Do Domestic Dogs Understand Human Actions as Goal-Directed?

Understanding of other’s actions as goal-directed is considered a fundamental ability underlying cognitive and social development in human infants. A number of studies using the habituation-dishabituation paradigm have shown that the ability to discern intentional relations, in terms of goal-directedness of an action towards an object, appears around 5 months of age. The question of whether non-human species can perceive other’s actions as goal-directed has been more controversial, however there is mounting evidence that at least some primates species do. Recently domestic dogs have been shown to be particularly sensitive to human communicative cues and more so in cooperative and intentional contexts. Furthermore, they have been shown to imitate selectively. Taken together these results suggest that dogs may perceive others'' actions as goal-directed, however no study has investigated this issue directly. In the current study, adopting an infant habituation-dishabituation paradigm, we investigated whether dogs attribute intentions to an animate (a human) but not an inanimate (a black box) agent interacting with an object. Following an habituation phase in which the agent interacted always with one of two objects, two sets of 3 trials were presented: new side trials (in which the agent interacted with the same object as in the habituation trial but placed in a novel location) and new goal trials (in which the agent interacted with the other object placed in the old location). Dogs showed a similar pattern of response to that shown in infants, looking longer in the new goal than new side trials when they saw the human agent interact with the object. No such difference emerging with the inanimate agent (the black box). Results provide the first evidence that a non-primate species can perceive another individual’s actions as goal-directed. We discuss results in terms of the prevailing mentalisitic and non-mentalistic hypotheses regarding goal-attribution.     

Genetic enhancement--a threat to human rights?

Genetic enhancement is the modification of the human genome for the purpose of improving capacities or 'adding in' desired characteristics. Although this technology is still largely futuristic, debate over the moral issues it raises has been significant. George Annas has recently leveled a new attack against genetic enhancement, drawing on human rights as his primary weapon. I argue that Annas' appeal to human rights ultimately falls flat, and so provides no good reason to object to genetic technology. Moreover, this argument is an example of the broader problem of appealing to human rights as a panacea for ethical problems. Human rights, it is often claimed, are 'trumps': if it can be shown that a proposed technology violates human rights, then it must be cast aside. But human rights are neither a panacea for ethical problems nor a trump card. If they are drafted into the service of an argument, it must be shown that an actual human rights violation will occur. Annas' argument against genetic technology fails to do just this. I shall conclude that his appeal to human rights adds little to the debate over the ethical questions raised by genetic technology.     

Aging, eye movements, and object-location memory

This study investigated whether "intentional" instructions could improve older adults' object memory and object-location memory about a scene by promoting object-oriented viewing. Eye movements of younger and older adults were recorded while they viewed a photograph depicting 12 household objects in a cubicle with or without the knowledge that memory about these objects and their locations would be tested (intentional vs. incidental encoding). After viewing, participants completed recognition and relocation tasks. Both instructions and age affected viewing behaviors and memory. Relative to incidental instructions, intentional instructions resulted in more accurate memory about object identity and object-location binding, but did not affect memory accuracy about overall positional configuration. More importantly, older adults exhibited more object-oriented viewing in the intentional than incidental condition, supporting the environmental support hypothesis.     

Complex functions of the brain

Over the course of the last 50 years it has been possible to solve a number of basic problems in neurobiology. Interest is now turning more and more to problems concerning so-called “higherρ brain functions, including cognition. Examples from the visual system in primates are presented. First relatively elementary problems are illustrated, such as how long it takes to perceive an object or to respond to a stimulus or combinations of stimuli. Top-down modification of perception by expectation is demonstrated in an illusion of misdirected gaze. Interdisciplinary questions straddling the sciences and the humanities are also approached, such as which part of the brain mediates conscious perception. Finally, the problem of causality and freedom of will is addressed, taking into account the knowledge accumulated in the neurosciences during the last 5 decades.     

Performance correlates of social behavior and organization: Social rank and complex problem solving in crab-eating macaques (M. fascicularis)

Seventeen male crab-eating macaques, drawn from two captive troops, were tested on a series of complex problem solving tasks in a Wisconsin General Test Apparatus (wgta). The animals were trained on a series of 6-trial object quality learning set problems followed by a series of 10-trial object quality learning set problems. They were then given problems in which the correct stimulus object was reversed part way through the problem. After the animals reached criterion on this task, the reversal learning set was then extinguished. High ranking animals made more intraproblem errors than low ranking animals on the 6-trial problems, but there was no relationship between social status and the rapidity with which the object quality learning set was established. Animals that received overtraining on the 6-trial problems transferred their learning virtually intact to the 10-trial problems; however, high ranking animals without overtraining made more errors than low ranking animals. On reversal learning and reversal extinction, high ranking animals made more errors on critical trials, indicating that they formed and extinguished the reversal set more slowly than low ranking animals. Object quality sets, as measured by trial-2 performance, were not affected by the reversal conditions. Supported by USAMRDC Contract No. DADA 17-73-C-3007.     

