Spatial knowledge of children with spina bifida in a virtual large-scale space

The spatial knowledge of 18 children with spina bifida and 18 healthy control children (matched according to sex, age, and verbal IQ) was investigated in a computer-simulated environment. All children had to learn a route through a virtual floor system containing 18 landmarks. Controlling for cognitive abilities, the results revealed that children with spina bifida showed impaired route knowledge but not an impaired landmark knowledge. Thus the results suggest that children with spina bifida are not impaired in all large-scale abilities similarly. The impairments of the children with spina bifida are more accentuated in more behaviour based measurements, which indicates a relation to the reduced mobility of the children with spina bifida.     

Social network as a moderator in the relation between trauma exposure and trauma reaction: a survey among UN soldiers and relief workers

Social network as a moderator between trauma exposure and post-trauma symptomatology was studied. Two samples--relief workers and UN soldiers--were assessed on trauma exposure, social network and three dependent measures related to post-trauma reactions. Regression analysis and interaction plots were used to determine the presence of interaction effects between trauma exposure and social network. All four network variables moderated the relationship between trauma exposure and post-trauma reactions among relief workers, while among UN soldiers only two such buffer effects were found. Furthermore, among UN soldiers one of these interaction effects was reversed, indicating social support to be important for those low on trauma exposure, while among relief workers support was important in the high-exposure condition. The results indicate a difference with respect to the importance of social network as a moderator between groups exposed to different kinds of war trauma. Differences in motivational systems may also exist. However, further research will have to establish this.     

Visual bridgingof empty gaps in the optic flow

This is a study of perception of bending motion and jointed rigid motions over large invisible segments of a bending line. In this project, we investigated the visual perception of changing form of lines, built up by a series of dots and presented under highly reduced pictorial conditions. The changing form was indicated by one or two moving and continuously changing visible fragments of the line. The most extreme condition studied was the perception of the bending of an initially vertical 24-dot line, visually represented only by the stationary base dot and the two moving dots at its top. In this experiment, nearly all subjects reported experiencing a smooth bending connection over the 21-dot empty gap. Three experiments are described and analyzed. The results suggest that the human visual system is astonishingly well adapted for derivation of relevant figurai information from such severely reduced, continuously changing optical presentation. An explanation in terms of automatic sensory mechanisms related to the physiological receptive field effect is proposed.     

The effect of specific hypnotic suggestions on blood pressure in normotensive subjects

Twenty normotensive subjects participated on a voluntary basis in an experiment designed to study the effects of specific suggestions on blood pressure (BP). After an induction procedure, the experimental group received suggestions presumed to be relatively nonactivating, although capable of lowering or raising BP. A control group was used to record the BP changes over time. All subjects met for one session. Eight subjects from the experimental group met for a second session. Both adaptation and induction resulted in significant BP decreases. A specific suggestion to increase BP gave a significant result when compared to the induction point. There was no significant change from induction to the BP decrease suggestion. Both systolic and diastolic BP behaved in the same way. A second experimental session resulted in no significant change compared with the first session. Also, no significant difference was found in suggestibility scores from the first to the second session. The results are in line with previously published studies.     

AMULTIDIMENSIONAL SCALING APPROACH TO THE PERCEPTION OF ART. II

G oude G. A multidimensional scaling approach to the perception of art. II. Scand. J. Psychol ., 1972, 13 , 272–284.—Three series of experiments with multidimensional scaling of art experiences (of eight paintings) were performed. In the first series groups which had followed lectures in art history were compared to otherwise similar groups without lecturing within this field. The second study compared four age-groups (8, 10, 12 and 14 years). The third series was a comparative study with a group of schizophrenic patients.     

A general approach to procrustes pattern rotation

A method is introduced for oblique rotation to a pattern target matrix specified in advance. The target matrix may have all or only some of its elements specified. Values are estimated by means of a general procedure for minimization with equality constraints. Results are shown using data from Harman and Browne.The author is indebted to K. G. Jöreskog and M. W. Browne for many helpful suggestions and comments throughout the course of this study. Thanks are also due P. H. Schönemann and H. Weiner.     

Vector analysis in visual perception of rolling motion

Summary The well-known visual effect of seeing an isolated, point on the rim of a rolling wheel as moving in a cycloidal track was used for a study of visual vector analysis under non-redundant conditions.Under actual experimental conditions a mean difference of about 20% was found between the mathematically predicted and the perceptual vector analysis. A considerable interperson variation in deviation from the analysis was found. Some Ss showed a deviation of only a few per cent from the mathematically correct response.This investigation was made possible by grants from the Swedish Council for Social Science Research.     

TREBIG: A 360/75 FORTRAN program for three-mode factor analysts designed for big data sets

In the analysis of multifactor, longitudinal data, it has long been the practice of investigators to factor analyze the data in each time period separately and then compare the factor structures by eye. This has obvious problems and various measures of similarity were devised, none of which really worked properly. In recent years, other procedures have been proposed to better handle these sorts of data (i.e., Corballis, 1970; Jöreskog, 1970; Tucker, 1966). Tucker’s solution is termed “3-mode factor analysis,” which is essentially the Eckart-Young decomposition of a set of matrices that are derived by collapsing a tensor of order three. It has the advantage of combining the factor analyzes of each time period and indicating how the changes occur.     

Perceived direction of rotary motion

The starring point for this study was the rotating trapezoidal window. The aim was to reanalyze the problem of information about direction of rotation that is available in simplified proximal stimulations and to study empirically if the Ss utilized the possibilities demonstrated in the theoretical analyses. These analyses showed that a distal poin t moving in a horizontal circular path gives different proximal stimulations when moving clockwise and counterclockwise Further, a distal vertical line moving with its midpoint in the same path has a proximal change of length with different phase relations with the horizontal back-and-forth motion for the two directions. The proximal stimulation is ambiguous, however, unless some restrictions or “decoding principles” are introduced. In the first two experiments it was shown that the Ss could not report “correct” direction of motion of the point but were able to do so about the vertical line. In a third experiment a second vertical line was introduced. This necessitates a determination of relative distance to the two lines. It was shown that the proximally shorter line was usually perceived further away than the proximally longer one. The results are discussed with reference to the trapezoidal window. and some hypotheses are stated.     

A VERSATILE EYE-MOVEMENT RECORDER

A small, light eye-movement recorder, capable of registering eye movements from the smallest voluntary movements to movements of 20 degrees of arc, is described. A miniature light projector gives a beam of infrared (or blue) light, which is reflected by the cornea of the eye. The beam is deflected by any movement of the eye. An optical system transforms the motion of the beam into changes of light intensity. These are translated into magnified fluctuations of current in a multiplier phototube. The output is translated into graphic form by an ink-writer fitted with a D.C. amplifier. The apparatus, except for the writer but including a helmet, weighs about 300–500 g and is mounted on the subject's head without appreciably disturbing the field of vision.