Rotational and translational components of motion parallax: observers' sensitivity and implications for three-dimensional computer graphics

The motion of objects during motion parallax can be decomposed into 2 observer-relative components: translation and rotation. The depth ratio of objects in the visual field is specified by the inverse ratio of their angular displacement (from translation) or equivalently by the inverse ratio of their rotations. Despite the equal mathematical status of these 2 information sources, it was predicted that observers would be far more sensitive to the translational than rotational component. Such a differential sensitivity is implicitly assumed by the computer graphics technique billboarding, in which 3-dimensional (3-D) objects are drawn as planar forms (i.e., billboards) maintained normal to the line of sight. In 3 experiments, observers were found to be consistently less sensitive to rotational anomalies. The implications of these findings for kinetic depth effect displays and billboarding techniques are discussed.     

Common morality as an alternative to principlism.

Unlike the principles of Kant, Mill, and Rawls, those of principlism are not action guides that stem from an underlying, integrated moral theory. Hence problems arise in reconciling the principles with each other and, indeed, in interpreting them as action guides at all, since they have no content in and of themselves. Another approach to "theory and method in bioethics" is presented as an alternative to principlism, though actually the "alternative" predates principlism by about 10 years. The alternative's account of morality stays close to ordinary, common morality with its rules and ideals, which in turn are grounded in aspects of human nature. As such, morality must be understood to be a rational, impartial, and public system that is incumbent on everyone. Morality is a unified and integrated system. The moral rules and ideals are also "culture-" and "profession-sensitive" in that they are interpreted more specifically within these various contexts.     

An advocacy intervention program for women with abusive partners: Six-month follow-up

Presented the 6-month follow-up findings of an experimental intervention designed to provide postshelter advocacy services to women with abusive partners. The intervention involved randomly assigning half the research participants to receive the free services of an advocate, 4 to 6 hours per week, for the first 10 weeks postshelter. One hundred forty-one battered women were interviewed about their experiences immediately upon their exit from a domestic violence shelter: 95% of the sample were interviewed 10 weeks thereafter (postintervention), and 93% were successfully tracked and interviewed 6 months later. At the 6-month follow-up, participants in both groups reported increased social support, increased quality of life, less depression, less emotional attachment to their assailants, and an increased sense of personal power. Although women in both groups reported some decrease in physical abuse over time, there were no statistically significant differences between those with and those without advocates, and abuse continued to be a problem for many women. Those who were still involved with their assailants continued to experience higher levels of abuse and had been more economically dependent upon the men prior to entering the shelter. Women who had worked with advocates continued to report being more satisfied with their overall quality of life than did the women in the control group. The authors thank the Editor and anonymous reviewers for their helpful comments. Thanks also to all present and past staff of the Community Advocacy Project, who helped in data collection and analyses. This work was supported by National Institute of Mental Health Grant 1R01 MH 44849.     

Response acquisition by Siamese fighting fish (Betta splendens) with delayed visual reinforcement

Male Siamese fighting fish, Betta splendens, swam through a ring in an aquarium, breaking a photocell beam and initiating an unsignaled, resetting delay interval. Following delays of 0 s, 10 s, or 25 s, a 15-s mirror presentation released an aggressive display by the fish. Swimming through the ring increased in the absence of either a period of acclimatization to the reinforcer (analogous to magazine training when appetitive reinforcers are used) or explicit training of the response by the experimenters. Response rates were a decreasing function of delay duration. Other fish exposed to a schedule of response-independent mirror presentations failed to acquire and maintain the response. The results demonstrate the robustness and generality of the phenomenon of response acquisition with delayed reinforcement. They further qualify earlier observations about behavioral mechanisms involved in the phenomenon.     

Acceptance and commitment therapy: Altering the verbal support for experiential avoidance

Acceptance and Commitment Therapy (ACT) is a behavior-analytically-based psychotherapy approach that attempts to undermine emotional avoidance and increase the capacity for behavior change. An overview of this approach is given, followed by several specific examples of the techniques used within ACT. In each instance the behavioral rationale of these techniques is described. A contemporary view of verbal relations provides the basis for new approaches to adult outpatient psychotherapy.     

Working with Lesbians,Gays, and Bisexuals: Addressing Heterosexism in Supervision

Heterosexism is a form of multicultural bias that has the potential to harm both clients and supervisees. Supervisors are encouraged to examine their own heterosexist lens as a first step in providing a safe environment in which supervisees can challenge their own heterosexism. The issue of heterosexism is first discussed from an ethical vantage point. The second section of the article examines four facets of heterosexism (discrimination, lack of knowledge, stereotyping, and insensitivity) and how they might be exhibited by the supervisor in the supervision arena. Special topics discussed in this section include: the possible consequences of “coming out” in the supervisory context; the presence of heterosexism in the foundational family systems theory; the need for recognition of the special family characteristics of lesbians, gays, and bisexuals; the value of personal and professional relationships with persons who are gay, lesbian, and bisexual; common heterosexist stereotypes and research that refutes them; and the use of language. The final section of the article offers suggestions for working with supervisees around these issues.     

A PRELIMINARY PROCEDURE FOR PREDICTING THE POSITIVE AND NEGATIVE EFFECTS OF REINFORCEMENT-BASED PROCEDURES

In the current investigation, a modification was made to the preference assessment described by Pace, Ivancic, Edwards, Iwata, and Page (1985) to predict the effects of stimuli when used in a differential-reinforcement-of-other-behavior (DRO) schedule for 2 clients with severe self-injurious behavior (SIB) and profound mental retardation. Based on the results of the preference assessment, three types of stimuli were identified: (a) high-preference stimuli associated with high rates of SIB (HP/HS), (b) high-preference stimuli associated with relatively lower rates of SIB (HP/LS), and (c) low-preference stimuli associated with low rates of SIB (LP/LS). Consistent with the results of the preference assessment, the DRO schedule with HP/HS stimuli resulted in increased SIB, and the DRO schedule with LP/LS stimuli resulted in no changes in SIB. HP/LS stimuli were demonstrated reinforcers but did not result in a change in SIB when used in a DRO schedule. Thus, the stimulus preference assessment may be useful clinically in some situations for predicting both the beneficial and the negative side effects of stimuli in DRO procedures.