To read two pages,I need 5 minutes,but give me 5 minutes and I will read four: how to change productivity estimates by inverting the question

Past research has shown that people underestimate the time they need to complete large tasks, whereas completion times for smaller tasks are often overestimated, suggesting higher productivity estimates for larger than for smaller tasks. By replacing the traditional question about how much time a given work will take with a question about how much work can be completed within a given amount of time, we also found the opposite pattern. Both trends could reflect a general tendency to underestimate large amounts (of work as well as time) relatively to small ones. This ‘magnitude bias’ was explored in two studies where students estimated reading tasks, a third where IT‐professionals estimated software projects, and a fourth where participants imagined a familiar walk, divided into time segments or part distances of varying lengths. Copyright © 2010 John Wiley & Sons, Ltd.     

Goal-discrepant situations prime goal-directed actions if goals are temporarily or chronically accessible

This research tested the hypothesis that perception of goal-discrepant situations automatically (i.e., without conscious intent) facilitates access to representations of instrumental actions if goal representations are mentally accessible. Employing a probe-recognition paradigm, Experiment 1 established that sentences describing situations that are discrepant with the goal of "looking well-groomed" (e.g., having dirty shoes) automatically increased the accessibility of representations of appropriate instrumental actions (e.g., polishing) in comparison to control situations, but only when participants frequently pursued the goal. Experiments 2a and 2b suggest that this effect was due to chronic accessibility of the goal representation and demonstrate that the same effects occur if the accessibility of the goal is temporarily enhanced (by subliminal priming) for people that nonfrequently pursue the goal.     

The Novaco Anger Scale-Provocation Inventory (1994 version) in Dutch forensic psychiatric patients

We examined the psychometric properties of the Novaco Anger Scale-Provocation Inventory (NAS-PI, 1994 version) in Dutch violent forensic psychiatric patients and secondary vocational students. A confirmatory factor analysis of the subscale structure of the NAS was carried out, reliability was investigated, and relations were calculated between NAS-PI scores and other measures of personality traits and problem behaviors. The 3-subscale structure of the original NAS could not be confirmed. However, the internal consistency of the NAS and the PI was excellent, and the test-retest reliability of the NAS was good. The validity of the NAS and the PI was supported by a meaningful pattern of correlations with alternative measures of anger and personality traits. Forensic psychiatric outpatients displayed higher NAS scores than secondary vocational students, but inpatients scored even lower than this nonclinical control group. Our preliminary conclusion is that the NAS-PI is a valuable instrument for the assessment of anger in Dutch violent forensic psychiatric patients.     

Comfort constrains graphic workspace: Test results of a 3D forearm model

Human movement performance is subject to many physical and psychological constraints. Analyses of these constraints may not only improve our understanding of the performance aspects that subjects need to keep under continuous control, but may also shed light on the possible origins of specific behavioral preferences that people display in motor tasks. The goal of the present paper is to make an empirical contribution here. In a recent simulation study, we reported effects of pen-grip and forearm-posture constraints on the spatial characteristics of the pen tip's workspace in drawing. The effects concerned changes in the location, size, and orientation of the reachable part of the writing plane, as well as variations in the computed degree of comfort in the hand and finger postures required to reach the various parts of this area. The present study is aimed at empirically evaluating to what extent these effects influence subjects' graphic behavior in a simple, free line-drawing task. The task involved the production of small back-and-forth drawing movements in various directions, to be chosen randomly under three forearm-posture and five pen-grip conditions. The observed variations in the subjects' choice of starting positions showed a high level of agreement with those of the simulated graphic-area locations, showing that biomechanically defined comfort of starting postures is indeed a determinant of the selection of starting points. Furthermore, between-condition rotations in the frequency distributions of the realized stroke directions corresponded to the simulation results, which again confirms the importance of comfort in directional preferences. It is concluded that postural rather than spatial constraints primarily affect subjects' preferences for starting positions and stroke directions in graphic motor performance. The relevance of the present modelling approach and its results for the broader field of complex motor behavior, including the manipulation of tools, is indicated briefly. Received: 9 March 1998 / Accepted: 27 November 1998     

Deliberate control of continuous motor performance

The authors examined the means by which people vary movement parameters to satisfy more than 1 constraint at a time in a repetitive motor task. The authors expected that when participants (N = 12) were simultaneously confronted with spatial and temporal constraints in an ellipse-drawing task, they would either exploit the intrinsic amplitude-frequency relationships or activate less natural control regimes to prioritize their movement goals. By focusing on local amplitude and frequency errors and parameter changes from 1 movement to the next, the authors distinguished parameter changes that reflected exploitation of biomechanics from those that required deliberate control. The findings demonstrated that at low movement speeds, participants can pursue multiple movement goals simultaneously; at higher speeds, their capacity to satisfy multiple task goals is reduced. The authors used a new method of inferring deliberate control from movement kinematics in the present study.     

On the inference of personal authorship: enhancing experienced agency by priming effect information

Three experiments examined whether the mere priming of potential action effects enhances people's feeling of causing these effects when they occur. In a computer task, participants and the computer independently moved a rapidly moving square on a display. Participants had to press a key, thereby stopping the movement. However, the participant or the computer could have caused the square to stop on the observed position, and accordingly, the stopped position of the square could be conceived of as the potential effect resulting from participants' action of pressing the stop key. The location of this position was primed or not just before participants had to stop the movement. Results showed that (subliminal as well as supraliminal) priming of the position enhanced experienced authorship of stopping the square. Additional experimentation demonstrated that this priming of agency was not mediated by the goal or intention to produce the effect.     

Androgenetic alopecia: stress of discovery

The psychological problems of men in the initial stages of alopecia androgenetica (hereditary male hair loss) have seldom been studied. We evaluated two groups of 80 men with alopecia androgenetica in Stages II to IV, indicating the amount of hair loss (overall N=160; for Group I: M=48 yr., SD=18.2; for Group II: M=50 yr., SD=18.0) who visited a dermatology clinic for benign dermatological complaints but not for hair loss, by questionnaires and interview, retrospectively. As predicted, hair problems were reported to be significantly greater overall at the moment of discovery of hair loss than later. About half of the men reported feeling annoyed to very annoyed about the discovery of hair loss. For those patients, provision of information by internet might facilitate a visit to the dermatologist.     

EthoVision: A versatile video tracking system for automation of behavioral experiments

The need for automating behavioral observations and the evolution of systems developed for that purpose is outlined. Video tracking systems enable researchers to study behavior in a reliable and consistent way and over longer time periods than if they were using manual recording. To overcome limitations of currently available systems, we have designed EthoVision, an integrated system for automatic recording of activity, movement, and interactions of animals. The EthoVision software is presented, highlighting some key features that separate EthoVision from other systems: easy file management, independent variable definition, flexible arena and zone design, several methods of data acquisition allowing identification and tracking of multiple animals in multiple arenas, and tools for visualization of the tracks and calculation of a range of analysis parameters. A review of studies using EthoVision is presented, demonstrating the system’s use in a wide variety of applications. Possible future directions for development are discussed.