A multistage ranking model

In this paper, we propose a (n–1)² parameter, multistage ranking model, which represents a generalization of Luce's model. We propose then×n item-rank relative frequency matrix (p-matrix) as a device for summarizing a set of rankings. As an alternative to the traditional maximum likelihood estimation, for the proposed model we suggest a method which estimates the parameters from thep-matrix. An illustrative numerical example is given. The proposed model and its differences from Luce's model are briefly discussed. We also show some specialp-matrix patterns possessed by the Thurstonian models and distance-based models.     

“Active” and “passive” learning of three-dimensional object structure within an immersive virtual reality environment

We used a fully immersive virtual reality environment to study whether actively interacting with objects would effect subsequent recognition, when compared with passively observing the same objects. We found that when participants learned object structure by actively rotating the objects, the objects were recognized faster during a subsequent recognition task than when object structure was learned through passive observation. We also found that participants focused their study time during active exploration on a limited number of object views, while ignoring other views. Overall, our results suggest that allowing active exploration of an object during initial learning can facilitate recognition of that object, perhaps owing to the control that the participant has over the object views upon which they can focus. The virtual reality environment is ideal for studying such processes, allowing realistic interaction with objects while maintaining experimenter control.     

Meditation and psychosocial adaptation: An exploratory study

The current study examined differential patterns of interrelationships between meditators and nonmeditators on issues pertaining to psychosocial adaptation. Subjects (N=66) were randomly selected from mailing lists provided by theAssociation of Transpersonal Psychology or were solicited via classified advertising in theChicago Tribune and theDallas Morning News. The findings of the current study indicate that there are no differences between meditators and nonmeditators on level of psychosocial adaptation. However examination of the zero-order correlations between dependent measures revealed differential patterns of interrelationships within the meditator and nonmeditator groups. The findings suggest that further research is needed which expands upon the influence of meditation on psychosocial adaptation by addressing topics specific to meditative practice. The implications for the development of qualitative research methods designed to investigate psychosocial parameters in transpersonal psychology are discussed.     

Exploration of virtual mazes by rhesus monkeys (<Emphasis Type="Italic">Macaca mulatta</Emphasis>)

A chasm divides the huge corpus of maze studies found in the literature, with animals tested in mazes on the one side and humans tested with mazes on the other. Advances in technology and software have made possible the production and use of virtual mazes, which allow humans to navigate computerized environments and thus for humans and nonhuman animals to be tested in comparable spatial domains. In the present experiment, this comparability is extended even further by examining whether rhesus monkeys (Macaca mulatta) can learn to explore virtual mazes. Four male macaques were trained to manipulate a joystick so as to move through a virtual environment and to locate a computer-generated target. The animals succeeded in learning this task, and located the target even when it was located in novel alleys. The search pattern within the maze for these animals resembled the pattern of maze navigation observed for monkeys that were tested on more traditional two-dimensional computerized mazes.     

Communality of a variable: Formulation by cluster analysis

The communality of a variable represents the degree of its generality acrossn – 1 behaviors. Domain-sampling principles provide a fundamental conception and definition of the communality. This definition may be alternatively stated in eight different ways. Three definitions lead to precise formulas that determine thetrue value of the communality: (i) from thek necessary and sufficient dimensions derived by iterated factoring, (ii) from then – 1 remaining variable-domains, and (iii) fromk' multiple clusters of then variables. Seven definitions provide approximation formulas: (i) one from thek dimensions as initially factored, (ii) one from then – 1 remaining variables, and (iii) five from a single cluster. Rank of the matrix is not a desiratum in some definitions. Using an example designed by Guilford to illustrate multiple-factor analysis, applications of the formulas based on the three precise definitions recover the true communalities, and five approximation formulas each gives values closer than thead hoc estimates usually employed in factor analysis.The writer wishes to express his indebtedness to C. F. Wrigley and H. Kaiser for their many helpful constructive criticisms.     

Pulsation patterns of sinusoids vs. critical band noise

Pulsation patterns of both sinusoidal and critical band “maskers” at f_M = 400 Hz, 1 kHz, 2 kHz, and 4 kHz are compared. At the slope towards low frequencies, the pulsation pattern of a sinusoid is up to 30 dB lower than the pattern of a critical band noise; at the upper slope, only small differences (4 dB) are noticed. Variations in the temporal configuration of the stimulus yield a great variety of pulsation patterns for one and the same “masker.” Therefore, the interpretation of pulsation patterns as a quantitative measure of the ear’s frequency selectivity is still obscure. On the other hand, a comparison of pulsation patterns of different “maskers,” measured with one and thesame stimulus paradigm, seems to be useful.

