During embryogenesis, the basic axon scaffold of the nervous system is formed by special axons that pioneer pathways between groups of cells. To find their way, the pioneer growth cones detect specific cues in their extracellular environment. One of these guidance cues is netrin. Observations and experimental manipulations in vertebrates and nematodes have shown that netrin is a bifunctional guidance cue that can simultaneously attract and repel axons. During the formation of this basic axon scaffold in Caenorhabditis elegans, (...) the netrin UNC‐6 is expressed by neuroglia and pioneer neurons, providing hierarchical guidance cues throughout the animal. Each cue has a characteristic role depending on the cell type, its position and the developmental stage. These roles include activities as global, decussation and labeled‐pathway cues. This hierarchical model of UNC‐6 netrin‐mediated guidance suggests a method by which guidance cues can direct formation of basic axon scaffolds in developing nervous systems. (shrink)

The present study employed the gaze-contingent window paradigm to investigate parafoveal and peripheral cueing and masking effects on saccadic selectivity in a triple-conjunction visual search task. In the cueing conditions, the information shown outside the gaze-contingent window was restricted to the feature or feature pair shared between the target and a particular distractor type. In the masking conditions, no stimulus features were shown outside the window. Significant cueing and masking effects on saccadic selectivity were observed for saccades directed at items (...) within the window, where all features were visible across experimental conditions. Cueing a particular feature or feature pair biased saccadic selectivity towards this feature or feature pair, while masking generally reduced saccadic selectivity. These findings support the concept of visual guidance being a preattentive process that operates in parallel across the display. © 2001 Published by Elsevier Science Ltd. (shrink)

According to the spreading hypothesis of object-based attention, a subliminal cue that can successfully capture attention to a location within an object should also cause attention to spread throughout the whole cued object and lead to the same-object advantage. Instead, we propose that a subliminal cue favors shifts of attention between objects and strengthens the between-object link, which is coded primarily within the dorsal pathway that governs the visual guidance of action. By adopting the two-rectangle method and using an (...) effective subliminal cue to compare with the classic suprathreshold cue, we found a different result pattern with suprathreshold cues than with subliminal cues. The suprathreshold cue replicated the conventional location and object effects, whereas a subliminal cue led to a different-object advantage with a facilitatory location effect and a same-object advantage with an inhibitory location effect. These results support our consciousness-dependent shifting hypothesis but not the spreading hypothesis. (shrink)

Summary John Stuart Mill's classic tale of disillusionment from a ‘narrow creed’, an overt as much as a covert theme of his Autobiography (London, 1873), has for many years served as a guide to the search for the causes and sources of his ‘enlargement-of-the-utilitarian-creed’ project. As a result, in analyses of Mill's mature views, Samuel Taylor Coleridge—and friends—commonly take centre stage in terms of influence, whereas John's father—James Mill—is reduced either to a supernumerary or a villain in the last act (...) of John's intellectual development. However, students of Mill's works should not take at face value the story presented in Autobiography. Mill's own emphasis on the role of his ‘new influences’ has led scholars to disregard the role of his ‘old influences’ in his attempt to create a broader theory of living—one which takes into account both the intellectual and the emotional capacities of individuals. A close look at key aspects of John Stuart Mill's ‘enlargement project’ suggests that James Mill may have played a more positive role than is usually acknowledged. A way into the intellectual affinity of the two Mills is the person they both kept returning to for guidance and inspiration throughout their lives: Plato. (shrink)

ABSTRACTHumans are social beings that often interact in multi-individual environments. As such, we are frequently confronted with nonverbal social signals, including eye-gaze direction, from multiple individuals. Yet, the factors that allow for the prioritisation of certain gaze cues over others are poorly understood. Using a modified conflicting gaze paradigm, we tested the hypothesis that fearful gaze would be favoured amongst competing gaze cues. We further hypothesised that this effect is related to the increased sclera exposure, which is characteristic of fearful (...) expressions. Across three experiments, we found that fearful, but not happy, gaze guides observers’ attention over competing non-emotional gaze. The guidance of attention by fearful gaze appears to be linked to increased sclera exposure. However, differences in sclera exposure do not prioritise competing gazes of other types. Thus, fearful gaze guides attention among competing cues and this effect is facilitated by increased sclera exposure... (shrink)

