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P McGeorge

Publications and source records attributed to P McGeorge.

8 recordsLinked to original sources

The influence of visual symmetry on the encoding of objects.

Two experiments examined how symmetry affects the visual encoding of simple flat objects (lamellae). Experiment 1 showed that subjects encode a lamella's shape as both a facsimile and its enantiomorph. In Experiment 2 the errors made when responding to symmetrical and asymmetrical stimuli showed that there were three factors affecting the reproduction of a symmetrical stimulus. These are, in order of decreasing influence, (i) the orientation of the axis of symmetry, (ii) the presence of overall symmetry (irrespective of orientation), and (iii) identity of the orientation of the elements of the response in relation to those of the stimulus. They also show that symmetry is likely to be reproduced even where the reproduction is not of the same shape as the original stimulus. The relevance of these results to representation of objects is discussed.

Adolescent↗

Anaesthetists' attitudes to teamwork and safety.

A questionnaire survey was conducted with 222 anaesthetists from 11 Scottish hospitals to measure their attitudes towards human and organisational factors that can have an impact on effective team performance and consequently on patient safety. A customised version of the Operating Room Management Attitude Questionnaire (ORMAQ) was used. This measures attitudes to leadership, communication, teamwork, stress and fatigue, work values, human error and organisational climate. The respondents generally demonstrated positive attitudes towards the interpersonal aspects of their work, such as team behaviours and they recognised the importance of communication skills, such as assertiveness. However, the results suggest that some anaesthetists do not fully appreciate the debilitating effects of stress and fatigue on performance. Their responses were comparable with (and slightly more favourable than) those reported in previous ORMAQ surveys of anaesthetists and surgeons in other countries.

Anesthesia↗

Anaesthetists' Non-Technical Skills (ANTS): evaluation of a behavioural marker system.

BACKGROUND: Non-technical skills are critical for good anaesthetic practice but are not addressed explicitly in normal training. Realization of the need to train and assess these skills is growing, but these activities must be based on properly developed skills frameworks and validated measurement tools. A prototype behavioural marker system was developed using human factors research techniques. The aim of this study was to conduct an experimental evaluation to establish its basic psychometric properties and usability. METHOD: The Anaesthetists' Non-Technical Skills (ANTS) system prototype comprises four skill categories (task management, team working, situation awareness, and decision making) divided into 15 elements, each with example behaviours. To investigate its experimental validity, reliably and usability, 50 consultant anaesthetists were trained to use the ANTS system. They were asked to rate the behaviour of a target anaesthetist using the prototype system in eight videos of simulated anaesthetic scenarios. Data were collected from the ratings forms and an evaluation questionnaire. RESULTS: The results showed that the system is complete, and that the skills are observable and can be rated with acceptable levels of agreement and accuracy. The internal consistency of the system appeared sound, and responses regarding usability were very positive. CONCLUSIONS: The findings of the evaluation indicated that the ANTS system has a satisfactory level of validity, reliability and usability in an experimental setting, provided users receive adequate training. It is now ready to be tested in real training environments, so that full guidelines can be developed for its integration into the anaesthetic curriculum.

Adult↗

The role of left-right symmetry in the encodement of spatial orientations.

Three experiments investigated a hypothesis, suggested by studies of the difficulties of discriminating between shapes forming symmetrical pairs, that spatial orientations of thin flat plates (lamellae) may be encoded in a plane, the encodement consisting of two enantiomorphs. The results indicated that participants encoded the spatial orientation of lamellar stimuli in terms of the difference in cogency between their two enantiomorphic elements (Expt 1). The difference in the cogency of the two enantiomorphs is related to the orientation of the plane containing the lamellar stimulus with respect to the participant's fronto-parallel plane (Expt 2). The two possible orientations of a lamella which yield the same difference of cogency, but which differ in spatial orientation (e.g. lamella 'b' set at 30 degrees or set at 150 degrees) are distinguished by the manner in which the two enantiomorphic elements are arranged with respect to their axis of symmetry (Expt 3). The results suggest that the orientation of a lamella may be encoded as a two-dimensional representation and hence that three dimensions may be encoded by two by means of enantiomorphs. Implications of this finding for the encodements of three-dimensional solids, wherein pronounced contours may fulfil the same role as do the edges of lamella, are discussed briefly.

Adult↗

Perceived similarity of shapes is an asymmetrical relationship: a study of typical contours.

Two experiments are reported in which the relationship between perceived similarity amongst simple geometric solids and the set of projections arising from rotation of the typical contour of the solids about a vertical axis in its plane are examined. The results indicate (1) that judgments of similarity are affected by pronouncedness of typical contours, (2) similarity of simple geometrical solids is an asymmetrical attribute, in that where a set of possible projections of model X contains a set of possible projections of model Y, then model Y is judged as more similar to model X than X is to Y. The implications of this asymmetry for perceptual constancy and theories of object recognition are discussed.

Adult↗

The role of typical contours in the encodement of objects in three-dimensional arrays.

Two experiments are reported in which the relationship between the orientation of the typical contour of a lamella in relation to the observer, and the ability of the observer to learn the correct position and orientation of sets of lamellae in three-dimensional arrays, was examined. For lamellae presented with their typical contour in a plane other than the observer's frontoparallel plane, the results of both experiments indicated that participants encoded lamellae in such a way that their typical contour appeared to be closer to the observer's frontoparallel plane than the respective stimulus. The relationship of the present findings to previous results on children's drawings and to the concept of the picture plane are considered.

Adolescent↗

The relationships between psychometric intelligence and learning in an explicit and an implicit task.

An experiment is reported examining the relation of implicit grammar learning and series completion tasks to a standard measure of psychometric intelligence, the Wechsler Adult Intelligence Scale-Revised (WAIS-R; D. Wechsler, 1981). The results replicate and extend an earlier study by A. S. Reber, F. F. Walkenfeld, and R. Hernstadt (1991) and provide the following support for the differences between explicit and implicit tasks: (a) The implicit task was less strongly related to Full Scale IQ, and (b) the implicit task appeared to be independent of age. The implicit and explicit tasks exhibited a quite different pattern of relations to the factors known to underlie WAIS-R performance. Although both tasks showed significant links with a Perceptual Organization factor, only the series completion task showed a significant link with the Attention factor.

Adult↗