Shaping the location of a pigeon's peck: effect of rate and size of shaping steps.

For several pigeons, pecking at particular locations within a ten-inch-wide response area was reinforced by grain presentations. The reinforced locations changed systematically to "shape" response location back and forth across the area. The rate and size of these shifts in reinforced locations were varied in both between-subject and within-subject comparisons to evaluate the influence of these variables on the shaping process. Larger step sizes produced larger shifts in location for all sizes inspected, with all sizes from .5 to 3.0 inches effective in shaping behavior. More rapid steps were approximately as effective as slower steps for all rates of shift inspected from 25 reinforcers to 400 reinforcers per step. These data suggest that shaping peck location proceeds most efficiently with rapid, relatively large shifts in criterion performance.     

Evaluation of eye movement variables of Chinese and American readers

Eye movements were recorded while competent readers of English and Chinese read in their respective languages. There were no important differences in oculometric patterns of fixation pause durations for Chinese and American readers, suggesting that cognitive aspects of reading are more important than perceptual ones in determining eye movement patterns and fixation pauses of competent readers. An analysis of undershoot saccades associated with return of the eyes from the end of one line to the beginning of the next line suggests that these occur more frequently during reading than during the performance of similar eye movements that are more perceptually determined, however, the amount of undershoot does not discriminate between readers of alphabetic and logographic texts.     

Maternal representations: A clinical and subjective phenomenological view

The relationship — as represented — is proving to be of growing value in our thinking about clinical problems such as “intergenerational transfer.” It is also an extremely positive influence in our thinking about how the interpersonal world is remembered, abstracted, and lived. Yet, the nature of a “represented relationship” remains unclear. This paper is an attempt to clarify some of the problems and areas for needed study regarding this concept. The mother's representation of her infant and of the people in her own life who have played “maternal roles” will be taken as the model. First, we will explore the richness and complexity of these representations and conclude that, for clinical purposes, different models are used to simplify this richness and render it therapeutically useful. Three models will be discussed. The first is the disfortion model which measures the distance between the mother's subjective experience of her interaction or relationship with another and some objective, observable “reality.” The model of overdeter-mining themes is a second model, largely the inspiration of psychoanalysis but inclusive of Bowlby's theory of attachment. Here psychobiological and/or psychodynamic themes organize the clinical material. Finally, a coherence model is discussed. Here the motive is goodness of the narrative construction rather than the historical “truth.” A second issue discussed is the capacity to represent dyads vs. triads and actual vs. second-hand narrated relationships. These issues are crucial for notions not only about the nature of such representations but also their limitations in understanding family interactions and relationships, i.e., where many members are concerned. A third issue concerns the nature of the subjective experience for a mother when a representation of her infant or herself in relation to the infant is “activated.” There exists here an unknown typology of experience. Finally, we will discuss what all of the above have to contribute to our further understanding of the nature of represented relationships.     

The prematurity stereotype: Empirical evidence and implications for practice

The prematurity stereotype is defined as a set of biased beliefs about infants who are identified as having been born prematurely. This article reviews studies that have explored how this prematurity stereotype may negatively influence adults' perceptions of, expectations for, and behavior toward premature infants. The findings from these studies are considered in the context of more general knowledge about how expectations can influence behavior and result in self-fulfilling prophecies. Recent research designed to investigate how prematurity stereotyping can be reduced also is described and evaluated. Finally, the implications of this program of research for intervention with parents of premature infants and suggestions for future research directions are discussed.     

Unformulated experience,dissociation, and Nachträglichkeit

The paper is divided into two parts. The first part is an interpersonal/relational psychoanalytic account of some relationships between dissociation, time, and unformulated experience. Trauma, and the dissociation to which trauma leads, freezes time, which makes it impossible to formulate certain kinds of new experience. Instead, potential new meanings remain unformulated. The route of clinical access to frozen time is the interpersonal field: to thaw time and allow new experience, the ways in which the interpersonal field is itself frozen need to be addressed. A clinical illustration of these ideas is offered. The second part of the paper presents and explores a point of confluence between the views in Part 1 and certain aspects of French psychoanalysis, with particular reference to the concept of Nachträglichkeit in the work of Jean Laplanche and Haydée Faimberg.     

A validation of eye movements as a measure of elementary school children's developing number sense

The number line estimation task captures central aspects of children's developing number sense, that is, their intuitions for numbers and their interrelations. Previous research used children's answer patterns and verbal reports as evidence of how they solve this task. In the present study we investigated to what extent eye movements recorded during task solution reflect children's use of the number line. By means of a cross-sectional design with 66 children from Grades 1, 2, and 3, we show that eye-tracking data (a) reflect grade-related increase in estimation competence, (b) are correlated with the accuracy of manual answers, (c) relate, in Grade 2, to children's addition competence, (d) are systematically distributed over the number line, and (e) replicate previous findings concerning children's use of counting strategies and orientation-point strategies. These findings demonstrate the validity and utility of eye-tracking data for investigating children's developing number sense and estimation competence.     

Individual differences in chess expertise: a psychometric investigation

Starting from controversies over the role of general individual characteristics (especially intelligence) for the attainment of expert performance levels, a comprehensive psychometric investigation of individual differences in chess expertise is presented. A sample of 90 adult tournament chess players of varying playing strengths (1311-2387 ELO) was screened with tests on intelligence and personality variables; in addition, experience in chess play, tournament participation, and practice activities were assessed. Correlation and regression analyses revealed a clear-cut moderate relationship between general (and in particular numerical) intelligence and the participants' playing strengths, suggesting that expert chess play does not stand in isolation from superior mental abilities. The strongest predictor of the attained expertise level, however, was the participants' chess experience which highlights the relevance of long-term engagement for the development of expertise. Among all analysed personality dimensions, only domain-specific performance motivation and emotion expression control incrementally contributed to the prediction of playing strength. In total, measures of chess experience, current tournament activity, intelligence, and personality accounted for about 55% of variance in chess expertise. The present results suggest that individual differences in chess expertise are multifaceted and cannot be reduced to differences in domain experience.     

Behavioral alterations in mice lacking the translation repressor 4E-BP2

The requirement for de novo protein synthesis during multiple forms of learning, memory and behavior is well-established; however, we are only beginning to uncover the regulatory mechanisms that govern this process. In order to determine how translation initiation is regulated during neuroplasticity we engineered mutant C57Bl/6J mice that lack the translation repressor eukaryotic initiation factor 4E-binding protein 2 (4E-BP2) and have previously demonstrated that 4E-BP2 plays a critical role in hippocampus-dependent synaptic plasticity and memory. Herein, we examined the 4E-BP2 knockout mice in a battery of paradigms to address motor activity and motor skill learning, anxiety and social dominance behaviors, working memory and conditioned taste aversion. We found that the 4E-BP2 knockout mice demonstrated altered activity in the rotating rod test, light/dark exploration test, spontaneous alternation T-maze and conditioned taste aversion test. The information gained from these studies builds a solid foundation for future studies on the specific role of 4E-BP2 in various types of behavior, and for a broader, more detailed examination of the mechanisms of translational control in the brain.