Après avoir donné quelques informations générales sur le corpus des Sermons de Nicolas de Cues, l’article se centre sur le concept de manuductio (fait de prendre par la main). Issue de la tradition dionysienne, il s’agit là d’une notion très importante pour le Cusain. L’intellect humain ne découvre que peu à peu les réalités les plus hautes, il a besoin pour cela d’un guide expérimenté qui l’initie à la pratique de la contemplation. L’art des Conjectures, l’enseignement du De Visione Dei, (...) les développements trinitaires du Cribratio Alkorani sont présentés par Nicolas comme des manuductiones. Ici l’on montre que le sermon est bien conçu par le Cusain comme une manuductio dans la foi, menant les fidèles à une compréhension plus profonde de l’être et de l’agir du Christ. La philosophie joue un rôle, limité, mais réel, dans cette guidance vers l’intelligence de la foi. (shrink)

There is increasing evidence for directional guidance of growing axons by molecular gradients in target tissues. Aside from biochemical studies on gradients and their role, the capability of axons to approach their target position from different aspects of a two-dimensional field is itself an indication for guidance by gradients. According to this criterion, such guidance is expected to be involved not only in map-formation in the visual system but also in targeting of receptor cell axons in the (...) olfactory bulb. In this paper, physico-chemical concepts of visual mapping are adapted to olfactory targeting. In both cases there must be sophisticated processing of graded cues in the growing tip of the axon for growth cone navigation. In visual map formation, a target position is determined by influences of cues depending on the position of axonal origin; in olfactory targeting, however, these influences are expected to be based on properties of the receptor-cell-specific molecules (possibly including the receptor molecule itself), as well as by gene regulation affecting the levels of expression. According to this concept, the main role of molecules expressed in a receptor-cell-type specific manner is not matching specific counterparts on the target tissue, but instead quantitative modulation of growth cone steering for sensing the direction towards the target position. (shrink)

Our understanding of neuronal migration has been advanced by multidisciplinary approaches. At the cellular level, tangential and radial modes of neuronal migration contribute to different populations of neurons and have differential dependence on glial cells. At the molecular level, extracellular guidance cues have been identified and intracellular signal transduction pathways are beginning to be revealed. Interestingly, mechanisms guiding axon projection and neuronal migration appear to be conserved with those for chemotactic leukocytes. BioEssays 24:821–827, 2002. © 2002 Wiley Periodicals, Inc.

The formation of blood vessels within the vascular system entails a variety of cellular processes, including proliferation, migration and differentiation. In many cases, these diverse processes need to be finely coordinated among neighbouring endothelial cells in order to establish a functional vascular network. For instance, during angiogenic sprouting specialized endothelial tip cells follow guidance cues and migrate extensively into avascular tissues while trailing stalk cells must stay connected to the patent blood vessel. The vascular endothelial growth factor (VEGF) and (...) Notch signalling pathways have emerged as the major players in governing these different cellular behaviours. In particular, recent work indicates an important role for Notch signalling in determining how an endothelial cell responds to VEGF. In this review, we provide an overview of these biochemically distinct pathways and discuss how they may interact during endothelial cell differentiation and angiogenesis. BioEssays 30:303–313, 2008. © 2008 Wiley Periodicals, Inc. (shrink)

During the formation of the brain, neuronal cell migration and neurite extension are controlled by extracellular guidance cues. Here, I discuss experiments showing that the messenger nitric oxide (NO) is an additional regulator of cell motility. NO is a membrane permeant molecule, which activates soluble guanylyl cyclase (sGC) and leads to the formation of cyclic GMP (cGMP) in target cells. The analysis of specific cells types in invertebrate models such as molluscs, insects and the medicinal leech provides insight how (...) NO and cyclic nucleotides affect the wiring of nervous systems by regulating cell and growth‐cone motility. Inhibition of the NOS and sGC enzymes combined with rescue experiments show that NO signalling orchestrates neurite outgrowth and filopodial dynamics, cell migration of enteric neurons, glial migration and axonogenesis of pioneer fibers. Cultured insect embryos are accessible model systems in which cellular mechanisms of NO‐induced cytoskeletal reorganizations can be analyzed in natural settings. Finally, I will outline some indications that NO may also regulate cell motility in the developing and regenerating vertebrate nervous system. BioEssays 27:495–505, 2005. © 2005 Wiley Periodicals, Inc. (shrink)

