Prism adaptation is a form of visuomotor training that produces both sensorimotor and cognitive aftereffects depending on the direction of the visual displacement. Recently, a neural framework explaining both types of PA-induced aftereffects has been proposed, but direct evidence for it is lacking. We employed Structural Equation Modeling, a form of effective connectivity analysis, to establish directionality among connected nodes of the brain network thought to subserve PA. The findings reveal two distinct network branches: a loop involving connections from the (...) parietal cortices to the right parahippocampal gyrus, and a branch linking the lateral premotor cortex to the parahippocampal gyrus via the cerebellum. Like the sensorimotor aftereffects, the first branch exhibited qualitatively different modulations for left versus right PA, and critically, changes in these connections were correlated with the magnitude of the sensorimotor aftereffects. Like the cognitive aftereffects, changes in the second branch were qualitatively similar for left and right PA, with greater change for left PA and a trend correlation with cognitive aftereffects. These results provide direct evidence that PA is supported by two functionally distinct subnetworks, a parietal–temporal network responsible for sensorimotor aftereffects and a fronto-cerebellar network responsible for cognitive aftereffects. (shrink)

1. It is a fact that developing a good proof theory for modal logics is a difficult task. The problem is not in having deductive systems. In fact, all the main modal logics enjoy an axiomatic prese...

When young children attempt to locate numbers along a number line, they show logarithmic (or other compressive) placement. For example, the distance between “5” and “10” is larger than the distance between “75” and “80.” This has often been explained by assuming that children have a logarithmically scaled mental representation of number (e.g., Berteletti, Lucangeli, Piazza, Dehaene, & Zorzi, 2010; Siegler & Opfer, 2003). However, several investigators have questioned this argument (e.g., Barth & Paladino, 2011; Cantlon, Cordes, Libertus, & (...) Brannon, 2009; Cohen & Blanc-Goldhammer, 2011). We show here that children prefer linear number lines over logarithmic lines when they do not have to deal with the meanings of individual numerals (i.e., number symbols, such as “5” or “80”). In Experiments 1 and 2, when 5- and 6- year-olds choose between number lines in a forced-choice task, they prefer linear to logarithmic and exponential displays. However, this preference does not persist when Experiment 3 presents the same lines without reference to numbers, and children simply choose which line they like best. In Experiments 4 and 5, children position beads on a number line to indicate how the integers 1 100 are arranged. The bead placement of 4- and 5-year-olds is better fit by a linear than by a logarithmic model. We argue that previous results from the number line task may depend on strategies specific to the task. (shrink)

Perfect adaptation in a dynamical system is the phenomenon that one or more variables have an initial transient response to a persistent change in an external stimulus but revert to their original value as the system converges to equilibrium. With the help of the causal ordering algorithm, one can construct graphical representations of dynamical systems that represent the causal relations between the variables and the conditional independences in the equilibrium distribution. We apply these tools to formulate sufficient graphical conditions for (...) identifying perfect adaptation from a set of first-order differential equations. Furthermore, we give sufficient conditions to test for the presence of perfect adaptation in experimental equilibrium data. We apply this method to a simple model for a protein signalling pathway and test its predictions in both simulations and using real-world protein expression data. We demonstrate that perfect adaptation can lead to misleading orientation of edges in the output of causal discovery algorithms. (shrink)

Let us call an integer part of an ordered field any subring such that every element of the field lies at distance less than 1 from a unique element of the ring. We show that every real closed field has an integer part.

The Constitution of the Athenians ascribed to Xenophon the orator.--The Politeia of the Spartans by Xenophon.--The Boeotian Constitution from the Oxyrhynchus historian.--The Constitution of Athens by Aristotle.