Gametogenesis processes and multilocus gene identity by descent.

With few exceptions, the determination of unconditional probability of genes shared identical by descent (IBD) by relatives can be very difficult, especially if the relationship is complex or if multiple loci are involved. It is particularly difficult if one needs the IBD probability in a explicit form, expressed in terms of interlocus recombination fractions. In this paper, I will further extend the concept of gametogenesis process introduced elsewhere and indicate that it completely determines the gene IBD events of interest in pedigrees. I will demonstrate that the gametogenesis process not only serves as a convenient conceptual framework in considering IBD events in pedigrees but also provides a simple yet powerful tool to solve a wide range of seemingly difficult problems. In particular, I consider the problem of multilocus IBD probability for relative pairs, k siblings, and a group of pedigree members. In addition, I consider the problem of multilocus autozygosity probability and the problem of gene preservation in close relatives.     

Crossing over...Markov meets Mendel

Chromosomal crossover is a biological mechanism to combine parental traits. It is perhaps the first mechanism ever taught in any introductory biology class. The formulation of crossover, and resulting recombination, came about 100 years after Mendel's famous experiments. To a great extent, this formulation is consistent with the basic genetic findings of Mendel. More importantly, it provides a mathematical insight for his two laws (and corrects them). From a mathematical perspective, and while it retains similarities, genetic recombination guarantees diversity so that we do not rapidly converge to the same being. It is this diversity that made the study of biology possible. In particular, the problem of genetic mapping and linkage-one of the first efforts towards a computational approach to biology-relies heavily on the mathematical foundation of crossover and recombination. Nevertheless, as students we often overlook the mathematics of these phenomena. Emphasizing the mathematical aspect of Mendel's laws through crossover and recombination will prepare the students to make an early realization that biology, in addition to being experimental, IS a computational science. This can serve as a first step towards a broader curricular transformation in teaching biological sciences. I will show that a simple and modern treatment of Mendel's laws using a Markov chain will make this step possible, and it will only require basic college-level probability and calculus. My personal teaching experience confirms that students WANT to know Markov chains because they hear about them from bioinformaticists all the time. This entire exposition is based on three homework problems that I designed for a course in computational biology. A typical reader is, therefore, an instructional staff member or a student in a computational field (e.g., computer science, mathematics, statistics, computational biology, bioinformatics). However, other students may easily follow by omitting the mathematically more elaborate parts. I kept those as separate sections in the exposition.     

Comparing the rates of speciation and extinction between phylogenetic trees

Over the past decade or so it has become increasingly popular to use reconstructed evolutionary trees to investigate questions about the rates of speciation and extinction. Although the methodology of this field has grown substantially in its sophistication in recent years, here I will take a step back to present a very simple model that is designed to investigate the relatively straightforward question of whether the tempo of diversification (speciation and extinction) differs between two or more phylogenetic trees, without attempting to attribute a causal basis to this difference. It is a likelihood method, and I demonstrate that it generally shows type I error that is close to the nominal level. I also demonstrate that parameter estimates obtained with this approach are largely unbiased. As this method can be used to compare trees of unknown relationship, it will be particularly well‐suited to problems in which a difference in diversification rate between clades is suspected, but in which these clades are not particularly closely related. As diversification methods can easily take into account an incomplete sampling fraction, but missing lineages are assumed to be missing at random, this method is also appropriate for cases in which we have hypothesized a difference in the process of diversification between two or more focal clades, but in which many unsampled groups separate the few of interest. The method of this study is by no means an attempt to replace more sophisticated models in which, for instance, diversification depends on the state of an observed or unobserved discrete or continuous trait. Rather, my intention is to provide a complementary approach for circumstances in which a simpler hypothesis is warranted and of biological interest.     

Vicarious learning from human models in monkeys

We examined whether monkeys can learn by observing a human model, through vicarious learning. Two monkeys observed a human model demonstrating an object-reward association and consuming food found underneath an object. The monkeys observed human models as they solved more than 30 learning problems. For each problem, the human models made a choice between two objects, one of which concealed a piece of apple. In the test phase afterwards, the monkeys made a choice of their own. Learning was apparent from the first trial of the test phase, confirming the ability of monkeys to learn by vicarious observation of human models.     

