Feature-based search asymmetries in pigeons and humans

Pigeon and human subjects searched for one target item amidst a number of identical distractors. Simple line forms were used. The target differed from the distractors only in terms of the presence or absence of a feature (a line or a gap); in some experimental series, the feature was present in the target; in others, the feature was in the distractors. The pigeons pecked at the target; the human subjects either reported the presence of the target or pointed to it with a light pen. The time between display onset and this response was recorded. Varied across experimental conditions were the number of distractors in the display, the nature of the stimulus forms, and certain procedural parameters; five conditions were run with pigeons and three with humans. Under all test conditions, the results from the human subjects replicated the previously reported search-asymmetry effect. That is, search speed was greater and decreased less with display size when the target bore the feature (line or gap) than when the distractors bore the feature; both yes/no and localization-response conditions yielded this effect. However, pigeons failed to show search asymmetry; neither line nor gap in a target facilitated search. The results suggest that early visual processing differs for pigeons and humans, that pigeon features differ from human features, or that search asymmetry was eliminated by the long practice given the pigeons.     

Biomedical science in supermarket tabloids

Supermarket tabloids present, as truthful, stories about biomedical science that are greatly exaggerated and often fictitious. Apparently a sizable portion of their large readership accepts these stories as correct. This is “scientific journalism” at its worst, but its standards are not wholly different from those of the mainline press. Allan Mazur is both a sociologist and a technologist. He received an M.S. in Engineering from UCLA and worked for several years as an aerospace engineer before obtaining a Ph.D. in sociology from Johns Hopkins University. He has been a member of the social science faculties of MIT and Stanford University, and is currently a professor in Syracuse University's Maxwell School of Citizenship and Public Affairs.The Dynamics of Technical Controversy (1981) is his major work on public disputes over technology, and he continues to work in this area as well as in biosociology.     

Modes of understanding and mindfulness in clinical medicine

Beginning with a case vignette, this paper uses a semiotic approach to analyze several different kinds of understanding used in clinical medicine. By outlining semiotic structures, four distinct modes of understanding can be defined: (1) the representational mode, corresponding to scientific medicine; (2) the pragmatic mode, constituting the basic standpoint of medicine; (3) the hermeneutic mode, underlying the empathic, humanistic spirit of medicine; and (4) the ontologic mode, associated with both the ethical and ritual aspects of medicine. Clarifying the relationship between these modes avoids common confusions in clinical situations. Although experienced clinicians intuitively use these different modes, they do not necessarily reflect upon them. They are instead mindful of them, and this unique multi-modal consciousness, I suggest, provides a model for integrating theory and practice.This work was supported in part by the Robert Wood Johnson Clinical Scholars Program.     

Psychological effects of prenatal diagnosis: The example of fetal echocardiography

This article presents two studies investigating the psychological effects of fetal echocar-diography (FE). The first compared the effects of FE in high risk and obstetrically normal women. High-risk women were more anxious beforehand and had more negative attitudes. Following a normal scan their attitudes and anxiety were equivalent to the controls but a large variation in postscan psychological changes was found. This variation was examined in the second study with a larger sample. Selected background variables predicted prescan anxiety and anxiety reduction following a normal scan. Quality of communication and feedback also determined postscan anxiety level and rated satisfaction in the two-week follow-up questionnaire. Some suggestions for routine medical practice are included.     

Smoking Prevention and the Concept of Risk1

Sixth-grade children in 22 schools received either a social-influences smoking-prevention program or routine health education. The social-influences program was designed to teach youth about peer, parent, and media influences affecting smoking onset and to provide them with skills in resisting these influences. Comparison schools were given no program, but were permitted to continue their usual provision of health education. Program impact was evaluated as a function of pretreatment risk of future smoking. Risk was defined with respect to both (a) the prevalence of social models who smoked and (b) previous smoking experience. Two-and-a-half-year results show program impact to vary with both kinds of risk. Smoking-experience risk interacted such that, at first, there was greater impact on children with experience, but on later follow-up the pattern reversed, with the greater treatment effects seen for those initially with limited experience. Social-models risk showed a direct relationship, with greater risk being associated with greater program impact. Implications both for evaluation research and prevention programs are discussed.     

A cross-validation of sex differences in the expression of depression

A considerable amount of evidence has accumulated indicating a greater rate of depression among females compared to males. In addition, recent investigations have revealed distinct patterns of depressive responding as a function of sex. The present study provided a cross-validational test of findings reported by Funabiki and colleagues. Male and female college students indicated the likelihood that they would engage in 79 behavioral analytically derived behaviors or cognitions if depressed. Stepwise discriminant function analyses were performed to determine maximum separation of male and female responses. This procedure yielded a 55.6% overall variable cross-validation rate. Many of the findings were consistent with Radloff and Rae's theoretical view of sex differences in learned susceptibility to depression. The data also suggest several avenues for future research and support the utility of investigating theories of depression within the context of a continuity between normal mood states and depressive phenomena.Useful comments on an earlier draft of this article were provided by Mark Hammarlund and Lorence S. Miller. The order of authorship was determined by the flip of a coin.     

Health care and the prospective Pareto principle

Issues of social justice in access to health care are examined from the standpoint of the "prospective," or "ex ante," Pareto principle, an ethical principle which holds that one policy is to be preferred over another if it betters the prospects of some persons while the alternative betters no one's prospects. It is suggested that this principle may validate a form of utilitarianism in health policy decisions, with equity demanding that everyone have access to a decent minimum of care but not necessarily to all highly expensive treatments.     

Visual movement perception: A comparison of sensitivity to vertical and horizontal movement

A psychophysical model that provides separate measures of judgmental standards and sensitivity is utilized to compare an O’s visual sensitivity for vertical and horizontal movement. The analysis indicates no consistent difference in sensitivity; those asymmetries that do exist simply appear to be due to idiosyncratic judgmental standards.