A perspective metric for visual slant and shape

Summary Linear retinal perspective as a cue for visual slant and shape is analyzed in terms of its geometrical and psychophysical properties. Geometrically, retinal perspective is defined as the visual-angle difference in the projective magnitudes of the near and far edges of slanted rectangles. The psychophysical effectiveness of retinal perspective is then determined in two experiments. In Experiment 1, the sensitivity of the eye to retinal perspective is shown to be inversely related to the visual-angle height of slanted rectangles which are rotated about a horizontal axis. In Experiment 2, the visual shape of monocularly observed slanted rectangles is shown to depend solely on a simple prediction derived from Weber's Law, in which it is assumed that perceived height is a linear function of visual-angle height.

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Zusammenfassung Die geometrischen und psychophysischen Eigenschaften der linearen retinalen Perspektive wurden analysiert, um festzustellen, welchen Einfluß die Perspektive auf gesehene Schräge und Form hat. Geometrisch wird die retinale Perspektive als die Sehwinkeldifferenz in der projektiven Größe der näheren und ferneren Kante schräger Rechtecke definiert. Die psychophysische Wirksamkeit der retinalen Perspektive wurde an Hand zweier Experimente gemessen. Im ersten wurde gezeigt, daß die Sensitivität des Auges für die retinale Perspektive eine negative Funktion der Sehwinkelhöhe schräger Rechtecke ist, wenn diese um eine waagerechte Achse gedreht sind. Im zweiten Experiment wurde festgestellt, daß die Sehform einäugig betrachteter schräger Rechtecke von einer einfachen Ableitung des Weberschen Gesetzes abhängig ist, in der angenommen wird, daß die wahrgenommene Körperhöhe des Rechteckes eine lineare Funktion der Sehwinkelhöhe des Retinabildes ist.

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These investigations were supported by research grants MH-08856 and MH-10,691 from the National Institute of Mental Health, United States Public Health Service. The advice of Robert Seibel in the calculations of the regression lines of Fig. 4, and the assistance of Robert Pasnak in the conduct of Experiment 2 are gratefully acknowledged. Technical assistance was rendered by J. L. Cohen, W. F. Garber, Martha Harsanyi, R. L. Kochman, S. Ludwig, and Judith Ann Muth.     

Book reviews

Timing in Temporal Tracking. By J. A. Michon. Soesterberg, Netherlands: Institute for Perception RVO-TNO, Netherlands. 1967. Pp. 127.

Human Performance. By Paul M. Fitts and Michael I. Posner. Belmont, California: Brook/Cole Publishing Co. 1967. Pp. x + 162. 14s.

Human Memory. By Jack A. Adams. New York: Mcgraw Hill. I967. Pp. ix + 326. $9.50.

Biological Foundations of Language. By Eric H. Lenneberg. With Appendices by Noam Chomsky and Otto Marx. New York and London: Wiley. 1967. Pp. xvi+489. £6.

The Genesis of Language: A Psycholinguistic Approach. Edited by Frank Smith and G. A. Miller. Cambridge, Massachusetts and London: The M. I. T. Press. Pp. xii + 400. $4.

Acquisition du Langage at Developpement de la Pensee. By H. Sinclair-de Zwart. Paris: Dound. 1967. Pp. vi+ 168. 23F.

Principles and Methods of Social Psychology. By E. P. Hollander. London and New York: Oxford University Press. 1967. Pp. xxiii + 520. 64s.

Current Perspectives in Social Psychology. Second Edition. Edited by E. P. Hollander and R. G. Hunt. London and New York: Oxford University Press. 1967. Pp. vii + 685. 40s. (paper).

The Use of Lateral Thinking. By Edward de Bono. London: Cape. 1967. Pp. 157. 18s.

“Instinct” and “Intelligence”: The Science of Behaviour in Animals and Man. By S. A. Barnett. London: Macgibbon & Kee. 1967. Pp. xiv + 250. 45s.     

Writing as an aid in pastoral counseling and psychotherapy

Summary A method of spontaneous note-writing has been presented. When the material is handled like any verbal associations in a therapeutic session, this technique has been especially helpful with the majority of patients in facilitating free association, overcoming resistance, gaining access to deep material more quickly, working through the positive and negative phases of the transference and promoting insight. It helps patients to expose themselves earlier in treatment, to express their conscious thoughts, and to furnish material for discussion. It is a form of mental catharsis.This technique aids in showing the progress, trends, and method of therapy, and to observe the needs and strivings of the patient. In a few instances, due to particular problems, the method was not advantageous. It means additional work for both therapist and patient. It cannot take the place of spontaneous verbalization in the therapeutic session; however, it can aid both patient and therapist in facilitating treatment, and provides another adjunct to the procedural psychotherapy.