An adaptive reference/test paradigm: Application to pulsed fluoroscopy perception

We developed an adaptive forced-choice method whereby reference and test presentations were alternated in order to minimize effects from variables such as subject attention level. In our demonstration example of an X-ray fluoroscopy perception study, we measured detectability of low-contrast objects in noisy image sequences and determined X-ray dose levels for equivalent detectability of identical contrasts for a new test acquisition method (fluoroscopy at 15 acq/sec) as compared with a reference (conventional fluoroscopy at 30 acq/sec). In preliminary experiments, we found a dose savings with the test method. We derived parameter uncertainties for the adaptive procedure and demonstrated their applicability with Monte Carlo simulations. Repeated experiments on a single subject demonstrated reduced standard errors due to the reduction of day-to-day variations. It is believed that the method can be applied in a variety of situations in which one needs to compare perception measurements.     

HIV-Antibody Testing: Beliefs Affecting the Consistency Between Women's Behavioral Intentions and Behavior1

A sample of 763 nonpregnant, heterosexual, sexually active women residing in an HIV-endemic area participated in a study to assess psychological predictors of HIV-antibody testing. In this sample, 464 women said that they might or would be tested that day, although only 56 did so. We examine salient beliefs that influenced testing decisions. In contrast to other studies, which have focused on predictors of behavioral intentions at only one point in time, the current study accounts for the fact that different concerns become salient to women at different stages of the counseling and testing process. Prior to counseling, women were deterred from testing because they feared the anxiety of waiting for their test results. This suggests that efforts aimed at same-day testing may be beneficial for increasing rates of test taking. After counseling and immediately preceding testing, women tended to follow through on their intentions if they believed that testing would better enable them to plan a pregnancy, and if they believed that it would not be too late for treatment. The implications of these findings for the counseling and testing process are discussed.     

Marginal maximum likelihood estimation for a psychometric model of discontinuous development

Item response theory models posit latent variables to account for regularities in students' performances on test items. Wilson's “Saltus” model extends the ideas of IRT to development that occurs in stages, where expected changes can be discontinuous, show different patterns for different types of items, or even exhibit reversals in probabilities of success on certain tasks. Examples include Piagetian stages of psychological development and Siegler's rule-based learning. This paper derives marginal maximum likelihood (MML) estimation equations for the structural parameters of the Saltus model and suggests a computing approximation based on the EM algorithm. For individual examinees, empirical Bayes probabilities of learning-stage are given, along with proficiency parameter estimates conditional on stage membership. The MML solution is illustrated with simulated data and an example from the domain of mixed number subtraction. The authors' names appear in alphabetical order. We would like to thank Karen Draney for computer programming, Kikumi Tatsuoka for allowing us to use the mixed-number subtraction data, and Eric Bradlow, Chan Dayton, Kikumi Tatsuoka, and four anonymous referees for helpful suggestions. The first author's work was supported by Contract No. N00014-88-K-0304, R&T 4421552, from the Cognitive Sciences Program, Cognitive and Neural Sciences Division, Office of Naval Research, and by the Program Research Planning Council of Educational Testing Service. The second author's work was supported by a National Academy of Education Spencer Fellowship and by a Junior Faculty Research Grant from the Committee on Research, University of California at Berkeley. A copy of the Saltus computer program can be obtained from the second author.     

Sensation seeking, television viewing motives, and home television viewing patterns

This study examined the relationships between sensation seeking and television viewing motives and home TV viewing preferences. A total of 189 participants completed a sensation seeking scale, rated the importance of several global television viewing motives, and indicated viewing frequency for 18 categories of TV programming. Findings indicated that, contrary to previously-reported results, high sensation seekers did not watch less television or rate it as less important in their lives compared to low sensation seekers. Sensation seekers did, however, indicate several program viewing preferences. Compared to low sensation seekers, high sensation seekers watched more music videos, daytime talk shows, stand-up comedy programs, documentaries, and animated cartoons; they watched fewer newscasts and drama series. Findings are discussed in terms of selective exposure processes and social-environmental influences on behavioral manifestations of sensation seeking.     

Sociocultural expectations of attractiveness for males

Sociocultural expectations of attractiveness for women have been studied extensively, but little research has focused on this topic with males. Using the two most popular men's fashion magazines (GQand Esquire), this study examined article and advertisement content as well as male models' body sizes to determine the extent to which men have received messages from the media on how to behave (e.g., diet, exercise) and look over a 32 year period (i.e., 1960–1992). Linear trend analyses revealed that the number of messages concerning physical fitness and health have increased as has the general popularity of health and fitness activities. Messages concerning weight and beauty, however, have declined since the late 1970s. In spite of these changes, measures of male models' body sizes have not changed significantly since the 1960s. These findings are discussed in the context of the sociocultural approach to eating disorders and recommendations for future research are provided.     

Stages of decompensation in combat-related posttraumatic stress disorder: A new conceptual model

This conceptual article presents a model of severe, chronic combat-related PTSD based on several years of longitudinal clinical observations of Vietnam veterans. The model describes a repeating cycle of decompensation that profoundly disrupts the veteran’s life. There appear to be “stages” of decompensation that can be described clinically and may be distinct physiologically. The stages describe a wide range of functioning, from adaptive to totally dysfunctional. PTSD core symptoms, as well as several other dimensions of clinical functioning, such as affect regulation, defenses, ego states, interactions with the environment, capacity for self-destruction/suicide and capacity for attachment and insight are described for each stage. Clinical and research implications are discussed.     

Addressing women's breast cancer risk and perceptions of control in medical settings

Many women with family histories of breast cancer deal with two distinct but related issues: their objective physical risk and the emotions this risk engenders. Studies indicate that approximately 70% of African American and white women are concerned about their chances of developing breast cancer someday and perceive themselves to be at risk. Health care providers, including psychologists, need to be aware of the special needs and psychosocial concerns of high-risk women with family histories of breast cancer, since perceptions of breast cancer risk influence screening practices. Providers need training in understanding the significance of specific family patterns of breast cancer, screening guidelines appropriate for women at risk, and the benefits and risks of available prevention options, including genetic screening. Delivering accurate information about both established risk factors known to elevate personal risk, such as age and family history, and factors which women associate with breast cancer, such as bumping and bruising a breast, smoking, and oral contraceptive use, is essential for promoting accurate risk perceptions and appropriate screening schedules.     

Cognitive moderators of alcohol's effects on anxiety

The present study was designed to test the prediction from the attention-allocation model that intoxication in the absence of a pleasant distractor will fail to produce anxiolytic effects. A second prediction, that the sequence of intoxication and exposure to the anxiety-producing situation would influence alcohol's effects, was also tested. Subjects were male social drinkers who received an 0.85 g/kg dose of alcohol or a placebo. Conventional statistical analysis of the results indicated an anxiolytic effect of alcohol on heart rate but a problem with this analysis is identified. An alternative interpretation provides no support for an anxiolytic effect. Exposure to the anxiety-producing stimulus prior to intoxication led to greater heart rate reactivity than if it followed intoxication.