Fixation Biases towards the Index Finger in Almost-Natural Grasping

We use visual information to guide our grasping movements. When grasping an object with a precision grip, the two digits need to reach two different positions more or less simultaneously, but the eyes can only be directed to one position at a time. Several studies that have examined eye movements in grasping have found that people tend to direct their gaze near where their index finger will contact the object. Here we aimed at better understanding why people do so by asking participants to lift an object off a horizontal surface. They were to grasp the object with a precision grip while movements of their hand, eye and head were recorded. We confirmed that people tend to look closer to positions that a digit needs to reach more accurately. Moreover, we show that where they look as they reach for the object depends on where they were looking before, presumably because they try to minimize the time during which the eyes are moving so fast that no new visual information is acquired. Most importantly, we confirmed that people have a bias to direct gaze towards the index finger’s contact point rather than towards that of the thumb. In our study, this cannot be explained by the index finger contacting the object before the thumb. Instead, it appears to be because the index finger moves to a position that is hidden behind the object that is grasped, probably making this the place at which one is most likely to encounter unexpected problems that would benefit from visual guidance. However, this cannot explain the bias that was found in previous studies, where neither contact point was hidden, so it cannot be the only explanation for the bias.     

Representation/Self-representation: A Tale of Two Portraits; or,Portraits and Social Science Representations

The problem of representation is profound for anthropology: how do representation and represented relate? What motivates or warrants bridges over the inevitable disconnection between the two? I suggest that photographs and portraits provide a rich basis for thinking about the particular sorts of warrant for anthropological representation. My most general suggestion is that anthropological representation may be conceived of as a form of portraiture, and that it is an exercise in ekphrasis (a verbal account or evocation of a typically non-present image or object). Portraits need social conventions (such as a name in the caption) to be taken as such; representation is a three-part relationship between object, image and society. Cases from Cameroonian studio photography and a portrait of Marilyn Strathern exemplify the argument.     

Amplifiers and the handicap principle in sexual selection: a different emphasis

Population genetic models have shown that female choice is a potential cause of the evolution of male display. In these models the display is assumed to be the immediate object of female choice. Here I present an explicit genetic model that shows that male display can evolve as a consequence of female choice even when the display is not the immediate object of choice. When females initially base their preferences on the existence of variance in a cue that is correlated with male viability, a rare display can evolve to fixation if it amplifies the previously recognized differences in males, (i.e. if it increases the resolution power of females with respect to the original cue). By definition, amplifying displays (or amplifiers) increase mating success of the more viable males and decrease mating success of the less viable males. Therefore, the higher the frequency of the preferred, more viable males, the more likely it is that amplifiers will evolve to fixation. The evolution of an amplifier is further facilitated by a genetic association that is built up between the amplifier allele and the more viable allele. If the expression of the amplifier is limited to the more viable males, the amplifier will evolve to fixation provided only that the change in total fitness to the more viable males (higher mating success, lower viability), is positive.     

Corruption and research

Last year there was a heated debate regarding clinical trials with AZT carried out in developing countries. AIDs vaccine trials also posed various dilemmas and ethical problems. In this paper I will consider the possibility of corruption in bioethics, and international multi-centre research will be taken as an example. International clinical trials will be seen from another perspective. I will try to show that the possibility of systemic corruption should be considered when designing an international multi-centre research trial which may involve countries in very different situations regarding corruption. I will analyze three different approaches to this problem and suggest some strategies regarding their capacity to exclude the possibility of corruption.     

Mind the gap: Encountering contemporary art through play

Knowing how to approach and experience contemporary art is a challenge to many people outside the art world. Emerging contemporary art, as the newest of this genre, is often the most challenging. This article recounts my own early struggles as a researcher in this field, and proposes a way of understanding the interaction between artist, artwork and perceiver based on my observations of how contemporary artists encounter each others' work. I argue that contemporary art, and especially emerging contemporary art, creates a space to play by creating an intentional gap in the physical form and/or the semantic structure of the artwork. The object of play is the co‐investigation of an idea initiated by the artist, facilitated by the form of the work and furthered by the encounter. Play, it is argued, is essential to emerging contemporary art as an activity, a communicative frame and a disposition. I draw from earlier theoretical connections between art, play and liberation, challenging some of these assertions, and bringing others into relevance in the contemporary context.     

Computational genomics

We now know how to read the sequences of nucleotide letters that comprise the genome at a rather frightening speed--a several-million-base bacterial genome in several days is not a problem for one of the sequencing centers, and a billion-base eukaryotic genome can be done in less than a year. But reading a text and understanding it are two different things. So how well can we understand the genome sequences? The answer to this question is central to the whole enterprise of genomics, and this is where computational analysis of genomes takes the driver's seat. Here I will try to briefly outline some major goals, problems, challenges and approaches of computational genomics. Such a young field is already quite diverse, and in this short article I will concentrate on several issues that seen to be critical for deciphering biology from genome sequences, rather than mathematical and computer-science aspects that are well covered in several excellent books.