Poison-based avoidance learning with flavored or colored water in guinea pigs

Guinea pigs were fed a solution which had a distinctive taste or appearance and one hr later were made sick by an intraperitoneal injection of lithium chloride. Upon recovery from the effects of sickness the animals in Expt 1 showed aversions to a weak tasting, sour solution or to a strong tasting, sweet solution. Animals in Expt 2 formed aversions to tap water which had been colored either red or blue while those in Expt 3 formed aversions to tap water which had been presented in either red or blue drinking tubes. When, however, sickness was not contingent upon drinking a distinctive solution there was no sign of decreased consumption of the test solutions. The differences between the outcome of the Expts 2 and 3 and those typically found with rats can be explained by the fact that guinea pigs appear to use both taste and visual cues in food selection whereas rats primarily use only gustatory cues. Since vision in the guinea pig is no more acute than vision in rats and substantially more limited than vision in other animals who have formed aversions to visual cues, the results of Expts 2 and 3 also suggest that the ability to form poison-based aversions to visual cues is not totally dependent upon a highly developed visual system.     

When what is said is important: A comparison of expert and attractive sources

Ninety-eight female subjects were presented with a statement made by an attractive or an expert source suggesting that people should sleep less than the usual eight hours. For approximately half of the subjects the source gave a simple statement of opinion, for the other half six separate supporting arguments were also presented. As predicted the manipulation of number of arguments provided had more influence on the effectiveness of the expert than the attractive source. Results were interpreted as supporting the hypothesis that quite different dynamics underly the persuasive power of attractive and expert individuals.     

Subjective duration: A functional measurement analysis

Subjects judged the total duration of two intervals of time that varied from 0 to 30 sec. The data obeyed the parallelism prediction of a simple weighted adding model. According to functional measurement methodology, this observed parallelism provides joint support for the adding model and for the assumption that the graphic rating response provides a valid interval scale. Furthermore, parallelism allowed construction of the psychophysical time function. The obtained function was essentially linear in the range 0-30 sec. This result is compared with results of previous studies, with particular regard to the method of fractionation. The usefulness of establishing a validated interval response measure for further studies of time perception was pointed out.     

Signal frequency and shock probability as determinants of prolonged vigilance performance in rhesus monkeys

The effects of changing signal frequency on a prolonged vigilance task were investigated by systematically increasing the average inter-trial interval between successive signals. During a 6-hr watch, vigilance performance remained constant when the rate of signal presentation was 40, 20, and 10 per hour. When the rate of signal presentation was reduced to 7 or 4 per hour, marked decrements in detection performance were observed. Similar vigilance decrements occurred when the average rate of signals per hour was kept constant (10 per hour) and the probability of receiving a shock for missing a signal was systematically varied. The results of this study indicate the importance of reinforcement factors in the control and maintenance of vigilance performance.     

President paragraphs

A collection of 220 paragraphs of graded value about U.S. presidents is given. The collection includes 16 paragraphs about each of nine presidents and 8 paragraphs about each of eight presidents. For each president, the paragraphs have one of four rough values for judgments of statesmanship, H, M⁺, M^-, and L. These paragraphs have proved useful in experimental applications of integration theory to attitude change. Other advantages of U.S. history as a source of issues and material for research on attitudes are also pointed out.     

Averaging model applied to the size-weight illusion

A theoretical model was given for the size-weight illusion based on a principle of information integration. Judged heaviness of lifted weights was assumed to be an average of two pieces of information, weight and size, with the latter receiving negative weighting in the model formulation. Two experiments based on a Weight by Size design gave fair support to the parallelism prediction of the integration model. The hypothesis that Ss were really judging density was shown to imply a divergence prediction, contrary to the data. The theoretical analysis was generalized to include negative, positive, and comparative illusions; these were differentiated according to whether the contextual information was integrated with negative weighting, positive weighting, or served as a yardstick of judgment.     

The relation between sample and population characteristic vectors

Data are reported which show the statistical relation between the sample and population characteristic vectors of correlation matrices with squared multiple correlations as communality estimates. Sampling fluctuations were found to relate only to differences in the square roots of characteristic roots and to sample size. A principle for determining the number of factors to rotate and interpret after rotation is suggested.This study was supported by the National Science Foundation, Grant GB 4230. The author wishes to express his appreciation for the use of Western Data Processing Center and the Health Sciences Computing Facility, UCLA. He also thanks Dr. Roger Pennell for extremely valuable assistance in a number of phases of the study.     

Self-Presentation,Reasoned Action,and Adolescents' Decisions to Smoke Cigarettes1

The effectiveness of a one-shot intervention on the social, medical or medical/social consequences of smoking in deterring adolescent smoking was evaluated. Four hundred twenty adolescents completed surveys which measured attitudes, subjective norms, stereotypes, self-presentational beliefs regarding smoking, intentions to smoke, and smoking status at three points in time. The predictive ability of a Theory of Reasoned Behavior and of Impression Management Theory in determining adolescent smoking decisions was also assessed.