Colour inputs to random-dot stereopsis.

Recently it has been claimed by Livingstone and Hubel that, of three anatomically and functionally distinct visual channels (the magnocellular, parvocellular interblob, and blob channels), only the magnocellular channel is involved in the processing of stereoscopic depth. Since the magnocellular system shows little overt colour opponency, the reported loss of the ability to resolve random-dot stereograms defined only by colour contrast seems consistent with this view. However, Julesz observed that reversed-contrast stereograms could be fused if correlated colour information was added. In the present study, 'noise' (non-corresponding) pixels were injected into random-dot stereograms in order to increase fusion time. All six subjects tested were able to achieve stereopsis in less than three minutes when there was only correspondence in colour and not in luminance, and three when luminance contrast was completely reversed. This ability depends on information about the direction of colour contrast, not just the presence of chromatic borders. When luminance and chromatic contrast are defined in terms of signal-to-noise ratios at the photoreceptor mosaic, chromatic information plays at least as important a role in stereopsis as does luminance information, suggesting that the magnocellular channel is not uniquely involved.     

Correlations Between Input and Output Units in Neural Networks

Correlation analyses of recent back-propagation neural networks show that network results are due to imbalances in stimulus input. Conclusions concerning the effects of receptive field size, hemispheric specialization, and other issues of relevance to psychology cannot therefore be drawn until the dominating effects of low-level correlations are removed. Statistical techniques for evaluating the stimulus materials for neural networks are introduced.     

Concreteness and item-to-list context associations in the free recall of items differing in context variability

Context variability can be defined as the number of preexperimental contexts in which a given concept appears. Following M. Steyvers and K. J. Malmberg's (2003) work, the authors have shown that concepts that are experienced in fewer preexperimental contexts generally are better remembered in episodic memory tasks than concepts that are experienced in a greater number of preexperimental contexts. The purpose of this article is to demonstrate that low context variability confers its memorial advantage because of stronger item-to-list context associations as compared with high context variability. Three experiments that use environmental context changes from study to test demonstrate that the low context variability advantage is eliminated when item-to-list context associations are not available because of environmental changes at test. In addition, the low context variability advantage is eliminated when inward processing at study prevents the formation of item-to-list context associations.     

Attention and movement execution during handwriting

Two studies were performed in order to test the hypothesis that movement execution during handwriting in skilled writers is independent of attention. Study I examined the relationship between attentional functioning and kinematic aspects of handwriting movements in 24 adult participants. A digitizing tablet was used for the assessment of handwriting movements. Participants were asked to perform a simple writing task and various components of their attention were assessed. Correlation analysis indicated no significant relationship between attention functions and both kinematic aspects of handwriting movements and quality of handwriting. In Study II, 20 participants underwent total sleep deprivation (TSD) for 24h. While attention, as assessed with alertness and vigilance tasks, deteriorated during TSD, the execution of handwriting movements, as assessed with a digitizing tablet, improved markedly. The quality of handwriting was not affected by TSD. These findings may suggest an independence between attention and movement generation during handwriting.     

Told in Memory of God’s People: Beloved

The purpose of this article is to show how Toni Morrison’s novel, Beloved, can be used in pastoral care and counseling courses to encourage the development of empathy and to illustrate themes in the communal contextual and intercultural paradigms emerging in the field of pastoral theology.     

Decreased Sensitivity to Phonemic Mismatch in Spoken Word Processing in Adult Developmental Dyslexia

Initial lexical activation in typical populations is a direct reflection of the goodness of fit between the presented stimulus and the intended target. In this study, lexical activation was investigated upon presentation of polysyllabic pseudowords (such as p rocodile for crocodile) for the atypical population of dyslexic adults to see to what extent mismatching phonemic information affects lexical activation in the face of overwhelming support for one specific lexical candidate. Results of an auditory lexical decision task showed that sensitivity to phonemic mismatch was less in the dyslexic population, compared to the respective control group. However, the dyslexic participants were outperformed by their controls only for word-initial mismatches. It is argued that a subtle speech decoding deficit affects lexical activation levels and makes spoken word processing less robust against distortion.     

Moving from Principles to Practice: Recommended Policy Changes to Promote Family-Centered Care

This paper emphasizes the value of family-centered care. Discussion highlights family-centered philosophies (e.g., Systems of Care [SOCs]) and practice models (i.e., wraparound) and identifies discrepancies between conceptualizations and actual practice. Data from multiple sources detail issues in fidelity to family-centered values and needs and risks experienced by siblings of children with severe emotional disturbance and their caregivers. This discussion provides a springboard for policy recommendations to strengthen family support programming and enhance family-centered care, from modifying funding streams such that systems extend their reach beyond children with full-blown, diagnosable problems (those meeting standards of "medical necessity), to supporting prevention and early intervention initiatives that address families as targets for intervention. Recommendations include ensuring that communities with SOC funding address the needs of families; broadening Medicaid rules and definitions; expanding the range of reimbursable activities and services; and increasing funding for evaluating family-centered care models and family support programming.     

The concurrent validity of the N-back task as a working memory measure

The N-back task is used extensively in literature as a working memory (WM) paradigm and it is increasingly used as a measure of individual differences. However, not much is known about the psychometric properties of this task and the current study aims to shed more light on this issue. We first review the current literature on the psychometric properties of the N-back task. With three experiments using task variants with different stimuli and load levels, we then investigate the nature of the N-back task by investigating its relationship to WM, and its role as an inter-individual difference measure. Consistent with previous literature, our data suggest that the N-back task is not a useful measure of individual differences in WM, partly because of its insufficient reliability. Nevertheless, the task seems to be useful for experimental research in WM and also well predicts inter-individual differences in other higher cognitive functions, such as fluid intelligence, especially when used at higher levels of load.     

Warmth and Contingency and Their Relationship to Maternal Attitudes Toward Parenting

In this study, the authors addressed the question of whether maternal parenting behaviors in terms of sensitivity, warmth, and contingency with respect to small infants were equally represented in attitudes toward parenting. Sixty mothers from central Germany with middle-class socioeconomic backgrounds were videotaped with their 1st born 3-month-old infant in a free-play and a caregiving episode in their home. The different maternal parenting components were behaviorally analyzed. Maternal attitudes toward parenting were assessed with self-report measures. The results showed that behavioral sensitivity was significantly associated with attitudes related to contingency, whereas behavioral warmth and contingency were not associated with maternal attitudes. The authors interpreted differential associations as a reflection of intuitive and explicit parenting strategies, with only sensitivity being explicitly represented.