The logical and empirical bases of conservation judgements

It is argued that conservation judgements are based on a particular combination of logical necessity and empirical belief. The empirical belief is that a given transformation will not alter a particular quantity (Elkind's conservation of identity). The logical aspect is a transitive deductive argument containing an initial equivalence of two quantities and the conservation of identity belief as premises which lead to the conclusion of maintained equivalence (Elkind's conservation of equivalence). In two experiments, it is shown that conservation of identity beliefs can be manipulated in subjects who have long since developed the capacity for transitive deductive inference. Untrained 10 year olds were unaware of how sublimation acts to alter certain quantities over particular transformations of shape. And untrained adults incorrectly believed that both the area and perimeter of a closed figure would be conserved over transformations which elongated the figure. Both groups of subjects could be trained in the correct conservation of identity beliefs and this affected their conservation of equivalence judgements in predicted ways. It is suggested that the locical aspect of conservation is developmentally stable and that the empirical aspect varies widely across problems and individuals because of its dependence on relevant experience.     

Detection of change in shape and its relation to part structure

Using a change detection paradigm (Barenholtz, E., Cohen, E. H., Feldman, J., & Singh, M. (2003). Detection of change in shape: An advantage for concavities. Cognition, 89(1) 1-9), we measured sensitivity to the changes of shapes and in particular the difference between detecting a new convex or concave vertex. We conclude that concave vertices per se are not more salient, but changes in the sequence of convexities and concavities along a contour are salient. We argue that these changes are likely to signal a change in perceived part structure.     

Causation,causal perception,and conservation laws

We investigated the perception of causation via the ability to detect conservation violations in simple events. We showed that observers were sensitive to energy conservation violations in free-fall events. Furthermore, observers were sensitive to gradually perturbed energy dynamics in such events. However, they were more sensitive to the effect of decreasing gravity than to that of increasing gravity. Displays with decreasing gravity were the only displays in which the energy profile was dominated by (apparent) potential energy, leading to an asymmetric trajectory.     

Rigidity in children's drawings and its relation with representational change

Four studies tested the application of to the drawing domain. In particular, we tested her claim that young children are inhibited in their attempts at changing their graphic representations (representational change) due to being constrained by the order in which the elements of the representation are drawn (procedural rigidity). The first study required 60 children (4- to 6-year-olds and an older comparison group of 8-year-olds) to make three drawings of a familiar and novel topic. From these drawings each child was measured for procedural rigidity. In a further drawing the child was asked to modify their usual representation of each topic. Regression analyses revealed procedural rigidity levels were not predictive of manipulation performance. A second study, testing 75 4- to 6-year-olds and a third study, testing 30 3- to 4-year-olds, revealed that when young children were specifically asked to manipulate rigid sub-procedures on a familiar topic they were indeed able to do so. Finally, a fourth study (testing 40 5-year-olds and 40 8-year-olds) removed the notational trace in drawing (a possible aid for procedural interruption) but this still produced no evidence of a relation between procedural rigidity and representational change. We suggest how the concept of procedural rigidity might be re-interpreted for the drawing domain so that the RR model can remain as a domain-general theory of cognitive development. We also suggest the development of information processing may be crucial for flexibility in drawing.     

The Aubert-Foerster phenomenon and its relation to Manifest Anxiety

Summary The narrowing of the visual field with an increase in distance between a person and a pre-set fixation point was investigated with 20 persons under stable background and with 10 persons under moving background conditions. Optical stimuli were introduced from the periphery and readings were taken at the limit of sharp perception of the figure by the subject. The Aubert-Foerster phenomenon, the easier recognition of small, near objects compared with larger, more distant objects subtending the same visual angle, was used as a starting point. The subjects were equally divided into high and low anxiety groups on the basis of Taylor's Manifest Anxiety Scale.The Aubert-Foerster phenomenon does exist in both experimental situations, under conditions of stable and moving background.Differences in visual angles and in amount of Aubert-Foerster phenomenon are found for the high and low anxiety groups under both experimental conditions.Under conditions of moving background with a centrally imposed task both experimental groups show greater narrowing of the visual angle than they did when exposed to stable background; on the contrary, the visual angle becomes increased when the centrally located task becomes simplified.

