Increasing the conspicuity of cyclists at night by using bicycle lights and clothing to highlight their biological motion to oncoming drivers

Reduced conspicuity is an important contributing factor to increased motor vehicle-bicycle crashes and cyclist fatalities at night. This study explored ways of making night-time cyclists more conspicuous to oncoming vehicles through cyclist clothing options and bicycle light position. Fifteen young participants (M = 29.1 ± 4.5 years) drove a closed-road at night and indicated when they first recognized a cyclist pedalling in place at the roadside, facing the approaching vehicle. The bicycle had a static forward-facing white light located either on the handlebars or the helmet and wore one of five clothing configurations: fluorescent vest, retroreflective vest, retroreflective ankle strips, retroreflective vest plus retroreflective ankle strips, retroreflective vest plus biomotion retroreflective strips. There was a significant effect of light position (p < 0.001) and clothing (p < 0.001), where recognition distances were longer when the light was helmet-mounted and when retroreflective strips were worn on the lower legs to highlight the cyclist’s biological motion compared to either of the vest conditions. There was also a significant interaction between light position and clothing (p = 0.007) such that the benefit of retroreflective strips was greater when the bicycle light was helmet-mounted rather than on the handlebars. Importantly, the benefits of leg markings were apparent even when positioned at the ankles alone. These findings highlight that retroreflective material is most useful for improving cyclist conspicuity at night when positioned on cyclists’ lower legs, particularly the ankles (highlighting the cyclist's pedalling motion), rather than on the torso, and have important practical implications for maximising cyclists’ conspicuity and hence safety on night-time roads.     

Régulations endogène et exogène des émotions : des processus complémentaires et indissociables

Studies dealing with emotion regulation have known a fast expansion during the last twenty years. Yet, they are most often based on models centered on endogenous cognitive and behavioral processes as well as the pursuit of welfare, and do not consider the social aspect of emotions and emotion expression which elicit exogenous emotion regulation processes from social interaction partners. The goal of this article is to show that both endogenous and exogenous emotion regulation processes are complementary and indivisible, and to suggest working hypotheses about how they connect. In the first part of this document, after a quick reminder of the different theoretical approaches of (individual) endogenous emotion regulation, we emphasize works about social approach behaviors (social affiliation) in emotional situations. These studies report that social interactions are sometimes sought as they would allow for the endogenous implementation of interpersonal emotion regulation strategies, especially by means of emotion expression. Individual and interpersonal endogenous emotion regulation processes would then complementarily modify the emotions experienced by an individual faced with a critical situation. The second part of this article underlines that social interaction partners actually are operators of exogenous emotion regulation processes rather than passive reservoirs of resources an individual may pick up to regulate their emotions. For that purpose, we especially consider the ways relatives (directly or indirectly, explicitly or implicitly) constrain the social affiliation behaviors and emotion expressions of an individual who experiences emotions. Thus, we argue that those behaviors are strongly influenced not only by the nature and intensity of emotions, but also by: firstly, social learning about how to feel, what to express and how to regulate emotions in a specific situation; secondly, features of the social environment as well as social expectations and demands about sharing emotions versus inhibiting their expression; and thirdly, the exogenous emotion regulation strategies a partner may use to regulate an individual's emotions. This set of studies entices us to consider endogenous and exogenous emotion regulation processes as acting jointly to promote not only the adaptation to emotional situations, but also the quality of social bonds between members of a social network. Social integration is thus central in the study of emotion regulation processes.     

Both fearful and happy expressions interact with gaze direction by 200 ms SOA to speed attention orienting

Attention orienting towards a gazed-at location is fundamental to social attention. Whether gaze cues can interact with emotional expressions other than those signalling environmental threat to modulate this gaze cueing, and whether this integration changes over time, remains unclear. With four experiments we demonstrate that, when perceived motion inherent to dynamic displays is controlled for, gaze cueing is enhanced by both fearful and happy faces compared to neutral faces. This enhancement is seen with stimulus-onset asynchronies ranging from 200–700?ms. Thus, gaze cueing can be reliably modulated by positive expressions, albeit to a smaller degree than fearful ones, and this gaze–emotion integration impacts behaviour as early as 200?ms post-cue onset.     