Growth cones are the highly motile structures found at the tips of growing axons and dendrites (neurites), which extend from neurones, during the development of the nervous system. They function both as detectors and transducers of extrinsic guidance cues and as regions where the neurite cytoskeleton is assembled. Without concerted neurite assembly, advance cannot occur. Assembly of the neurite cytoskeleton in growing neurites chiefly involves microtubule assembly at the growth cone. Some of the factors that may influence microtubule assembly (...) in growth cones are becoming apparent and include posttranslational modification of tubulin itself and microtubule associated proteins, particularly tau and MAP1B. (shrink)

Neural cell adhesion molecules of the immunoglobulin superfamily are important components of the network of guidance cues and receptors that govern axon growth and guidance during development. For neural cell adhesion molecule L1, the combined application of human genetics, knockout mouse technology, and cell biology is providing fundamental insight into the role of L1 in mediating neuronal differentiation. Disease-causing mutations as well as mouse models of L1 disruption can now be used to examine the relevance of L1 binding (...) specificities and signal transduction pathways that have been observed in vitro. BioEssays 20:668–675, 1998.© 1998 John Wiley & Sons Inc. (shrink)

The vertebrate nervous system performs the most complex functions of any organ system. This feat is mediated by dedicated assemblies of neurons that must be precisely connected to one another and to peripheral tissues during embryonic development. Motor neurons, which innervate muscle and regulate autonomic functions, form an integral part of this neural circuitry. The first part of this review describes the remarkable progress in our understanding of motor neuron differentiation, which is arguably the best understood model of neuronal differentiation (...) to date. During development, the coordinate actions of inductive signals from adjacent non‐neural tissues initiate the differentiation of distinct motor neuron subclasses, with specific projection patterns, at stereotypical locations within the neural tube. Underlying this specialisation is the expression of specific homeodomain proteins, which act combinatorially to confer motor neurons with both their generic and subtype‐specific properties. Ensuring that specific motor neuron subtypes innervate the correct target structure, however, requires precise motor axon guidance mechanisms. The second half of this review focuses on how distinct motor neuron subtypes pursue highly specific projection patterns by responding differentially to spatially discrete attractive and repulsive molecular cues. The tight link between motor neuron specification and axon pathfinding appears to be established by the dominant role of homeodomain proteins in dictating the ways that navigating motor axons interpret the plethora of guidance cues impinging on growth cones. BioEssays 23:582–595, 2001. © 2001 John Wiley & Sons, Inc. (shrink)

Neural cell adhesion molecules of the immunoglobulin superfamily are important components of the network of guidance cues and receptors that govern axon growth and guidance during development. For neural cell adhesion molecule L1, the combined application of human genetics, knockout mouse technology, and cell biology is providing fundamental insight into the role of L1 in mediating neuronal differentiation. Disease-causing mutations as well as mouse models of L1 disruption can now be used to examine the relevance of L1 binding (...) specificities and signal transduction pathways that have been observed in vitro. BioEssays 20:668–675, 1998.© 1998 John Wiley & Sons Inc. (shrink)

The connectivity patterns of many neural circuits are highly ordered and often impressively complex. The intricate order and complexity of neuronal wiring remain not only a challenge for questions related to circuit functions but also for our understanding of how they develop with such an apparent precision. The chemotropic guidance of the growing axon by target‐derived cues represents a central paradigm for how neurons get connected with the correct target cells. However, many studies reveal a remarkable variety of important (...) target‐independent wiring mechanisms. These mechanisms include axonal sorting, axonal tiling, growth cone polarization, as well as cell‐intrinsic mechanisms underlying growth cone sprouting, and neurite branching. Our review focuses on target independent wiring mechanisms and in particular on recent progress emerging from studies on three different sensory systems: olfactory, visual, and somatosensory. We discuss molecular mechanisms that operate during axon‐axon interactions or constitute axon‐intrinsic functions and outline how they complement the well‐known target‐dependent wiring mechanisms. (shrink)

The quest for molecular mechanisms that guide axons or specify synaptic contacts has largely focused on molecules that intuitively relate to the idea of an “instruction.” By contrast, “permissive” factors are traditionally considered background machinery without contribution to the information content of a molecularly executed instruction. In this essay, I recast this dichotomy as a continuum from permissive to instructive actions of single factors that provide relative contributions to a necessarily collaborative effort. Individual molecules or other factors do not constitute (...) absolute instructions by themselves; they provide necessary context for each other, thereby creating a composite that defines the overall instruction. The idea of composite instructions leads to two main conclusions: first, a composite of many seemingly permissive factors can define a specific instruction even in the absence of a single dominant contributor; second, individual factors are not necessarily related intuitively to the overall instruction or phenotypic outcome. (shrink)

