Auditory spatial attention capture,disengagement, and response selection in normal aging

Attention control is a core element of cognitive aging, but the specific mechanisms that differ with age are unclear. Here we used a novel auditory spatial attention task to evaluate stimulus processing at the level of early attention capture, later response selection, and the lingering effects of attention capture across trials in young and older adults. We found that the shapes of spatial attention capture gradients were remarkably similar in young and older adults, but only the older group had lingering effects of attention capture on the next trial. Response selection for stimulus-response incompatibilities took longer in older subjects, but primarily when attending to the midline location. The results suggest that the likelihood and spatial tuning of attention capture is comparable among groups, but once attention is captured, older subjects take longer to disengage. Age differences in response selection were supported, but may not be a general feature of cognitive aging.     

Spatial and non-spatial visual discrimination learning in zebrafish (Danio rerio)

Zebrafish (Danio rerio) provide an excellent model for assessment of molecular processes of neurodevelopment. To determine the functional importance of molecular events during neurodevelopment, we have developed methods for assessing learning in zebrafish in a three-chambered fish tank. In the first study, simple escape response was assessed. Zebrafish tested with a moving net learned to escape to another chamber more rapidly over the six sessions of training than the fish with the still net which did not learn. Upon reversal of the contingencies, the fish switched to the inactive net rapidly learned to suppress the escape response and fish formerly in the inactive net condition learned to avoid the moving net. In the second study, spatial discrimination learning was assessed. Zebrafish were trained on a right-left position discrimination to avoid the active net. Zebrafish showed significant improvement in escape responses over six sessions of training with three trials per session. In the third study, red-blue non-spatial discrimination learning was assessed. There was a significant improvement over the first six training sessions. With the reversal of contingencies, there was a significant decline of performance. With continued training, the fish again significantly improved avoidance. These studies found an effective motivational stimulus and procedure for studying escape behavior in zebrafish; a procedure whereby zebrafish would learn both spatial and non-spatial discrimination. These methods are being developed to help determine the functional importance of molecular events during zebrafish neurodevelopment. Accepted after revision: 20 August 2001 Electronic Publication     

A systems framework for understanding social settings

In this paper, we argue that attempts to change social settings have been hindered by lack of theoretical advances in understanding key aspects of social settings and how they work in a dynamic system. We present a systems framework for understanding youths' social settings. We focus on three aspects of settings that represent intervention targets: social processes (i.e., patterns of transactions between two or more people or groups of people), resources (i.e., human, economic, physical, temporal resources), and organization of resources (i.e., how resources are arranged and allocated). We postulate that these setting aspects are in dynamic transaction with each other, resulting in setting outcomes. Discussion focuses on the implications of our theoretical framework for setting intervention.     

Links among attachment dimensions, affect, the self, and perceived support for broadly generalized attachment styles and specific bonds

Measures of adult attachment reflect both respondents' broadly generalized styles as well as bonds with specific attachment figures. Using Cronbach, Gleser, Nanda, and Rajaratnam's (1972) Multivariate Generalizability analyses, the authors estimated the extent to which correlations among attachment, affect, the self, and perceived social support occurred for both styles and bonds. In two studies, participants rated attachment, affect, the self, and perceived support when thinking about their mothers, fathers, and romantic partners. In both studies, attachment dimensions reflected specific bonds much more so than generalized styles. When correlations reflected specific bonds, both anxious and avoidant dimensions were strongly linked to high negative affect, low positive affect, and low perceived support. In contrast, evidence for links between attachment and affect was inconclusive when correlations reflected generalized styles. Links between attachment and the self depended on the type of self-construct and whether styles or bonds were analyzed.     

