The recognition of affective states associated with players’ non-verbal behavior in volleyball

The visible non-verbal behavior of volleyball players after a point might indicate their affective state. The purpose of the present study was to investigate whether the point outcome (i.e., win vs. loss) and the importance of the situation (i.e., first vs. fifth set) influence how well the affective states (indexed through non-verbal behavior) can be recognized. For this purpose, 111 participants were presented 60 video excerpts showing the non-verbal behavior of volleyball teams immediately after a rally and asked whether the shown team had just won or lost a point. The results indicated that the recognition rate was significantly higher for won (80.09%) than for lost points (65.56%) as well as for points of the fifth set (77.84%) than for points of the first set (68.51%). Furthermore, an explorative analysis showed that the recognition rate was significantly higher for won points of the fifth set (89.19%) than for those of the first set (72.13%).     

Approximately Efficient Solutions in Vector Optimization

An approach to approximating solutions in vector optimization is developed for vector optimization problems with arbitrary ordering cones. This paper presents a study of approximately efficient points of a given set with respect to a convex cone in an ordered Banach space. Existence results for such approximately efficient points are obtained. A domination property related to these existence results is observed and then it is proved that each element of a given set is approximated by the sum of a point in a convex cone inducing the ordering and a point in a finite set consisting of such approximately efficient points of the set.     

Perceptual saliency of points along the contour of everyday objects: a large-scale study

The aim of this large-scale study was to find out which points along the contour of a shape are most salient and why. Many subjects (N=161) were asked to mark salient points on contour stimuli, derived from a large set of line drawings of everyday objects (N=260). The database of more than 200,000 marked points was analyzed extensively to test the hypothesis, first formulated by Attneave (1954), that curvature extrema are most salient. This hypothesis was confirmed by the data: Highly salient points are usually very close to strong curvature extrema (positive maxima and negative minima). However, perceptual saliency of points along the contour is determined by more factors than just local absolute curvature. This was confirmed by an extensive correlational analysis of perceptual saliency in relation to ten different stimulus factors. A point is more salient when the two line segments connecting it with its two neighboring salient points make a sharp turning angle and when the 2-D part defined by the triplet of salient points is less compact and sticks out more.     

Access to knowledge of spatial structure at novel points of observation

Adults were asked to judge the self-to-object directions in a room from novel points of observation that differed from their actual point at times only by a rotation and at other times only by a translation. The results show for the rotation trials that the errors and latencies when a novel point was imagined were worse than the baseline responses from their actual points of observation, and the latencies varied as a function of the magnitude of the to-be-imagined rotation. For the translation trials, on the other hand, the errors and latencies when a novel point was imagined were comparable to the baseline responses from their actual point and did not vary significantly across the different imagined station points. The evidence indicates that subjects know the object-to-object relations directly, without going through the origin of a coordinate system. In addition, similarities in processing during imagination on the one hand, and perception and action on the other are discussed.     

Fixation and attention in apparent motion

The likelihood of reporting a figure in motion was measured when the point of fixation was systematically separated from the point of attention. More reports of optimal motion were made when the two points were separated than when they were close together. Control tests showed that the reduction in the probability of seeing motion through the center of fixation was more likely due to the structure of the eye than to the conflict of fixation point and object in illusory motion. The notion of attention as a perceptual event contributes little to these results.     

Human performance on the traveling salesman problem

Two experiments on performance on the traveling salesman problem (TSP) are reported. The TSP consists of finding the shortest path through a set of points, returning to the origin. It appears to be an intransigent mathematical problem, and heuristics have been developed to find approximate solutions. The first experiment used 10-point, the second, 20-point problems. The experiments tested the hypothesis that complexity of TSPs is a function of number of nonboundary points, not total number of points. Both experiments supported the hypothesis. The experiments provided information on the quality of subjects’ solutions. Their solutions clustered close to the best known solutions, were an order of magnitude better than solutions produced by three well-known heuristics, and on average fell beyond the 99.9th percentile in the distribution of random solutions. The solution process appeared to be perceptually based.     

Subspace K-means clustering

To achieve an insightful clustering of multivariate data, we propose subspace K-means. Its central idea is to model the centroids and cluster residuals in reduced spaces, which allows for dealing with a wide range of cluster types and yields rich interpretations of the clusters. We review the existing related clustering methods, including deterministic, stochastic, and unsupervised learning approaches. To evaluate subspace K-means, we performed a comparative simulation study, in which we manipulated the overlap of subspaces, the between-cluster variance, and the error variance. The study shows that the subspace K-means algorithm is sensitive to local minima but that the problem can be reasonably dealt with by using partitions of various cluster procedures as a starting point for the algorithm. Subspace K-means performs very well in recovering the true clustering across all conditions considered and appears to be superior to its competitor methods: K-means, reduced K-means, factorial K-means, mixtures of factor analyzers (MFA), and MCLUST. The best competitor method, MFA, showed a performance similar to that of subspace K-means in easy conditions but deteriorated in more difficult ones. Using data from a study on parental behavior, we show that subspace K-means analysis provides a rich insight into the cluster characteristics, in terms of both the relative positions of the clusters (via the centroids) and the shape of the clusters (via the within-cluster residuals).     