Although disoriented young children reorient themselves in relation to the shape of the surrounding surface layout, cognitive accounts of this ability vary. The present paper tests three theories of reorientation: a snapshot theory based on visual image-matching computations, an adaptive combination theory proposing that diverse environmental cues to orientation are weighted according to their experienced reliability, and a modular theory centering on encapsulated computations of the shape of the extended surface layout. Seven experiments test these theories by manipulating four properties (...) of objects placed within a cylindrical space: their size, motion, dimensionality, and distance from the space’s borders. Their findings support the modular theory and suggest that disoriented search behavior centers on two processes: a reorientation process based on the geometry of the 3D surface layout, and a beacon-guidance process based on the local features of objects and surface markings. Ó 2010 Elsevier Inc. All rights reserved. (shrink)

This paper proposes to argue that ecological justice that is rooted in an ecocentric approach to nature is the key to achieving integral human development which goes beyond ‘development that is only worth our while’. Ecological justice is achievable if there is a clear understanding of relations at two distinct levels - one, the relation among humans and another between the entire human community and other elements of the ecosystem. These relations are the basis of the alliances that we form (...) to address issues of integral human development. The focus of the paper is the second kind of alliance that is based on an understanding of the relation between the human and the non-human realm. However, an ‘alliance’ is normally formed between partners with equal standing. Is there a sense in which both humans and the non-human world can be considered to be ‘equal partners in an alliance? The paper considers how one might establish this by examining diverse philosophical viewpoints that have addressed the issue of the treatment of non-human animals for anthropocentric ends. It discusses whether equality between parties is necessary for the formation of an alliance drawing extensively from ethical theories and examples from the world. From rights approach, recipients of justice, to care ethics, several theories offer guidance to support what would constitute a ‘humane’ approach to non-human animals. While these approaches crucially pin the broad perspective, they have not explicitly considered the role of an alliance between humans and non-human animals in achieving a basic level of wellbeing for the latter. Taking cues from the different kinds of ‘ruling over’ from Stuart Gray’s understanding of the relation between humans and non-human nature, the paper seeks to establish that an alliance between humans and the non-human realm is possible even without committing to their equal status and this could form the basis of ecological justice and well-being. (shrink)

The proposed model consists of 1) a Phonological Planning Component to plan the symbolic and relational goals for an utterance, 2) a Phonetic Planning Component to plan the quantitative details of the acoustic goals and how they will be achieved articulatorily, and 3) a Motor-Sensory Implementation Component to ensure that the goals are achieved on time. The temporal characteristics specified in the Phonetic Planning Component include durations between acoustic landmarks, as well as parameters of Lee’s TauG-Guidance equation, which determine (...) how a movement evolves over time. Movement coordination is assumed to be based on movement endpoints (rather than onsets) and accomplished via Tau-coupling (Lee 1998). Both the Phonetic Planning and Motor-Sensory Implementation components are assumed to make use of general-purpose, phonology-extrinsic, timekeeping mechanisms to represent, specify, and track time. Supporting evidence includes greater timing precision at movement endpoints compared to other parts of movements, suggesting the separate control of the timing of movement endpoints compared to other parts of movement. This evidence challenges models in which all parts of a movement trajectory are controlled by the same equation of motion, but supports models in which a) each abstract, symbolic phonological representation maps onto spatial and temporal characteristics of the part(s) of movement most closely related to the goal of producing a planned set of acoustic cues to signal the phonological contrast (often the endpoint), b) movements are coordinated primarily based on the goal-related part of movement, and c) speakers give priority to the accurate implementation of the part(s) of movement most closely related to the phonological goals. Further support for phonology-extrinsic timing comes from three types of evidence suggesting that surface durations are represented during speech production. Finally, phonology-extrinsic timing is supported by greater timing variability for repetitions of longer intervals, assumed to be due to noise in a general-purpose (and phonology-extrinsic) timekeeping process. The evidence appears to be incompatible with models that have a unified Phonology/Phonetics Component, with models which do not represent the surface timing of phonetic events, nor with models in which timing in speech production is not represented, specified and tracked by a general-purpose timekeeping mechanisms. (shrink)

