Aristotle’s Immovable Movers: A Sketch

In keeping with a view that is explicitly formulated by Aristotle in his Motion of Animals, general kinetic principles must be specified according to the different types of movable entities existing in the universe. At issue, essentially, are the motions of the stars and the motions of animals. Whereas the cosmological immovable mover is the object of two complementary analyses (in Bk. VIII of Physics and in Chs. 6 and 7 of Bk. XII of Metaphysics), information on the immovability of the first mover responsible for animal motion is to be found in the psychological and psycho-physiological treatises (On the Soul, in Bk. I, Chs. 3 and 4, and in Bk. III, Ch. 10 and in Ch. 6 of the Motion of Animals). But it is also found in Ch. 7, Bk. XII of the Metaphysics, in the very context of the argument concerning the absolutely first immovable mover of the world. This suggests that the two types of motion, that of the stars and that of animals, however distinct the arguments about them are, rest on a single scheme, and maybe even on a common principle. This is liable to surprise us, as much as stars and animals appear to us to belong to heterogeneous orders of reality. But the situation is different for Aristotle, who, as attentive as he is to differences, tends nonetheless to conceive the stars as living things of a particular kind. This fact is the source of a series of difficulties that Aristotle generously left for his many commentators to solve. Aim of this text, which was initially directed to a larger audience, is to set some of these complex issues in both simple and up to date terms.     

Parametric induction of animacy experience

Graphical displays of simple moving geometrical figures have been repeatedly used to study the attribution of animacy in human observers. Yet little is known about the relevant movement characteristics responsible for this experience. The present study introduces a novel parametric research paradigm, which allows for the experimental control of specific motion parameters and a predictable influence on the attribution of animacy. Two experiments were conducted using 3D computer animations of one or two objects systematically introducing variations in the following aspects of motion: directionality, discontinuity and responsiveness. Both experiments further varied temporal kinematics. Results showed that animacy experience increased with the time a moving object paused in the vicinity of a second object and with increasing complexity of interaction between the objects (approach and responsiveness). The experience of animacy could be successfully modulated in a parametric fashion by the systematic variation of comparably simple differential movement characteristics.     

La répression émotionnelle et son rôle en psychopathologie

In the context of studies on mechanisms of emotional treatment and regulation in affective blunting, this paper focalizes on those whose objective is to disminish awareness of subjective emotional experience. The cognitive mechanism of repression is first presented, defined as a coping strategy which, used in a habitual way, is conceptualised as a personality dimension. Its role on the whole panel of emotional components and the researches on its underlying cognitive mechanisms, in particular those which may explain the observed memory deficits for negative emotional events, are developed. The paper also presents models of maturation of emotional awareness, differentiating several hypothetic ways of emotional treatment which determine specific emotional subjective experiences. In regard of studies which have explored these modes of emotional treatment in alexithymia, hypotheses on their role in the blunting of affect process and on the quality of subjective experience are proposed.     

Profils multidimensionnels de jeunes enfants trisomiques bulgares

This study examines links between cognitive, communicative, socioemotional and psychomotor abilities in 20 Bulgarian institutionalised children with Down syndrome. These children were evaluated by means of the Early Cognitive Development Assessment Scales (ECDAS, Nader-Grosbois, 1993), the Early Social Communication Scales (ECSP, Guidetti and Tourrette, 1993), and two grids of socioemotional and psychomotor indicators, inspired by the Trandisciplinary Play-Based Assessment (TPBA, Linder, 1990). Several analyses of developmental patterns were performed in order to identify specificities in the structural organisation of abilities in Bulgarian Down syndrome children in situation of abandonment or negligence: comparison of means of scores in distinct domains, correlations, clusters of variables, analysis of individual profiles by clusters of cases. The results indicate: weakness in vocal imitation and in joint attention; limited relationships between communicative abilities; local homologies between some cognitive and communicative abilities implicating a lack of integration; particular links between specific dimensions of socioemotional and psychomotor adaptation and certain cognitive and communicative abilities in these Down syndrome children.     