Discussion of a set of points in terms of their mutual distances

Necessary and sufficient conditions are given for a set of numbers to be the mutual distances of a set of real points in Euclidean space, and matrices are found whose ranks determine the dimension of the smallest Euclidean space containing such points. Methods are indicated for determining the configuration of these points, and for approximating to them by points in a space of lower dimensionality.This paper was written in response to suggestions by Harold Gulliksen and by M. W. Richardson. The latter is working on a psychophysical problem in which the dimensionality of a set of points whose mutual distances are available is a central idea.     

Indifference sets of reference points in multi‐objective integer linear programming

Reference point approaches for multi‐objective problems rely on the definition of an achievement scalarizing function that projects reference points onto the non‐dominated solution set. In this paper, we investigate the behaviour of reference points using a Tchebycheff metric‐based scalarizing function in multi‐objective pure integer linear programming (MOILP). Since the non‐dominated solutions are discrete in MOILP, there are multiple reference points that lead to the same solution, i.e. there are indifference sets on the reference point space. We investigate some properties of the reference points in MOILP and also the graphical representation of indifference sets for tri‐objective problems. We further investigate properties of the reference points when additional limitations on the objective function values are introduced. Copyright © 2001 John Wiley & Sons, Ltd.     

Canonical analysis of two convex polyhedral cones and applications

Canonical analysis of two convex polyhedral cones consists in looking for two vectors (one in each cone) whose square cosine is a maximum. This paper presents new results about the properties of the optimal solution to this problem, and also discusses in detail the convergence of an alternating least squares algorithm. The set of scalings of an ordinal variable is a convex polyhedral cone, which thus plays an important role in optimal scaling methods for the analysis of ordinal data. Monotone analysis of variance, and correspondence analysis subject to an ordinal constraint on one of the factors are both canonical analyses of a convex polyhedral cone and a subspace. Optimal multiple regression of a dependent ordinal variable on a set of independent ordinal variables is a canonical analysis of two convex polyhedral cones as long as the signs of the regression coefficients are given. We discuss these three situations and illustrate them by examples.     

Careful what you say to yourself: Exploring self-talk and youth tennis performance via hierarchical linear modeling

Researchers have examined self-talk and performance in tennis matches, but the current understanding of speech-to-performance associations in tennis is hindered by conflicting evidence from self-report and observation, and by the use of relatively simple statistical analyses that fail to account for speech and performance events being nested within both points and individuals over time throughout a tennis match. In the current study, 28 youth tennis players (M_age = 12 years) were observed, and their speech and performance coded with the Self-Talk and Gestures Rating Scale. The relation between self-talk and performance was measured on the same point (K), as well as on the subsequent point (K+1). Bivariate (non-nested) analyses supported a concurrent, but not a predictive relation between self-talk and performance, consistent with prior work. With multivariate, hierarchical linear modeling that accounts for total points played in a set within person, and player behavior on the prior point, we found that positive and negative self-talk were strongly related to concurrent point performance, and to a less extent, to subsequent K+1 point performance. The occurrence of positive self-talk on point K appeared to increase the odds of winning the subsequent point compared to when positive self-talk talk did not appear, but the margin was small. Researchers should continue to observe self-talk in athletes, as well as examine multilevel speech-to-performance associations, especially when data are gathered within naturalistic settings in real time.     

难度－价值权衡情境下的项目选择及其眼动特征

本研究采用行为和眼动技术,通过设置难度—价值权衡情境,考察在学习时间有限的条件下,学习者如何选择学习项目,以及该过程如何发生。结果发现：(1)被试更多选择得分期望最高的项目,而非分值最高或最简单的项目。(2)选择学习项目的过程不存在计算项目得分期望的过程。结果表明,学习者项目选择不仅基于难度或价值,而是会权衡难度和价值,选择得分期望最高的项目。该过程不符合补偿性决策理论的预期,与非补偿性理论预期一致。     

The optimal number of alternatives at a choice point with travel time considered

The problem of optimal design is considered for tasks that can be represented as n choice points with a_i alternatives per choice point. Examples are mazes or multiple choice tests. Some fixed time t′ elapses between choice points, say traveling from one to the other or reading a question, and additional time t is spent considering each alternative at the choice point. For fixed total time, the goal is to find the optimum number of choice points and the optimum number of alternatives at each choice point. In general, the longer the time spent between choice points, the greater the optimum number of alternatives at each point.     

Is the Critical Point for Aperture Crossing Adapted to the Person-Plus-Object System?

