Why professional athletes need a prolonged period of warm-up and other peculiarities of human motor learning

Professional athletes involved in sports that require the execution of fine motor skills must practice for a considerable length of time before competing in an event. Why is such practice necessary? Is it merely to warm-up the muscles, tendons, and ligaments, or does the athlete's sensorimotor network need to be constantly recalibrated? In this article, the authors present a point of view in which the human sensorimotor system is characterized by: (a) a high noise level and (b) a high learning rate at the synaptic level (which, because of the noise, does not equate to a high learning rate at the behavioral level). They argue that many heuristics of human skill learning, including the need for a prolonged period of warm-up in experts, follow from these assumptions.     

Kierkegaard’s Regulative Sacrifice: A Post-Kantian Reading of Fear and Trembling

Abstract

The present paper suggests to consider Kierkegaard’s use of Abraham’s story in Fear and Trembling in regulative terms, that is, to consider it as a model – not for our moral behaviour but rather for our religious behaviour. To do so, I first rely on recent literature to argue that Kierkegaard should be regarded as a distinctively post-Kantian philosopher: namely, a philosopher who goes beyond Kant in a way that is nevertheless true to the spirit of Kant’s original critical philosophy. Then, I present a post-Kantian reading of Fear and Trembling, focusing on the problematic implications that result from comparing this text with Hegel’s theory of recognition. Finally, I submit that sacrifice in Fear and Trembling is a regulative notion in a Kantian sense. This interpretation addresses some of the most problematic aspects of the text. I conclude that the regulativity of sacrifice may be regarded as an important and perhaps an essential component of Kierkegaard’s overall philosophical strategy.     

Kant’s sacrificial turns

This paper addresses the role of the notion of sacrifice in Kant’s theoretical philosophy, practical philosophy, and in his account of religion. First, I argue that kenotic sacrifice, or sacrifice as ‘withdrawal’, plays a hidden and yet important role in the development of Kant’s transcendental philosophy. Second, I focus on Kant’s practical philosophy, arguing that the notion of sacrifice that is both implied and explicitly analyzed by Kant is mainly suppressive sacrifice. However, Kant’s account is fundamentally ambiguous, as sometimes the kenotic meaning of sacrifice seems to resurface, especially in the context of Kant’s discussion of the happiness of others as an end in itself. Because religious notions are regarded by Kant as necessary transitional forms (Darstellungen) to be used to make moral ideas applicable to the world, I then scrutinize Kant’s view of sacrifice as an improper symbol, and I analyze Kant’s arguments for such a dismissal and discuss the subject matter in recent literature. Finally, I examine the role of sacrifice in Kant’s account of Christ as the prototype of pure moral disposition. I conclude by arguing that Kant indeed grasped the importance of including kenotic dynamics in practical philosophy but was somehow unable or unwilling to integrate it into the formal grounding of his ethics. This tension, however, effectively provides an entry point for features that can be found in the post-Kantians.     

Are good students desirable friends? Evidence for friendship selection among elementary students / ¿Son los buenos estudiantes amigos deseables? Evidencia para la selección de amistad entre estudiantes de educación primaria

Abstract

This study assesses the relationship between friendship networks and academic performance among third graders from one school in Santiago, Chile. Longitudinal social network analysis (RSiena) was used to test whether friendship selection is driven by academic performance and if befriended peers tend to influence each other on their academic performance, including gender as a covariate. Results show a positive relationship between academic performance and number of friendship nominations received, and a higher probability of same-gender friendships. Students with higher academic achievement are more likely to be nominated as friends, especially by peers with lower academic achievement. These results suggest that elementary students value high performance as a desirable characteristic in their friends.     

Looking for unexpected results: the need to systematize the registration of environmental variables / Buscando resultados inesperados: la necesidad de sistematizar el registro de variables ambientales

Abstract

Why is replicating cognitive neuroscience results so difficult? Here we discuss a possible bias that could determine the systematic omission of control variables. A methodology based on the notion that cognitive processes are encapsulated undermines the adequate characterization of both the sample and its experimental context. Systematically exploring the impact of the sample and context variables implies discussing and developing standard experimentation practices. We propose actively searching for unexpected results as a starting point to do so.     

Latent Differential Equation Modeling of Self-Regulatory and Coregulatory Affective Processes

We examine emotion self-regulation and coregulation in romantic couples using daily self-reports of positive and negative affect. We fit these data using a damped linear oscillator model specified as a latent differential equation to investigate affect dynamics at the individual level and coupled influences for the 2 partners in each couple. Results indicate an absence of damping of relationship-specific affect within individuals in the sample. When both positive and negative affect are modeled at the individual level, the influence of positive affect is greater than that of negative affect. At the dyad level, the findings indicate coupled influences in both positive and negative affect between partners. With regard to positive affect, females are sensitive to their partners' overall displacement from average as well as their rate of change; males are sensitive only to their partners' displacement from average. For negative affect both partners are sensitive to each other's displacement from average, yet there are no coupled influences for rates of change in this dimension. We interpret the influence of the parameters on the system by examining the expected behavior of the system as a function of varying parameter values.     

An Unscented Kalman Filter Approach to the Estimation of Nonlinear Dynamical Systems Models

In the past several decades, methodologies used to estimate nonlinear relationships among latent variables have been developed almost exclusively to fit cross-sectional models. We present a relatively new estimation approach, the unscented Kalman filter (UKF), and illustrate its potential as a tool for fitting nonlinear dynamic models in two ways: (1) as a building block for approximating the log–likelihood of nonlinear state–space models and (2) to fit time-varying dynamic models wherein parameters are represented and estimated online as other latent variables. Furthermore, the substantive utility of the UKF is demonstrated using simulated examples of (1) the classical predator-prey model with time series and multiple–subject data, (2) the chaotic Lorenz system and (3) an empirical example of dyadic interaction.     

Changing Parties,Changing Partisans: The Personalization of Partisan Attachments in Western Europe

This article investigates the effects of the deep transformations in the relationship between West European class‐mass parties and their electorates. Particular attention is paid to the changing nature of individuals' partisan attachments, which are hypothesized to be less rooted in social and ideological identities and more in individual attitudes towards increasingly visible partisan objects. The main objective of this article is to examine the influence of voters' attitudes towards one of these “objects”—the party leaders—in determining psychological attachments with the parties. The analysis concentrates on the two main cleavage‐based parties in Britain, Germany, Italy, and the Netherlands. The empirical findings highlight the declining ability of social identities (class and religious) to predict individual feelings of partisan attachment, as well as the growing influence of voters' attitudes towards party leaders. The concluding section points to the crucial role that political psychology can play in our understanding of democratic elections' outcomes.     

Depressed mothers' newborns show longer habituation and fail to show face/voice preference

Twenty neonates of depressed and nondepressed mothers failed to show an initial visual preference for their mother's versus a female stranger's face/voice. Subsequently, infants were habituated to their mother's face and voice. Infants of depressed mothers required 1/3 more trials and almost twice as long to habituate. A posthabituation test with their mother and a different female stranger revealed a preference for the stranger's face for 9 out of the 10 newborns of the nondepressed mothers. Again, the infants of depressed mothers displayed no visual preference. These findings reveal differences in depressed mothers newborns' speed of habituation and face/voice preferences. ©2002 Michigan Association for Infant Mental Health.