Cross-modal slant and curvature matching of stereo- and motion-induced surfaces

In many laboratory setups and in many day-to-day situations, a unique solution of the structure-fromtwo-views problem is unobtainable. Yet, when the visual system is presented with two projections in a sequence, it nevertheless appears to generate a reasonably stable percept of structure. In the research reported here, we examined whether the same surface would be perceived when subjects were presented with a pair of views that alternated in time monocularly (two-frame motion) or were shown simultaneously to both eyes (stereo). In Experiment 1, we studiedslant perception: human observers were asked to match the slant of a motion-induced planar surface with its stereo-induced counterpart. In Experiment 2, the perceivedcurvature of parabolic surfaces was matched in a similar way. The results show that motion-induced slant is matched with ahigher value of the stereo-induced slant. However, the curvature experiment showed that motion-induced curvature is matched with alower stereo-induced curvature. One possible explanation may be that the slant and curvature are internally inconsistent in at least one of the modalities.     

Self-Other and Third-person Anchored Modes of Thinking in Psychological Expertise: Cognitive Concomitants of Behaviourist,Client-centred,and Psychoanalytic Concepts

Information about people (A and B) can be processed consistent with two alternative modes of thinking: (1) an SO-mode conceiving of A and B as “self” versus “other,” and (2) a 3P-mode conceiving of A and B as “he/she called A” versus “he/she called B.” Previous research showed strong SO-anchoring biases in laypersons' thinking, so the present study focused on psychological experts' thinking. SO- and 3P-modes were associated with the formation of personalized and depersonalized representations of A and B respectively, so it was hypothesized that thinking in psychoanalytic terms would involve both modes, whereas the use of client-centred and behaviourist terms would trigger the SO- and the 3P-mode respectively. Data obtained from experts in psychotherapy confirmed the hypotheses except that the SO-mode was not less but more dominant in thought shaped in the behaviourist way than in thought shaped in the client-centred way. The results shed light on the role of scientific language and discourse as a general instrument of professional thought and communication.     

The Impact of Social Influences in the Context of Attitude,Self-Efficacy,Intention, and Previous Behavior as Predictors of Smoking Onset1

Three different constructs for measuring social influence were utilized in the present study to explain adolescents' present and future smoking behavior at 6 (T2), 12 (T3), and 18 months (T4) after the first test. Social influence was assessed by measuring the social norms, perceived smoking behavior, and direct pressure. The impact of the social influence constructs was also assessed in the context of broader models, including attitudes and self-efficacy expectations, intention, and previous behavior. The three social influence measures correlated significantly with intention and behavior. Stepwise regression analyses showed that perceived behavior and pressure made significant contributions, after entering social norms, in explaining actual and future adolescent smoking behavior. Adding attitudes and self-efficacy increased the predictive power of the model significantly. In agreement with the theory of Fishbein & Ajzen (1975), intention was the most powerful predictor in explaining present and future smoking behavior. Attitudes, self-efficacy, and the social influences also made small unique contributions improving the explanatory power by approximately 5%. Previous behavior, however, had a substantial unique contribution in predicting future behavior after attitudes, social influences, self-efficacy, and intention were entered in the equations. Since social influences may exert their impact via different routes, it is recommended that smoking prevention programs discuss not only overt pressures such as direct pressure from peers, parents, and media, but also address the more covert social pressures such as modeling and the adolescents' ability to cope with these covert influences. Furthermore, norms on nonsmoking should be made explicit.     

Examining Sex Differences in Altering Attitudes About Rape: A Test of the Elaboration Likelihood Model

This intervention sought to improve first-year college students' attitudes about rape. The Elaboration Likelihood Model (ELM) was used to examine men and women's attitude change processes. Both quantitative and qualitative methodologies were used to examine how men and women construed rape prevention messages. Results indicated numerous sex differences in the ways in which men and women experienced and changed during and after the rape prevention intervention. Women seemed to use more central-route attitude change processes and showed more lasting change from the intervention at 2-month follow-up, whereas men seemed to attend more to peripheral cues of the speaker and demonstrated more transient attitude change.     

Protein-binding assays for adrenocorticoids

The measurement of the adrenocortical hormones, Cortisol and corticosterone, m blood plasma has previously best been done by procedures employing varying degrees of purification of the hormone, followed by photometric or fluorimetric quantitation. These methods have been relatively difficult or laborious, particularly in the case of the procedures that most specifically measure the hormoneof intent. These limitations are considerably overcome by new assays for Cortisol and corticosterone based on the principle of competitive protein-binding of the steroids in the presence of radioactively labeled steroid of the same molecular species. These methods are described and data on the specificity of such a method for corticosterone are presented and compared with one of the better fluorimetric assays.     

Fixed-interval behavior maintained by conditioned reinforcement

The key-pecking of a pigeon was reinforced with grain on an 18-min second-order schedule. During the 18 min, a key peck which completed a 3-min fixed interval produced a stimulus of 0.5-sec duration. The first 3-min fixed interval completed after 18 min resulted in primary reinforcement. Behavior characteristic of fixed-interval schedules was produced on both the 3-min components and the 18-min schedule. This performance was shown to be enhanced whenever the 0.5-sec stimulus was also presented before the presentation of grain.     

Effect of sex education on the sexual and contraceptive practices of female teenagers in Mexico City

After reviewing the literature on the relationship between sex education and sexual and contraceptive behavior, the National Research Council (1987) recently concluded that the existing evaluation of the effects of sex education on sexual and contraceptive practice is helpful but not sufficient. 1 possible explanation for the different results obtained are the diverse sociodemographic characteristics of the sample(s) of teens under consideration. Another aspect which might account for the differences seen in the literature focuses on the areas covered in the course. In Mexico, no studies have been undertaken which deal with the relationship between sex education and sexual and contraceptive behaviors. A study carried out with 392 adolescent females ages 16-17 of lower and middle lower socioeconomic status showed that merely attending a sex education course did not affect the initiation or continuation of sexual activity, contraceptive behavior, or even the perception of accessibility to contraception. Providing information on sexuality, partner relationships, and where contraception can be obtained does not appear to have any effect on sexual activity. Receiving information on pregnancy prevention and obtaining contraceptives was found to be related to contraceptive use. Although less dramatic, information about partner relationships and sexuality produced increases in contraceptive use.