Despite the wealth of research showing that psychological contract breach (PCB) has negative outcomes for individuals, knowledge about the influence of the social context in which breaches are experienced is still scarce. This is surprising, as scholars have argued that work climates, such as when unit members are generally highly committed, could buffer an individual’s negative experiences at work. Yet, to date, the unit climate and PCB literatures have largely remained separated and our main goal is to integrate these fields. (...) This is especially timely and relevant, because recent work in the unit climate literature indicates that merely looking at the average climate level might not be enough, because the climate’s strength (i.e., the agreement or homogeneity within the unit) could also provide important social cues. Building on these recent advances, we develop and test a theoretical framework which links both climate concepts to PCB. More specifically, we hypothesized that especially when all unit members are highly and homogeneously committed, an employee would reframe their PCB in such a way that it would less adversely affect work engagement and turnover intentions. Using data from 1,272 employees across 36 healthcare units, multilevel structural path analyses supported this three-way interaction. By answering recent calls for more ‘social PCB research’ and integrating the unit climate and PCB literatures, we aim to provide guidance to scholars and practitioners who want to understand in more depth the social context’s influence on PCB. (shrink)

Little is known about distance processing in patients with posterior brain damage. Although many investigators have claimed that distance estimates are normal or abnormal in some of these patients, many of these observations were made informally and the examiners often asked for relative, and not absolute, distance estimates. The present investigation served two purposes. First, we wanted to contrast the use of distance information in peripersonal space for perceptual report as opposed to visuomotor control in our visual form agnosic patient, (...) DF. Second, we wanted to see to what extent her abilities to process distance cues were dependent on binocular vision, in light of Milner et al.'s (1991) observations of preserved stereopsis in DF, and Dijkerman et al.'s (1996) and Marotta et al.'s (1997) observations that her visual guidance of grasping may be particularly dependent on binocular vision of the target. We hypothesized that DF's visuomotor responses would show normal sensitivity to target distance, while her perceptual estimates would not. In the first experiment, we required DF and two age- and sex-matched control subjects to reach out and grasp black cubes placed at varying distances, or to estimate the distance of the cubes from the hand starting position without making a reaching movement. In the second experiment, we required DF and two age-matched control subjects to point as rapidly and accurately as possible to small LED targets which differed in spatial location, under binocular and monocular conditions. The results showed that, relative to the control subjects, DF's grasping movements produced normal peak velocity-distance scaling-when she reached for blocks which varied in depth or pointed to LED targets which were presented at different distances in depth. In contrast, in the cube experiment, her verbal estimates of object distance were poorly scaled, although they improved slightly under the binocular conditions. The results are discussed in terms of current theories of processing streams in extrastriate visual cortex and the distinction between categorical and coordinate spatial processing. (shrink)

Identification of the molecular mechanisms underlying axonal branching in vivo has begun in several neuronal systems, notably the projections formed by dorsal root ganglion (DRG) neurons or retinal ganglion cells (RGC). cGMP signalling is essential for sensory axon bifurcation at the spinal cord, whereas brain‐derived neurotrophic factor (BDNF) and ephrinA signalling establish position‐dependent branching of RGC axons. In the latter system, the degradation of specific signalling components, via the ubiquitin‐proteasome system, may provide an additional mechanism involved in axon branching of (...) RGC. The process of arborisation is essential for neurons to innervate multiple targets and to build topographic maps. The various forms of branching found in different types of neurons are regulated by distinct signalling pathways activated by multiple extracellular cues in addition to axonal guidance factors. These signalling cascades, together with transcriptional programs, most likely interact and trigger the polymerisation or depolymerisation of the actin and tubulin cytoskeleton to regulate branching. (shrink)

A considerable challenge confronts, any developing neuron. Before it can establish a functional and specific connection, it must extend an axon over tens and sometimes hundreds of microns through a complex and mutable environment to reach one out of many possible destinations. The field of axonal guidance concerns the control of this navigation process. To satisfactorily identify the cell interactions and molecular mechanisms that mediate axonal guidance, it is essential to first identify the pertinent cell populations. Embryonic surgeries (...) have provided solid information on which tissues are critical and which are irrelevant to the navigation of motor axons within the chick embryo. The gross anatomical nerve pattern is established as axons respond to both positive (path) and negative (barrier) tissue environments. Analysis of the interactions of motoneurons with these tissues reveals that several cellular interactions – chemotaxis, substratum preference, and perhaps contact paralysis – are important to the common patterns of motor axon advance. Axons simultaneously interact with population‐specific cues that have begun to be identified on the tissue level. (shrink)