Agents,objects, and their powers in Suarez and Hobbes

The paper examines the place of power in the action theories of Francisco Suarez and Thomas Hobbes. Power is the capacity to produce or determine outcomes. Two cases of power are examined. The first is freedom or the power of agents to determine for themselves what they do. The second is motivation, which involves a power to which agents are subject, and by which they are moved to pursue a goal. Suarez, in the Metaphysical Disputations, uses Aristotelian causation to model these two forms of power. Freedom is efficient causation, but in a special form that I explain as involving something that ordinary causation does not – the contingent determination of outcomes. Motivating power is final causation, which Suarez characterizes as the power of a goal or end to move us to attain it through its goodness or desirability. Suarez regards these two forms of power as consistent – we can be moved by the goodness of a goal freely to determine for ourselves that we act in order to attain it. Hobbes denied the existence of all forms of power beyond ordinary causation, the power of one motion in matter to determine another. So he denied the very existence both of freedom and of any form of motivating power beyond the ordinary causal power of desires as materially based psychological states to produce actions. The goodness itself of a goal never moves us, whether to desire the goal in the first place or to act in order to attain it. The paper examines Hobbes’s arguments and their consequence – establishing the foundations for Hume’s scepticism about practical reason.     

An Auto‐Ethnographic Study of “Open Dialogue”: The Illumination of Snow

This auto‐ethnographic study describes the changes in the author's thinking and clinical work connected to her first‐hand experience of Open Dialogue, which is an innovative, psychosocial approach to severe psychiatric crises developed in Tornio, Finland. In charting this trajectory, there is an emphasis on three interrelated themes: the micropolitics of U.S. managed mental health care; the practice of “dialogicality” in Open Dialogue; and the historical, cultural, and scientific shifts that are encouraging the adaptation of Open Dialogue in the United States. The work of Gregory Bateson provides a conceptual framework that makes sense of the author's experience and the larger trends. The study portrays and underscores how family and network practices are essential to responding to psychiatric crises and should not be abandoned in favor of a reductionist, biomedical model.     

Locke's theory of classification

In §155 of his New Theory of Vision Berkeley explains that a hypothetical ‘unbodied spirit’ ‘cannot comprehend the manner wherein geometers describe a right line or circle’.1 ¹All references to Berkeley are from, A. A. Luce and T. E. Jessop (eds.), The Works of George Berkeley, Bishop of Cloyne (London: Thomas Nelson and Sons, Ltd., 1948) The following abbreviations are used: An Essay Towards A New Theory of Vision, section x = New Theory x; Philosophical Commentaries, entry x = Commentaries x; Part I of A Treatise concerning the Principles of Knowledge, section x = Principles x. All other references to Berkeley's works are of the form The Works of George Berkeley, Bishop of Cloyne, volume x, page y = Works, x, y. The reason for this, Berkeley continues, is that ‘the rule and compass with their use being things of which it is impossible he should have any notion.’ This reference to geometrical tools has led virtually all commentators to conclude that at least one reason why the unbodied spirit cannot have knowledge of plane geometry is because it cannot manipulate a ruler or a compass. In this article I will show that such an interpretation is flawed. I will instead argue that Berkeley's understanding of Euclidian geometry was based on Isaac Barrow's account of the foundations of geometry. On this view geometrical objects are conceived in terms of the idealized motion that generates the objects of geometry. Consequently, that what the unbodied spirit cannot do in this context is to form an idea of motion rather than being unable to handle geometrical tools.     

