The placebo puzzle: putting together the pieces.

This article outlines and assesses the main theories of the placebo effect and suggests how they might sit together in a larger model of placebo etiology. Among the approaches considered are expectancy theory, emotional change theory, classical conditioning, and the biological approach. Although these are sometimes assumed to be competing models, in many cases they shed light on different pans of the placebo puzzle. Expectancies are the core of most placebo effects in human beings. The effects of expectancies are sometimes unmediated but in other cases are mediated by changes in emotional state, immune system function, perception, or behavior. Although expectancies are implicated in most placebo effects, a small number of placebo effects may be solely attributable to nonconscious contingency learning.     

Construct Validity and Reliability of Hartman's Color Code Personality Profile1

The three reliability and two construct validity studies presented here represent the first psychometric research on the commercially successful and popular Hartman Color Code Personality Profile. The reliability studies found high reliability after 3 and 6 weeks. The construct validity studies substantiated that the Color Code assesses some personality traits. The magnitude of the error variance suggests caution, however, in using the Color Code classifications at the individual level.     

Understanding the central processing limit in consistent-mapping visual search tasks

Effects of load (i.e., the number of stimuli in the display) have been observed in multiple-frame studies using a consistent mapping of stimuli to responses (e.g., Fisher, 1982, 1984). In a series of four experiments, it is shown that these effects are not the consequence of differences across the high- and low-load conditions in either decision noise or peripheral masking. Additionally, it is shown that of two modes of limited capacity (a limited-channel and divided-capacity model) considered as possible explanations of load effects in tasks where subjects are required to locate a target, only one--the limited-channel model--is consistent with the results from all three location tasks. Finally, it is argued that the limited-channel model predicts not only the behavior observed in the four consistent-mapping experiments reported in this article but also the behavior observed in several related consistent-mapping tasks (Kleiss & Lane, 1986; Shiffrin & Gardner, 1972).     

Mass media treatment of violence in sports and its effects

There appears to be a strong relationship between mass media portrayals of violence and real-life violence itself. This article reviews the available literature on the effects of media treatment of sports violence; analyzes the theoretical explanations for this treatment; and makes proposals on how the problems of both sports violence and its media coverage may be remedied, with a particular focus on amateur hockey in Canada.     

The association between teacher attitudes, behavioral intentions, and smoking and the prevalence of smoking among seventh-grade students.

Seventh-grade students and teachers from twenty-three middle and junior high schools were surveyed to determine the association between teacher attitudes, behavioral intentions, and smoking behavior and the prevalence of student smoking. Teacher attitudes toward smoking policies were found to be strongly related to the current smoking behavior of the teacher but not consistently related to student smoking. In addition, teacher likelihood of intervening showed a modest association with teacher smoking status, with current smokers generally indicating being the least likely to intervene for student possession or use of cigarettes. Teacher intentions to intervene were strongly associated with the prevalence of smoking among boys but not girls.     

Associative regulation of Pavlovian fear conditioning: unconditional stimulus intensity, incentive shifts, and latent inhibition.

Conditional stimuli (CS) associated with painful unconditional stimuli (US) produce a naloxone-reversible analgesia. The analgesia serves as a negative-feedback regulation of fear conditioning that can account for the impact of US intensity and CS predictiveness on Pavlovian fear conditioning. In Experiment 1 training under naloxone produced learning curves that approached the same high asymptote despite US intensity. Shifting drug treatment during acquisition had effects that paralleled US intensity shifts. In Experiment 3 naloxone reversed Hall-Pearce (1979) negative transfer using a contextual CS, indicating that conditional analgesia acquired during the CS-weak-footshock phase retards acquisition in the CS-strong-footshock phase. Experiment 5 used a tone CS in both a latent-inhibition and a negative-transfer procedure. Only negative transfer was blocked by naloxone. Therefore, negative transfer but not latent inhibition is mediated by a reduction of US processing.