Visual perception of smoothly curved surfaces from double-projected contour patterns

This research was designed to examine how human observers are able to perceive the 3-dimensional structure of smoothly curved surfaces from projected patterns of surface contours. Displays were generated by using a method of double projection that made it possible to cover a surface with a wide range of contour patterns of varying geometric structure and to eliminate systematic variations of image shading. The compelling impression of 3-dimensional form from these patterns provides strong evidence that the ability of observers to perceptually interpret surface contours is considerably less restrictive than would be reasonable to expect on the basis of existing computational models. Results suggest that the perceptual analysis of surface contours is able to exploit statistical regularities of contour structure over appropriately large regions of visual space.     

Understanding the Determinants of Consumer Composting Behavior1

This study compared 3 models of waste management behavior: (a) a theory of reasoned action model, (b) an environmental belief-behavior model, and (c) an integrated waste management model which is based on the theory of planned behavior. The three models were compared using data from a sample of over 1,400 individual respondents who each completed a survey and a 2-week diary of their consumer composting activities. Overall, the results suggest that while the environmental beliefs-behavior model and the integrated waste management models both fit the data well, the integrated waste management model provided better predictive power and offers significant insight into the factors that influence composting behavior.     

Unification,Reduction, and Non-Ideal Explanations

Kitcher's unification theory of explanation seems to suggest that only the most reductive accounts can legitimately be termed explanatory. This is not what we find in actual scientific practice. In this paper, I attempt to reconcile these ideas. I claim that Kitcher's theory picks out ideal explanations, but that our term explanation is used to cover other accounts that have a certain relationship with the ideal accounts. At times, versions and portions of ideal explanations can also be considered explanatory.     

Distinguishing Context Effects From Context Errors in Judgments of Behavior1

Context effects (assimilation and contrast) are examined in relation to accuracy in judgments of stimuli. Context effects are distinguished from context errors. This is shown to depend on one's definition of true scores, rater tendencies (leniency-severity) relative to true scores, and the direction and magnitude of observed context effects. The framework is illustrated empirically in a study of contrast effects involving performance judgments. Implications for reliability, validity, and agreement of behavior judgments in practice are explored.     

Are All Hostility Scales Alike? Factor Structure and Covariation Among Measures of Hostility1

Few studies have examined the correlational and structural relationships between measures of hostility that may predict coronary heart disease. Using data from a population-based study (N= 2,682), we examined the factor structure among the five subscales from Siegel's (1986) Multi-dimensional Anger Inventory, the three subscales from Spielberger et al.'s (1985) anger expression scales, a Cook-Medley (Cook & Madley, 1954) hostility subscale that measures cynicism, and items measuring hostility from four scales that assess Type A behavior. Eight separate factors were identified: hostile anger expression, perceived control over the expression of one's anger, frequency of anger, ease of anger provocation, brooding, hostile outlook, cynicism, and sullenness. These results suggest that the structure of hostility measures is more complex than previous factor analyses have suggested. Our findings point to the dangers in assuming that a factor structure can be generalized beyond the data on which it is based to provide theoretical statements about psychological structure. The new scales appear to be valid because they correlate with demographic variables and indicators of social support in the expected directions.     

The relationship of spiritual maturity to level of object relations development and God image

Several theoretical studies have suggested that spiritual maturity parallels psychological maturity from an object relations perspective in that both involve a relationality that is characterized by mature dependence (Shackelford, 1978; Pingleton, 1984). In addition, previous research has suggested that there is a positive relationship between level of object relations development and God image (Rizzuto, 1979; McDargh, 1983, 1986; Birky & Ball, 1988; Brokaw, 1991). In light of this, the present study theoretically and empirically explored the notion that both level of object relations development and God image are positively correlated with spiritual maturity. The results suggest initial support for the present hypotheses. Theoretical as well as clinical implications of the results are discussed.This paper was presented at the 1994 American Psychological Association Annual Meeting, Los Angeles, CA.     

Me,us and them: Political identification and the third-person effect in the 1993 Australian federal election

Three days prior to the 1993 Australian federal election 54 Australian university students who identified with one of the two major political parties were surveyed regarding their perceptions of media campaign impact on self and others. Results provided evidence of a third-person effect (Davison, 1983) wherein respondents judged others us more influenced by the election campaign than themselves. Consistent with predictions derived from social identity theory and self-categorization theory (e.g. Turner, Hogg, Oakes, Reicher and Wetherell, 1987), political ingroup members were also judged as less injuenced by campaign content than political outgroup members. Respondents who identified strongly with their preferred party judged self and ingroup members as less influenced by campaign content than did other respondents, and showed more evidence of positive intergroup differentiation. At the same time, however, these respondents exaggerated self–ingroup differences, challenging the theoretical assumption that intergroup diferentiation is associated with ingroup assimilation. Judgements of media impact on self and other also depended on the direction of the campaign message. Respondents believed ‘voters in general’ were persuaded in line with the intent of campaign content, while outgroup members were seen to be persuaded by material favouring their own side but to be uninfluenced by counter-attitudinal content. Election propaganda, irrespective of direction, was seen to amplify existing party preferences in self and ingroup members. Hence the relative invulnerability of self to media impact was pronounced when respondents judged the impact of pro-outgroup messages. Results suggest that perceptions of self–other differences in media vulnerability are influenced by the subjectively salient social relationship between self and other, and are governed by motivational needs, such as self-esteem, social-identity, and differentiation from others (cf. Brewer, 1991; Hogs and Abrams, 1993).     

Prepulse inhibition of the startle eyeblink as an indicator of temporal summation

The inhibition of the human startle eyeblink response was assessed in three experiments in which the duration of the prepulse was manipulated. In all cases, inhibition of startle was more pronounced as prepulse duration increased from 6 to 50 msec. Inhibition of startle amplitude for single prepulses was not significantly different from that for paired prepulses (Experiment 1), but inhibition was more pronounced as prepulse intensity increased (Experiment 3). Varying the interval between prepulse offset and startle-stimulus onset had no significant effect on inhibition (Experiment 2). These data demonstrate the sensitivity of startle inhibition to prepulse duration, and suggest that this response system can be used to evaluate early temporal summation in the auditory system.