     

Place learning in virtual space III: Investigation of spatial navigation training procedures and their application to fMRI and clinical neuropsychology

This paper describes the utilization of a desktop virtual environment task, the Computer-Generated (C-G) Arena, in the study of human spatial navigation. First, four experiments examined the efficacy of various training procedures in the C-G Arena. In Experiment 1, participants efficiently located a hidden target after only observing the virtual environment from a fixed position (placement learning). In Experiment 2, participants efficiently located a hidden target after only observing an experimenter search the virtual environment (observational learning). In Experiment 3, participants failed to display alatent learning effect in the virtual environment. In Experiment 4, all training procedures effectively taught participants the layout of the virtual environment, but the observational learning procedure most effectivelytaught participants the location of a hidden target within the environment. Finally, two experiments demonstrated the application of C-G Arena procedures to neuroimaging (Experiment 5) and neuropsychological (Experiment 6) investigations of human spatial navigation.     

Latent pattern analysis of conscious cooperation for developing sustainable transport

• This study explores the emerging pattern of conscious cooperation in travel mode selection for developing sustainable transport. A conceptual model for investigating the formation of conscious cooperation is examined based on a multi-factor latent cluster analysis of the survey data from Chinese cites. The study identifies three dominant patterns including the diversity average pattern, the pro-social pattern and the pro-environment pattern. An analysis of such patterns reveals that improving mobility and accessibility is more important than increasing availability of transport facilities for enhancing conscious cooperation. It finds out that there is much more to be done in addressing the concern of travelers on social equity and environment for sustainable transport development. These findings above provide better understanding of the formation of conscious cooperation for developing sustainable transport.

     

CARRYING THE BURDEN OF PAST VIOLENCES

Through a comparative study of two Palestinian transnational youth movements, this article seeks to understand how the transnational sphere traverses not just space but also time. I analyze how the Palestinian Youth Movement and the Gaza Youth Breaks Out movement understand themselves as carrying the burden of past violences in their promise to continue the Palestinian struggle and lead it toward a just and peaceful solution. Particularly, I am interested in how these movements interpret and conceive of the violences of 1948 and their continuation in present violences from different temporal, and not just spatial, standpoints. I examine the temporalities from which and to which transnational Palestinian movements speak, as well as how they orient themselves, through backward and forward movements, toward past–present–future. The article highlights how temporal differences form tensions that are often overlooked by transnational scholars and activists.     

Evidence against integration of spatial maps in humans: generality across real and virtual environments

A real-world open-field search task was implemented with humans as an analogue of Blaisdell and Cook’s (Anim Cogn 8:7–16, 2005) pigeon foraging task and Sturz, Bodily, and Katz’s (Anim Cogn 9:207–217, 2006) human virtual foraging task to 1) determine whether humans were capable of integrating independently learned spatial maps and 2) make explicit comparisons of mechanisms used by humans to navigate real and virtual environments. Participants searched for a hidden goal located in one of 16 bins arranged in a 4 × 4 grid. In Phase 1, the goal was hidden between two landmarks (blue T and red L). In Phase 2, the goal was hidden to the left and in front of a single landmark (blue T). Following training, goal-absent trials were conducted in which the red L from Phase 1 was presented alone. Bin choices during goal-absent trials assessed participants’ strategies: association (from Phase 1), generalization (from Phase 2), or integration (combination of Phase 1 and 2). Results were inconsistent with those obtained with pigeons but were consistent with those obtained with humans in a virtual environment. Specifically, during testing, participants did not integrate independently learned spatial maps but used a generalization strategy followed by a shift in search behavior away from the test landmark. These results were confirmed by a control condition in which a novel landmark was presented during testing. Results are consistent with the bulk of recent findings suggesting the use of alternative navigational strategies to cognitive mapping. Results also add to a growing body of literature suggesting that virtual environment approaches to the study of spatial learning and memory have external validity and that spatial mechanisms used by human participants in navigating virtual environments are similar to those used in navigating real-world environments.     

