Contents of Volume 16

Volume Contents

Contents of Volume 16     

Responses to olfactory stimuli in spotted hyenas (Crocuta crocuta): I. Investigation of environmental odors and the function of rolling

Olfaction is crucial to spotted hyenas (Crocuta crocuta), yet there are no controlled studies of their reactions to odors. In Experiment 1, the authors examined responses of captive hyenas to various environmental (prey, nonprey animal, and plant) odors. Subjects approached and sniffed all odors equally but preferentially licked prey odors, scent marked next to odors, and rolled in animal-based odors. In Experiment 2, the authors examined the function of rolling by applying odors to the pelts of captive hyenas. When hyenas wore carrion, they gained positive social attention (increased investigation and allogrooming) from pen mates, but when they wore camphor, the normal social greeting ceremony was curtailed. Thus, olfactory stimuli elicit specific responses, influence where behavior is directed, and can be used to affect social interaction.     

Age,executive function,and social decision making: a dorsolateral prefrontal theory of cognitive aging

Current neuropsychological models propose that some age-related cognitive changes are due to frontal-lobe deterioration. However, these models have not considered the possible subdivision of the frontal lobes into the dorsolateral and ventromedial regions. This study assessed the age effects on 3 tasks of executive function and working memory, tasks dependent on dorsolateral prefrontal dysfunction; and 3 tasks of emotion and social decision making, tasks dependent on ventromedial prefrontal dysfunction. Age-related differences in performance were found on all tasks dependent on dorsolateral prefrontal dysfunction. In contrast, age-related differences were not found on the majority of the tasks dependent on ventromedial prefrontal dysfunction. The results support a specific dorsolateral prefrontal theory of cognitive changes with age, rather than a global decline in frontal-lobe function.     

False memories of the future: a critique of the applications of probabilistic reasoning to the study of cognitive processes

The authors argue that the ways in which people-scientists and laymen-use probabilistic reasoning is predicated on a set of often questionable assumptions that are implicit and frequently go untested. They relate to the correspondence between the terms of a theory and the observations used to validate the theory and to the implicit understandings of intention and prior knowledge that arise between the conveyer and the receiver of information. The authors show several ways in which the use of probabilistic reasoning rests on a priori commitments to a partitioning of an outcome space and demonstrate that there are many more assumptions underlying the use of probabilistic reasoning than are usually acknowledged. They unfold these assumptions to show how several different interpretations of the same results in behavioral decision theory and cognitive psychology are equally well supported by "the facts." They then propose a more comprehensive approach to mapping cognitive processes than those currently used, one that is based on the analysis of all of the relevant alternative interpretations presented in the article.     

On euthanasia: blindspots in the argument from mercy

In the euthanasia debate, the argument from mercy holds that if someone is in unbearable pain and is hopelessly ill or injured, then mercy dictates that inflicting death may be morally justified. One common way of setting the stage for the argument from mercy is to draw parallels between human and animal suffering, and to suggest that insofar as we are prepared to relieve an animal's suffering by putting it out of its misery we should likewise be prepared to offer the same relief to human beings.
In this paper, I will argue that the use of parallels between human and animal suffering in the argument from mercy relies upon truncated views of how the concept of a human being enters our moral thought and responsiveness. In particular, the focus on the nature and extent of the empirical similarities between human beings and animals obscures the significance for our moral lives of the kind of human fellowship which is not reducible to the shared possession of empirical capacities.
I will suggest that although a critical examination of the blindspots in these arguments does not license the conclusion that euthanasia for mercy's sake is never morally permissible, it does limit the power of arguments such as those provided by Rachels and Singer to justify it. I will further suggest that examination of these blindspots helps to deepen our understanding of what is at stake in the question of euthanasia in ways that tend otherwise to remain obscured.     

Source monitoring in a generative task

Following exposure to experimenter-provided examples of space creatures, people tend to conform to the features contained in the examples when creating their own novel space creatures. In three experiments, we manipulated factors known to affect source-monitoring accuracy to determine how these manipulations would influence conformity to experimenter-provided examples. In Experiment 1 we altered people's cognitive agenda by means of the instructions given before the drawing task. In Experiment 2 we examined how time pressure would affect the level of conformity, and in Experiment 3 we manipulated the availability of the creatures during the drawing task by making them available to half the participants. Conformity decreased when extended source-monitoring processes were engaged and increased when these processes were disrupted. The results from the three experiments were consistent with the principles of the source-monitoring framework.     

Weathering a political storm. A contextual perspective on a psychological research controversy

In the spring of 1999, a storm of controversy arose at the local, state, and national levels surrounding an article on the effects of child sexual abuse published in 1998 in Psychological Bulletin. The article was vehemently denounced by various media outlets, conservative grassroots organizations, members of the general public, state legislatures, and ultimately by the United States Congress. The authors chronicle these unprecedented events and related challenges faced by the American Psychological Association. The authors also describe the Association's efforts to resolve the crisis, while staunchly upholding academic freedom and scientific integrity, and review the lessons learned for the field of psychology.     

Behavioral and electrical brain measures of semantic priming in patients with Alzheimer's disease: implications for access failure versus deterioration hypotheses

This study investigated the nature of anomia and semantic memory deficits in patients with Alzheimer's disease (DAT). We measured reaction time (RT) and the N400 event-related brain potential (ERP) in a word-picture semantic priming paradigm for DAT patients and elderly controls. For patients, pictures were classified as a function of the individual's naming ability to determine whether naming deficits reflected a failure to access a picture's name or reflected a deterioration of its semantic representation. As expected, DAT patients had significantly poorer naming performance than controls. For successfully named pictures, robust RT and ERP priming effects were obtained in both groups. In DAT patients, priming for unnamed pictures was heterogeneous. The results are discussed in terms of current hypotheses of semantic memory deficits in DAT.