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.     

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.     

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.     

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.     

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.     

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.     

Flashpoints in Interpreting Paul

In this article, Luther Seminary New Testament scholar Arland Hultgren outlines the unresolved issues of the “New Perspective on Paul”: (1) the question of legalism in pre‐Pauline Judaism; (2) justification by faith; and (3) the use of the objective or subjective genitive in the “pistis Christou Debate.” On the question as to whether Luther got Paul right, Hultgren points out a difficulty, namely, those addressing this question frequently fail to designate precisely what they mean by “Lutheran.”     

The genetic versus pharmacological invalidation of the cannabinoid CB(1) receptor results in differential effects on 'non-associative' memory and forebrain monoamine concentrations in mice

The endocannabinoid CB(1) receptor has been implicated in the inhibitory control of learning and memory. In the present experiment, we compared the behavioral response of CB(1) receptor knockout mice (CB(1)R(-/-)) with animals administered CB(1) receptor antagonist/inverse agonist SR141716A (rimonabant; 3 mg/kg IP, 30 min pre-trial) in terms of acquisition and retention of a habituation task and changes in cerebral monoamines. The results can be summarized as follows: (i) the acute and chronic invalidation of the CB(1) receptor resulted in an increase of behavioral habituation during the first exposure to an open field, indicative of enhanced acquisition of the task; (ii) CB(1)R(-/-) mice, but not rimonabant-treated animals, showed enhanced retention of the habituation task when re-tested 48 h and 1 week subsequent to the first exposure to the open field, respectively; (iii) the facilitation of retention of the habituation task in CB(1)R(-/-) mice was accompanied by a selective and site-specific increase in serotonin activity in hippocampus; and (iv) rimonabant-treated animals displayed 'antidepressant-like' neurochemical alterations of cerebral monoamines, that is, most parameters of monoaminergic activity were increased especially in dorsal striatum and hippocampus. Taken together, the present findings demonstrate that the genetic disruption of the CB(1) receptor gene can cause an improvement of behavioral habituation, which is considered to represent a form of 'non-associative' learning. Furthermore, our data support the assumption of a rimonabant-sensitive cannabinoid receptive site that is different from the 'classical' CB(1) receptor and which, under physiological conditions, might be involved in the inhibitory control of the acquisition but not retention of non-associative learning tasks.     

Improving judgement with prepaid expert advice

Decision makers (“Judges”) often make decisions after obtaining advice from an Advisor. The two parties often share a psychological “contract” about what each contributes in expertise to the decision and receives in monetary outcomes from it. In a laboratory experiment, we varied Advisor Experitise and the opportunity for monetary rewards. As expected, these manipulations influenced advice quality, advice taking, and Judge post‐advice decision quality. The main contribution of the study, however, was the manipulation of the timing of monetary rewards (before or after the advising interaction). We found, as predicted, that committing money for expert—but not novice—advice increases Judges' use of advice and their subsequent estimation accuracy. Implications for advice giving and taking are discussed. Copyright © 2004 John Wiley & Sons, Ltd.