The Fire Chief microworld generating program: An illustration of computer-simulated microworlds as an experimental paradigm for studying complex decision-making behavior

Computer-simulated microworlds bridge the gap between the complexity of field investigations and the rigor of laboratory studies. The purpose of this paper is to draw attention to the major methodological issues involved in developing and using computer-simulated microworlds for the psychological study of complex decision-making behavior. These issues comprise flexibility and generality in the microworlds that can be created, adequate psychological validity, automatic trial administration and data logging, capacity to interface simulations of psychological processes, and adequate testing and documentation. Each of these issues is illustrated by indicating how it has been addressed in Fire Chief, a microworld generating program specifically designed for creating realistic, yet controllable, decision-making task environments in the psychology laboratory. Fire Chief (Omodei & Wearing, 1993a) is introduced as both fully portable to other research teams and suitable for use in many different contexts requiring a complex task situation.     

Individual differences in preschoolers' physiological and verbal responses to videotaped angry interactions

Individual differences in selection of intensity of angry interactions and physiological and self-reported responses to interadult anger were examined in preschoolers (N=34). Children watched two videotaped angry interactions between adults, while their heart rates and skin conductance responses and levels were monitored; then they were interviewed. Before the second argument, children were given the perceived choice of watching an intense or mild angry exchange. Individual differences in responding to the angry interactions were found. Both (a) children with relatively higher externalizing behavior problems and (b) boys who chose to watch intense anger had lower tonic heart rates; 80% of boys with externalizing problems chose to watch intense anger. Further, children who chose to watch intense anger (a) exhibited lower declines in heart rates upon the presentation of the argument, (b) perceived the actors as more angry, and (c) reported lower amounts of distress during the argument than those who chose mild anger.     

An observation of gender-specific teacher behavior in the ESL classroom

For the most part, gender-differentiated teacher behavior in English as a Second Language classrooms in the United States has not been examined. Does the preference for male students demonstrated by both male and female teachers in American classrooms (Sadker et. al., 1992) also occur in ESL classrooms? If so, are ESL teachers aware they show such bias? To find out, the author observed and evaluated, both quantitatively and qualitatively, classroom interactions of four ESL teachers. The teachers, two males and two females, were white, American-born, and had finished graduate studies. All but one of the ESL teachers observed showed remarkable equality in their classroom interactions with the genders. The results are discussed, and future research directions proposed.     

Menstrual-related perceptual changes in women with premenstrual syndrome: Factors to consider in treatment

The state-dependent model of premenstrual syndrome (PMS) suggests that women's perceptions of daily stressors are affected by menstrual cycle phase. Our objective was to further examine the applicability of this model to perceptions of specific kinds of daily stressors and to explore its generalizability to perceptions involving significant others. Thirty-two undergraduate women, 10 PMS and 22 asymptomatic controls, completed the Daily Stress Inventory (DSI) and the Daily Rating Form (DRF) for 35 days. Questionnaires measuring perceived social support and self-esteem were completed premenstrually and postmenstrually. Results indicated that all women perceived a greater number of stressors as being severe premenstrually as compared to postmenstrually. Furthermore, all women perceived a lesser number of signifcant others as being present in their social support network premenstrually. However, only the PMS women were less satisfied with their social support and had more negative self-esteem premenstrually as compared to postmenstrually. Results are discussed within the context of designing treatment intermentions for women with PMS.     

Object recognition contributions to figure-ground organization: Operations on outlines and subjective contours

In previous research, replicated here, we found that some object recognition processes influence figure-ground organization. We have proposed that these object recognition processes operate on edges (or contours)detected early in visual processing, rather than on regions. Consistent with this proposal, influences from object recognition on figure-ground organization were previously observed in both pictures and stereograms depicting regions of different luminance, but not in randomdot stereograms, where edges arise late in processing (Peterson & Gibson, 1993). In the present experiments, we examined whether or not two other types of contours—outlines and subjective contours—enable object recognition influences on figure-ground organization. For both types of contours we observed a pattern of effects similar to that originally obtained with luminance edges. The results of these experiments are valuable for distinguishing between alternative views of the mechanisms mediating object recognition influences on figure-ground organization. In addition, in both Experiments 1 and 2, fixated regions were seen as figure longer than nonfixated regions, suggesting that fixation location must be included among the variables relevant to figure-ground organization.     

Measuring and predicting the effects of alcohol consumption on contrast sensitivity for stationary and moving gratings

Contrast sensitivity was measured for 12 healthy young males while sober, after ingestion of an alcohol placebo, and after ingestion of alcohol (95% grain alcohol; mean estimated blood alcohol level = .088%). Observations were made for both stationary gratings and gratings that traveled through a circular path and required pursuit eye movements. The significant alcohol-related reduction in contrast sensitivity was 2.6 times greater for moving (.29-log-unit reduction) than for stationary gratings (.11-log-unit reduction). The loss in contrast sensitivity for the moving gratings of high spatial frequency (12 cpd) was particularly severe (.37 log unit). Estimated blood alcohol level was correlated with the loss in contrast sensitivity for moving gratings (r = .61), but not with the loss for stationary gratings. Estimated blood alcohol level was strongly correlated with the difference between the loss in contrast sensitivity to moving and stationary gratings (r = .75). These results are consistent with reports that alcohol consumption degrades the ability to make pursuit eye movements. Subjects’ perceived intoxication level was not a reliable predictor of any index of visual performance.     

An investigation of the sampling distributions of item discrimination indices

The sampling properties of four item discrimination indices (biserialr, Cook's indexB, theU–L 27 per cent index, and DeltaP) were investigated in order to ascertain their sampling properties when small samples drawn from actual test data rather than constructed data were employed. The empirical results indicated that the mean index values approximated the population values and that values of the standard deviations computed from large sample formulas were good approximations to the standard deviations of the observed distributions based on samples of size 120 or less. Goodness of fit tests comparing the observed distributions with the corresponding distribution of the product-moment correlation coefficient based upon a bivariate normal population indicated that this correlational model was inappropriate for the data. The lack of adequate mathematical models for the sampling distributions of item discrimination indices suggests that one should avoid indices whose only real reason for existence was the simplification of computational procedures.This research reported herein was performed pursuant to a contract (OE-2-10-071) with the United States Office of Education, Department of Health, Education and Welfare.