The aftermath of 9/11: effect of intensity and recency of trauma on outcome

Does trauma exposure have a long-term impact on the brain and behavior of healthy individuals? The authors used functional magnetic resonance imaging to assess the impact of proximity to the disaster of September 11, 2001, on amygdala function in 22 healthy adults. More than three years after the terrorist attacks, bilateral amygdala activity in response to viewing fearful faces compared to calm ones was higher in people who were within 1.5 miles of the World Trade Center on 9/11, relative to those who were living more than 200 miles away (all were living in the New York metropolitan area at time of scan). This activity mediated the relationship between group status and current symptoms of posttraumatic stress disorder. In turn, the effect of group status on both amygdala activation (fearful vs. calm faces) and current symptoms was statistically explained by time since worst trauma in lifetime and intensity of worst trauma, as indicated by reported symptoms at time of the trauma. These data are consistent with a model of heightened amygdala reactivity following high-intensity trauma exposure, with relatively slow recovery.     

Activity, Passivity, Self-Denigration, and Self-Promotion: Toward an Interactionist Model of Interpersonal Dependency

ABSTRACT Although dependency in adults is inextricably linked with passivity and submissiveness in the minds of many theoreticians, clinicians, and researchers, evidence has accumulated which suggests that in certain situations, dependency is actually associated with high levels of activity and assertiveness. Three experiments were conducted to test the hypothesis that when a dependent person is concerned primarily with getting along with a peer, he or she will “self-denigrate” (i.e., will utilize strategies that ensure that a peer will be evaluated more positively than he or she is on a laboratory task), but when a dependent person is concerned primarily with pleasing an authority figure, he or she will “self-promote” (i.e., will adopt strategies that increase the likelihood that he or she will be evaluated more positively than a peer on a laboratory task). This hypothesis was supported in all three experiments. Theoretical implications of these findings are discussed, and an interactionist model of interpersonal dependency is briefly described.     

Manual Movement in Sign Languages: One Hand Versus Two in Communicating Shapes

In sign languages, the task of communicating a shape involves drawing in the air with one moving hand (Method One) or two (Method Two). Since the movement path is iconic, method choice might be based on the shape. In the present studies we aimed to determine whether geometric properties motivate method choice. In a study of 17 deaf signers from six countries, the strongest predictors of method choice were whether the shape has any curved edges (Method One), and whether the shape is symmetrical across the Y‐axis (Method Two), where the default was Method One. In a second study of ASL dictionary entries for which the movement path of the sign is iconic of an entity's shape, the same predictors surfaced. These tendencies are captured in the Lexical Drawing Principle, which is coherent with biological constraints on movement in general. Drawing in the air with two hands, however, is costly, both cognitively and biomechanically. Furthermore, it distinguishes signers from non‐signers, who draw shapes with only one hand. Signers assume this extra cost in the lexicon because of the enhanced iconicity the possibility of two hands offers; they assume it in drawing shapes in the air because they apply the same linguistic principle they use in the lexicon. Additionally, having a choice of methods allows the signer to benefit from over‐specification in providing redundant information about the shape, enhancing comprehensibility and resolving ambiguity.     

Semantic memory retrieval: Deadlining the typicality effect

Corbett and Wickelgren (1978), employing a speed-accuracy tradeoff method for verifying category membership, found that while the estimated strength of the category-instance association was higher for category examples given more frequently as instances of the category (i.e. higher instance dominance), retrieval dynamics did not vary across levels of instance dominance. The Corbett and Wickelgren data challenged the claims of models of speeded sentence verification that postulated differences in the retrieval processes of high- and low-dominance category-instance associations (e.g. Smith, Shoben, & Rips, 1974). We argued that Corbett and Wickelgren very probably used category instances of debatable membership status in their low-instance dominance category examples, thus making it impossible to decide which responses to these items were correct. This, in turn, rendered their low-instance dominance data uninterpretable. Two partial replications of the Corbett and Wickelgren study were carried out, each with four subjects, and 10 variable lags between the stimulus presentation and the response signal. When care was taken that each category instance clearly belonged to its respective category, an estimate of the rate at which information accumulated towards its asymptote was greater for high-dominance, high-typicality items than for low-dominance, medium-typicality items. However, there were no dominance or typicality differences in the estimates of this asymptotic strength. In contrast, in the study in which low-dominance, low-typicality items were of questionable category membership, the results were similar to those obtained by Corbett and Wickelgren. These data support the idea that there is a continuous accumulation of information in the semantic memory sentence verification task.