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.     

The commonsense conception and its relation to scientific theory

Abstract

In this paper I discern two concepts of meaning: meaning O ‐ which is assigned by us on the basis of our commonsense conception in order to constitute our own daily reality — and meaning I, which we assign when we interpret reality scientifically. Authors who contend that the commonsense conception is nothing but a kind of scientific theory, do not see that the two fields of life have their own concept of meaning. Commonsense and science are not separate from each other, however: though both have their own practices, the way we interpret reality scientifically presupposes our commonsense conception.     

The development of gaze following and its relation to language

We examined the ontogeny of gaze following by testing infants at 9, 10 and 11 months of age. Infants (N = 96) watched as an adult turned her head toward a target with either open or closed eyes. The 10- and 11-month-olds followed adult turns significantly more often in the open-eyes than the closed-eyes condition, but the 9-month-olds did not respond differentially. Although 9-month-olds may view others as 'body orienters', older infants begin to register whether others are 'visually connected' to the external world and, hence, understand adult looking in a new way. Results also showed a strong positive correlation between gaze-following behavior at 10-11 months and subsequent language scores at 18 months. Implications for social cognition are discussed in light of the developmental shift in gaze following between 9 and 11 months of age.     

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.     

On the relation between preference and resistance to change

Nevin (1979) noted that preference in concurrent chains and resistance to change in multiple schedules were correlated, in that both measures were affected similarly by variations in parameters of reinforcement such as rate, immediacy, and magnitude. To investigate the relationship between preference and resistance to change directly, we used a within-session procedure that arranged concurrent chains in one half of the session and a multiple schedule in the other half. The same variable-interval schedules served as terminal links in concurrent chains and as the components of the multiple schedule, and were signaled by the same stimuli. After performances had stabilized, responding in the multiple schedule was disrupted by delivering response-independent reinforcement during the blackout periods between components. Both preference in concurrent chains and relative resistance to change of multiple-schedule responding were well described as power functions of relative reinforcement rate, as predicted by current quantitative models (Grace, 1994; Nevin, 1992b). In addition, unsystematic variation in preference and resistance to change was positively correlated, which suggests that preference and resistance to change are independent measures of a single construct. That construct could be described as the learning that occurs regarding the prevailing conditions of reinforcement in a distinctive stimulus situation.