The National Institutes of Health (NIH) State-Of-the-Science Conference on Preventing Violence and Related Health-Risking Social Behaviors in Adolescents — A Commentary

Although youth in the United States remain substantially more violent than adolescents and young adults in most industrial countries, the National Institutes of Health's (NIH) State-of-the-Science Conference on Preventing Violence and Related Health-Risking Social Behaviors in Adolescents identified many reasons for optimism about our capacity to develop effective prevention and intervention responses. The research is getting better and contrary to popular opinion we do know a lot about what does work. Future advances will depend upon our insistence on the use of effectiveness evidence and the development of a taxonomy which will facilitate cross disciplinary communication.     

Knowledge is not everything: analysis of children's performance on a haptic comparison task

The relative effects of developmental level and domain-specific knowledge on children's ability to identify and make similarity decisions about object concepts based only on haptic (touch) information were investigated. Children aged 4-9 years with varying levels of dinosaur knowledge completed a cross-comparison task in which they haptically explored pairs of familiar (dinosaur) and unfamiliar (sea creature) models that varied in terms of their degree of differentiability. Older children explored models more exhaustively, found more differentiating features and consequently made fewer errors than younger children did. High knowledge enabled children to identify models correctly, but was also associated with the use of a hypothesis testing strategy, which led children to make greater numbers of "miss" errors on the cross-comparison task. Performance in the control domain illustrated that the hypothesis testing strategy was specific to the high knowledge domain. Potential explanations for the role of knowledge and development in haptic exploration are considered.     

Emotion-modulated performance and activity in left dorsolateral prefrontal cortex

Functional MRI (fMRI) was used to examine the relationship between processing of pleasant and unpleasant stimuli and activity in prefrontal cortex. Twenty volunteers identified the colors in which pleasant, neutral, and unpleasant words were printed. Pleasant words prompted more activity bilaterally in dorsolateral prefrontal cortex (DLPFC) than did unpleasant words. In addition, pleasant words prompted more activity in left than in right DLPFC. Response speed to pleasant words was correlated with DLPFC activity. These data directly link positive affect, enhanced performance, and prefrontal activity, providing some of the first fMRI evidence supporting models of emotional valence and frontal brain asymmetry based on electroencephalography (EEG).     

Neural correlates of evaluation associated with promotion and prevention regulatory focus

Higgins (1997, 1998) proposed two self-regulatory or motivational systems—one sensitive to gains (promotion) and one sensitive to losses (prevention). To examine the interaction of motivation and cognition, participants made good/bad or abstract/concrete judgments about concepts during fMRI scanning. After scanning, participants rated the extent to which each stimulus was good and bad and completed a questionnaire that measured promotion/prevention orientation. For each participant, contrast maps were generated representing the association between neural processing and stimulus valence (good/bad), and these factors were then regressed against participants’ promotion and prevention focus scores. For the good/bad but not for the abstract/concrete task, promotion focus was associated with greater activity in the amygdala, anterior cingulate, and extrastriate cortex for positive stimuli, and prevention focus was associated with activity in the same regions for negative stimuli; these results are consistent with the hypothesis that the way in which evaluative information is processed is influenced by individual differences in self-regulatory focus.     

Two-digit comparison: decomposed, holistic, or hybrid?

We investigate whether two-digit numbers are decomposed for purposes of numerical comparison (e.g., choosing the larger one). Earlier theorists concluded that numbers are processed holistically (Brysbaert, 1995; Dehaene, Dupoux, & Mehler, 1990), or that holistic and decomposed processes operate in parallel (Nuerk, Weger, & Willmes, 2001). In the present experiment, we presented pairs of two-digit numbers with a decade distance of either zero (e.g., 54-57) or one (54-61). If a holistic process contributes to two-digit comparison, there should be an overall distance effect for number pairs with a decade distance of one. On the other hand, if numbers are decomposed and a holistic comparison does not contribute, this overall distance effect should be absent for these number pairs. Evidence is found that, at least in the present task settings, numbers are not compared holistically. The results are interpreted in terms of a recently proposed theory of numerical cognition (Verguts & Fias, 2004; Verguts, Fias, & Stevens, in press).