Perception of visual inclination in a real and simulated urban environment

The perceived inclination of slopes is generally overestimated. We claim that overestimation depends on the use of impoverished stimuli and on the distance between the observer and an inclined surface. In experiment 1, participants reported the perceived inclination of a set of urban roads from two different viewing distances. Observers did not overestimate the perceived inclination of slopes when they saw roads from the shorter viewing distances, whereas they slightly overestimated the perceived inclination of slopes from the farther distance. In experiment 2, participants reported the perceived inclination of a set of stereoscopic slides representing the same urban roads as in experiment 1. Here, observers did not overestimate the perceived inclination of slopes when the projected stereoscopic image contained horizontal disparity and simulated the shorter viewing distance; while they revealed a slight overestimation from the farther distance. We found always overestimation when the binocular image did not contain horizontal disparity, independently from the viewing distance. In conclusion, slopes are overestimated when (a) horizontal disparity is absent, and (b) the viewing distance is increased.     

Defense mechanisms: An approach from the perspective of personal construct psychology

The psychoanalytic concept of defense mechanisms was theoretically and empirically approached from the perspective of personal construct psychology, in an attempt to investigate its cognitive components. Thirty neurotic clients of the Psychotherapeutic Center in Stuttgart, Federal Republic of Germany, were investigated by means of the Questionnaire for Defense Categories (Ehlers & Peter, 1989) and the Repertory Grid Test (Kelly, 1955). Tight construing, extremity of emotional evaluation, construal of the symptom as having positive implications, and construed similarity between certain aspects of the self were observed in clients who frequently used the defense mechanisms denial, rationalization, and turning against the object.     

Testing the validity of the paddle method for the kinesthetic and visual-kinesthetic perception of inclination

We tested the validity of the paddle method for measuring both the kinesthetic and visual-kinesthetic perception of inclination. In three conditions, subjects performed three different tasks: (1) rotating a manual paddle to a set of verbally given inclinations (blindfolded subjects), (2) rotating a manual paddle to the same set of verbally given inclinations after specific kinesthetic training (blindfolded subjects), and (3) rotating the paddle to a set of fixed visual inclinations after the kinesthetic training. The results showed a high degree of accuracy and precision in the second and third task but not in the first one. When subjects were asked to rotate a manual paddle to a set of verbally given inclinations, they used three main anchors (0°, 45°, 90°). Furthermore, the paddle method is biased by a kinesthetic deficiency, namely a rotational problem of the wrist that can be corrected by means of specific training.