Some symmetric,invariant measures of multivariate association

A distinction is drawn between redundancy measurement and the measurement of multivariate association for two sets of variables. Several measures of multivariate association between two sets of variables are examined. It is shown that all of these measures are generalizations of the (univariate) squared-multiple correlation; all are functions of the canonical correlations, and all are invariant under linear transformations of the original sets of variables. It is further shown that the measures can be considered to be symmetric and are strictly ordered for any two sets of observed variables. It is suggested that measures of multivariate relationship may be used to generalize the concept of test reliability to the case of vector random variables.     

Using ROC curves to test models of recognition memory: The relationship between presentation duration and slope

Many theories of memory predict that the slope of the z-transformed receiver-operating characteristic (ROC) curve should decrease with increases in the memory strength of old items. While several prior studies have failed to demonstrate this effect, the results of two experiments demonstrate that increasing presentation duration can reduce the slope of the z-transformed ROC curve. These results raise questions about the generality of prior results and of dual-process theories designed to accommodate those results. We close by emphasizing that determining the experimental circumstances that affect whether or not the slope of the z-transformed ROC curve decreases will provide important constraints on theories of recognition memory.     

Configuration-specific attentional modulation of flanker- -target lateral interactions

Elements of a contour are often easier to detect when they possess collinearity, with their local orientations matching the global orientation of the contour. We recently reported attentional modulation of such lateral interactions between a central near-threshold target Gabor patch and flanking high-contrast patches (Freeman et al, 2001 Nature Neuroscience 4 1032-1036). Here, we examined whether such attentional effects reflect specific modulation of mechanisms sensitive to collinear configurations, or instead more general modulation of sensitivity to either the global or local orientation-components of the stimulus. Thresholds for detecting a central Gabor target were measured, while observers also judged the Vernier alignment between one pair of flankers and ignored a second flanker pair (when present). Target contrast-thresholds were facilitated only when attending collinear flankers. There was no facilitation when attending flankers that shared only local orientation with the target, or flankers that fell on a global axis aligned with target orientation but having orthogonal local orientation. Ignored collinear flankers had no effect on target thresholds. These results demonstrate strong and specific attentional modulation of contour-integration mechanisms in early vision sensitive to collinear configurations.     

On the logic of testing the independence assumption in the process-dissociation procedure

Theprocess-dissociation procedure is designed to provide quantitative estimates of the influence of explicit and implicit memory in a variety of tasks. The procedure relies on the assumption that these two forms of memory produce independent influences on performance. Prior investigators have attempted to test this assumption by determining whether the parameter representing the influence of implicit memory (denotedA) is constant across experimental conditions. I argue that the constancy of A cannot provide an appropriate test of the independence assumption, because (1) the prediction of constancy can be generated without the assumption of independence, obviating the need to posit independence; and (2) the constancy ofA does not necessarily imply independence, even if one assumes that a dependency hypothesis, supplemented by ancillary assumptions (Curran & Hintzman, 1995), predicts differences inA. I close by emphasizing that we can test the independence assumption by using standard procedures that compare the fit of a model that assumes independence with the fit of a model that assumes dependence.     

The influence of competition and performance goals on decoding complex emotions

Motivation and Emotion - The present research examines the processes through which competitive contexts influence performance in an understudied domain: social perception. In two experiments (one...     

Discovery of the pendulum and spring dynamics in the early stages of walking

The authors investigated the self-selected, overground walking patterns of 7 children (aged 11 months to 1 year, 5 months) at the initiation of walking (brand-new walkers [BNWs]) and for the next 6 months at 1-month intervals. Walking speed, stride length, and stride frequency increased significantly between the first 2 visits without significant changes in height and weight. The authors calculated sagittal plane angular accelerations of the center of mass over the foot for each step as an indicator of the escapement pulse. Results for the acceleration profiles changed after the 1st visit to positive, single-peaked accelerations that occurred < 0.20 s after initial foot contact. Increases in sagittal plane hip angular displacement and decreases in frontal plane pelvic angular displacement were observed. The pattern changes suggest that children quickly discover appropriately timed and directed escapements that initiate and support the conservative sagittal plane pendulum and spring dynamics observed in older children.     

Approach and avoidance motivation in the social domain

This research put Gable's (in press) hierarchical model of approach-avoidance social motivation to empirical test using newly developed measures of friendship-approach and avoidance goals. The results from Study 1 supported the psychometric soundness of the new goal measures and showed the anticipated differential predictive patterns for the two goals. The results from Study 2 provided further evidence of the psychometric soundness of the new goal measures and provided support for the full hierarchical model in longitudinal analyses of subjective well-being and physical symptomotology. Implications of the present research for understanding motivation both within and beyond the social domain are discussed.     

Color and Psychological Functioning

ABSTRACT— Color is a ubiquitous perceptual experience, yet little scientific information about the influence of color on affect, cognition, and behavior is available. Accordingly, we have developed a general model of color and psychological functioning, which we present in this article. We also describe a hypothesis derived from this model regarding the influence of red in achievement contexts. In addition, we report a series of experiments demonstrating that a brief glimpse of red evokes avoidance motivation and undermines intellectual performance, and that it has these effects without conscious awareness or intention. We close with thoughts on the need for rigorous scientific work on color psychology.     

Plasma interleukin-6 and soluble IL-6 receptors are associated with psychological well-being in aging women.

OBJECTIVE: This study tested the hypothesis that psychological well-being would predict lower plasma levels of inflammatory factors in aging women. DESIGN: One hundred thirty-five women ages 61-91 years (M = 74.5 years) participated in this study. After completing self-administered questionnaires in their homes, participants stayed overnight at the General Clinical Research Center (GCRC) at the University of Wisconsin-Madison. Blood samples for cytokine analyses were obtained in participants' homes after the GCRC visit. MAIN OUTCOME MEASURES: Psychological well-being and ill-being, history of health problems, and health behaviors were assessed via self-administered questionnaires. Detailed medical history and concurrent health measures were obtained during the GCRC stay. Enzyme-linked immunosorbent assays were used to determine interleukin-6 (IL-6) and soluble IL-6 receptor (sIL-6R) concentrations in plasma. RESULTS AND CONCLUSION: Regression analyses showed that plasma IL-6 levels were lower in women scoring higher on positive relationships, whereas sIL-6R levels were lower in women scoring higher on purpose in life, even after a variety of sociodemographic and health factors were controlled. These outcomes, combined with the absence of significant links with other measures of well-being and ill-being, suggest selective patterns of association between later life inflammatory processes and psychological factors, particularly those focused on positive ties with others and purposeful engagement.