When passing through apertures, individuals scale their actions to their shoulder width and rotate their shoulders or avoid apertures that are deemed too small for straight passage. Carrying objects wider than the body produces a person-plus-object system that individuals must account for in order to pass through apertures safely. The present study aimed to determine whether individuals scale their critical point to the widest horizontal dimension (shoulder or object width). Two responses emerged: Fast adapters adapted to the person-plus-object system by maintaining a consistent critical point regardless of whether the object was carried while slow adapters initially increased their critical point (overestimated) before adapting back to their original critical point. The results suggest that individuals can account for increases in body width by scaling actions to the size of the object width but people adapt at different rates.     

Multiple points of entry into a circular enclosure prevent place learning despite normal vestibular orientation and cue arrays: evidence for map resetting

This study identified sources of map orientation critical for successful spatial problem solving by rats of a plus maze embedded in water. Disorientation slowed, but it did not prevent acquisition of goal location. Use of a circular enclosure with multiple points of entry prevented reliable goal location. A single entry point enabled the rats to locate a fixed goal. A cue array within the enclosure was ineffective in providing orientation. These data suggest that stable map orientation can be derived from entry location when enclosure geometry is uniformative, but is not readily taken from cue arrays. They further suggest that map orientation is reset when rats enter an enclosure.     

On the interpretation of common factors: A criticism and a statement

The concept of simple structure is criticized for lack of objectivity and for failure to produce invariance of (a) factor loadings under change of battery, and (b) individual scores on primary traits under change of tests. It is also criticized on the grounds that simple structure yields at best the factors which were put in and that, by suitable manipulation of tests, any set of factors may be represented in a battery by tests which will yield a simple structure. A procedure for rotation is developed which locates the first rotated axis to pass through a cluster of tests which, by hypothesis, contain a common factor and to project all tests into a hyperplane orthogonal to this factor. The second factor is then located to pass through the projections of a second cluster of tests defining the second factor, and so on, until all hypothecated factors have been located. Any residual interrelations may then be rotated graphically to the most plausible arrangement.     

Investigating the effect of mental set on insight problem solving

Mental set is the tendency to solve certain problems in a fixed way based on previous solutions to similar problems. The moment of insight occurs when a problem cannot be solved using solution methods suggested by prior experience and the problem solver suddenly realizes that the solution requires different solution methods. Mental set and insight have often been linked together and yet no attempt thus far has systematically examined the interplay between the two. Three experiments are presented that examine the extent to which sets of noninsight and insight problems affect the subsequent solutions of insight test problems. The results indicate a subtle interplay between mental set and insight: when the set involves noninsight problems, no mental set effects are shown for the insight test problems, yet when the set involves insight problems, both facilitation and inhibition can be seen depending on the type of insight problem presented in the set. A two process model is detailed to explain these findings that combines the representational change mechanism with that of proceduralization.     

中学生考试活动绩效影响因素模型的初步研究

对573名中学生进行调查研究。根据路径分析结果建立初始模型．通过竞争模型的比较,建立了中学生考试活动绩效影响因素结构方程模型：家庭因素和考试心理素质对考试活动绩效有直接效应,而学校因素、自身因素和考试心理问题与考试活动绩效之间存在间接效应;学校因素、自身因素和考试心理问题互为中介分别通过家庭因素和考试心理素质对考试活动绩效产生间接影响;考试心理素质和家庭因素互为中介对考试活动绩效产生影响。通过对超水平发挥组和发挥失常组进行比较发现,不同组之间的结构方程模型具有一致性,但是变量间的路径系数有所不同。     

Alternative reference points and outcome evaluation: the influence of affect

Two studies examined the effect of affective states on decision outcome evaluation under the presence or absence of salient alternative reference points. Alternative reference points exist when there are 2 possible referents from which an outcome can be evaluated, and the outcome is judged as good from the perspective of one referent and bad from the perspective of the other. The results support a motivational process of evaluating outcomes in which individuals select the reference point that allows them to maintain positive mood or improve negative mood. Mood measurements taken before and after the task revealed that those in positive moods maintained their mood whether or not they had alternative reference points in the evaluation of their outcomes. Those in negative affective states improved their mood only when there was an alternative reference point that allowed the outcome to be compared favorably; when there was no such alternative reference point, they maintained their negative mood.     

Mentally walking through doorways causes forgetting: The location updating effect and imagination

Researchers have documented an intriguing phenomenon whereby simply walking through a doorway causes forgetting (the location updating effect). The Event Horizon Model is the most commonly cited theory to explain these data. Importantly, this model explains the effect without invoking the importance or reliance upon perceptual information (i.e., seeing oneself pass through the doorway). This generates the intriguing hypothesis that the effect may be demonstrated in participants who simply imagine walking through a doorway. Across two experiments, we explicitly test this hypothesis. Participants familiarised themselves with both real (Experiment 1) and virtual (Experiment 2) environments which served as the setting for their mental walk. They were then provided with an image to remember and were instructed to imagine themselves walking through the previously presented space. In both experiments, when the mental walk required participants to pass through a doorway, more forgetting occurred, consistent with the predictions laid out in the Event Horizon Model.