The perception of multiple simultaneously presented forms as a function of foveal spacing

Using five capital letters as the form stimuli and tachistoscopic presentation, an exposure duration was determined for each S that yielded 80% identification accuracy when single letter displays were presented. Then the increment in exposure duration necessary for a correct identification of all letters on a display on 80% of the trials was determined for 2, 3, and 4 letter displays. In view of evidence that perceptual independence breaks down when stimuli are spaced much closer than 1° apart in the fovea, the effect of different foveal spacing of the form stimuli in the display was studied. Spacings of 1/2, 3/4, and 1° of angle were employed. Less than a 30% increment in exposure duration was necessary to recognize 2 form displays at the same accuracy level as single form. But no further increase in exposure duration was necessary to recognize 3 and 4 form displays at the same accuracy criterion. Evidence for positive correlation of sensory perceptual error for forms spaced less than 1° apart in the fovea was found.     

Psychosocial Predictors of Young Adolescent Cigarette Smoking: A Sixteen-Month,Three-Wave Longitudinal Study1

Understanding the psychosocial factors that predict cigarette smoking onset in young people is of crucial importance for prevention efforts. The present study examined prospective psychosocial predictors of smoking in a three-wave longitudinal data set. Similar in design to an earlier study by Chassin, Presson, Sherman, Corty, and Olshavsky (1984), the present study replicated their work, and extended it by (a) using composite predictors derived from exploratory factor analysis, (b) including prior behavior as a predictor, (c) using a design extended over three waves of data collection, and (d) using a sample composed primarily of urban teenagers. Subjects were 3295 7th-grade students at the beginning of the study. The subjects completed a questionnaire containing items tapping cigarette smoking behavior and psychosocial items that have previously been shown to predict smoking behavior. Forty-one psychosocial items on the Wave 1 (initial) questionnaire were factor analyzed, and five factors were retained. Subscale scores were constructed based on these factors and were used as predictors. Regression analyses were performed using the subscales and pretest smoking frequency to predict a continuous measure of smoking, and discriminant analyses were performed to predict transitions between qualitative levels of smoking. Prior smoking behavior was the most important predictor of future smoking. Four of the subscales, Social Disapproval, Risk Taking/Rebelliousness, Perceived Smoking Prevalence, and Motivation to Comply, were significant predictors. One subscale, Physical Consequences from Smoking, was not predictive of smoking in any of the analyses. The effect sizes cross-validated well. It is suggested that an integrative model of smoking initiation developed by Flay, d'Avernas, Best, Kersell, and Ryan (1983) best summarizes the results of the present study.     

Axiomatic foundations of a three-set guttman simplex model with applicability to longitudinal data

In this paper the usual two-set Guttman simplex model is extended to three sets. The axiomatic foundations of this extention are presented. Two cases are discussed. In Case 1 there is a three-set joint order, while in Case 2 there is a two-set joint order consistent across all levels of the third set. Case 2 represents the first clear formulation of a longitudinal developmental scale. The model is discussed in terms of its most straightforward application, longitudinal developmental data, and in terms of other possible applications.This research was supported in part by NSF grant BNS 8108145.     

Cigarette smoking and chewing gum: response to a laboratory-induced stressor.

The current study examined the anxiolytic effects of cigarette smoking and chewing gum on urge to smoke, withdrawal, and anxiety in response to a public speaking task in 45 undergraduate smokers. Participants were asked to smoke, chew gum, or do nothing in response to the stressor. Participants completed measures of anxiety, withdrawal symptoms, and urge to smoke pre- and poststressor. The smoke group reported fewer urges to smoke pre- and poststressor than the other groups. The smoke and gum groups reported fewer withdrawal symptoms than did the control group poststressor. Chewing gum was helpful in managing levels of withdrawal symptoms compared with the control group. Groups did not differ on measures of anxiety. Results suggest that smoking in response to a stressor may not reduce levels of affective stress. Furthermore, chewing gum may be helpful in managing withdrawal symptoms in response to a stressor.