Imagery intervention in open and closed tennis motor skill performance

To assess use of imagery intervention in performance of two tennis motor skills the quasi-experimental design included a pre- and posttest and a control group. The tennis service shot and service receiving skill were selected as representative of open and closed skills, respectively. 48 subjects, male tennis players, whose ages ranged from 16 to 18 yr. (M = 17.2), were divided into two groups: (1) Technical practice only which was used as control group and (2) Imagery group who received both imagery and technical practice. Analysis of covariance showed a significant main effect for the imagery intervention on the closed skill (p = .002). Findings suggest that imaging a positive outcome may be more powerful in improving performance of closed skill movements than of open skill movements.     

Changing Patterns of Gender Portrayals in Portuguese Television Advertisements1

The purpose of this study was to identify patterns in Portuguese television advertisements and interpret changes in the portrayal of gender roles using data collected 7 years apart: 1996 and 2003. We grouped 11 attributes of the central figure displayed in 623 evening commercials using a k‐means cluster procedure. There were 4 distinct groups of advertisements that emerged, 2 of them characterizing a predominantly male central figure and the other 2 a female central figure. The overall increase in women portrayed in advertisements from 1996 (32.9%) to 2003 (40.8%) is reflected in a shift toward an increase of advertisements with a female central figure in the typically male “narrator” cluster. Practical implications of these findings are discussed.     

Automated gait analysis in the open-field test for laboratory mice

In this article, an automated and accurate mouse observation method, based on a conventional test for motor function evaluation, is outlined. The proposed measurement technique was integrated in a regular open-field test, where the trajectory and locomotion of a free-moving mouse were measured simultaneously. The system setup consisted of a transparent cage and a camera placed below it with its lens pointing upward, allowing for images to be captured from underneath the cage while the mouse was walking on the transparent cage floor. Thus, additional information was obtained about the position of the limbs of the mice for gait reconstruction. In a first step, the camera was calibrated as soon as it was fixed in place. A linear calibration factor, relating distances in image coordinates to real-world dimensions, was determined. In a second step, the mouse was located and its body contour segmented from the image by subtracting a previously taken “background” image of the empty cage from the camera image. In a third step, the movement of the mouse was analyzed and its speed estimated from its location in the past few images. If the speed was above a 1-sec threshold, the mouse was recognized to be running, and the image was further processed for footprint recognition. In a fourth step, color filtering was applied within the recovered mouse region to measure the position of the mouse’s paws, which were visible in the image as small pink spots. Paws that were detected at the same location in a number of subsequent images were kept as footprints—that is, paws in contact with the cage floor. The footprints were classified by their position relative to the mouse’s outline as corresponding to the front left or right paw or the hind left or right paw. Finally, eight parameters were calculated from the footprint pattern to describe the locomotion of the mouse: right/left overlap, front/hind base, right/left front limb stride, and right/left hind limb stride. As an application, the system was tested using normal mice and mice displaying pentobarbital-induced ataxia. The footprint parameters measured using the proposed system showed differences of 10% to 20% between normal and ataxic mice.     

Perceptual Bias in Speech Error Data Collection: Insights from Spanish Speech Errors

This paper studies the reliability and validity of naturalistic speech errors as a tool for language production research. Possible biases when collecting naturalistic speech errors are identified and specific predictions derived. These patterns are then contrasted with published reports from Germanic languages (English, German and Dutch) and one Romance language (Spanish). Unlike findings in the Germanic languages, Spanish speech errors show many patterns which run contrary to those expected from bias: (1) more phonological errors occur between words than within word; (2) word-initial consonants are less likely to participate in errors than word-medial consonants, (3) errors are equally likely in stressed and in unstressed syllables, (4) perseverations are more frequent than anticipations, and (5) there is no trace of a lexical bias. We present a new corpus of Spanish speech errors collected by many theoretically naïve observers (whereas the only corpus available so far was collected by two highly trained theoretically informed observers), give a general overview of it, and use it to replicate previous reports. In spite of the different susceptibility of these methods to bias, results were remarkably similar in both corpora and again contrary to predictions from bias. As a result, collecting speech errors “in the wild” seems to be free of bias to a reasonable extent even when using a multiple-collector method. The observed contrasting patterns between Spanish and Germanic languages arise as true cross-linguistic differences.     

Principal Congruences on Semi-De Morgan Algebras

In this paper we use Hobby's duality for semi-De Morgan algebras, to characterize those algebras having only principal congruences in the classes of semi-De Morgan algebras, demi-pseudocomplemented lattices and almost pseudocomplemented lattices. This work extends some of the results reached by Beazer in [3] and [4].     

The Performance of Pre‐Founding Entrepreneurial Teams: The Importance of Learning and Leadership

Entrepreneurial teams often struggle with simultaneous task and team challenges at an early stage of new venture creation. The way in which teams shape their teamwork is key in leveraging performance in the pre‐founding phase. Learning should help the team in establishing good teamwork and in expanding its members’ entrepreneurial capabilities. Leadership is needed to facilitate and guide this learning. Accordingly, we investigated learning and leadership as facilitators of performance in the pre‐founding phase. Specifically, we examined team reflexivity as a collective internal learning process and boundary spanning behaviour as an externally directed individual activity, operating at different levels in fostering team and individual performance. Charismatic team leadership was examined as a catalyst of learning, shaping team and individual performance ultimately. The multilevel mediation model was tested based on data from 196 members of 58 teams of a venture creation programme. Team reflexivity predicted team and individual performance. Boundary spanning behaviour was not related to performance. As hypothesised, charismatic team leadership predicted team and individual performance, both mediated by team reflexivity. This research highlights the relevance of team learning in pre‐founding teams and emphasises leadership in shaping learning and moving new ventures forward.     

Worry and obsessional symptoms: a correlational analysis.

Several studies have suggested that worry and obsessional symptoms are systematically associated. In the present study, the relationship between worry and obsessional symptoms was confirmed. Measures included a worry content measure, a worry visual analogue scale, a modification of the everyday checking behaviours scale, and the MOCI. Worry was found to be more consistently associated with checking and doubting, than washing and slowness. It is suggested that worry and obsessional symptoms both occur in response to stress. In addition, it is suggested that worry and checking are functionally similar, and Generalised Anxiety Disorder may represent a 'cognitive' variant of obsessional checking.     

Visual space perception and visually directed action.

The results of two types of experiments are reported. In 1 type, Ss matched depth intervals on the ground plane that appeared equal to frontal intervals at the same distance. The depth intervals had to be made considerably larger than the frontal intervals to appear equal in length, with this physical inequality of equal-appearing intervals increasing with egocentric distance of the intervals (4 m-12 m). In the other type of experiment, Ss viewed targets lying on the ground plane and then, with eyes closed, attempted either to walk directly to their locations or to point continuously toward them while walking along paths that passed off to the side. Performance was quite accurate in both motoric tasks, indicating that the distortion in the mapping from physical to visual space evident in the visual matching task does not manifest itself in the visually open-loop motoric tasks.