Donor and recipient: Social development,social interaction,and evolutionary processes

This review examines recent books on altruism and prosocial behaviour. Psychological approaches, biological approaches, and economic approaches are covered. The list of variables known to influence prosocial behaviour includes situational determinants, motivational orientations, and personality variables. Psychological theories emphasizing norms, cost-benefit calculations, and developmental factors have been used successfully to explain prosocial behaviour. Attention is given to models of helping and social and therapeutic treatment programmes. Genetic variables in prosocial behaviour are also reviewed.     

Status of perfusion scintigraphy in the diagnostic strategy in cerebrovascular disorders and space-occupying lesions

The results of an evaluation of the perfusion scintigraphy findings of 350 hospitalised neurological patients and 55 more strictly selected neurosurgical patients with cerebrovascular complaints, revealed an accuraty of 83%, a sensitivity of 89%, and a specificity of 83%. The selection of the patients had no influence on the results as a whole. Compared with contrast-medium angiography, incorrect diagnosis must be expected in 17% of the cases. This includes erroneous negative findings in 10% of the cases. Grounds for misinterpretations are suggested, and the biological and methodological limitations of the method are set forth.     

Controversies and existence claims in chemistry: The theory of resonance

Controversies, i.e., multiple theory confrontations, may have a strong impact on the development of science. By an analysis of the so-called “resonance controversy” in chemistry the view that controversies and their resolution differ considerably from the process of theory succession is defended. It is argued that controversies are symptomatic of foundational problems, produce theory-scattering or domain-splitting, and induce ontological shifts. An explication is given of the role of existence claims and the applicability of Ockham's Razor in the resolution of controversies. The requirement of a realistic interpretation of theories at all times, as defended by some philosophers, is criticised.     

The nature of adaptation in distance perception based on oculomotor cues

In previous work by the senior authors, brief adaptation to glasses that changed the accommodation and convergence with which objects were seen resulted in large alterations in size perception. Here, two further effects of such adaptation are reported: alterations in stereoscopic depth perception and a change when distance is represented by a response of S’s arm. We believe that the three effects are manifestations of one primary effect, an alteration of the relation between accommodation and convergence on the one hand and the distance they represent in the nervous system (registered distance) on the other. This view was supported by the results of two experiments, each of which demonstrated that the alterations in stereoscopic depth perception could be obtained after adaptation periods which had provided no opportunity to use stereoscopic vision, and that the adaptation effect was larger for depth perception than for size perception when it was obtained under the same conditions; the latter finding was expected if both effects resulted from the same change in registered distance. In three of the five experiments here reported, the variety of cues that could represent veridical distance during the adaptation period was limited. In one condition of adaptation, only the pattern of growth of the retinal images of objects that S approached and the kinesthetic cues for S’s locomotion served as cues to veridical distance. In two other conditions S remained immobile. In one of these, only the perspective distortion in the projection of the scene that S viewed mediated veridical distance, and in the other one familiar objects of normal size were successively illuminated in an otherwise totally dark field, conditions from which opportunities to use stereoscopic vision were again absent. After exposure to each of these adaptation conditions, adaptive changes in perceived size and larger ones in perceived stereoscopic depth were obtained. Because we found that familiar size may serve as the sole indicator of veridical distance in an adaptation process, we concluded that it can function as a perceptual as distinguished from an inferential cue to distance.     

Adaptation in distance perception based on oculomotor cues

Accommodation and convergence primarily serve to adjust the eyes to the distance of the object viewed, but, once made, these oculomotor adjustments serve as cues for the object’s distance. Experiments are reported that show that the relation between oculomotor adjustments and the distances they signify can be changed by adaptation to glasses that cause alteration in the oculomotor adjustments with which objects are viewed. This changed relation manifested itself in marked alterations of size perception. Wearing, for 30 min, glasses that caused a change in accommodation and convergence corresponding to a smaller object distance and equivalent to 1.5 lens diopters caused subsequent mean size increases that ranged from 50% to 65%. Adaptation to glasses that changed oculomotor adjustments in the same amount but in the opposite direction resulted in decreases in perceived sizes that varied from 18% to 40%, dependent on the distance of the test object. These were the results of size estimates obtained before and after the adaptation period under conditions where only accommodation and convergence served as cues for distance. A newly developed test of size perception was also used, in which S adjusted the size of the projected image of an array of familiar objects on a screen until the size of the objects appeared normal. Again, such adjustments were made before and after the adaptation period, and size differences were obtained that were in the direction to be expected of adaptation and varied in amount between 12% and 33%, dependent on the distance of the screen. The reason for the different amounts of size change measured by the two kinds of tests was investigated.     

