Transparent layer constancy

Perceived transparency was studied as a constancy problem. In the episcotister (E-) model of scission, luminances are partitioned into layer and background components; four luminances determine values of two layer parameters that specify constancy of a transparent layer on different backgrounds. The E-model was tested in an experiment in which 12 Ss matched 24 pairs of four-luminance patterns by adjusting two luminances of the comparison pattern. Both the standard and the comparison were perceived as a transparent layer on a checkerboard. The E-model predicts matches when layer values are identical in the two patterns. One parameter was constant, constraining the adjustment along the second dimension. Obtained values corresponded well with E-predictions. Alternative models based on local luminance or average contrast ratios accounted for less variability. Results indicate that transparency models should utilize luminance, not reflectance, as the independent variable.     

Discriminative properties of morphine that modulate associations between tastes and lithium chloride

Wistar rats learned to withhold consumption of a target solution when morphine preceded presentation of the target solution and lithium chloride (LiCl) and to consume the same target solution when saline preceded the presentation of the solution. After this serial feature discrimination training, morphine did not block the formation of a Pavlovian association between saccharin and LiCl but did suppress consumption of familiar tap water. After Pavlovian conditioning, morphine blocked the formation of an association between saccharin and LiCl but did not suppress consumption of a familiar tap water solution. The roles of morphine and saline can be interchanged. It appears that the morphine discriminative stimulus is calling up a representation of neither the conditioned stimulus nor the unconditional stimulus alone, but rather a modified representation of some aspect of their association.     

The early development of empathy: Self-regulation and individual differences in the first year

A longitudinal study of 45 mothers and their first-born infants was conducted to identify developmentally meaningful, individual differences in children's primitive empathic responding at 12 months of age, and to determine whether differences in self-regulatory skills assessed at 4 months might underlie any differences in empathic responding observed. Personal distress responses analogous to those observed in older children and adults were identified in one-third of the sample at 12 months of age. These distress responses were associated with indices of poorer self-regulatory skills in social contexts at 4 months of age. The results are interpreted within the broader framework of the development of self-regulatory strategies in the early childhood years.This research was supported by grants from the Australian Research Council, the National Research Fellowship Scheme, and the Macquarie University Research Grant Scheme. We thank Judy Chan, Alison Malbourne, Sylvana Sturevska, and Lorraine Smith for their assistance in data collection and analysis.     

Time courses in visual-information processing: Some theoretical considerations

Summary In the literature two different views with regard to the time course of activation of recognition units —hypothetical entities that represent identity information —are proposed. Both views are derived from a restricted set of phenomena in visual perception. The first view gets its intuitions from phenomena such as those summarized by Bloch's law; these phenomena show integration or summation of activation over time. This grow-and-grow view assumes that recognition units accumulate activation gradually over times The second view finds its inspiration in phenomena such as Mach-bands and simultaneous contrast; these phenomena show inhibition or steady-state suppression over time. This grow-and-shrink view assumes that the activation levels increase fast initially and then start to decrease.The perception literature strongly suggests that it may be light intensity that determines whether mainly integration (and phenomena such as Bloch's law) or inhibition (and phenomena such as Mach-bands) is obtained. So it is also likely that both information-processing views apply only to a limited range of intensity conditions; the grow-and-grow view to conditions of low-flight intensities, and the grow-and-shrink view to conditions of intermediate-and high-light intensities.It is argued that, to arrive at a complete view, a visual phenomenon that applies to the complete range of light intensities should be taken as a background for generating hypotheses about time courses in visual-information processing. The Broca-Sulzer effect is such a phenomenon. Starting from this phenomenon a simple, synthesizing, information-processing model is derived that is compatible with both the grow-and-grow view and the grow-andshrink view. It is shown that, besides the relevant temporal properties, this model also produces the appropriate spatial properties.     

Indeterminacy of the isomorphism heuristic

Summary We are less prone today than in Köhler's time to believe in a unified science. The Gestalt program could therefore safely abandon the psychophysical isomorphism heuristic if it wished to. Indeterminacy of the heuristic might be a reason for doing so. The determination of the components involved in the isomorphism of the visual field as well as the electrocortical events would have to occur simultaneously. In the Gestalt program, however, components are determined by their position in the whole. They can therefore not be compared in different contexts, so no independent test of a candidate heuristic is possible.     

Time courses in visual-information processing: Some empirical evidence for inhibition

Summary In the literature two different views on the time course of activation of recognition units — hypothetical units that represent identity information — are proposed. The first view assumes that the recognition units accumulate activation gradually over time. The second assumes that the activation levels increase fast initially and then start to decrease. Hagenzieker and Van der Heijden (1990) have proposed a more general information-processing model, which is compatible with both views. In this model a treshold determines what type of time course will be obtained. For below-threshold-activation values a gradual accumulation of activation will be found; for above-threshold values activation levels will first increase and then, because of inhibition, decrease. This model served as a starting-point for the present paper. Elaboration of this model led to two testable hypotheses with regard to identification performance. The first prediction is that evidence for inhibition should be observed only under relatively bright luminance conditions. The second is that, given inhibition, the amount of the effect of this inhibition should increase over time. A partial-report bar-probe task was used to test the predictions. The experiment involved two luminance conditions and the information was sampled at two different moments in time. To control for possible localization artefacts a digit-naming task was also used. Evidence for inhibition was found in both luminance conditions. In accordance with the model the amount of the effect of inhibition increased over time.     

Individual Differences in the Pursuit of Self-Uniqueness Through Consumption

In this paper, we report an original study of the relationships between self-attributed need for uniqueness and several consumer dispositions. The results indicate that the self-attributed need for uniqueness is related to consumers' desires for scarce, innovative, and customized products and to consumers' preferences for unusual shopping venues, but not to consumers' susceptibilities to normative influence. Moreover, we find that these relationships are mediated by a latent variable reflecting individual differences in the tendency to pursue uniqueness through consumption. The theoretical and practical implications of these results are discussed along with directions for future research.     

Transformation of Perception of Trauma by Child Survivors of the Holocaust in Group Therapy

Intensive work with child survivors of the Holocaust has made us aware of the clinical importance of understanding the ways children perceive their traumas and the conclusions they draw about how they must live their lives. When these perceptions are transformed congruently with the child's development, the survivors can cope quite well. In this paper we refer to now middle-aged survivors who are still guided by their child perceptions. We will describe how we have used conjoint group psychotherapy to facilitate processes of transformation even at this late stage. The model we provide for trauma work with Holocaust survivors whose traumatization occurred decades ago may well provide tools to reduce future suffering of children who are victims of massive traumatization today.