It is evident that, being a member of the organization, the team has to cue the influx of the green management concepts. This study focuses on the aspect of team management in green enterprises. Applying leadership theory to sample green enterprises, this paper proposes that political skills of team leadership have moderating effects on the relationship between team conflict and performance at both the individual and team levels. Empirical data were collected from 85 dyads of leaders and team members in (...) 36 green enterprises in China. It was found that the leaders’ political skills weakened the negative effects of relationship conflict on individual performance and team performance. Further, leaders’ political skills strengthened the positive effects of task conflict on individual and team performance. The results of this study deepen the cognition of two types of team conflict in theory and provide theoretical guidance for green enterprises in carrying out effective team conflict management and practical political skills training for leaders. (shrink)

This paper reflects on the idea of ‘visualization’ of legal rules as part of an account of rule following in action. Presenting an alternative to Van Schooten’s (Jurisprudence and communication. Deborah Charles, Liverpool, 2012) account of interpretation, I first distinguish between two modes of interpretation: rehearsing and discursive. I argue that the former is the more basic one, relating to our respecting sources, rather than noticing signs, in action. In other (Wittgensteinian) words, we have to understand how we take (...) class='Hi'>guidance from rules. This account can profit from an analysis of what ‘seeing’ amounts to. Taking my cue from Merleau-Ponty, I point to the intertwinement between agent and world in seeing, in rule-following, and eventually in legal rule-following. The proof of the pudding is an alternative account of the time-honoured paradigm of legal interpretation: Hart’s ‘no vehicles in the park’. I show how this example is predicated on detecting ‘depth-clues’ in a rule, which allow an agent to correlate his vantage point to a vanishing point of a rule. The example illustrates a key-feature of rule following: reflexivity. I cannot follow a rule unless I project myself into its picture. (shrink)

Des collégiens lisaient le contenu d'une brochure ou d'un cédérom afin de répondre à des questions relatives aux caractéristiques de trois professions et devaient ensuite rappeler les informations correspondant aux réponses à ces questions ainsi que des informations proches de ces informations dans le texte. Une moitié des informations à rappeler était signalée par la mise en gras. Les résultats montrent des mécanismes de traitement analogues dans la brochure et le cédérom. Les résultats mettent aussi en évidence deux modalités différentes (...) de traitement de la signalisation des informations. Une modalité est relative à la signalisation perceptive périphérique - la mise en gras des informations -; l'autre modalité concerne le questionnement, c'est-à-dire les questions posées. La modalité relative au questionnement conduit à un meilleur rappel final des informations.The effects of two types of text presentation are studied in a experimental situation similar to vocational guidance. Two groups of junior- high school students with computing skills were examined. The first group received the text in a booklet and the second recieved the text on a CD-ROM. Two tasks were given: a research task examining the selection process and then a memory task examining the integration process. Moreover we measured the influence of typographical cues and the instructional system on these two tasks. As far as the information presentation is concerned, the results show that it did not affect the process of selection and the integration of the information. For the text cues, in both groups , the cueing was found to have an effect on the selection process but not in the integration process of the researched information. Researched information can be recalled more easily than information that is only read but the beneficial effect of typographical cues does not add to the beneficial effect of researched information. We propose future research on the effectiveness of different types of cues in function of differences on domain and computing systems expertises. (shrink)

