories, the question has led to an affirmative answer to theγ problem itself, so that such an answer has almost come to be expected for relevant logics worth taking seriously. We exhibit here, however, another large and interesting class of logics-roughly, the Boolean extensions of theW — free relevant logics (and, precisely, the well-behaved subsystems of the 4-valued logicBN4) — for which γ fails.     

A method of weighing qualitative preference axioms

A method is developed for determining the absolute and relative strengths of qualitative preference axioms in normative Bayesian decision theory. These strengths are calculated for the three most common qualitative axioms; transitivity, the sure-thing principle, and dominance. The relative strength of the latter two axioms with respect to transitivity is calculated for special cases, and a bound is derived which is applicable to a larger class of decision problems. Possible implications of this theoretical work for decision heuristics are discussed.     

Male and female nurturing: Perceptions of style and competence

College men and women evaluated male and female characters in five stories about babysitters. The characters: (1) refused to babysit, (2) babysat with minimal caretaking activities, (3) babysat with an active play style, (4) babysat with a quiet play style, or (5) babysat with a combined style. The refuser was considered most masculine but was consistently devalued. The quiet play, the active play, and combined caretakers were evaluated most positively. Evaluations of babysitters were more dependent on the behaviors they engaged in than on their gender. Nurturing men and women were both valued.An earlier version of this paper was presented at the annual meeting of the American Psychological Association, Los Angeles, August 1985.     

Developmental Career Assessment and Counseling: The C-DAC Model

The C-DAC model seeks to implement current development theory and to use innovative assessment measures together with improved counseling methods to improve vocational and life career counseling. At this stage, the project pays more attention to assessment, partly because if one is to counsel with career maturity in mind, one must understand the developmental status of the counselee. In career counseling, facts as well as feelings are important. Therefore, in this article the authors deal with the assessment of career development in detail, treating interests (measured by the Strong) and expressed preferences as basic status data to be viewed in the light of career maturity, the salience of life roles, and the values sought in life as moderator variables. The instruments are described and their use shown in a sample profile for assessment and checking by the reader in another readily available published source.     

Six Approaches to the Assessment of Career Maturity

This article discusses the construct of career maturity and briefly reviews research that identifies factors associated with this construct. Brief reviews of 6 instruments designed to measure career maturity are included: The Career Maturity Inventory (Crites, 1978a, 1978b), the Career Development Inventory (Super, Thompson, Lindeman, Jordaan, & Myers, 1988), the Adult Career Concerns Inventory (Super, Thompson, & Lindeman, 1988), the Assessment of Career Decision Making (Harren, 1979; Buck & Daniels, 1985), the Career Beliefs Inventory (Krumboltz, 1994), and the Career Decision Scale (Osipow, Carney, Winer, Yanico, Koschier, 1976). Issues associated with the assessment of career maturity are also discussed.     

Prime time advertisements: Repetition priming from faces seen on subject recruitment posters

Repetition priming is defined as a gain in item recognition after previous exposure. Repetition priming of face recognition has been shown to last for several months, despite contamination by everyday exposure to both experimental and control faces in the interval. Here we show that gains in face recognition in the laboratory are found from faces initially seen in a rather different context— on subject recruitment posters, even when the advertisements make no specific mention of experiments involving face recognition. The priming was greatest when identical pictures were shown in the posters and in the test phase, although different views of faces did give significant priming in one study. Follow-up studies revealed poor explicit memory for the faces shown on the posters. The results of these experiments are used to develop a model in which repetition priming reflects the process of updating representations of familiar faces.     

Longitudinal Correlates of Arrest Status Among At-Risk Males

We examined the longitudinal adjustment, from grade 4 to grade 11, of a sample (n = 76) of boys judged to be at-risk for developing antisocial behavior patterns. We also examined subgroups of the sample differentiated by risk status and arrest records at grade 11. Antisocial behavior patterns exhibited by these boys demonstrated considerable stability over time. Differences were noted among high and lower-risk groups who were and were not arrested. In particular, measures of academic and social skills dimensions were related to better overall adjustment as indicated by lower arrest rates. Implications of these results for intervention are presented.