Comparison of the trunk-pelvis and lower extremities sagittal plane inter-segmental coordination and variability during walking in persons with and without chronic low back pain

Inter-segmental coordination can be influenced by chronic low back pain (CLBP). The sagittal plane lower extremities inter-segmental coordination pattern and variability, in conjunction with the pelvis and trunk, were assessed in subjects with and without non-specific CLBP during free-speed walking. Kinematic data were collected from 10 non-specific CLBP and 10 non-CLBP control volunteers while the subjects were walking at their preferred speed. Sagittal plane time-normalized segmental angles and velocities were used to calculate continuous relative phase for each data point. Mean absolute relative phase (MARP) and deviation phase (DP) were derived to quantify the trunk-pelvis and bilateral pelvis-thigh, thigh-shank and shank-foot coordination pattern and variability over the stance and swing phases of gait. Mann-Whitney U test was employed to compare the means of DP and MARP values between two groups (same side comparison). Statistical analysis revealed more in-phase/less variable trunk-pelvis coordination in the CLBP group (P < 0.05). CLBP group demonstrated less variable right or left pelvis-thigh coordination pattern (P < 0.05). Moreover, the left thigh-shank and left shank-foot MARP values in the CLBP group, were more in-phase than left MARP values in the non-CLBP control group during the swing phase (P < 0.05). In conclusion, the sagittal plane lower extremities, pelvis and trunk coordination pattern and variability could be generally affected by CLBP during walking. These changes can be possible compensatory strategies of the motor control system which can be considered in the CLBP subjects.     

Explaining after by before: Basic aspects of a dynamic systems approach to the study of development

The basic properties of a dynamic systems approach of development are illustrated by contrasting two simple equations. One, y_t+1 = f (y_t), is characteristic of dynamic systems models. The other, y_i = f (x_i), refers to what, for the sake of simplicity, is referred to as the standard developmental approach. We give illustrations from cognitive, language and social development to show the characteristic differences of these two types of models and show their complementarity. The article further compares the “Bloomington” with the “Groningen” approach to dynamic systems theorizing in developmental psychology. It continues with a discussion of two important questions. One involves the issue of measurement and the nature of developmental variables from the viewpoint of dynamic systems. The second concerns the question of short- and long-term time scales in developmental models, which is discussed on the basis of an example, namely dyadic interaction of young children in the context of different social statuses.     

Social dynamics in the preschool

In this paper, we consider how concepts from dynamic systems (such as attractors, repellors, and self-organization) can be applied to the study of young children’s peer relationships. We also consider how these concepts can be used to explore basic issues involving early peer processes. We use the dynamical systems approach called state space grid (SSG) analysis and consider how it can be expanded beyond the study of dyads to the study of larger social groups and networks. In particular, we explore the role of homophily—that is, behavioral and sex similarity—as factors in the self-organization of young children’s social groups. A dynamic systems approach allows for consideration of peer processes difficult to assess using more traditional approaches.     

Putting motion in emotion: Do dynamic presentations increase preschooler's recognition of emotion?

In prior research, preschoolers were surprisingly poor at naming the emotion purportedly signaled by prototypical facial expressions—when shown as static images. To determine whether this poor performance is due to the use of static stimuli, rather than dynamic, we presented preschoolers (3-5 years) with facial expressions as either static images or dynamic audiovisual clips. Dynamic clips presented face alone (Study 1, N = 48) or face, body movement, and vocal intonation (Study 2, N = 72). Contrary to expectations, dynamic presentation did not increase children's naming of the emotion in either study and decreased it in Study 1.     

Continuous visual cues trigger automatic spatial target updating in dynamic scenes

Dynamic tasks often require fast adaptations to new viewpoints. It has been shown that automatic spatial updating is triggered by proprioceptive motion cues. Here, we demonstrate that purely visual cues are sufficient to trigger automatic updating. In five experiments, we examined spatial updating in a dynamic attention task in which participants had to track three objects across scene rotations that occurred while the objects were temporarily invisible. The objects moved on a floor plane acting as a reference frame and unpredictably either were relocated when reference frame rotations occurred or remained in place. Although participants were aware of this dissociation they were unable to ignore continuous visual cues about scene rotations (Experiments 1a and 1b). This even held when common rotations of floor plane and objects were less likely than a dissociated rotation (Experiments 2a and 2b). However, identifying only the spatial reference direction was not sufficient to trigger updating (Experiment 3). Thus we conclude that automatic spatial target updating occurs with pure visual information.     

Majority merging by adaptive counting

The present paper introduces a belief merging procedure by majority using the standard format of Adaptive Logics. The core structure of the logic ADM ^c (Adaptive Doxastic Merging by Counting) consists in the formulation of the conflicts arising from the belief bases of the agents involved in the procedure. A strategy is then defined both semantically and proof-theoretically which selects the consistent contents answering to a majority principle. The results obtained are proven to be equivalent to a standard majority operator for bases with partial support.     

Logical dynamics of some speech acts that affect obligations and preferences

In this paper, illocutionary acts of commanding will be differentiated from perlocutionary acts that affect preferences of addressees in a new dynamic logic which combines the preference upgrade introduced in DEUL (dynamic epistemic upgrade logic) by van Benthem and Liu with the deontic update introduced in ECL II (eliminative command logic II) by Yamada. The resulting logic will incorporate J. L. Austin’s distinction between illocutionary acts as acts having mere conventional effects and perlocutionary acts as acts having real effects upon attitudes and actions of agents, and help us understand why saying so can make it so in explicit performative utterances. We will also discuss how acts of commanding give rise to so-called “deontic dilemmas” and how we can accommodate most deontic dilemmas without triggering so-called “deontic explosion”.     

基于元认知的认知学习对动态能力影响的实证研究

通过实证研究勾勒出符合动态特征的元认知理论框架,提出构成元认知的6个要素,分别归为元认知策略、元认知调控和元认知知识三个维度.并借助结构方程模型重点分析了元认知、认知学习和动态能力的相关性,以及基于元认知的认知学习对动态能力演化的影响.     

Interlevel Relations and Manipulative Causality

Summary  The topic of this article is the analysis of the relations between different levels of reality. The core argument is based on considerations of both an epistemology of action and manipulative causality as a criterion of object identity. The argumentation is extended towards the concepts of self-organization and self-regulation. Finally, several views on reduction and the problems of emergence and complexity are discussed.     

The biological foundations of cognitive science

Cognitive Science originated in reactions against behaviorism that were motivated in significant part by the example of the computer. The computer raised the exciting possibility that mind could be understood almost entirely independently of brain: if the operations of the mind are akin to the execution of a program, then almost all the relevant aspects of mind would be captured by that program, independently of whatever was running it, be it transistors or neurons. This presumed independence of cognitive science from biology has waned considerably in recent decades, but in this paper, I argue that there is at least one crucial aspect of biology that has yet to be appreciated for its relevance to mental and other normative processes—the thermodynamics of living systems. In particular, I argue that the emergence of normativity in general—and normative function and representation in particular—depends on special systems that are far from thermodynamic equilibrium; these form the interface between the factual world of atoms and molecules and the normative world of mind. The nature of that emergence, in turn, imposes strong constraints on how the central nervous system functions, and, therefore, on how cognition is realized.