Elevation and reduction of plasma tryptophan and their effects on aggression and perceptual sensitivity in normal males

Data from experimental animals suggest that 5-hydroxytryptamine (5HT) may have an inhibitory effect on aggression, while clinical studies have found a correlation between pathological aggression and low brain 5HT. To investigate this relationship further we used amino acid mixtures designed to raise or lower the levels of the 5HT precursor, tryptophan. Normal male subjects were given tryptophan-depleted, balanced, or tryptophan-supplemented ammo acid mixtures and tested for aggression 5 hours later. The balanced amino acid mixture served as a control for the tryptophan depletion and supplementation. Testing for aggression was done using the Buss paradigm in which subjects deliver electric shocks to a (nonexistent) partner in response to stimulus tones. Duration and intensity of shock delivered were the measures of aggression, while responsivity to the stimulus tones was the measure of perceptual sensitivity. Neither tryptophan supplementation nor tryptophan depletion had any effect on these measures of aggression or perceptual sensitivity. We conclude that raising or lowering the synthesis of brain 5HT through alterations in tryptophan availability does not influence aggression in normal males as measured by the Buss task.     

Configural biases and reversible figures: evidence of multilevel grouping effects

Four experiments sought to identify the processes underlying 2 classes of grouping effects that are readily produced with a hierarchical figure type known as ambiguous triangles. Previous work has shown that aligning small equilateral triangles in particular configurations can both facilitate and interfere with observers' ability to report the pointing direction of the individual triangles. We determined that selectively adapting the observer to low-frequency gratings of the same orientation as the aligned triangles markedly altered the interfering and facilitative effects of the global configuration only when an accuracy measure of performance was used. When a response latency measure was used, no effect of the same adaptation condition was found. Results are discussed in terms of multiple levels of grouping effects in the visual system and the differential sensitivity of these levels to basic neural adaptation.     

The impact of communal-mastery versus self-mastery on emotional outcomes during stressful conditions: a prospective study of Native American women

Past research has examined the stress resiliency of individuals high in sense of personal-mastery. However, it has been theorized that within more collectivist cultures, a sense of shared efficacy, which we call communal-mastery, may be more central to people's resiliency in the face of challenging life circumstances. We compared the impact of sense of self-mastery (i.e., I am the key to my success) to that of communal-mastery (i.e., I am successful by virtue of my social attachments) in a prospective study among a group of rural 103 Native American women residing on Indian Reservations in Montana. We found that women high in communal-mastery experienced less increase in depressive mood and anger, especially when faced with high stress circumstances, than women who were low in communal-mastery. In addition, the beneficial impact of communal-mastery was found to be more effective than self-mastery for these women.     

Attending to the big picture: mood and global versus local processing of visual information

Two experiments employed image-based tasks to test the hypothesis that happier moods promote a greater focus on the forest and sadder moods a greater focus on the trees. The hypothesis was based on the idea that in task situations, affective cues may be experienced as task-relevant information, which then influences global versus local attention. Using a serial-reproduction paradigm, Experiment 1 showed that individuals in sad moods were less likely than those in happier moods to use an accessible global concept to guide attempts to reproduce a drawing from memory. Experiment 2 investigated the same hypothesis by assessing the use of global and local attributes to classify geometric figures. As predicted, individuals in sad moods were less likely than those in happier moods to classify figures on the basis of global features.     

Anxiety-related bias in the classification of emotionally ambiguous facial expressions

High- and low-trait socially anxious individuals classified the emotional expressions of photographic quality continua of interpolated ("morphed") facial images that were derived from combining 6 basic prototype emotional expressions to various degrees, with the 2 adjacent emotions arranged in an emotion hexagon. When fear was 1 of the 2 component emotions, the high-trait group displayed enhanced sensitivity for fear. In a 2nd experiment where a mood manipulation was incorporated, again, the high-trait group exhibited enhanced sensitivity for fear. The low-trait group was sensitive for happiness in the control condition. The mood-manipulated group had increased sensitivity for anger expressions, and trait anxiety did not moderate these effects. Interpretations of the results related to the classification of fearful expressions are discussed.     

Attributional Style, Self-Esteem, and Human Immunodeficiency Virus: A Test of the Hopelessness and Self-Esteem Theories of Depression

Research on the hopelessness and self-esteem theories of depression (Abramson, Metalsky, & Alloy, 1989; Metalsky, Joiner, Hardin, & Abramson, 1993) suggests that HIV-infected persons with depressotypic attributional style (AS) and low self-esteem (SE) may be at risk for onset of a syndrome referred to as hopelessness depression (HD). In a prospective study conducted to test these theories, measures of anxiety and depression, AS, and SE were administered to 85 HIV+ and 43 HIV– men; symptoms were reassessed 6 months later. Results indicated that: (1) The interaction of AS, SE, and HIV status predicted change in HD symptoms, but not overall depression or anxiety symptoms; (2) HIV+ men with depressotypic AS and high SE had increased HD symptom levels while other men with high SE had decreased HD symptom levels; (3) HD symptoms remained stable over the 6-month interval among men with low SE; and (4) High SE predicted decreases in anxiety symptoms among HIV– men, but not among HIV+ men. Contrary to the study hypothesis, these findings suggest that among individuals with life-threatening illnesses such as HIV infection, those with depressotypic AS and high SE may be at highest risk for onset of HD.     

Sexual deviations as conditioned behaviour: A hypothesis

While it has been frequently suggested that sexual deviations are learned, the learning has usually been thought of as taking place during one traumatic experience. From a study of 45 sexual deviants, the authors believe that it is often a much more gradual process occurring during masturbation to a memory, which need not have been sexually stimulating at the time of the initial experience and which often alters with the passage of time. The hypothesis is illustrated from case histories of pedophilia, exhibitionism, homosexuality, voyeurism and transvestism. The implications for both aversive treatment of deviations and positive conditioning to normal sex are considered.     

Evaluating fidelity: predictive validity for a measure of competent adherence to the Oregon model of parent management training

When efficacious interventions are implemented in real-world conditions, it is important to evaluate whether or not the programs are practiced as intended. This article presents the Fidelity of Implementation Rating System (FIMP), an observation-based measure assessing competent adherence to the Oregon model of Parent Management Training (PMTO). FIMP evaluates 5 dimensions of competent adherence to PMTO (i.e., knowledge, structure, teaching skill, clinical skill, and overall effectiveness) specified in the intervention model. Predictive validity for FIMP was evaluated with a subsample of stepfamilies participating in a preventive PMTO intervention. As hypothesized, high FIMP ratings predicted change in observed parenting practices from baseline to 12 months. The rigor and scope of adherence measures are discussed.