Stephen Hawking and the virtue of discretion

Jacques Arnould thanks Stephen Hawking for his warning, but then quickly moves on to contend: the present moment provides an opportunity for Homo sapiens on Earth to rediscover the virtue of discretion.     

A physiologically motivated model for change detection in audition

Burbeck & Luce (Perception & Psychophysics, 1982, 32 (2), 117–133) argue that their simple reaction time data is best accounted for by the parallel operation of a change and a level detector. Here a specific example of such a compound model is tested. The primary focus is on the change detector which is modeled after a post inhibitory rebound (PIR) neuron. PIR neurons are plausible candidates for the “off” units found throughout the auditory system. The level detector is assumed to be a simple leaky integrator. Computer simulations of the compound model are compared to simple reaction time data. The results, although not without some deficiencies, support the model.     

A developmental study of learning disabilities and memory

Seven-, ten-, and thirteen-year-old learning-disabled (LD) and non-learning-disabled (NORM) children were presented specially structured lists of 38 words each and tested for free recall. Each list contained only four semantically related words. Two of the four related words were presented contiguously (serial positions 9 and 10) and the other two words were spaced (serial positions 20 and 30). All children recalled disproportionately more adjacent words (item 9 or 10) than any other words. Spaced words (items 20 and 30) were less likely to be recalled by the younger children than by the older children and by the LDs than by the NORMS. These findings provided support for the distinction between automatic and purposive semantic processing. NORMs' recall was governed by purposive semantic processing to a greater extent than was LDs' recall. However, no group or age differences were observed in automatic semantic processing.     

Development of the Career Exploration Survey (CES)

The development, properties, and uses of the Career Exploration Survey (CES) are described. The CES is intended to (a) facilitate further theory development and empirical research on how exploration affects career decisions, development, and job outcomes, such as job satisfaction, commitment, and turnover; (b) provide a network of variables for investigating the dynamics of the exploration process; and (c) provide a set of criterion measures for examining the effects of personal characteristics and educational treatments on career exploration behaviors and beliefs. The CES is based on a conceptual framework derived from theories of exploration, stress, motivation, and career preference. It consists of seven measures of the career exploration process, three reactions to exploration, and six beliefs about exploration. Dimensionality, reliability, and validity data are presented for four studies comprising 680 observations across 601 individuals.     

Moral reasoning development and graduate education

The Defining Issues Test (DIT) of moral reasoning development was administered to 20 advanced and 20 first-year graduate students, plus 40 college graduates matched to the graduate groups on sex, age, and verbal ability. A two-way ANOVA design was used to infer whether graduate education, selection, maturation, or a combination of these effects is (are) associated with group differences on the DIT. Results suggest that differences found between the graduate students and college graduates can be accounted for by a combination of maturational and selection effects, contrary to the hypothesized effects of formal education.     

The effects of commercial interruption of violent and nonviolent films on viewers' subsequent aggression

Aggressive responses following the viewing of violent and nonviolent films were studied. Groups of subjects saw one of three full-length films: (1) a staged violent film, (2) a realistic violent film, or (3) a nonviolent film. For half of the groups of subjects, films were interrupted periodically by sets of commercials. Results confirmed predictions that aggressive responses will be greater after viewing aggressive films than nonaggressive films, and that aggressive responses will be greater if films are interrupted by commercials than when not interrupted. A hypothesis predicting an interaction such that aggressive responses will be maximal when violent films are interrupted by commercials was supported. No differences in aggressiveness following presentation of realistic and staged violent films were found.     

Imagery,propositions, and the form of internal representations

This paper has four major sections: First, we review the basic arguments offered by Pylyshyn (Psychological Bulletin, 1973, 80, 1–24) and others against using imagery as an explanatory construct in psychology. Second, we consider each of these points and find none that speak against any but the most primitive notions of imagery. Third, we review the results of various experiments on imagery. In each case, we compare two explanations of the findings: one which assumes the existence of a surface image manifesting emergent properties, and one which assumes that all internal representations are coded in terms of “abstract propositions.” We find imagery hypotheses to be at least as adequate as those based on propositional representation. Finally, we conclude that debate about the ultimate foundations of internal representation is fruitless; the empirical question is whether images have properties that cannot be derived directly from more abstract propositional structures.     

Validation of the sensation scale,a measure of subjective physiological responses to alcohol

The Sensation Scale was originally constructed to measure the subjective experience of physiological changes following alcohol consumption. Reduction of the original scale of 31 variables on the basis of face validity resulted in six ‘factors’ comprising 26 variables and one ‘other’ factor. These sortings are shown to have good interrater reliability. Furthermore, evidence is presented from two experiments that five of the six factors discriminated between nonalcoholic male subjects who drank either a beverage containing a moderate dose of alcohol or a nonalcoholic beverage.     

An experimental analysis of impulsivity and impulse control in humans

In choosing between small, immediate and large, delayed reward, an organism behaves impulsively if it chooses the small reward and shows impulse control if it chooses the large reward. Work with nonhumans suggests that impulsivity and impulse control may be derived from gradients of delayed reinforcement. A model developed by Ainslie and by Rachlin suggests that preference for the rewards should be a function of when the choice is made: small reward with no delay may be preferred to large reward with delay X, but adding delay T to both alternatives should shift preference to the large reward. Three experiments investigated this preference reversal in humans, using termination of 90 dba white noise as the reinforcing event. Experiment 1 showed that under some instructional conditions 90-sec noise off with no delay was preferred over 120-sec noise off after a 60-sec delay, but that preference shifted to the large reward when a 15-sec delay (T) was added to both alternatives. Experiment 2 replicated this preference reversal under two conditions of large, delayed reward, and with three rather than two values of T. Experiment 3 confirmed this effect of T and showed that some humans committed themselves to the large reward when commitment could be made some time before presentation of the reward alternatives. These data support the Ainslie-Rachlin model and extend it to human choice behavior.