Where do you know what you know? The representation of semantic knowledge in the human brain

Mr M, a patient with semantic dementia--a neurodegenerative disease that is characterized by the gradual deterioration of semantic memory--was being driven through the countryside to visit a friend and was able to remind his wife where to turn along the not-recently-travelled route. Then, pointing at the sheep in the field, he asked her "What are those things?" Prior to the onset of symptoms in his late 40s, this man had normal semantic memory. What has gone wrong in his brain to produce this dramatic and selective erosion of conceptual knowledge?     

Diagnosing smallpox: would you know it if you saw it?

The intentional release of anthrax in the United States in 2001 and other recent acts of terrorism have highlighted the possibility of intentional release of smallpox by terrorists. Little is known about physicians' ability to diagnose smallpox, especially in the critical first days, when the potential for rapid control of transmission is greatest. During December 2002 and January 2003, primary care and emergency physicians at a large urban academic medical center were surveyed regarding the diagnosis and management of patients who present with vesicular rash illness. In addition to demographic and training-related questions, the questionnaire included items about perceived comfort in diagnosing and evaluating rashes, knowledge of the key differential diagnostic characteristics of chickenpox and smallpox, and the diagnostic interpretation of color photographs of patients with smallpox or chickenpox. Responses were summarized as a perceived comfort score, a differential diagnosis score, and a picture score. Of 266 eligible physicians, 178 (67%) responded. Of these, 95% thought clinicians need more education about bioterrorism; only 17% reported comfort in diagnosing smallpox. Although most physicians recognized pictures of smallpox and chickenpox, only 36% correctly answered 3 of 4 questions regarding differential diagnosis, an important aspect of identifying cases early. Those who were comfortable diagnosing rash illnesses had higher differential diagnosis scores. Strategies for bioterrorism-related training could take advantage of physicians' awareness of their own knowledge deficits.     

Do chimpanzees know what conspecifics know?

We conducted three experiments on social problem solving by chimpanzees, Pan troglodytes. In each experiment a subordinate and a dominant individual competed for food, which was placed in various ways on the subordinate's side of two opaque barriers. In some conditions dominants had not seen the food hidden, or food they had seen hidden was moved elsewhere when they were not watching (whereas in control conditions they saw the food being hidden or moved). At the same time, subordinates always saw the entire baiting procedure and could monitor the visual access of their dominant competitor as well. If subordinates were sensitive to what dominants did or did not see during baiting, they should have preferentially approached and retrieved the food that dominants had not seen hidden or moved. This is what they did in experiment 1 when dominants were either uninformed or misinformed about the food's location. In experiment 2 subordinates recognized, and adjusted their behaviour accordingly, when the dominant individual who witnessed the hiding was replaced with another dominant individual who had not witnessed it, thus demonstrating their ability to keep track of precisely who has witnessed what. In experiment 3 subordinates did not choose consistently between two pieces of hidden food, one of which dominants had seen hidden and one of which they had not seen hidden. However, their failure in this experiment was likely to be due to the changed nature of the competition under these circumstances and not to a failure of social-cognitive skills. These findings suggest that at least in some situations (i.e. competition with conspecifics) chimpanzees know what conspecifics have and have not seen (do and do not know), and that they use this information to devise effective social-cognitive strategies. Copyright 2001 The Association for the Study of Animal Behaviour.     

Workshop on "What do you need to know about doing cell biology experiments in space?"

The "What do you need to know about doing cell biology experiments in space?" workshop represented a continued international collaboration between cell culture hardware developers and scientists, partly due to the enhanced collaboration in space life sciences spurred on by the International Space Life Sciences Working Group. The workshop was organized into three sessions. The first session provided an overview of the general effects of space flight, including definition of the microgravity environment, the radiation environment, and issues surrounding mass transport. The session concluded with an important overview of using space centrifuges as Earth gravity (1-g) controls, including understanding the contribution of inertial shear forces. The second session described existing and planned hardware facilities developed to support cell culture research, ranging from small hand-held hardware to breadbox-sized Shuttle middeck hardware to complete facility racks. Hardware designed for use on the Shuttle, ISS, and in free flyers was described. The third session provided advice from experienced space flight cell biology principal investigators to new investigators in the field. This special issue of the Journal of Gravitational Physiology includes externally peer-reviewed papers from all three sessions.     

Better the devil you know? Guidelines for insightful utilization of nrDNA ITS in species-level evolutionary studies in plants

The internal transcribed spacers (ITS) of the nuclear ribosomal 18S-5.8S-26S cistron continue to be the most popular non-plastid region for species-level phylogenetic studies of plant groups despite the early warnings about their potential flaws, which may ultimately result in incorrect assumptions of orthology. It has been gradually realized that the alternative target regions in the nuclear genome (low-copy nuclear genes, LCNG) are burdened with similar problems. The consequence is that, to date, developing useful LCNG for non-model organisms requires an investment in time and effort that hinders its use as a real practical alternative for many labs. It is here argued that ITS sequences, despite drawbacks, can still produce insightful results in species-level phylogenetic studies or when non-anonymous nuclear markers are required, provided that a thoughtful use of them is made. To facilitate this, two series of guidelines are proposed. One helps to circumvent problems of ITS amplification from the target organism, including spurious results from contaminants, paralogs and pseudogenes, as well as detection of sequencing artifacts. The other series helps to find out causes for unresolved clades in phylogenetic reconstruction, to integrate gene phylogenies, to distinguish horizontal transfer from lineage sorting, and to reveal if ITS phylogeny is not a good estimate of organism phylogeny.     