Effects of inferiority and superiority in groups on recognition memory and confidence

Summary Three dependent variables were derived from an extended Signal-Detection paradigm: memory performance, confidence level, and response-bias. In the assessment of memory items, S and 2 confederates were exposed periodically to fictitious results which implied inferiority or superiority of S. Memory performance was generally better in group situations than when the subject was alone. Within groups, inferiority motivated S to improve. Significant confidence differences between correct and false judgments and, if S judged falsely, a high susceptibility to cognitions about S's relative performance, led theoretically to a distinction between internal and external cues and to the assumption that S wished to avoid uncertainty. Response-bias was found to be independent of motivation and very close to expected stimulus occurrence. The reward/cost theory of Thibaut and Kelley accounts for the motivation engendered and is linked to some theoretical considerations about processing objectively classifiable stimuli in social context.

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Zusammenfassung Aus einem erweiterten Signal-Detection-Paradigma wurden 3 abhängige Variablen abgeleitet: Gedächtnisleistung, Sicherheitsniveau und Response-bias. Bei der Beurteilung von Gedächtnisaufgaben wurden einer Vp und 2 Mitwissern des Vl von Zeit zu Zeit fiktive Ergebnisse gezeigt, die entweder Unterlegenheit oder Überlegenheit der Vp induzierten. Verglichen mit einer Alleinsituation stieg die Gedächtnisleistung allgemein in Gruppensituationen. Innerhalb von Gruppensituationen wurde die Vp durch Unterlegenheit motiviert, sich zu verbessern. Signifikante Unterschiede in der Sicherheit zwischen richtigen und falschen Urteilen und hohe Beeinflußbarkeit durch Kognitionen über den relativen Leistungsstand der Vp bei Fehlerurteilen führte theoretisch zu einer Unterscheidung zwischen innerem und äußerem Aufschluß und zu der Annahme, daß die Vp Unsicherheit vermeiden will. Der gefundene Response-bias war unabhängig von Motivation und sehr nahe bei der Wahrscheinlichkeit des Auftretens der Reize. Die reward/cost Theorie von Thibaut und Kelley kann die erzeugte Motivation erklären und wird mit einigen theoretischen Überlegungen über die Verarbeitung objektiv definierbarer Reize im sozialen Kontext verknüpft.

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This research was supported by research grants from the Deutsche Forschungsgemeinschaft allotted to the Sonderforschungsbereich 24 at the University of Mannheim, West Germany. We are grateful to Mary Madden, Pauline Sadler, and Jennifer S. Sentance for their cooperation on the English translation.

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This article is partly based on a Diplom-thesis by the second author entitled Effekte von Überlegenheit und Unterlegenheit in Gruppen auf Gedächtnisleistung und Skalengebrauch.     

Negation of Park's transformations

Zusammenfassung Parks Kritik beruht, meiner Ansicht nach, auf einem entscheidenden Mißverständnis meiner Intentionen: es geht mir überhaupt nicht um eine Argumentation gegen eine Transformationsgrammatik à la Chomsky, und nicht einmal in erster Linie gegen die Absicht mancher Psycholinguisten, eine derartige Theorie in ihren psychischen Funktionen aufzuzeigen. Ich möchte lediglich dafür plädieren, daß die Psycholinguistik in erster Linie psychologische (und nicht linguistische) Überlegungen und Modellvorstellungen als Leitlinien verwendet.     

Adaptation in the constancy of visual direction measured by a one-trial method

Adaptation to field displacement during head movements in the direction with the head rotation and in the direction against it was produced under otherwise identical conditions and compared; the field displacement rate was also varied. A rapid training procedure was used, and a novel one-trial test was employed that could measure the adaptation well enough to compare the effects of various training conditions. The one-trial test measured the magnitude of one of the manifestations of adaptation, the apparent displacement of a stationary target during head movements. This apparent horizontal target displacement was transformed into an oblique one by having the head movements that brought forth the apparent target displacement simultaneously cause an objective vertical target displacement. The slant of the resultant apparent motion path varied with the magnitude of the apparent horizontal target displacement. It was measured by having S reproduce its slant angle. It was found that adaptation to field displacement in the direction with the head rotation was consistently greater than adaptation to the opposite displacement conditions. An explanation for this result is offered.