Segmentation of object outlines into parts: a large-scale integrative study

In this study, a large number of observers (N=201) were asked to segment a collection of outlines derived from line drawings of everyday objects (N=88). This data set was then used as a benchmark to evaluate current models of object segmentation. All of the previously proposed rules of segmentation were found supported in our results. For example, minima of curvature (i.e. locations along the contour where negative curvature takes an extreme value) were often used as segmentation points. The second point of a pair connected by a segmentation line often depended on more global shape characteristics such as proximity, collinearity, symmetry, and elongation. Based on these results, a framework is presented in which all of the previously proposed (and now empirically validated) segmentation rules or rules for part formation are integrated.     

A comparison of cue competition in a simple and a complex design

Recent evidence suggests that controlled reasoning processes play an important role in cue competition in human causal learning (see De Houwer, J., Beckers, T., & Vandorpe, S. (2005). Evidence for the role of higher-order reasoning processes in cue competition and other learning phenomena. Learning &Behavior, 33(2), 239-249, for a review). Until now, this evidence comes almost exclusively from studies with simple designs that involved only a limited number of cues. Little is known about the role of controlled reasoning processes when the design is more complex. It is important to examine this issue because the complexity of the design could determine the resources that are available for reasoning and thus the role that reasoning plays in cue competition. We directly compared cue competition in a simple and a complex design. The results showed that complexity of the design affected retrospective cue competition but not forward cue competition. More fine grained analyses with respect to retrospective cue competition showed that unovershadowing but not backward blocking differed significantly between complexity conditions.     

The representation of multiplication facts: developmental changes in the problem size, five, and tie effects

In this study, we investigated the development of basic effects that have been found in single-digit multiplication arithmetic: the problem size, five, and tie effects. Participants (9-, 10-, and 11-year-olds and adults) performed a production task on simple multiplication. The procedure replicated study [Canadian Journal of Psychology, Vol. 39, pp. 338-366], but the results show that the gradual decrease of the problem size effect ends in sixth grade. We report analyses on raw latencies and state trace analyses that take into account reaction time scaling as a function of age. The results show that 11-year-olds do not differ significantly from adults on any of the three effects. Before 11 years of age, interesting developmental changes occur.     

Tense and Agreement dissociations in German agrammatic speakers: underspecification vs. hierarchy

The aim of the present paper was to investigate whether German agrammatic production data are compatible with the Tree-Pruning-Hypothesis (TPH; Friedmann & Grodzinsky, 1997). The theory predicts unidirectional patterns of dissociation in agrammatic production data with respect to Tense and Agreement. However, there was evidence of a double dissociation between Tense and Agreement in our data. The presence of a bidirectional dissociation is incompatible with any theory which assumes a hierarchical order between these categories such as the TPH or other versions thereof (such as Lee's, 2003 top--down hypothesis). It will be argued that the data can better be accounted for by relying on newer linguistic theories such as the Minimalist Program (MP,), which does not assume a hierarchical order between independent syntactic Tense and Agreement nodes but treats them as different features (semantically interpretable vs. uninterpretable) under a single node.     

Avoidance behavior can function as a negative occasion setter

The authors put forward the hypothesis that avoidance learning can result from the fact that participants learn (a) that a stimulus is followed by an unconditioned stimulus (US) when the avoidance behavior is not emitted and (b) that the stimulus is not followed by the US when the avoidance behavior is emitted. As such, avoidance behavior is assumed to function as a negative occasion setter. The results of a contingency judgment experiment involving 65 students showed that avoidance behavior indeed has the unique functional properties of a negative occasion setter (resistance to counterconditioning and selective transfer of modulation).     

Testing the multiple in the multiple read-out model of visual word recognition

This study provided a test of the multiple criteria concept used for lexical decision, as implemented in J. Grainger and A. M. Jacobs's (1996) multiple read-out model. This account predicts more inhibition (or less facilitation) from a masked neighbor when accuracy is stressed more but more facilitation (or less inhibition) when the speed of responding is emphasized more. The authors tested these predictions by stressing accuracy (Experiment 1) and response speed (Experiment 2). The results of Experiment 1 showed a stronger neighbor-inhibition effect in the stress-on-accuracy condition than in the control condition. The results of Experiment 2 showed facilitation because of the neighbor prime in the stress-on-speed condition relative to the control condition. These results corroborate the multiple criteria account.     

Retrieval of incidental stimulus-response associations as a source of negative priming

Priming effects of ignored distractor words were investigated in a task-switching situation that allowed an orthogonal variation of priming and response compatibility between prime and probe. Across 3 experiments, the authors obtained a disordinal interaction of priming and response relation. Responding was delayed in the ignored repetition condition if different responses were required for identical stimuli in the prime and probe (negative priming). Repeating the prime distractor in the probe facilitated responding if the same response was required in the prime and in the probe (positive priming). The same pattern of results was replicated in a letter-matching task without task switching (Experiment 4). Findings lend support to a new model that explains negative priming in terms of an automatic retrieval of incidental stimulus-response associations.     

Temperament, personality, and developmental psychopathology as childhood antecedents of personality disorders

To contribute to the case for a dimensional conceptualization of psychopathology in general and maladaptive personality or personality disorders in particular, the present paper reviews the evidence for a dimensional representation of childhood temperament and personality. The review of temperament and variable-centered as well as person-centered approaches to childhood personality leads us to propose five broadband dimensions that capture individual differences in children and adolescents: extraversion, emotional stability, agreeableness, conscientiousness, and openness/intellect. Our analysis of the CBCL (Achenbach, 1991) and the DIPSI (currently under development at Ghent University), two dimensional models for childhood psychopathology, suggests two common broadband factors, internalizing and externalizing. The relations between the dimensional representation of childhood temperament/personality and psychopathology are documented with data from general population and clinical samples of children and adolescents. The article concludes with a proposal on how the higher-order dimensions emerging from studies of adaptive and maladaptive individual differences in childhood could be integrated in a common dimensional model.