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Zusammenfassung Der Winkel zwischen der Blickrichtung und der Sehrichtung, bei welchem ein peripher dargebotener Gegenstand eben erkannt wird, nimmt bei gleichbleibender Größe des Netzhautbildes ab, wenn der Beobachtungsabstand vergrößert wird: Aubert-Foerster-Phänomen.Dieses Phänomen stellt den Ausgangspunkt vorliegender Arbeit dar, in der 30 Versuchspersonen herangezogen wurden, um die Frage nach der Gesichtsfeldeinengung mittels peripher vor unbewegtem und bewegtem Hintergrund einwandernder Figuren zu untersuchen. Die Versuchspersonen in den beiden Versuchsklassen wurden nach Taylors Manifest Anxiety Scale in Gruppen von hohem und niedrigem Anxiety-Wert zusammengefaßt.Das Aubert-Foerster-Phänomen tritt in beiden Versuchssituationen auf, d.h. beim Fixieren der Figuren vor dem bewegten als auch dem unbewegten Hintergrund.Für die hohen und niedrigen Anxiety-Gruppen bestehen in beiden Versuchsklassen Unterschiede hinsichtlich der nach dem Aubert-Foerster-Phänomen zu erwartenden Winkelgröße.Bei den Versuchen vor bewegtem Hintergrund wird der experimentell bestimmte Winkel größer als der theoretisch erwartete, wenn die Anzahl der Reize vermindert, d. h. die Aufgabe vereinfacht wird. Es besteht offenbar eine direkte Beziehung zwischen der geforderten Aufmerksamkeit an der Stelle deutlichsten Sehens und der peripheren Sehleistung.

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Dr. Mangans help in the collection of the data and his advice were greatly appreciated.     

An empirical typology of perfectionism in early-to-mid adolescents and its relation with eating disorder symptoms

Although the association between perfectionism and eating disorder (ED) symptoms is well-established, debate remains about the relative contribution of two central dimensions of perfectionism, that is, Personal Standards (PS) perfectionism and Evaluative Concerns (EC) perfectionism, in the prediction of ED symptoms. This study used cluster analysis to establish naturally occurring combinations of PS and EC perfectionism in early-to-mid adolescents (N = 656; M age = 13.9 years). Evidence was obtained for four perfectionism profiles: (1) maladaptive perfectionism (high PS and high EC), (2) pure evaluative concerns perfectionism (high EC only), (3) adaptive perfectionism (high PS, low EC), and (4) non-perfectionism (low on both PS and EC). A comparison of participants in these four clusters in terms of ED symptoms suggests that a combination of high personal standards and evaluative concerns (rather than the presence of one of these two dimensions alone) is most strongly related to ED symptoms.     

Theory change as dimensional change: conceptual spaces applied to the dynamics of empirical theories

This paper offers a novel way of reconstructing conceptual change in empirical theories. Changes occur in terms of the structure of the dimensions—that is to say, the conceptual spaces—underlying the conceptual framework within which a given theory is formulated. Five types of changes are identified: (1) addition or deletion of special laws, (2) change in scale or metric, (3) change in the importance of dimensions, (4) change in the separability of dimensions, and (5) addition or deletion of dimensions. Given this classification, the conceptual development of empirical theories becomes more gradual and rationalizable. Only the most extreme type—replacement of dimensions—comes close to a revolution. The five types are exemplified and applied in a case study on the development within physics from the original Newtonian mechanics to special relativity theory.     

The development of metalinguistic awareness and its relation to reading achievement

The relation between certain aspects of metalinguistic ability and reading, e.g., morpho-phonological ability and reading, has been well documented in the literature. What has not been fully discussed is the relation between structural-relational (semantic-syntactic) linguistic knowledge and reading development. This study examined two types of questions about this relation: (a) which aspects of structural-relational metalinguistic awareness in what forms and during which age periods are significantly related to reading achievement? and (b) what is the relation between metalinguistic awareness in oral language processing and written language processing? Sixty-four subjects, from fourth graders to adults, participated in the study. Each subject was asked to judge and produce corrections of nongrammatical, anomalous, and ambiguous stimulus items in sentences and passages. These items were presented in both oral and written modes. Results indicated that reading achievement and age were positively related to metalinguistic ability. Subjects were better able to judge than produce correct forms. While ambiguity was the most difficult task, nongrammaticality was the most discriminating task. Good readers' performance on oral tasks equalled their performance on written tasks by adulthood.     

The principle of additivity and its relation to clinical decision making

Clients (N = 178) with varying degrees of organic indicators were administered a psychological battery including the Memory for Designs Test (MFD; Graham & Kendall, 1960) to assess the extent to which joint presence of organic indicators affected the sensitivity of the MFD in identifying organicity. Joint presence failed to add to the discriminability of the MFD, although individual instruments such as the PIAT (Arithmetic) and WAIS-R (PIQ less than VIQ) clearly discriminated across the MFD.     

The structure of the self-concept and its relation to psychological adjustment

Research on the relation between the structure of the self-concept and psychological adjustment has produced seemingly inconsistent findings. Some research suggests that greater pluralism in self-concept structure enhances adjustment, whereas other research suggests that greater unity in the structure enhances adjustment. Four studies examined the relations among measures of self-concept structure and their relations with adjustment. The measures of self-concept structure included two that we viewed as reflecting self-concept pluralism (self-complexity and self-concept compartmentalization) and four that we viewed as reflecting self-concept unity (self-concept differentiation, self-concept clarity, self-discrepancies, and the average correlation among participants' self-aspects). The measures of self-concept pluralism were unrelated to one another, were unrelated to the measures of self-concept unity, and were unrelated to the measures of adjustment. The measures of self-concept unity were moderately related to one another and were moderately related to the measures of adjustment.