Cue competition effects in the planarian

The learning abilities of planarian worms (Dugesia tigrina) were assessed by using a number of Pavlovian conditioning paradigms. Experiment 1 showed that planaria were susceptible to basic conditioning in that they readily developed a conditioned response to a change in ambient luminance when it was consistently paired with an electric shock over a number of trials. In Experiment 2, the change in luminance was presented in a compound with a vibration stimulus during conditioning. Subsequent tests revealed poor conditioning of the elements compared with control groups in which the animals were conditioned in the presence of the elements alone, an instance of overshadowing. In Experiment 3, pre-training of one of the elements before compound conditioning resulted in blocking of learning about the other element. These results add to other studies that have reported cue competition effects in animal species belonging to different phyla (chordate, mollusk, arthropod), suggesting that learning in these phyla could be ruled by similar principles. The results are discussed adopting an evolutionary-comparative approach.     

Putting the ‘heart’ back into community psychology: some South African examples

In this paper we explore the impact of emotional dynamics in the field of community psychology and the value of psychodynamic concepts in making sense of this. Emotional processes have often not been very well acknowledged or conceptualized in writing in the area of community psychology practice. This neglect is understandable given the individualizing, pathologizing and medicalizing assumptions underlying many psychological theories of emotion. Psychodynamic ideas may, however, make a useful contribution to understanding central concerns in community psychology in so far as they are able to shed light on emotional processes in groups, the political determinants of emotional response and the emotional dynamics of power, which are all central to the thinking of community psychologists. Using examples drawn from a long-term programme of consultation to community-based services in South Africa, we explore the potential of psychoanalytic understandings of emotional processes in illuminating some of the complexities and challenges faced in developing effective community partnerships and working towards the empowerment of communities.     

Thirty Years Later: An Oncologist Reflects on Kubler-Ross's Work

As compared with conventional vaccine production systems, plant-made vaccines (PMVs) are said to enjoy a range of advantages including cost of production and ease of storage for distribution in developing countries. In this article, we introduce the science of PMV production, and address ethical issues associated with development and clinical testing of PMVs within three interrelated domains: PMVs as transgenic plants; PMVs as clinical research materials; and PMVs as agents of global health. We present three conclusions: first, while many of the ethical issues raised by PMVs are familiar, PMVs add a new dimension to old issues, and raise some novel issues for ethicists and policy-makers; secondly, it is premature to promise broad applicability of PMVs across the developing world without having demonstrated their feasibility; thirdly, in particular, proponents of PMVs as a solution to global health problems must, as a condition of the ethical conduct of their research, define the commercial feasibility of PMVs for distribution in the developing world.     

Going the distance: Extra-symbolic contributions to the symbolic control of spatial attention

Over the past 30 years, researchers have used symbolic cues such as spatial words and arrows to direct observers' attention to the location of target objects that appear at a single, fixed distance in simple visual environments; however, they have done so by using symbolic cues that provide only partial—directional—information about the spatial location of target objects. Thus, it remains unclear whether observers can only shift their attention broadly in the cued direction in response to these cues or whether they can shift their attention to the specific location of the target by combining an expectation about direction (derived from apprehension of the directional cue) with an expectation about distance (derived from some extra-symbolic cue). The results of two experiments showed that observers do shift their attention to relatively coarse spatial locations by combining expectancies about direction and distance, and that the extent to which observers do so is modulated by the presence of visible markers and the expected distance of the target. These findings are important because they provide the first evidence that extra-symbolic information about distance contributes to the symbolic control of spatial attention.     

A genetic two-factor model of the covariation among a subset of Multidimensional Aptitude Battery and Wechsler Adult Intelligence Scale—Revised subtests

The phenotypic and genetic factor structure of performance on five Multidimensional Aptitude Battery (MAB) subtests and one Wechsler Adult Intelligence Scale—Revised (WAIS-R) subtest was explored in 390 adolescent twin pairs (184 monozygotic [MZ]; 206 dizygotic (DZ)). The temporal stability of these measures was derived from a subsample of 49 twin pairs, with test–retest correlations ranging from .67 to .85. A phenotypic factor model, in which performance and verbal factors were correlated, provided a good fit to the data. Genetic modeling was based on the phenotypic factor structure, but also took into account the additive genetic (A), common environmental (C), and unique environmental (E) parameters derived from a fully saturated ACE model. The best fitting model was characterized by a genetic correlated two-factor structure with specific effects, a general common environmental factor, and overlapping unique environmental effects. Results are compared to multivariate genetic models reported in children and adults, with the most notable difference being the growing importance of common genes influencing diverse abilities in adolescence.     

Men,Women, and the Self-Presentation of Achievement

This study examined men's and women'sself-presentation of academic achievement in aninteractional context. First-year college students wereled to expect an interaction with a peer to discussacademic achievement. However, the peer was actually aconfederate who portrayed his or her achievement in aboastful, moderate, or self-deprecating manner. Prior tothe anticipated interaction, subjects were induced to describe their own academic achievement andmake predictions about their first-semester grade pointaverages (GPAs) to be shared with the peer. Men's GPApredictions were highest in the boastful condition (and higher than their actual GPAs), nexthighest in the moderate condition, and lowest (and lowerthan their actual GPAs) in the self-deprecatingcondition. Women's predicted GPAs,unexpectedly,didnotvary by condition. Women were less comfortable inpredicting their GPAs than men, and there was a tendencyfor men to be more comfortable than women whileobserving the boastful peer and women to be morecomfortable than men while observing the self-deprecatingpeer. Results are discussed with regard to past researchand self-in-relation theory.     

The Bank Job: A Field Study of Sexually Discriminatory Performance on a Neutral-Role Task

Sixty-four checks were cashed in a field examination of sex role discrimination using a non-sex-role stereotyped (neutral role) task. Experimenter (customer) sex, subject (teller) sex, amount of the check, and bank branch were varied to produce a 2 × 2 × 2 × 2 design. Transaction times were longer for female customers than for male customers, and were longer with male tellers than with female tellers. Results were interpreted as supporting the hypothesis of greater sex role salience in cross-sex, as compared with same-sex dyads. Suggestions are made for further research using neutral-role tasks to better define certain role concepts.