Calculation of additional heart rates using oxygen consumption and carbon dioxide production: A comparative analysis

Research, to date, on the occurrence of additional heart rates during behavioral stressors has employed oxygen consumption as the index of metabolic activity. Although this is the obvious first choice, in certain situations measures of carbon dioxide production may be more readily obtained. The analysis presented in this paper explored the intuitively appealing notion that, since oxygen consumption and carbon dioxide production are themselves intimately related, carbon-dioxide-production measures may also be appropriate in the “additional heart rate” methodology. Data from the most recent additional-heart-rate paper by Turner and colleagues were thus reexamined, and additional heart rates during mental arithmetic and a video game were separately calculated for the 24 subjects by first using oxygen consumption and then by using carbon dioxide production. The values obtained were very highly correlated; the coefficients for the task: periods themselves were 0.99 and 0.96, respectively. Use of carbon-dioxide-production data-in this manner would, therefore, seem to be appropriate.     

Novelty Seeking and Reward: Implications for the Study of High-Risk Behaviors

Novelty seeking and sensation seeking are constructs useful in predicting human risk-taking behaviors. This predictive relation purportedly reflects some rewarding aspect of experiencing novelty. Research has confirmed this assumption. Rats display an increase in preference for an environment that has been differentially paired with novel stimuli. The physiological mechanisms mediating this rewarding effect of novelty involve the neurotransmitter dopamine, whereas those controlling novelty seeking do not. The mechanisms involved in drug seeking and reward show parallel dissociations. This concordance between novelty and drug-abuse research suggests that novelty and drug stimuli may interact in biologically and behaviorally meaningful ways. Indeed, preliminary research examining cocaine and novelty and published work with amphetamines support this suggestion. There is clear need for further systematic research on novelty reward and related processes at all levels of analysis: genetic, biological, behavioral, and social.     

Effects of Violent Versus Nonviolent Video Games on Children's Arousal, Aggressive Mood, and Positive Mood

This study investigated the relationship between violent video games and children's mood. A total of 71 children aged 8 to 12 years played a paper-and-pencil game, a nonviolent video game, and a violent video game. Results indicate that arousal, as measured by heart rate and self-reported arousal, increased significantly after playing the violent video game, as compared with the other two game conditions, with girls reporting more arousal than did boys. There was no significant increase in aggressive mood scores for either boys or girls after playing the violent game. Positive mood, as measured by positive affect, showed no significant increases or decreases after playing either video game. However, positive mood, as measured by general mood, showed a significant increase after playing the violent game for both boys and girls, but only as compared with the paper-and-pencil game. Results are interpreted in terms of social learning and cognitive information processing theories of aggression.     

Using the memory activation capture (MAC) procedure to investigate the temporal dynamics of hypothesis generation

Research investigating top-down capture has demonstrated a coupling of working memory content with attention and eye movements. By capitalizing on this relationship, we have developed a novel methodology, called the memory activation capture (MAC) procedure, for measuring the dynamics of working memory content supporting complex cognitive tasks (e.g., decision making, problem solving). The MAC procedure employs briefly presented visual arrays containing task-relevant information at critical points in a task. By observing which items are preferentially fixated, we gain a measure of working memory content as the task evolves through time. The efficacy of the MAC procedure was demonstrated in a dynamic hypothesis generation task in which some of its advantages over existing methods for measuring changes in the contents of working memory over time are highlighted. In two experiments, the MAC procedure was able to detect the hypothesis that was retrieved and placed into working memory. Moreover, the results from Experiment 2 suggest a two-stage process following hypothesis retrieval, whereby the hypothesis undergoes a brief period of heightened activation before entering a lower activation state in which it is maintained for output. The results of both experiments are of additional general interest, as they represent the first demonstrations of top-down capture driven by participant-established WM content retrieved from long-term memory.     

Sensation seeking, impulsive decision-making, and risky sex: implications for risk-taking and design of interventions

In an HIV prevention study, 2949 ninth-grade students in 17 high schools in two Midwestern U.S. cities were administered scales measuring sensation seeking and impulsive decision-making and their separate and combined relationships to a number of indicators of sexual risk-taking. Measures of sexual risk-taking included intentions to have sex, ever had sex, number of lifetime sexual partners, been pregnant or caused a pregnancy, used a condom, used marijuana, had unwanted sex when drunk, had unwanted sex under pressure, said no to sex, used alcohol or partner used alcohol before sex. Strong associations were observed between each of the measures and sexual risk-taking for most of the indicators. Strongest associations were found among sexually active students high on both sensation seeking and impulsive decision-making and weakest associations among students low on both measures. Implications for design of interventions in health campaigns are discussed.     

Evaluation of an evolutionary model of self-preservation and self-destruction.

According to deCatanzaro's mathematical model of self-preservation and self-destruction, staying alive actually may reduce inclusive fitness for an individual who is low in reproductive potential and, at the same time, poses such a burden to close kin that it costs them opportunities for reproduction. Predictions generated from this model were tested using 175 university students as subjects and variables constructed from a 164-item questionnaire. The criterion variables were separate measures of depression, hopelessness, and suicide ideation and behavior. The predictor variables derived from the model were separate measures of reproductive potential of the individual, the individual's perceived benefit or cost to kin, and reproductive potential of the individual's kin. As predicted, there were negative and significant bivariate correlations between each of the model-generated predictor variables and one or more of the criterion variables. Multiple regression analyses showed that benefit to kin was the best predictor of both depression and hopelessness. Discriminant analysis showed that reproductive potential of kin significantly differentiated suicide attempters from nonattempters. Overall, our results support and extend deCatanzaro's model and empirical findings.