Predictive testing and oncogenes

Case vignette: sharing unanticipated genetic information. The Questor family has experienced an unusual number of malignancies in the past two generations and has been advised by an oncologist that the p53 oncogene known as Li-Fraumeni Syndrome may be present in the family genome. The option of predictive genetic testing has been raised and several branches of the family have chosen to undergo screening to determine whether they are at risk for cancer because of the gene. Roger and Liz Questor have arranged for screening of themselves and their three children, ages 12, 10, and 7. The couple has, by all appearances, been happily married for 14 years. None of the family members are found to carry the oncogene; however, the geneticist conducting the analyses has made an interesting incidental discovery. The 10-year-old child is not the biological progeny of Roger Questor. Although the 12- and 7-year-olds are clearly the biological children of the couple, it is evident that the 10-year-old born to Liz Questor was fathered by a person other than Roger. What are the ethical obligations of the geneticist with respect to any sharing or disclosure of the information that has been discovered incidentally? What course of action, if any, do you recommend?     

Attentional bias to threat: Roles of trait anxiety, stressful events, and awareness

Attentional biases for threat stimuli were assessed in high and low trait anxious subjects (n = 66) using a probe detection task. To examine the effects of trait anxiety and situational stressors, each subject was tested three times: Under no stress, laboratory-induced stress, and examination-induced stress. To evaluate the role of awareness, half the word stimuli were presented very briefly (14 msec) and masked, and the other half were presented for 500 msec without a mask. Results showed that high trait anxious subjects under exam stress showed an attentional bias towards unmasked threat stimuli compared with low trait subjects. This effect was not found under lab-induced stress, suggesting that the attentional bias for unmasked threat in high trait subjects may be a function of a prolonged stressor, rather than a transient increase in state anxiety. The results from the masked exposure condition were not predicted; high trait anxious subjects shifted attention towards the spatial location of threat words despite lack of awareness of their lexical content, but this bias was only apparent in the no-stress condition. The results are discussed in relation to recent cognitive theories of anxiety.     

Does stimulus correspondence account for the Simon effect? Comments on Hasbroucq and Guiard (1991)

Summary In a recent paper analysing the Simon effect, Hasbroucq and Guiard (1991) concluded that stimulus congruence, a correspondence relationship between stimulus components, accounts for the Simon effect and explains its reversal in the Hedge and Marsh experiment (1975). We contend that their definition of stimulus congruence is applied inconsistently, which invalidates their conclusion. It is argued here that the effect of display-control arrangement correspondence (Simon, Sly, & Vilapakkam, 1981) is an alternative account that fits the presented data better. In a second experiment, Hasbroucq and Guiard (1991) claimed to have invalidated the suggestion that display-control arrangement correspondence could be considered to be an alternative account of the findings in their Experiment 1. However, we assert that the type of display-control arrangement employed in their second experiment was so unpredictable that no effect of display-control arrangement correspondence could occur.     

Indirect modes of aggression among women of Buenos Aires,Argentina

This study utilizes the construct indirect aggression to investigate aggressive behavior among middle class Argentine women and men by administering an attitude and self-report survey to 95 inhabitants of Buenos Aires and by analyzing ethnographic interviews and observations conducted over a nine month period in 1992. An examination of sex roles in Argentina, including machismo and marianismo, provide a cultural context for interpreting aggression. Factor analyses revealed the presence of indirect aggression (e.g., social manipulation, gossip, exclusion) in addition to verbal and physical aggression. Survey and ethnographic findings converge in suggesting that women employ more indirect aggression than men, while men utilize more physical aggression. While competition and aggression are salient elements of social life for both sexes, women and men tend to favor different approaches. The findings are compared with the literature on female aggression from other cultural settings. We conclude that cultural and evolutionary perspectives elucidate aspects of female aggression.We would like to thank the Ford Foundation for providing the financial support to make this research possible. We would also like to thank Patricia de Gyldenfeldt and Debbie Bandura for their endless contributions with translations, ideas, and help in general. Finally, we would like to thank Eckerd College, la Universidad del Salvador, and Michael Hobson for their base of support, all those in Argentina, especially Agueda, Andrea, Carmen, Cecilia, Claudio, Daniela, Heidi, Ingrid, Javier, Julio, María, Mariela, Roberto, and Victor, who offered their enthusiastic assistance and ideas, and Victoria Burbank, Ayala Gabriel, and the anonymous reviewer for their helpful suggestions.     