Overground gait training using virtual reality aimed at gait symmetry

This study investigated if training in a virtual reality (VR) environment that provides visual and audio biofeedback on foot placement can induce changes to spatial and temporal parameters of gait during overground walking. Eighteen healthy young adults walked for 23 min back and forth on an instrumented walkway in three different conditions: (i) real environment (RE), (ii) virtual environment (VE) with no biofeedback, and (iii) VE with biofeedback. Visual and audio biofeedback while stepping on virtual footprint targets appearing along a straight path encouraged participants to walk with an asymmetrical step length (SL). A repeated-measures, one-way ANOVA, followed by a pairwise comparison post-hoc analysis with Bonferroni's correction, was performed to compare the step length difference (SLD), stance phase percentage difference (SPPD), and double-support percentage difference (DSPD) between early and late phases of all walking conditions. The results demonstrate the efficacy of the VE biofeedback system for training asymmetrical gait patterns. Participants temporarily adapted an asymmetrical gait pattern immediately post-training in the VE. Induced asymmetries persisted significantly while later walking in the RE. Asymmetry was significant in the spatial parameters of gait (SLD) but not in the temporal parameters (SPPD and DSPD). This paper demonstrates a method to induce unilateral changes in spatial parameters of gait using a novel VR tool. This study provides a proof-of-concept validation that VR biofeedback training can be conducted directly overground and could potentially provide a new method for treatment of hemiplegic gait or asymmetrical walking.     

The Relative Dominance of Schemata in a Manual Tracking Task: Input Patterns,System Dynamics,and Movement Patterns

As subjects repeatedly track the same spatiotemporal pattern, they learn to anticipate the pattern and thereby to reduce their effective time delay. The successive organization of perception hypothesis suggests that subjects progress from an error-nulling mode to a pursuit mode, in which they respond to the estimated instantaneous input pattern, and then to a precognitive mode, in which they rely on memory of the input pattern or movement pattern. We used a transfer of training experiment involving position and rate control systems to distinguish among these strategies by determining the relative dominance of schemata for the input pattern, system dynamics, and movement pattern. Results indicated that subjects relied on a memorized movement pattern, which is characteristic of the precognitive mode. Adaptations of this transfer methodology may be useful in testing other theories that postulate multiple schemata for the control of perceptual-motor behavior.     

Children's use ofGet passives

Children's use ofget in passivelike constructions was examined in this study. Fifty-eight children at three age levels were tested twice on imitation, comprehension, and production tasks. For the imitation and comprehension tasks, passive sentences withget were modeled in one instance and withbe in the other instance. On both tasks, children performed significantly better on theget items than on thebe items. For the production tasks, active sentences were used as the experimental stimuli. Among 928 production responses possible, children produced 423get passives and 6be passives. The frequency ofget passives increased with increasing age. Qualitative analyses were performed to determine agerelated changes in the pattern of linguistic strategies chosen. These data were consistent with predictions derived from a model of lexical directionality: Children used moreget thanbe passives and more truncated than full passives.     

Things are always more complicated than you think: An open systems approach to the organizational effects of computer-automated technology

The effects of computerized office and factory automation are examined. An open systems framework is used to organize this literature. The review suggests that the benefits of technology are derived from theintermediate effects of the technology on organizational processes (the task structure, personnel system, formal structure, and informal organization). Thus, it is misleading to examine thedirect effects of computerized technology on organizational outcomes such as profits and satisfaction. Some of the effects of technology on the organizational processes are inevitable (e.g., changes in informal communication patterns). Others are determined less by the technology than by management decisions. The key to achieving success with computerized technology is matching changes in organizational processes to each other, as well as to the technology and the larger environment of the organization.Ann Majchrzak is currently Associate Professor of Human Factors at the Institute of Safety and Systems Management at the University of Southern California. She has recently written two books on the subject of technological change. Katherine J. Klein is an Assistant Professor of Industrial and Organizational Psychology in the Psychology Department of the University of Maryland at College Park.     

Comparison of grasping movements made by healthy subjects in a 3-dimensional immersive virtual versus physical environment

Virtual reality (VR) technology is being used with increasing frequency as a training medium for motor rehabilitation. However, before addressing training effectiveness in virtual environments (VEs), it is necessary to identify if movements made in such environments are kinematically similar to those made in physical environments (PEs) and the effect of provision of haptic feedback on these movement patterns. These questions are important since reach-to-grasp movements may be inaccurate when visual or haptic feedback is altered or absent. Our goal was to compare kinematics of reaching and grasping movements to three objects performed in an immersive three-dimensional (3D) VE with haptic feedback (cyberglove/grasp system) viewed through a head-mounted display to those made in an equivalent physical environment (PE). We also compared movements in PE made with and without wearing the cyberglove/grasp haptic feedback system. Ten healthy subjects (8 women, 62.1 ± 8.8 years) reached and grasped objects requiring 3 different grasp types (can, diameter 65.6 mm, cylindrical grasp; screwdriver, diameter 31.6 mm, power grasp; pen, diameter 7.5 mm, precision grasp) in PE and visually similar virtual objects in VE. Temporal and spatial arm and trunk kinematics were analyzed. Movements were slower and grip apertures were wider when wearing the glove in both the PE and the VE compared to movements made in the PE without the glove. When wearing the glove, subjects used similar reaching trajectories in both environments, preserved the coordination between reaching and grasping and scaled grip aperture to object size for the larger object (cylindrical grasp). However, in VE compared to PE, movements were slower and had longer deceleration times, elbow extension was greater when reaching to the smallest object and apertures were wider for the power and precision grip tasks. Overall, the differences in spatial and temporal kinematics of movements between environments were greater than those due only to wearing the cyberglove/grasp system. Differences in movement kinematics due to the viewing environment were likely due to a lack of prior experience with the virtual environment, an uncertainty of object location and the restricted field-of-view when wearing the head-mounted display. The results can be used to inform the design and disposition of objects within 3D VEs for the study of the control of prehension and for upper limb rehabilitation.     