Many have thought that exercises of skill are intentional. The argument of the paper is that this thesis fails to account for important types of mistakes and errors. In what psychologists and linguists call “verbal slips with semantic bias”, a speaker mistakenly switches, reverses, or blends certain conceptual contents. Nevertheless, the speaker has successfully exercised an intellectual skill, insofar as her slip uses concepts in conformity to semantic and logical rules. To flesh out how one might successfully exercise skills without (...) doing so intentionally, the paper appeals to the idea of habit. Verbal slips thus show how human skillfulness has a considerably wider scope than is often supposed. (shrink)

The prospects for a complete stochastic theory of microscopic phenomena are considered. The two traditional schools of stochastic physics, the diffusion process school and the zero-point electromagnetic field school, are reviewed. A completely relativistic theory, stochastic field theory, is proposed as an extension of the ideas of these two schools. Within the context of stochastic field theory we present the following new results: an elementary stochastization scheme which produces the zero-point electromagnetic field; a physical interpretation of the mathematical methods developed (...) by Lukosz for calculating zero-point energies; a calculation of the first-order Lamb shift which generalizes that of Welton; a new setting for a finite-temperature theory; and comments on the bag model for quark confinement. (shrink)

Pest control operations andexperimentation on sentient animals such as thebrushtail possum can cause unnecessary andavoidable suffering in the animal subjects.Minimizing animal suffering is an animalwelfare goal and can be used as a guide in thedesign and execution of animal experimentationand pest control operations.The public has little sympathy for the possum,which can cause widespread environmentaldamage, but does believe that control should beas painless as possible. Trapping and poisoningprovide only short-term solutions to the possumproblem and often involve methods that causesuffering. Intrusive experiments (...) connected withthese methods of control and published in thelast 6 years are reviewed. Many of theexperiments do not attain the welfare standardsrequired by members of the public.Possums also act as vectors for bovinetuberculosis. While this is not as important inthe minds of the public as environmentaldegradation, as long as people wish to continueraising cattle, this disease needs to becontrolled.Immunocontraception is a humane means ofcontrolling possums with wide publicacceptance. The use of vaccines for cows and/orpossums would also cause far less sufferingthan present eradication operations. Researchinto these methods does require some intrusiveexperimentation. This can be reduced if liveanimals are not used for secondary antibodyharvesting, if adequate analgesia is provided,and if potential vaccines or contraceptives aretested under conditions that would beexperienced in the field. (shrink)

There is more than enough evidence to show that cock-fighting, quail-fighting, and even partridge-fighting were favourite sports among the Greeks , no matter what part of the mediterranean world they inhabited. Whether Romans ever shared these passions is another question altogether. When Saglio contributed his article on cock-fighting to the Dictionnaire des antiquitis grecques et romaines, he limited himself to the transports it caused the Greeks. For this he was reprimanded, obliquely, by Schneider, asserting—but neglecting to support the assertion in (...) detail—that Romans also took a keen interest in Hahnenkämpfe. Subsequently, Magaldi set out to prove the existence of formal ludi gallinarii at Pompeii, while Jennison mustered such evidence as could be found for all three forms of avian combat in Rome. Hence, apparently, it has become the communis opinio that Romans shared the Greeks' taste for these ‘raffish’ amusements. (shrink)

Democratic politics is always identity politics and there are some varieties of identity politics without which full and genuine democratic cooperation would not be possible. Indeed, the very existence of a democratic people involves mobilization of political concern and action around a democratic national identity. But a genuinely democratic national identity must be an open identity that can accommodate internal complexity and acknowledge external responsibilities. Moreover, in democracies characterized by a history of discrimination and oppression, there must also be political (...) space for a revitalizing identity politics that initially mobilizes political concern and action around the identities of those groups that have been subject to discrimination and oppression. Yet a revitalizing identity politics is likely to go awry if it is hostile to the possibility of reconciliation between the oppressed and former oppressors, or intrinsically resistant to political collaborations that might transcend the boundaries of familiar social groups. (shrink)

Two criteria for rigid designation are distinguished; one according to which 'e' is rigid if 'e might not have been e' is false and the other according to which 'e' is rigid if it designates the same thing in all possible worlds in which it designates anything at all. Such criteria are not equivalent since 'x could not but be f' is not entailed by 'nothing other than x could be f'. I illustrate the latter lack of entailment.