Truth-ratios,process, task,and knowledge

In this paper, I delineate two major problems facing reliabilist approaches in epistemology. I argue that Alvin Goodman's (1986) position fails to solve either problem. I then suggest an alternative reliabilist approach that ties truth-ratio assessments to particular, well-specified cognitive tasks. I claim that a well-specified cognitive task is an empirical hypothesis about a system that involves the specification of input and output types and nomic correlations (including statistical correlations) that underlie the system's performance. On my approach, one characterizes processes by reference to the system's dispositions across the situations consistent with the task. Characterization is best understood as revealing a strategy or a set of strategies for generating outputs from inputs relying on certain nomic correlations associated with the task.     

Temporal discrimination learning of operant feeding in goldfish (Carassius auratus)

Operant temporal discrimination learning was investigated in goldfish. In the first experiment, there was a fixed daily change in illumination. Eight subjects were trained to operate a lever that reinforced each press with food. The period during which responses were reinforced was then progressively reduced until it was 1 hr in every 24. The final 1-hr feeding schedule was maintained over 4 weeks. The feeding period commenced at the same time each day throughout. The food dispensers were then made inactive, and a period of extinction ensued for 6 days. The pattern of responding suggested that the fish were able to exhibit temporal discrimination in anticipation of feeding time. This pattern of responding persisted for a limited number of days during the extinction procedure. The second experiment produced evidence that operant temporal discrimination could develop under continuous illumination.     

Exchange delays and impulsive choice in adult humans.

Choice responding by adult humans in a discrete-trial task was examined as a function of conditions that manipulated either the delay to point delivery or the delay between points and their exchange for money. In point-delay conditions, subjects chose between an "impulsive" alternative that provided a small amount of points immediately and a "self-control" alternative that provided a larger amount of points delayed by 15, 30, or 60 s. Points were exchanged for money immediately following the session. Subjects preferred the self-control alternative. In exchange-delay conditions, subjects chose between a small amount of points exchangeable for money immediately following the session and a larger amount of points exchangeable for money after 1 day, 3 weeks, or 6 weeks. A self-control preference observed for all subjects in the 1-day exchange-delay condition reversed to exclusive impulsive preference for 4 of the 6 subjects when choice conditions involved exchange delays of 3 or 6 weeks. These results show that human choice is sensitive to the manipulation of exchange delays and that impulsive preference can be obtained with exchange delays on the order of weeks.     

Functions of the environment in behavioral evolution

This paper explores some of the ways in which the environment functions with respect to behavior within an explanatory framework analogous to that of evolutionary biology. In both the behavioral and organic domains, the environment functions differently with respect to individual occurrences and evolutionary units. Within the behavioral domain, the problem of accounting for an occurrence of an operant instance differs from that of accounting for the existence of the operant unit of which the instance is a part. Maintaining these distinctions in levels of analysis within the behavioral domain, we focus first on operant units and operant instances as products of evolutionary processes occurring in the behavioral domain and second upon the causal role of the environment with respect to the existence of operant units and the occurrence of operant instances. The environment's function is selective with respect to origin, maintenance, suppression, and extinction of behavioral populations. At the level of operant instances, the environment has instantiating functions-evocative or alterative. Evocative functions are exemplified by discriminative relations, and alterative functions include both conditional and motivative relations. Implications are considered regarding extension of the analogy to more complex behavior-environment relations.