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.     

Measurement of perceived oscillation

In earlier studies of perceived oscillation a comparison stimulus placed at a different distance and in a different direction from the observer than the Standard stimulus was used. The usual indicators were angles relating the turning positions, produced on a comparison stimulus, to a physical frame of reference, common for Standard and comparison. In three experiments where both Standard and comparison were “full-cuc,” the effect of different spatial arrangements was studied. Difference in distance did not affect the angles describing the response, nor did monocular or binocular vision, but difference in direction from the observer and the order of giving the two turning positions, combined with the position of the comparison stimulus before responding, had significant effects. The difference between Standard and comparison stimulus, which in an earlier series of experiments with artificial Standard stimuli had been rather large, was not very large for most conditions in the present experiments, where a real object was used as Standard stimulus. The correspondence was better, however, if another indicator, the angle describing the perceived extent of oscillation, was used. The spatial arrangements of Standard and comparison stimulus affect this indicator less than the indicators relating the perceived turning positions to the axes of the physical space.     

Evaluation of a Swedish version of the Job Stress Survey

The present study assesses and evaluates the psychometric properties of a Swedish version of the Job Stress Survey (JSS; Spielberger, 1991; Spielberger & Vagg, 1999). This instrument is constructed to measure generic sources of occupational stress encountered by employees in a wide variety of work settings, settings that often result in psychological strain. The JSS was administered to metal assembly industry workers and medical service personnel in northern Sweden (n= 1186). The exploratory factor analysis showed that there is a high similarity between the present Swedish version and the original American version. Internal reliabilities of the scales, as well as test-retest reliabilities were shown to be high, and concurrent validity, as examined by comparisons with the Perceived Stress Questionnaire Index (Levenstein et al., 1993) was found to be satisfactory. The consistency of these findings is discussed with particular focus on groups of employees, gender, and cross-cultural evaluations.     

Haptic perception of texture gradients

To pick up 3-D aspects of pictures is arguably the most difficult problem concerning tactile pictorial perception by the blind. The aim of the experiments reported was to examine the potential utility of texture gradients in this context. Since there is no theoretical basis for predicting absolute values of 3-D properties from 2-D patterns read by the finger pads, the abilities of participants to perceive gradients lying between known maxima and minima were assessed. Experiment 1 involved blindfolded sighted participants making verbal magnitude estimations of texture-gradient magnitudes corresponding to plane surfaces at different slants. In experiment 2 the participants' task was to orient a surface at a slant corresponding to the texture gradients depicted tactually, and experiment 3 required early-blind participants to attempt the same task. The results revealed that participants can scale the magnitudes of texture gradients with high precision and that they can also accurately produce surface slants from depictions, providing the extreme conditions are clearly defined and there are opportunities for learning. Texture gradients appear as informative to the blind as they do to the sighted. To what extent these data can be generalised to other gradients and textures or to other projections of 3-D scenes remains to be investigated.     

Individual response patterns and the effects of different behavioral methods in the treatment of agoraphobia

The importance of individual response patterns in agoraphobic patients was examined in the present study. Forty psychiatric outpatients with agoraphobia were assessed in individually relevant natural phobic situations. During this behavioral test their heart rates were measured continuously, and self-ratings of experienced anxiety were made at fixed intervals. On the basis of their reactions in the test situation, the patients were divided into two groups showing different response patterns—behavioral and physiological reactors. Within each group the patients were randomly assigned to one behaviorally-focused method (exposure in vivo, E) and one physiologically-focused method (applied relaxation, AR). The patients were treated individually for 12 sessions. Both treatments yielded significant improvements on most measures; 60% of the E group and 70% of the AR group patients were clinically improved after treatment. The between-group comparisons showed that both treatments did equally well both for behavioral and physiological reactors. Thus, the differential effects for these methods obtained in previous studies were not seen.     

Cognitive bias in dizziness: emotional Stroop and autobiographical memories

Dizziness is commonly associated with anxiety, and is often caused by a dysfunction of the balance system. While a link between dizziness and both anxiety disorders and depression has been established, less is known about information processing in dizziness. In the first experiment we tested whether 15 patients with dizziness would display an emotional Stroop effect for panic-related words. Also included was a control group of 15 persons. The Stroop task was preceded by ratings of personal relevance of the Stroop words and followed by a surprise free recall of the words. Results showed a Stroop effect for panic-related words in the dizziness group, but the interaction did not reach significance (p = 0.08). Separate analysis of dizziness-related panic words however resulted in a significant group x condition interaction. In the free recall of Stroop words a main effect of word category was found, with more panic-related words being recalled. The second experiment investigated autobiographical memories in 14 patients with dizziness and 14 matched controls. Results showed a group x condition interaction with less specific memories being recalled following positive cue-words in the dizziness group. The overall pattern of results suggests that dizziness is related to deficits in information processing, which could be targeted in treatment.