Can emancipatory, decolonial histories of science be extracted from objects collected from—or made visible to history by—the archives of colonialism? To answer this question, this essay presents the case study of a rhinoceros horn amulet (qarn al-khartit), an ethnographic object collected by the British anthropologist Winifred Blackman during her fieldwork in Egypt in the late 1920s. Markedly decentering the traditional colonial history of how the rhinoceros horn was collected and displayed as an object in European museums, the essay follows the (...) trail of the rhinoceros horn back to the site of its collection in Egypt to reveal a strikingly different story: one of non-Western histories of science/magic/medicine, gender, race, and enslavement, all set against the backdrop of Egypt’s imperial pursuits in East Africa. The essay proposes the method of decolonial materialism to “read” objects, like the rhinoceros horn, as archives of scientific knowledge otherwise. (shrink)

Ecologists are challenged by the need to bridge and synthesize different approaches and theories to obtain a coherent understanding of ecosystems in a changing world. Both food web theory and regime shift theory shine light on mechanisms that confer stability to ecosystems, but from different angles. Empirical food web models are developed to analyze how equilibria in real multi-trophic ecosystems are shaped by species interactions, and often include linear functional response terms for simple estimation of interaction strengths from observations. Models (...) of regime shifts focus on qualitative changes of equilibrium points in a slowly changing environment, and typically include non-linear functional response terms. Currently, it is unclear how the stability of an empirical food web model, expressed as the rate of system recovery after a small perturbation, relates to the vulnerability of the ecosystem to collapse. Here, we conduct structural sensitivity analyses of classical consumer-resource models in equilibrium along an environmental gradient. Specifically, we change non-proportional interaction terms into proportional ones, while maintaining the equilibrium biomass densities and material flux rates, to analyze how alternative model formulations shape the stability properties of the equilibria. The results reveal no consistent relationship between the stability of the original models and the proportionalized versions, even though they describe the same biomass values and material flows. We use these findings to critically discuss whether stability analysis of observed equilibria by empirical food web models can provide insight into regime shift dynamics, and highlight the challenge of bridging alternative modelling approaches in ecology and beyond. (shrink)

Pylyshyn argues that early vision is cognitively impenetrable, and therefore – contrary to knowledge-based theories of perception – that perception is noncontinuous with cognition. Those processes that are included in “early vision,” however, represent at best only one component of perception, and it is important that it is not the component with which most knowledge-based theories are concerned. Pylyshyn's analysis should be taken as a possible source of refinement of knowledge-based theories of perception, rather than as a condemnation of them.

Histories 1.40 is designed to set the scene for Galba's assassination. It begins by bringing the emperor into the crowded Forum, but then it switches to Otho and his followers, dwelling on the horror, not of the act they plan , but of their readiness to commit it. The text is not problematical, but since the point behind the first two sentences is not entirely clear, this has prompted occasional emendation, repeated discussion, and continuing perplexity. The difficulty arises, in good (...) measure, from the assumption that Tacitus is saying much the same as Plutarch . As has been remarked more than once, the two authors no doubt drew their material from the common source, but they have in mind different time-frames and different viewpoints. Nor does this end the matter. A skewed perspective on these sentences has also led one scholar to dissect the chapter in a manner purporting to show that Galba's fate, not the Othonians' willingness to bring it about, is Tacitus' main concern. (shrink)

It is not enough, says Quintilian , to assemble the various parts of a speech. The orator must arrange his points in the natural and logical order for his purposes, and he must unify the different sections so skilfully that no join will show , producing a single body instead of assorted limbs. If we define ascommissura the rhetorical device which welds together different themes or chapters with an associative link in word or thought , Tacitus already had this lesson (...) by heart when he wrote the Germania. That he exploited the same technique in his major works, concentrating on his transitions as hard as would Macaulay on his, appears not to have been noticed, and certainly has not received systematic study. (shrink)