To know or not to know? Genetic ignorance, autonomy and paternalism

This paper examines some arguments which deny the existence of an individual right to remain ignorant about genetic information relating to oneself--often referred to as 'a right to genetic ignorance' or, more generically, as 'a right not to know'. Such arguments fall broadly into two categories: 1) those which accept that individuals have a right to remain ignorant in self-regarding matters, but deny that this right can be extended to genetic ignorance, since such ignorance may be harmful to others, particularly those to whom one is genetically related (the 'harm to others objection') and 2) those which contend that, even if genetic ignorance is only self harming, it is not something to which individuals can rationally or morally claim to have a 'right' at all, since they defend their claims on autonomy-respecting grounds and ignorance is inimical to autonomy (the 'incoherence objection'). I argue that defenders of a right not to know have some plausible responses to the 'harm to others objection', they and their opponents reach an impasse in which both sides are left voicing concerns about the paternalistic implications of the other's point of view. I conclude that defenders of a right not to know would, therefore, advance their position further by analysing it in terms of values other than those of autonomy and rights.     

So you think you can edit?

This article presents one scientist''s perspective on the transition from life at the bench to an editorial career.     

Do dolphins know their own minds?

Knowledge of one's own states of mind is one of the varieties of self-knowledge. Do any nonhuman animals have the capacity for this variety of self-knowledge? The question is open to empirical inquiry, which is most often conducted with primate subjects. Research with a bottlenose dolphin gives some evidence for the capacity in a nonprimate taxon. I describe the research and evaluate the metacognitive interpretation of the dolphin's behaviour. The research exhibits some of the difficulties attached to the task of eliciting behaviour that both attracts a higher-order interpretation while also resisting deflationary, lower-order interpretations. Lloyd Morgan's Canon, which prohibits inflationary interpretations of animal behaviour, has influenced many animal psychologists. There is one defensible version of the Canon, the version that warns specifically against unnecessary intentional ascent. The Canon on this interpretation seems at first to tell against a metacognitive interpretation of the data collected in the dolphin study. However, the model of metacognition that is in play in the dolphin studies is a functional model, one that does not implicate intentional ascent. I explore some interpretations of the dolphin's behaviour as metacognitive, in this sense. While this species of metacognitive interpretation breaks the connection with the more familiar theory of mind research using animal subjects, the interpretation also points in an interesting way towards issues concerning consciousness in dolphins.     

What do we know about serotonin?

The present review focuses on what is known of basic serotonin physiology in the human body. Here, we describe serotonin biochemistry and metabolism and summarize the results of studies that have contributed significantly to our understanding of serotonin physiology. We report the well-established role of serotonin in cardiovascular, gastrointestinal, and circulatory physiology. Emphasis is placed on the role of serotonin in peripheral physiological systems rather than in the central nervous system. A brief overview is provided on the emerging role of serotonin in novel areas such as bone pathways and glucose uptake. We also report a select few animal studies and animal models that have provided worthwhile contributions to the understanding of serotonin in human physiology. In addition, we summarize the results of large-scale genetic studies on serotonin and serotonin transporter genes, performed in relation to behavioral and mood disorders.     

What would you do if you could sequence everything?

It could be argued that the greatest transformative aspect of the Human Genome Project has been not the sequencing of the genome itself, but the resultant development of new technologies. A host of new approaches has fundamentally changed the way we approach problems in basic and translational research. Now, a new generation of high-throughput sequencing technologies promises to again transform the scientific enterprise, potentially supplanting array-based technologies and opening up many new possibilities. By allowing DNA/RNA to be assayed more rapidly than previously possible, these next-generation platforms promise a deeper understanding of genome regulation and biology. Significantly enhancing sequencing throughput will allow us to follow the evolution of viral and bacterial resistance in real time, to uncover the huge diversity of novel genes that are currently inaccessible, to understand nucleic acid therapeutics, to better integrate biological information for a complete picture of health and disease at a personalized level and to move to advances that we cannot yet imagine.     

To know or not to know? Practices of knowledge and ignorance among Bidayuhs in an 'impurely' Christian world

This article seeks to render ignorance analytically and ethnographically productive by exploring practices and tropes of knowing and not-knowing among young Christian Bidayuhs in Sarawak, Malaysian Borneo. It argues that these Bidayuhs' professed ignorance of the old 'religion', adat gawai , cannot be dismissed as a simple lack of knowledge or reflection of sheer indifference. Instead, their invocations of ignorance could be understood as a productive, empowering device for dealing with the dangers of living in a world in which religious conversion remains an ongoing, incomplete process. Through this ethnographic analysis, the article also offers a reflexive critique of the knowledge-centred impulses that often shape anthropology's epistemological and methodological projects.  

Résumé

L'auteure cherche à rendre l'ignorance féconde du point de vue anecdotique et ethnographique en explorant les pratiques et figures rhétoriques liées à la connaissance et à l'ignorance chez les jeunes Bidayuhs chrétiens du Sarawak, dans la partie malaise de Bornéo. Elle affirme que l'ignorance de « l'ancienne religion >>, adat gawai , professée par ces Bidayuhs ne peut pas être réduite à un manque de connaissance ou à l'expression d'une simple indifférence. Elle pourrait, au contraire, constituer un dispositif productif et efficace permettant de gérer les dangers d'un monde dans lequel la conversion religieuse reste un processus permanent et incomplet. Par cette étude ethnographique, l'article offre aussi une critique des impulsions centrées sur le savoir qui donnent souvent forme aux projets épistémologiques et méthodologiques de l'anthropologie.