: The ability to respond to gaze cueing is essential for successful social interactions and social learning. An active area of research in human robot interactions focuses on the computational encoding of biologically realistic gaze cueing responses in robots. Studies of human development are a primary source of guidance for this field of research. The investigation of how perceived gazes constrain the developmental trajectories of visual attention in humans from childhood to adulthood might reveal important factors to implement realistic (...) gaze following in social robots. This study investigated spontaneous gaze following in 2 and 4-year-old children and adults. Participants saw faces of an adult gazing toward an object. We found that accuracy of gaze following improved significantly with age. The results are discussed considering the development of the executive control of visual attention in humans and its possible implication in implementing gaze following in social robotics. Keywords: Gaze Following; Eye Tracking; Visual Attention; Social Robotics; Developmental Trajectories Ispirare la robotica: traiettorie evolutive della capacità di seguire la direzione dello sguardo negli esseri umani Riassunto: La capacità di seguire la direzione dello sguardo è essenziale per il successo delle interazioni sociali e per l’apprendimento sociale. Un’area di ricerca particolarmente attiva nell’ambito dell’interazione uomo-robot si focalizza sulla codifica computazionale della capacità di seguire la direzione dello sguardo nei robot. Studiare come la capacità di seguire lo sguardo possa influenzare l’attenzione visiva negli esseri umani dall’infanzia all’età adulta può rivelare importanti informazioni per implementare la capacità di seguire lo sguardo nei robot sociali. Questo studio ha indagato la capacità spontanea di seguire la direzione dello sguardo in bambini di 2 e 4 anni e negli adulti. I partecipanti hanno osservato una serie di volti umani con lo sguardo rivolto verso un oggetto. I risultati hanno indicato che l’accuratezza nel gaze following migliora in modo significativo con l’età. I risultati sono stati discussi considerando il ruolo del controllo esecutivo dell’attenzione visiva negli esseri umani e le sue possibili implicazioni per implementare l’abilità di seguire la direzione dello sguardo nei robot sociali. Parole chiave: Seguire la direzione dello sguardo; Eye Tracking; Attenzione visiva; Robot sociali; Traiettorie evolutive. (shrink)

The first two parts of the book are lectures given by Dr. Cuénot at the first annual conference in October 1966 of the Pierre Teilhard de Chardin Association of Great Britain and Ireland. Then follows a comment made by Professor Garaudy at the conference. The text concludes with an original essay by Dr. Cuénot which examines Teilhard's influence on contemporary thinkers.

Cet ouvrage est une réédition numérique d’un livre paru au XXe siècle, désormais indisponible dans son format d’origine.

Se apuntan algunas reflexiones relevantes sobre el ethos universitario en el contexto del exilio republicano español de 1939. En concreto, de autores como Fernando de los Ríos, Joaquín Xirau y José Gaos, exponentes todo ellos de un saber desarraigado en busca de nuevos resortes de poder. Se tiene además en cuenta el caso de María Zambrano, cuyo aparente desinterés por la cuestión universitaria es indicio de un saber coherente con su exilio e irreductible a la disciplina académica, de un saber (...) que ha renunciado al poder y exige un nuevo ethos. (shrink)

This striking Lacanian contribution to discourse analysis is also a critique of contemporary psychological abstraction, as well as a reassessment of the radical opposition between psychology and psychoanalysis. This original introduction to Lacan's work bridges the gap between discourseanalytical debates in social psychology and the social-theoretical extensions of discourse theory. David Pavón Cuéllar provides a precise definition and a detailed explanation of key Lacanian concepts, and illustrates how they may be put to work on a concrete discourse, in this case (...) a fragment of an interview obtained by the author from the Mexican underground Popular Revolutionary Forces (EPR). Throughout the book, Lacanian concepts are compared to their counterparts in psychology. Such a comparison reveals insuperable incompatibilities between the two series of concepts. The author shows that Lacan's psychoanalytical terminology can neither be translated nor assimilated to the terms of current psychology. Among the notions in actual or potential competition with Lacanian concepts, the book deals with those proposed by semiology, Marxism, phenomenology, constructionism, deconstruction, and hermeneutics. Taking a stand on those theoretical positions, each chapter includes detailed discussion of the contribution of classical approaches to language; including Barthes, Bakhtin, Althusser, Politzer, Wittgenstein, Berger and Luckmann, Derrida, and Ricoeur. There is sustained reference in the body of the text to the arguments of Lacan and Lacanians, of Miller, Milner, Soler, and Zizek. At the same time, in the extensive notes accompanying the text, there is a systematic reappraisal and reinterpretation of debates and pieces of research work in social psychology, especially in a discursive and critical domain that has incorporated elements of psychoanalytic theory. (shrink)

The particle internal clock conjectured by de Broglie in 1924 was investigated in a channeling experiment using a beam of ∼80 MeV electrons aligned along the 〈110〉 direction of a 1 μm thick silicon crystal. Some of the electrons undergo a rosette motion, in which they interact with a single atomic row. When the electron energy is finely varied, the rate of electron transmission at 0° shows a 8% dip within 0.5% of the resonance energy, 80.874 MeV, for which the (...) frequency of atomic collisions matches the electron’s internal clock frequency. A model is presented to show the compatibility of our data with the de Broglie hypothesis. (shrink)