Individual Differences in Diving: Intelligence,Personality, and Underwater Adaptation

Diving is an activity that is carried out in an extreme environment with extraordinary psychophysical demands. It requires the divers to undergo an adaptive process in order to survive, to be able to take advantage of their capabilities, and to achieve an efficient performance. In this ex post facto study, data from a sample of military personnel participating in scuba diving courses (N = 649) were analyzed. Our aim was to verify the role of individual differences in the adaptation to an extreme and hostile environment. The results indicate the existence of psychological variables that differentiate between divers and the general population, those who pass or fail the diving course, and between groups of divers who obtain differential levels of performance in underwater tasks. These findings support that dispositional characteristics have utility for the identification of suitable personnel for professional diving.     

Theoretical trajectories: Dreams and dreaming from Freud to Bion

This paper aims at comparing Freud's and Bion's conceptual models on dreams and dreaming. Beyond both authors’ shared disposition vis‐à‐vis problems posed by knowledge, a critical gap opens regarding their differing clinical practices. It is hypothesized that their ideas do not belong to irreconcilable paradigms, but that there are continuities besides discontinuities more frequently highlighted between Freudian statements on psychic functioning – described in his theory on dreams – and Bion's findings in his development of both the original theory and the connections between dreaming and thinking. Firstly, Freud's and Bion's epistemological sources are examined as well as their creative use and historical environment. Then certain general theoretical and clinical issues are considered concerning their theories on dreams, the evolution of their ideas and corresponding clinical contexts. In a third section, their confluences and dissimilarities are dealt with, including clinical vignettes belonging to the authors to illustrate their interpretative modes of working. This is meant to show both an implicit theoretical–clinical complementarity and the fact that, though their routes bifurcate about the function of dreams, there remain connecting paths. Lastly, the final remarks review certain issues that have frequently been controversial between these lines of thought.     

Microstimulation reveals opposing influences of prelimbic and infralimbic cortex on the expression of conditioned fear

Recent studies using lesion, infusion, and unit-recording techniques suggest that the infralimbic (IL) subregion of medial prefrontal cortex (mPFC) is necessary for the inhibition of conditioned fear following extinction. Brief microstimulation of IL paired with conditioned tones, designed to mimic neuronal tone responses, reduces the expression of conditioned fear to the tone. In the present study we used microstimulation to investigate the role of additional mPFC subregions: the prelimbic (PL), dorsal anterior cingulate (ACd), and medial precentral (PrCm) cortices in the expression and extinction of conditioned fear. These are tone-responsive areas that have been implicated in both acquisition and extinction of conditioned fear. In contrast to IL, microstimulation of PL increased the expression of conditioned fear and prevented extinction. Microstimulation of ACd and PrCm had no effect. Under low-footshock conditions (to avoid ceiling levels of freezing), microstimulation of PL and IL had opposite effects, respectively increasing and decreasing freezing to the conditioned tone. We suggest that PL excites amygdala output and IL inhibits amygdala output, providing a mechanism for bidirectional modulation of fear expression.     

Histamine enhances inhibitory avoidance memory consolidation through a H2 receptor-dependent mechanism

Several evidences suggest that brain histamine is involved in memory consolidation but the actual contribution of the hippocampal histaminergic system to this process remains controversial. Here, we show that when infused into the CA1 region of the dorsal hippocampus immediately after training in an inhibitory avoidance task, but not later, histamine induced a dose-dependent promnesic effect without altering locomotor activity, exploratory behavior, anxiety state or retrieval of the avoidance response. The facilitatory effect of intra-CA1 histamine was mimicked by the histamine N-methyltransferase inhibitor SKF-91844 as well as by the H2 receptor agonist dimaprit and it was blocked completely by the H2 receptor antagonist ranitidine. Conversely, the promnesic action of histamine was unaffected by the H1 receptor antagonist pyrilamine, the H3 receptor antagonist, thioperamide, and the NMDAr polyamine-binding site antagonist ifenprodil. By themselves, ranitidine, pyrilamine, thioperamide, and ifenprodil did not affect IA memory consolidation. Our data indicate that, when given into CA1, histamine enhances memory consolidation through a mechanism that involves activation of H2 receptors; however, endogenous CA1 histamine does not seem to participate in the consolidation of IA memory at least at the post-training times analyzed.     

Exploring Asian American racial identity

In this study the authors used cluster analysis to create racial identity profiles for a sample of Asian Americans using the People of Color Racial Identity Attitudes Scale (PCRIAS). A four-cluster solution was chosen: each cluster corresponded to one PCRIAS subscale and was named accordingly. Scores on the Asian American Racism-Related Stress Inventory and the Color-Blind Racial Attitudes Scale were compared across clusters. As expected, the Dissonance and Immersion clusters were characterized by relatively high racism-related stress and low levels of color-blind attitudes; the Conformity cluster showed roughly the opposite pattern. Surprisingly, the Internalization cluster showed a pattern similar to that for Conformity and thus may reflect "pseudoindependence" as discussed by Helms.     

Dependency in consumer media relations: an application to the case of teleshopping

• This paper analyses the teleshopping issue in terms of the Media Dependency Theory. The objective is to verify whether dependency relations between television shoppers and the television medium and television shopping are key variables to explain watching and buying behaviour. A model is proposed that integrates the dependency‐viewing‐purchase relation, tested on a sample of Spanish television shoppers. The results of the study confirm the direct relationship between the antecedents of dependency, dependency and future intentions of behaviour.

Copyright © 2006 John Wiley & Sons, Ltd.     

Goal orientation, motivational climate, and dispositional flow of high school students engaged in extracurricular physical activity

The purpose of this study was to examine the role of goal orientation, motivational climate, and dispositional flow in physical education lessons on extracurricular involvement in physical activity. Questionnaires were administered to 1,103 (792 athletes; 311 nonathletes) secondary school students (M age = 14.3 yr., SD = 0.7). Analysis showed significant mean differences between groups on goal orientation and dispositional flow in physical education lessons, but none for perception of motivational climate. These findings suggest that dispositional variables are related to extracurricular involvement in physical activity.