Perceived motion in structure from motion: Pointing responses to the axis of rotation

We investigated the ability to match finger orientation to the direction of the axis of rotation in structure-from-motion displays. Preliminary experiments verified that subjects could accurately use the index finger to report direction. The remainder of the experiments studied the perception of the axis of rotation from full rotations of a group of discrete points, the profiles of a rotating ellipsoid, and two views of a group of discrete points. Subjects’ responses were analyzed by decomposing the pointing responses into their slant and tilt components. Overall, the results indicated that subjects were sensitive to both slant and tilt. However, when the axis of rotation was near the viewing direction, subjects had difficulty reporting tilt with profiles and two views and showed a large bias in their slant judgments with two views and full rotations. These results are not entirely consistent with theoretical predictions. The results, particularly for two views, suggest that additional constraints are used by humans in the recovery of structure from motion.     

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.     

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.     

Effects of anxiety sensitivity on emotional response to a stress task

The purpose of this investigation was to further define the role of anxiety sensitivity, in relation to physiological arousal and the cognitive perception of anxiousness, as a determinant of anxiety. One hundred and thirty-two undergraduates at an urban university served as subjects. Two physiological measures of arousal and two cognitive measures of anxiety were used following an anxiety inducing task (mental arithmetic). The general expectation, which was supported, was that individual differences in anxiety sensitivity levels are more closely related to subjects' reported anxiousness in stressful conditions than are the actual physiological changes. Additionally, anxiety sensitivity was related to poststress levels of anxiety whereas trait anxiety was only related to pre- and postrelaxation levels of anxiety. Implications of the findings are addressed.     

Defaults in update semantics

The aim of this paper is twofold: (i) to introduce the framework of update semantics and to explain what kind of semantic phenomena may successfully be analysed in it: (ii) to give a detailed analysis of one such phenomenon: default reasoning.     

TEACHING MULTIPLICATION FACTS TO STUDENTS WITH LEARNING DISABILITIES

Multiple baseline designs were used to examine the effects of an instructional package on accuracy of performance in solving multiplication facts by 3 students with learning disabilities. The instructional package included the following components: (a) a modified instructional sequence in which multiplication facts were grouped into the zeros, ones, doubles, fives, and nines categories, and those remaining; (b) identification of the category in which each fact belonged; (c) mnemonic strategies associated with solving facts in each category; and (d) steps to be completed for solving facts in each category. Results indicated that the instructional package produced substantial and immediate effects. After receiving instruction, a participant's accuracy was often 100%, and this was maintained throughout the evaluation even as other strategies were introduced. Comparable results occurred across students, demonstrating replication of the effects of the instructional package.     

The Enjoyment of Sexist Humor,Rape Attitudes,and Relationship Aggression in College Students

The current study tested Freud's (1905/1960)theory that sexist humor may be associated withhostility toward women and extended previous researchshowing a link between hostile humor and aggression.Colleges students (N = 399 — approximately 92%white, 5% African American, and 3% other minorities)rated 10 sexist jokes on their perceived funniness.Results showed that the enjoyment of sexist humor waspositively correlated with rape-related attitudes andbeliefs, the self-reported likelihood of forcing sex,and psychological, physical, and sexual aggression inmen. For women, the enjoyment of sexist humor was only positively correlated with Adversarial SexualBeliefs and Acceptance of Interpersonal Violence. Womenalso found the jokes to be less enjoyable, lessacceptable, and more offensive than the men, but they were not significantly less likely to tell thejokes.     

Anger of women incest survivors

Adult women survivors of incest (n = 68) were compared to other women (n = 93) with respect to several questionnaire measures of manifest anger. The vast majority of the research participants were white, middle class, heterosexual, and Michigan residents. Incest survivors were angrier than other women, both in general and at their parents. Anger toward mother and anger toward father were comparable. Few incest survivors blamed either parent for the incest, except in those speciflc cases where the parent was a perpetrator. Not surprisingly, incest survivors were particularly angry at parent perpetrators when they were held responsible for the abuse. Incest occurred in families where other traumas were present, and the extent of these other traumas was also associated with increased anger at parents. Women who identified with feminism and who had participated in therapy were angrier at their parents than were other women. Therapy implications of these results were discussed.This paper is based on a doctoral dissertation submitted to the University of Michigan by the first author, under the supervision of the second author. The help and encouragement of committee members Margaret Buttenheim, Kathleen Faller, and Sheryl Olson are gratefully acknowledged. Howard Gottlieb, Judith Ballou, Donna Silbert, and Robert Daniels also contributed substantially to this research.Financial support was provided by the Society for the Psychological Study of Social Issues, the Horace D. Rackham School of Graduate Studies, and the Department of Psychology at the University of Michigan.