Multilevel Modeling with Correlated Effects

When there exist omitted effects, measurement error, and/or simultaneity in multilevel models, explanatory variables may be correlated with random components, and standard estimation methods do not provide consistent estimates of model parameters. This paper introduces estimators that are consistent under such conditions. By employing generalized method of moments (GMM) estimation techniques in multilevel modeling, the authors present a series of estimators along a robust to efficient continuum. This continuum depends on the assumptions that the analyst makes regarding the extent of the correlated effects. It is shown that the GMM approach provides an overarching framework that encompasses well-known estimators such as fixed and random effects estimators and also provides more options. These GMM estimators can be expressed as instrumental variable (IV) estimators which enhances their interpretability. Moreover, by exploiting the hierarchical structure of the data, the current technique does not require additional variables unlike traditional IV methods. Further, statistical tests are developed to compare the different estimators. A simulation study examines the finite sample properties of the estimators and tests and confirms the theoretical order of the estimators with respect to their robustness and efficiency. It further shows that not only are regression coefficients biased, but variance components may be severely underestimated in the presence of correlated effects. Empirical standard errors are employed as they are less sensitive to correlated effects when compared to model-based standard errors. An example using student achievement data shows that GMM estimators can be effectively used in a search for the most efficient among unbiased estimators. This research was supported by the National Academy of Education/Spencer Foundation and the National Science Foundation, grant number SES-0436274. We thank the editor, associate editor, and referees for detailed feedback that helped improve the paper.     

Externalizing psychopathology and the error-related negativity

Prior research has demonstrated that antisocial behavior, substance-use disorders, and personality dimensions of aggression and impulsivity are indicators of a highly heritable underlying dimension of risk, labeled externalizing. Other work has shown that individual trait constructs within this psychopathology spectrum are associated with reduced self-monitoring, as reflected by amplitude of the error-related negativity (ERN) brain response. In this study of undergraduate subjects, reduced ERN amplitude was associated with higher scores on a self-report measure of the broad externalizing construct that links these various indicators. In addition, the ERN was associated with a response-locked increase in anterior theta (4-7 Hz) oscillation; like the ERN, this theta response to errors was reduced among high-externalizing individuals. These findings suggest that neurobiologically based deficits in endogenous action monitoring may underlie generalized risk for an array of impulse-control problems.     

Recognition of temporal patterns: from engineering to psychology and back again.

An overview is presented on research conducted in our lab to quantify the underlying principles behind the recognition of temporal patterns. We have been developing a theory based upon pattern matching and time-series analysis, which allows us to model and understand how humans recognize familiar patterns evolving over time and how performance degrades with noise. While our studies are primarily scientific in nature, the work has application beyond the elucidation of psychological and physiological mechanisms. We illustrate an application of these ideas to computer-based human identification through gait analysis. This study also illustrates a novel approach to interdisciplinary research by integrating experimental psychology with that of engineering design.     

Familiarization effects for bilingual letter detection involving translation or exact text repetition.

In two experiments, English-Spanish bilinguals read passages, performing letter detection on some passages by circling target letters as they read. Detection passages were sometimes familiarized (primed) by prior reading of the same passage or a translation of it. Participants detected letters in English passages in Experiment 1 and in Spanish passages in Experiment 2. For both experiments, a missing letter effect occurred (depressed detection accuracy on frequent function words relative to less frequent content words). Familiarization promoted overall improvements in letter detection only for English passages, suggesting that reprocessing benefits depend on high language fluency. For Spanish passages, cognates engendered greater error rates than noncognates; the visual similarity of Spanish and English cognates apparently enabled faster identification of Spanish cognates in a way unaffected by familiarization of the whole text passage. Priming by familiarized text was significantly higher when the passages were in the same language than when they were in different languages, suggesting that the reprocessing benefits are at the word level instead of the semantic level. These results are consistent with the GO model of reading (Greenberg, Healy, Koriat, & Kreiner, 2004) but require an expanded consideration of attention redistribution processes in that model.     

Improving reading outcomes for children with learning disabilities: using brief experimental analysis to develop parent-tutoring interventions

The present study assessed the effects of summer parent tutoring on 3 children with learning disabilities using empirically derived reading interventions. Brief experimental analyses were used to identify customized reading fluency interventions. Parents were trained to use the intervention strategies with their children. Parents implemented the procedures during parent-tutoring sessions at home and results were measured continuously in high-word-overlap and low-word-overlap passages to determine whether generalization occurred. Parent and child satisfaction with the procedures was assessed. Results demonstrated generalized increases in reading fluency in both high-word-overlap and low-word-overlap passages as a function of parent tutoring. Also, acceptability ratings by children and their parents indicated that they viewed the interventions as acceptable and effective. Results are discussed in terms of structuring reading fluency interventions that promote generalization and maintenance of treatment effects.