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.     

Conditional Control of Fluid Consumption in an Occasion Setting Paradigm Is Independent of Pavlovian Associations

Drug states, flavors, and contextual cues were each trained as conditional discriminative stimuli to control a saccharin-LiCl association. In transfer tests, drug states transferred control over consumption to other flavored solutions and to food. Contexts and flavors transferred control only to other flavored solutions. Pavlovian control groups given direct pairings of context-LiCl or flavor-LiCl did not show reliable transfer. However, these control groups did show greater or the same aversion to the specific context or flavor predicting LiCl compared to the context or flavor discrimination groups. The dissociation of the discrimination and Pavlovian groups on transfer versus preference tests suggests that performance on the occasion setting task cannot be due to simple excitation or learning about a unique compound cue. Data from extinction procedures provide further support for the dissociation between simple excitation and occasion setting.     

Human d-amphetamine drug discrimination: methamphetamine and hydromorphone.

Standard measures of subjective and discriminative effects of drugs were compared in 5 human volunteers. Subjects responded on a second-order color-tracking procedure, where 30 mg of d-amphetamine served as a discriminative stimulus for one response and its absence as the discriminative stimulus for another response. Self-reported subjective effects were assessed concurrently using the single-dose questionnaire, subscales of the Addiction Research Center Inventory, and several analogue rating scales. On different days following discrimination acquisition, varying doses of d-amphetamine, methamphetamine, and hydromorphone were administered. In these test sessions, either response was reinforced. Methamphetamine and d-amphetamine occasioned dose-related increases in d-amphetamine appropriate responding; hydromorphone did not. Methamphetamine and d-amphetamine occasioned dose-related increases in reports of the drug received being most like "speed"; hydromorphone occasioned dose-related increases in reports of the drug received being most like "dope." All three drugs occasioned dose-related increases in reports of drug liking, and increases in the morphine-benzedrine group, amphetamine, and benzedrine group scales of the Addiction Research Center Inventory. This experiment demonstrated that although explicit discriminative control of behavior by a drug may covary with drug identification, it does not necessarily covary with other self-reported subjective effects. Thus, the complementary nature of the data provided by drug discrimination and standard subjective-effects measures provides quantitative and qualitative data useful in studying both relatively novel compounds and the behavioral biology of psychoactive drugs in general.     

Spectral and pattern response in the rabbit retina.

The advantages of presenting sensory data in terms of stimulus variables are stressed. Spectral sensitivity plots of local electroretinograms and ganglion cell discharges from the dark-adapted rabbit retina illustrate the utility of using this kind of procedure. Spectral data agreed with the literature demonstrating two cone and one rod process in this animal. The spectral sensitivities of both the local electroretinogram and ganglion cell spikes were closely similar. Data pertaining to pattern vision may also be subjected to the same type of analysis and described in terms of stimulus variables.     

Behavioral and pharmacological modulation of respiration in rhesus monkeys.

Changes in respiration associated with schedule-controlled behavior were determined in seated rhesus monkeys prepared with a pressure-displacement head plethysmograph for monitoring ventilation continuously during behavioral experiments. Subjects were trained to press a lever under fixed-ratio 40 and fixed-interval 300-s schedules of stimulus termination. Episodic increases in ventilation were closely associated with periods of responding under both schedules. Recurring episodes of increased ventilation occurred during fixed-ratio responding, and were separated by brief 10-s timeouts during which ventilation decreased. Under the fixed-interval schedule, both ventilation and response rate typically increased as the 300-s interval elapsed. The effects of cocaine, caffeine, and two adenosine agonists, 5'-N-ethylcarboxamidadenosine (NECA) and 2-(carboxyethylphenylamino)adenosine-5'-carboxamide (CGS 21680), on behavior and respiration were determined using a cumulative-dosing procedure. Drug-induced suppression of behavior eliminated the episodic increases in ventilation during the performance components of both schedules. Schedule-related increases in ventilation were compared to those produced by elevated levels of CO2 in inspired air. Exposure to 4% CO2 mixed in air increased ventilation in all subjects, and the combined effects of CO2 exposure and schedule-controlled responding on respiration appeared to be additive. The results suggest that behavioral activities may increase ventilation through increased metabolic demand and increased CO2 production.