Symmetry,complexity and perceptual economy: Effects of minimum and maximum simplicity conditions

According to Gestalt theory, the perceptual system works on economic principles and tends to reach the maximum efficiency (i.e., increase of quality, goodness, and accuracy) with minimum invested energy (i.e., reduction of processing load). In this study the effects of two concurrent stimulus constraints, symmetry and simplicity, were investigated with the following variables related to perceptual economy: Goodness judgement (Experiment 1), completion of semi-structured patterns (Experiment 2), duration of search for target patterns (Experiment 3), and the duration and accuracy of pattern detection (Experiment 4). The results suggest that the dominance of symmetry or simplicity depends upon the difficulty of the experimental task. Symmetry prevailed in less restrictive, more interesting, and easier perceptual tasks, such as goodness judgement and pattern completion (Experiments 1, 2, and, partly, Experiment 3), whereas simplicity prevailed in difficult and restricted conditions, such as the detection of briefly exposed stimuli (50 ms; Experiment 4). The results are discussed in the context of Koffka's concept of minimum and maximum simplicity. When the perceptual system has a small energy disposal, or when external conditions are difficult and restricted (minimum simplicity conditions), simplicity in stimulus pattern organization will be preferred. When the perceptual system has a large amount of energy, or when external situations are unrestricted and interesting (maximum simplicity conditions), fine and regular articulations of stimulus patterns will be preferred. Our study confirmed the prediction implied by the concept of minimum and maximum simplicity.     

How Groups Merge: The Effects of Merger Integration Patterns on Anticipated Commitment to the Merged Organization1

This study examined the influence of merger integration patterns on expectations about the merger process. The integration patterns included the absorb, in which the merged organization closely resembled the acquiring company; the blend, in which features of both companies were maintained, and the combine, in which the organization resembled neither pre-merger company. Undergraduates role-played employees of a merging organization and written scenarios manipulated the integration pattern and membership in the acquired or acquiring organization. Participants' commitment to the merged organization was most favorable in the combine pattern. Path analyses indicated that the relationship between merger integration pattern and organizational commitment is mediated by the conditions of intergroup contact, perceptions of organizational support, organizational unity, and the degree of threat experienced.     

Symmetry and selective attention: A dissociation between effortless perception and serial search

It is widely assumed that symmetry is an important visual primitive, probably encoded without the need for attention. Julesz’s (1981) definition ofeffortless perception, which states that any stimulus property perceived for exposure durations of 160 msec or less is detected preattentively, contributed greatly to this belief.Single pattern studies confirm that symmetry is detected within this limit. In the present study, however, Julesz’s operationalization is compared with themultiple pattern visual search task, to see whether symmetry as a wholistic property is detected in parallel. The results show that symmetry detection times are highly dependent on the number of distractor patterns. The findings are similar for dot patterns, wire polygons, solid block shapes, and simple parentheses. We conclude that symmetry detection per se requires selective attention, but that some related grouping or segmentation mechanism may operate preattentively.     

The study of locomotor pointing in virtual reality: The validation of a test set-up

The goal of this experiment was to validate an experimental set-up for studying locomotor pointing. The specific and also original element of this set-up was the interactive nature of virtual reality and movement production. This interaction was achieved through the coupling of a treadmill and a Silicon Graphics system. This latter system generated on a screen (3 × 2.3 m) an environmental array that moved according to the action produced by subjects on a treadmill. The task was to place either foot on a spatial target that appeared on the floor in front of the subject’s displacement trajectory. We analyzed the step length patterns of subjects approaching these targets, along with the current target-subject relationship. The results are in agreement with aperception-action coupling type of control mechanism that operates continuously as the subject approaches the desired target. Apparently, these findings mirror observations of real-life locomotion, indicating that the present set-up provides a valid and useful tool for examining human locomotion.