Implications of measurement of eye fixations for a psychophysics of form perception

It was suggested that insights into feature analysis of processes involved in form identification might be gained from an analysis of eye movements made by Ss as they identified patterns. Fixations were measured during identifications of histoforms, polygons, and Vargus 10 figures. Eye fixations were measured, and Ss rated sections of the figures in terms of their importance. Eye fixations were measured in terms of number of changes and duration of fixations. The number of changes in fixation were found to reflect only individual differences. Duration of fixation was found to vary significantly with location within figures, with fixations being longest where changes of contour occurred. There was also a tendency to look longer at the top of polygons and Vargus 10 figures and at the center of histoforms. Ratings of importance were highest for sections of figures fixated for longer duration-generally areas in which changes of contour were present.     

Basic objects in natural categories

Categorizations which humans make of the concrete world are not arbitrary but highly determined. In taxonomies of concrete objects, there is one level of abstraction at which the most basic category cuts are made. Basic categories are those which carry the most information, possess the highest category cue validity, and are, thus, the most differentiated from one another. The four experiments of Part I define basic objects by demonstrating that in taxonomies of common concrete nouns in English based on class inclusion, basic objects are the most inclusive categories whose members: (a) possess significant numbers of attributes in common, (b) have motor programs which are similar to one another, (c) have similar shapes, and (d) can be identified from averaged shapes of members of the class. The eight experiments of Part II explore implications of the structure of categories. Basic objects are shown to be the most inclusive categories for which a concrete image of the category as a whole can be formed, to be the first categorizations made during perception of the environment, to be the earliest categories sorted and earliest named by children, and to be the categories most codable, most coded, and most necessary in language.     

A note on the use of A′ as a measure of sensitivity

The use of A′, a nonparametric measure of sensitivity in tests of recognition memory, is discussed. In particular, two formulas for computing A′ are considered. One formula, which was reported in a recent paper by Berch (1975), should be used only when the observed hit rate is greater than or equal to the false alarm rate. A second formula is presented for computing A′ when the hit rate is less than the false alarm rate.     

On the development of national attitudes in children

The present study consists of three related experiments which are concerned with the development of national attitudes in children between the ages of seven and twelve. It was predicted on the basis of a structural interpretation of Allport's three-stage developmental theory of prejudice that national attitudes will increase at first due to increasing consistency of judgment and decrease afterwards due to cognitive differentiation. The hypothesis is partially confirmed with respect to the attitudes of children towards other countries but not confirmed with respect to the attitudes of children towards people who are perceived as foreigners. A tentative explanation is offered for the last finding. It was shown moreover that the attitudes of older children display more cognitive balance than those of younger children. In connection with the last problem, a quantified modification Bf Heider's theory of balanced states was introduced.     

Hue discrimination as a function of stimulus luminance

The relation between hue discrimination and stimulus luminance was investigated. It was found that discrimination was best at the highest luminance and deteriorated at the lowest, except in the yellow region.     

Assessing the effects of factors that might underlie the differential perception of acquaintance and stranger rape

There is evidence to suggest that in an acquaintance rape the victim is perceived less favorably and there is more leniency toward the perpetrator than in a stranger rape. The purpose of the present study was to assess the perceptual effects of factors that might underlie this differential perception. Victim-perpetrator attraction and ambiguity in victim's desire for intercourse were varied since both are often perceived to occur at a much higher frequency in acquaintance rape than stranger rape. The design of the study was a 3 (victim-perpetrator attraction — minimal, moderate, maximal) × 2 (ambiguity in desire for intercourse — ambiguous, relatively unambiguous) × 2 (gender of subject — male, female) factorial. The results indicated that ambiguity had a significant effect on perceptions. More specifically, perception tended to be less favorable toward the victim and more lenient toward the defendant when there was ambiguity in the victim's desire for intercourse. Additionally, when compared to females, males' perception tended to be less favorable toward the victim and more lenient toward the perpetrator. There were no other significant main effects or interactions. The implications of these findings for the differential perception of acquaintance and stranger rape are discussed.     

Risk taking as a predictor of adolescent sexual activity and use of contraception

A hypothesis of high-risk behaviors associated with adolescent sexual activity and lack of contraceptive use was tested in a longitudinal random sample of both male and female youths. The data were part of the Rutgers Health and Human Development Project. 1380 subjects were ascertained by random telephone calling were given self-report questionnaires and personality profiles including the Zuckerman's Sensation Seeking Scale, and Jackson's Personality Research Form in 1979 and 1981. Incidence of sexual activity and use of contraceptives increased with age from age 12-21. Cohort effects were apparent with use of some contraceptive methods. Of the variables indicating risk- taking, disinhibition, impulsivity and experience seeking, there were significant associations between sexual activity and disinhibition and experience seeking, for females. There were no significant associations between these variables and sexual activity in males. Contrary to the hypothesis, there were no relationships between either consistency of birth control use or reliability of the method used and behavioral indicators of risk-taking. Thus this 1st study in the field that included both males and females from the general population, as opposed to college students, found that sexually active adolescents were higher risk-takers than virgins, but no relationship between risk-taking and effectiveness of contraception was observed.