The PSYCHLAB programming system: A tool for developing experimental control programs

The PSYCHLAB system is designed to facilitate the task of writing experimental control programs. The system consists of two major components: (1) a collection of procedures and functions to facilitate presenting stimuli, collecting responses, and measuring response times and (2) a high-level language (LAB-TALK) designed to organize and sequence events in experiments. The PSYCHLAB system is formally an interpreter that will interpret programs written in LAB-TALK. The interpreter is customized to perform the detailed functions of each trial in an experiment. The occurrence of these trials is controlled by the LAB-TALK program. Thus, once a particular experimental paradigm has been represented in a customized version of the interpreter, many different experiments in that paradigm can be programmed by variations in the LAB-TALK program.     

Personality diagnostic questionnaire-revised (PDQ-R) personality disorder scores and negative life events independently predict changes in hopkins symptom checklist (SCL-90) Psychopathology Scores

The present study employed a prospective design to investigate whether Personality Diagnostic Questionnaire—Revised (PDQ-R) scores and/or Hassles Scale—Revised (HS-R) scores predict changes in Axis I psychopathology levels over 1 month, in a nonclinical sample of young adults. The PDQ-R, HS-R, and Hopkins Symptom Checklist (SCL-90) were administered to a mixed-sex sample of 100 undergraduate students on two occasions separated by 1 month. Hierarchical multiple regression analyses indicated that (1) time 1 PDQ-R composite scores predicted changes in scores on 11 SLC-90 scales; (2) time 1 PDQ-R impairment/distress index scores predicted changes in SCL-90 general symptom index scores; (3) only one of the individual PDQ-R personality disorder subscales—the schizotypal personality disorder subscale—predicted changes in SCL-90 general symptom index scores; (4) HS-R scores predicted changes in scores on 9 SCL-90 scales; and (5) in only 3 of the 27 analyses conducted did the statistical interaction between PDQ-R and HS-R scores predict changes in SCL-90 scores. These findings indicate that personality disorder symptomatology and negative life events may independently predict changes in Axis I psychopathology levels and, thus, support the continued inclusion of Axis II and Axis IV in future versions of the Diagnostic and Statistical Manual of Mental Disorders.     

The philosophical works of wilfrid sellars

Expanded bibliography fromThe Metaphysics of Epistemology. Lectures by Wilfrid Sellars, edited by Pedro V. Amaral, Ridgeview Publ. Co., Atascadero, Calif. 1989, pp. 343–353, with addenda and corrigeda.     

Factors affecting entrapment in escalating conflicts: The importance of timing

Entrapping conflicts are those in which individuals continue to invest their resources—even in seemingly losing propositions-in large part to justify previous unfilled expenditures. It has been demonstrated that individuals define their motivation for investing very differently at the various stages of an entrapping conflict. One implication of this motivational dynamic is that various factors may differentially affect degree of entrapment (i.e., amount invested), depending upon the point in time at which they are introduced. The present studies were designed to test this notion. All subjects were given an initial monetary stake and had the opportunity to win more by taking part in an entrapping investment situation. In Experiment 1, half the subjects were provided with a payoff chart that made salient the costs associated with investing (Highcost salience condition) whereas half were not (Low-cost salience condition). Moreover, for half of the subjects the payoff chart was introduced before they were asked to invest (Early condition) whereas for the other half it was introduced after they had invested a considerable portion of their resources (Late condition). Entrapment was lower in the High salience-Early than in the Low salience-Early condition. However, there was no difference between groups in the Late condition. In Experiment 2, the perceived presence of an audience interacted with personality variables related to face-saving to effect entrapment. When the audience was described as “experts in decision making,” subjects high in public self-consciousness (or social anxiety) became less entrapped than those low on these dimensions. When the audience consisted of individuals who “wished simply to observe the experimental procedure,” however, high public self-consciousness (or social anxiety) individuals were significantly more entrapped than lows. Moreover, these interaction effects occurred when the audience was introduced late, but not early, into the entrapment situation. Taken together, these (and other) findings suggest that economic factors are more influential determinants of behavior in the earlier stages of an entrapping conflict, whereas face-saving variables are more potent in the later phases. Alternative explanations are discussed.     

Perceptual cues used in reproduction of inspired volume

Man is capable of reproducing an inspired lung volume (IV) with relative precision (±3 %–8 %). To investigate the importance of cues which may be used to determine IV, we performed two experiments. In each, the subject inspired a “standard” breath (from resting end~xpired lung volume) corresponding to 25%, 50%, or 75% of inspiratory capacity (IC) and then expired nearly completely. From this expired volume, the subject either tried to reproduce the tidal volume (i.e., volume of air inspired) of the first breath (volume reproduction) or to reproduce the previous end-inspired lung volume (position reproduction). The constant error indicated that subjects overestimated tidal volume by about 200 ml. Despite this overestimation, the variability of reproduction was less for volume reproduction than for position reproduction when IV was small. The JND for volume reproduction increased linearly with increasing IV, whereas the JND for position reproduction was similar at all IVs so that the Weber ratio decreased. These observations suggest that, in the perception of inspired volume, the sensation of end-inspired position is important when the inspired volume is large, but that subjects apparently rely on some other cue to reproduce small lung volumes accurately.