Learning to like it: Aesthetic perception of bodies,movements and choreographic structure

Appreciating human movement can be a powerful aesthetic experience. We have used apparent biological motion to investigate the aesthetic effects of three levels of movement representation: body postures, movement transitions and choreographic structure. Symmetrical (ABCDCBA) and asymmetrical (ABCDBCA) sequences of apparent movement were created from static postures, and were presented in an artificial grammar learning paradigm. Additionally, “good” continuation of apparent movements was manipulated by changing the number of movement path reversals within a sequence. In an initial exposure phase, one group of participants saw only symmetrical sequences, while another group saw only asymmetrical sequences. In a subsequent test phase, both groups rated all sequences on an aesthetic evaluation scale. We found that posture, movement, and choreographic structure all influenced aesthetic ratings. Separate ratings for the static body postures presented individually showed that both groups preferred a posture that maximized spatial symmetry. Ratings for the experimental sequences showed that both groups gave higher ratings to symmetrical sequences with “good” continuation and lower ratings to sequences with many path reversals. Further, participants who had been initially familiarized with asymmetrical sequences showed increased liking for asymmetrical sequences, suggesting a structural mere exposure effect. Aesthetic preferences thus depend on body postures, apparent movement continuation and choreographic structure. We propose a hierarchical model of aesthetic perception of human movement with distinct processing levels for body postures, movements and choreographic structure.     

Specificity of Task Constraints and Effects of Visual Demonstrations and Verbal Instructions in Directing Learners' Search During Skill Acquisition

In the present study, the efficacy of visual demonstrations and verbal instructions as instructional constraints on the acquisition of movement coordination was investigated. Fifteen participants performed an aiming task on 100 acquisition and 20 retention trials, under 1 of 3 conditions: a modeling group (MG), a verbally directed group (VDG), and a control group (CG). The MG observed a model intermittently throughout acquisition, whereas the VDG was verbally instructed to use the model's movement pattern. Participants in the CG received neither form of instruction. Kinematic analysis revealed that compared with verbal instructions or no instructions, visual demonstrations significantly improved participants' approximation of the model's coordination pattern. No differences were found in movement outcomes. Coordination data supported the visual perception perspective on observational learning, whereas outcome data suggested that the modeling effect is mainly a function of task constraints, that is, the novelty of a movement pattern.     

Center of Gravity Motions and Ankle Joint Stiffness Control in Upright Undisturbed Stance Modeled Through a Fractional Brownian Motion Framework

The authors modeled the center of gravity vertical projection (CG_V) and the difference, CP - CG_V, which, combined, constitute the center of pressure (CP) trajectory, as fractional Brownian motion in order to investigate their relative contributions and t heir spatiotemporal articulation. The results demonstrated that CG_V and CP - CG_V motions are both endowed in complementary tashion with strong stochastic and part-deterministic behaviors. In addition, if the temporal coordinates remain similar for all 3 trajectories by definition, the switch between the successive control mechanisms appears for shorter displacements for CP - CG_V and CG_V than for CP trajectories. Results deduced from both input (CG,) and muscular stiffness (CP - CG_V) thus provide insight into the way the central nervous system regulates stance control and in particular how CG and CP - CG are controlled.     

Changes in Saccadic and Manual Motor Control After Ocular Smooth Pursuit Adaptive Modifications

The gain of ocular smooth pursuit responses can be adaptively modified under certain circumstances. Evidence that these modifications are caused, at least partly, by changes at a sensory level comes from the fact that subsequent manual tracking movements generated during visual fixation are also modified in a similar manner. The question addressed in the present experiment was whether the modifications are constrained specifically to responses such as these, which are driven by retinal image motion, or whether they can also influence movements that make use of retinal image position. This was accomplished by comparing manual and oculomotor responses to step changes in target position before and after smooth pursuit adaptation. The results showed that, as with manual tracking movements, these responses were also modified by the adaptive procedure, although to a lesser extent. In particular, following a 20-min period in which subjects (N = 4) were submitted to a procedure designed to increase the gain of the smooth pursuit system, manual step tracking movements and ocular saccades displayed larger amplitudes than those shown prior to the adaptation. In addition, these gain changes were accompanied by appropriate alterations in response kinematics. Taken together, these results suggest that the mechanisms responsible for adaptive modifications in the smooth pursuit system are also able to more generally influence the processing of visuospatial information. The possible neurophysiological substrate underlying these mechanisms is discussed.