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.     

The effect of abnormal displacement of the retinal image during eye movements

The displacement of the images on the retina that results from a turning of the eye does not lead to an apparent motion of what is seen, It has been generally assumed that this is due to a compensating process which takes eye movement into account and serves to discount those image displacements that result from eye movements, It follows from this view that an abnormal image displacement, that is, an image displacement that is larger or smaller than the causing eye movement would warrant, should lead to an experienced displacement of the target. Abnormal image displacement was produced by placing the eye in the converging or diverging bundle of rays from a point source that form behind a strong positive lens; this arrangement yielded a disc-shaped image, the projection of the pupil onto the retina, which displaced abnormally during eye movements. By changing the position of the eye along the axis of the lens in relation to the crossing point of the bundle, the degree to which the displacement was abnormal could be varied, For various displacement rates ranging from 25% to 120 and 400% of normal, abnormal displacements produced by incidental eye movements remained unnoticed, Only where eye movements were intentional did some of our Ss report shifts of the perceived image. It is suggested that the organism copes with the image displacement resulting from the ever-present incidental eye movements not by compensation but by ignoring them.     

An extension of the concept of specific objectivity

Comparisons of subjects are specifically objective if they do not depend on the items involved. Such comparisons are not restricted to the 1-parameter logistic latent trait model, but may also be defined within ordinal independence models and even within the 2-parameter logistic model.