解脲支原体致病性认识的矛盾运动

解脲支原体(ureaplasmaurealyticumUU)是一种处于细菌与病毒之间的原核微生物,被认为是女性生殖道常见且有致病作用的病原体,可通过性交传播。但因许多正常女性阴道内可检测出UU,且其中一部分人无性生活史或亦无任何症状,即并非都具有致病性。临床检查到UU,并不能确定是寄生状态还是感染状态,给诊断与治疗带来困难,是临床中亟待解决的问题。通过UU致病性认识发展的矛盾运动,发现UU致病力受血清型、浓度、宿主状态等多方面因素的影响。     

Human and machine perception of biological motion

More than 30 years ago, Johansson was the first to show that humans are capable of recovering information about the identity and activity of animate creatures rapidly and reliably from very sparse visual inputs – the phenomenon of biological motion. He filmed human actors in a dark setting with just a few strategic points on the body marked by lights – so-called moving light displays (MLDs). Subjects viewing the MLDs reported a vivid impression of moving human forms, and were even able to tell the activity in which the perceived humans were engaged. Subsequently, the phenomenon has been widely studied and many attempts have been made to model and to understand it. Typical questions that arise are: How precisely is the sparse low-level information integrated over space and time to produce the global percept, and how important is world knowledge (e.g., about animal form, locomotion, gravity, etc.)? In an attempt to answer such questions, we have implemented a machine-perception model of biological motion. If the computational model can replicate human data then it might offer clues as to how humans achieve the task. In particular, if it can do so with no or minimal world knowledge then this knowledge cannot be essential to the perception of biological motion. To provide human data for training and against which to assess the model, an extensive psychophysical experiment was undertaken in which 93 subjects were shown 12 categories of MLDs (e.g., normal, walking backwards, inverted, random dots, etc.) and were asked to indicate the presence or absence of natural human motion. Machine perception models were then trained on normal sequences as positive data and random sequences as negative data. Two models were used: a k-nearest neighbour (k-NN) classifier as an exemplar of ‘lazy’ learning and a back-propagation neural network as an exemplar of ‘eager’ learning. We find that the k-NN classifier is better able to model the human data but it still fails to represent aspects of knowledge about body shape (especially how relative joint positions change under rotation) that appear to be important to human judgements.     

Infants perceive human point-light displays as solid forms

While five-month-old infants show orientation-specific sensitivity to changes in the motion and occlusion patterns of human point-light displays, it is not known whether infants are capable of binding a human representation to these displays. Furthermore, it has been suggested that infants do not encode the same physical properties for humans and material objects. To explore these issues we tested whether infants would selectively apply the principle of solidity to upright human displays. In the first experiment infants aged six and nine months were repeatedly shown a human point-light display walking across a computer screen up to 10 times or until habituated. Next, they were repeatedly shown the walking display passing behind an in-depth representation of a table, and finally they were shown the human display appearing to pass through the table top in violation of the solidity of the hidden human form. Both six- and nine-month-old infants showed significantly greater recovery of attention to this final phase. This suggests that infants are able to bind a solid vertical form to human motion. In two further control experiments we presented displays that contained similar patterns of motion but were not perceived by adults as human. Six- and nine-month-old infants did not show recovery of attention when a scrambled display or an inverted human display passed through the table. Thus, the binding of a solid human form to a display in only seems to occur for upright human motion. The paper considers the implications of these findings in relation to theories of infants' developing conceptions of objects, humans and animals.     

面孔识别动态增益效应研究综述

近年来,研究者围绕动态面孔识别中的动态增益效应开展了一系列的研究。本文围绕面孔熟悉程度和面孔的活动类型两个方面对与动态增益效应有关的一系列动态面孔认知研究进行了总结,并对不同研究的差异进行了比较和分析。最后,对动态面孔认知规律、眼动模式和脑机制等研究方向上的发展进行了展望。     

Anticipating intentional actions: The effect of eye gaze direction on the judgment of head rotation

Using a representational momentum paradigm, this study investigated the hypothesis that judgments of how far another agent’s head has rotated are influenced by the perceived gaze direction of the head. Participants observed a video-clip of a face rotating 60° towards them starting from the left or right profile view. The gaze direction of the face was either congruent with, ahead of, or lagging behind the angle of rotation. Following this, two static faces, at varying angles of rotation with respect to the end-point angle of the face in the video-clip, were presented simultaneously. The task of the participants was to decide which of the two heads was at an angle best resembling the angle of the end-point of the moving face. The critical test condition consisted of one test face oriented at 10° before, and the other at 10° after the end-point. The ‘lagging behind’ gaze condition elicited a significant underestimation of the rotation compared to the ‘congruent’ and ‘ahead’ gaze conditions. Participants did not exhibit similar biases when judging the rotation of several non-face control stimuli with visual features that mimicked different aspects of gaze direction. The findings suggest that when the gaze direction of a perceived agent is incongruent with the direction of the agent’s head motion observers automatically utilise this discrepancy to adjust their inferences about the agent’s intended heading direction.