Apparent contrast of suprathreshold gratings varies with stimulus orientation

Human contrast sensitivity is known to vary with both stimulus spatial frequency and orientation. Previous research has indicated, however, that the apparent contrast of a sinusoidal grating is independent of spatial frequency at suprathreshold levels. We have found that the apparent contrast of suprathreshold gratings is not independent of its orientation. Observers adjusted the apparent contrasts of vertical and oblique gratings to match a 40% standard. Contrast match deviations were found at a number of spatial frequencies, indicating a lack of contrast constancy with stimulus orientation. The apparent contrast of gratings in different orientations could not be predicted in any simple fashion from either contrast threshold differences or ratios.     

Variations in apparent spatial frequency with stimulus orientation: IL Matching data collected under normal and interferometric viewing conditions

Using an adjustment procedure, human observers matched the apparent spatial frequencies of sinusoidal gratings presented in different orientations (0, 45, 90, and 135 deg). Matches were made between all possible pairwise orientation combinations. Significant match deviations indicated that the apparent frequency of a grating depends on its orientation. The most consistent deviations were found between horizontal and vertical gratings, with horizontal gratings appearing to be of a lower spatial frequency than vertical gratings. These effects were relatively independent of stimulus contrast and persisted when the optics of the eye were bypassed with laser interferometry. A neurophysiological explanation of these effects is proposed.     

Factor structure of the Tennessee Self-Concept Scale for an institutionalized, disabled population

Separate factor analyses of responses to the Tennessee Self-concept Scale using item and scale data are reported for a sample of 255 disabled veterans. A global self-satisfaction factor and several subsidiary factors roughly approximate the external dimension of the scale. The internal dimension interacts with the external one in defining several factors but does not emerge as an independent dimension. Scale data yield a self-esteem factor incorporating both external and internal scales and a self-concept conflict-integration factor. The evidence supports the external dimension more than the internal dimension. The findings are consistent with previous studies that have not validated the two-dimensional design of the scale.     

Personality characteristics of the users of corporal punishment in the schools

The Rokeach Dogmatism Scale and the Eysenck Personality Questionnaire were correlated with educator-reported use of corporal punishment. Respondents were from a medium-size school system in Tennessee. Results indicated that closed-mindedness, as measured by the Rokeach scale, and Neuroticism, as measured by the Eysenck Scale, were highly correlated with reported use of corporal punishment. Of the remaining two dimensions of personality measured by the Eysenck questionnaire, Extraversion was found to be moderately correlated with reported use of corporal punishment while Psychoticism showed no significant relationship. A significant negative correlation was found between years of experience in teaching and use of corporal punishment. Frequency of physical punishment used on an educator when he/she was in grades K-12 was positively correlated with reported use of corporal punishment. Heavy users of corporal punishment tended to be relatively inexperienced, close-minded, neurotic, and impulsive as compared to their peers who did not use corporal punishment.     

Effects of d-amphetamine on self-aggression and posturing in stumptail macaques

The behavioral effects of d-amphetamine sulfate were studied in adult male stumptail macaques living within a large heterogeneous group in an outdoor enclosure. Among five subjects that received a range of doses (.01 to .3 mg/kg), d-amphetamine increased self-aggressive behavior and abnormal posturing in subjects that exhibited these types of behavior prior to drug administration, but it had no effect in subjects not exhibiting those activities in the absence of the drug. For the former subjects, the dose-effect curves for self-aggression were of an inverted U-shape analogous to the effect of d-amphetamine on schedule-controlled behavior. Over the range of doses studied, the curve for abnormal posturing was monotonic. The data indicate that d-amphetamine can have effects on untrained behavior in individual animals in a quasinatural environment that are qualitatively and quantitatively similar to the behavioral effects observed in other laboratory environments, and that d-amphetamine does not evoke or increase a behavioral response in individual subjects that do not exhibit the response in the absence of the drug.     

Empirical sleep assessment in the home: A convenient,inexpensive approach

We have previously reported on a sleep assessment device (SAD) that addresses shortcomings inherent in self-report sleep data and polysomnography. The SAD produces a sleep record by tape recording subjects' verbal responses to auditory cues spaced at fixed intervals throughout the night. In prior studies, the SAD proved to be a reliable and valid assessment tool according to electroencephalographic comparisons. Herein, we report on the unassisted home use of the SAD by eight normal volunteers and four bedmates. Subjects and bedmates completed sleep questionnaires for 12 nights and subjects also employed the SAD the last 6 nights. Comparisons of subjects and bedmates self-report sleep data before and during SAD use indicated that the SAD did not disrupt sleep. Subjects were able to self-administer successfully the SAD in their homes. SAD data closely matched subjects' self-report data. The present study found the SAD to be an accurate, unobtrusive, and easily utilized empirical measure of sleep in the natural environment. In so doing, it extends the demonstrated reliability and validity of the SAD from the sleep laboratory to the home with normal sleepers.     

Disentangling Type A behavior: The roles of ambition,insensitivity, and anxiety

This study identified stable components of Type A behavior as usually defined, and examined their relationships with more traditional psychological constructs. Overall scores on the most popular Type A measure (a version of the Jenkins Activity Survey) were moderately associated with ambition but largely unrelated to measures of adjustment. An item analysis yielded subcomponents of Drivenness and Involvement. Drivenness was unrelated to ambition, but was positively related to anxiety and negatively related to interpersonal perceptiveness. Involvement was positively related to ambition and to interpersonal competence. It is suggested that the Jenkins Activity Survey measures a heterogeneous mixture of constructive commitment and self-defeating responses that clouds its psychological interpretation.     

Two factors of restraint: concern for dieting and weight fluctuation

Factor analysis of the Restraint Scale produced two replicated factors: Concern for Dieting and Weight Fluctuation. Concern for Dieting reflects heightened attention to and emotional association with eating. Weight Fluctuation reflects extent of previously-experienced weight gain and loss. Weight Fluctuation was more highly positively correlated with indices of overweight status than was Concern for Dieting. Concern for Dieting was positively correlated with Public Self-Consciousness and Social Anxiety while Weight Fluctuation was not. Both versions of Restraint were weakly and inversely correlated with Body Image, although this relationship was mediated by degree of overweight status. The findings indicate that the two factors are sufficiently distinct to preclude combination into a single scale. Furthermore. Weight Fluctuation appears to be the more promising subscale for future research.