Visual perception of surface curvature: psychophysics of curvature detection induced by motion parallax

The continuous approach to optic-flow processing shows that the curvature of a moving surface is related to a second spatial derivative of the velocity field, the spin variation (Droulez & Cornilleau-Pérès, 1989). With this approach as a theoretical framework, visual sensitivity to the curvature of a cylinder in motion was measured using a task of discrimination between cylindrical and planar patches. The results confirm the predictions suggested by the theory: (1) Sensitivity to curvature was always greater when the cylinder axis and the frontal translation were parallel than when they were orthogonal. The ratio of curvature detection thresholds in the two cases was between 1.3 and 2.5; the value predicted from the spin variation theory is about 2. (2) Sensitivity to curvature increased strongly with the velocity of the motion but was only weakly affected by its amplitude and the duration of viewing for the range of values used in our experiments.     

Relationship of testosterone to men's family functioning at mid-life: A research note

Sociobiological theory suggests that aggression coupled with altruism is highly adaptive for males in all social systems, including the family, whereas sex-role convergence theory indicates that lower levels of aggression are most adaptive for men, particularly at mid-life. The purpose of this study was to determine the role that testosterone, as a proxy for aggression, plays as an adaptive mechanism in the lives of middle-aged males. The sample used in this study consisted of 37 middle-aged (39–50 years of age) males employed in professional occupations in a midwestern metropolitan area. Testosterone levels were regressed on factors typically found to be related to male satisfaction with family life at mid-life: marital satisfaction, parent-adolescent communication, amount of emotional expressiveness, and androgynous characteristics; recent positive and negative stressors and trait anxiety were statistically controlled. Results of step-wise multiple regression analysis indicated that low levels of testosterone were significantly (R = .34, P < .01) related to enhanced marital and parental relationships and androgynous behaviors; however, emotional expressiveness was significantly related to high levels of testosterone.     

Electronic language: A study of word processing by emotionally disturbed children and adolescents in residential treatment

The word-processing language use of a small group of severely emotionally disturbed children and adolescents was compared with their handwritten productions. A content analysis based on a total sample of 4,112 words was performed to explore the thematic and structrual language differences between the two writing modes. The findings indicate that the computer-mediated writing tended to improve some aspects of thematic expression, while the handwritten mode was preferable for certain structural characteristics.     

APPARENT COVARIATION BETWEEN CHILD HABIT DISORDERS: EFFECTS OF SUCCESSFUL TREATMENT FOR THUMB SUCKING ON UNTARGETED CHRONIC HAIR PULLING

We evaluated the effects of aversive taste treatment of thumb sucking on untreated trichotillomania (habitual hair pulling) in two children who chronically pulled their hair and sucked their thumbs. A combination of withdrawal and nonconcurrent multiple baseline designs showed that, concomitant with the successful treatment of thumb sucking, hair pulling was also eliminated. The results suggest an efficient method for changing behaviors that are difficult to treat directly.     

Juvenile homicide: The need for an interdisciplinary approach

Most of the empirical literature on juvenile homicide has emerged from the clinical experience of mental health professionals who have diagnosed and/or treated youngsters who killed. After a critical review of this literature, data on 787 juvenile homicide offenders are presented and discussed. These data indicate that intrafamilial killings represent but a small fraction of all homicides perpetrated by juveniles and that there are clear differences between intrafamilial and extrafamilial juvenile homicides.     

Testing the limits of the phonetic mnemonic system

Three experiments tested the efficacy of the phonetic mnemonic system under varying conditions of application. The first study attempted unsuccessfully to replicate and extend the work of Morris and Greer (1984), who had shown training in the phonetic mnemonic method to facilitate memorization of a serial list of two-digit numbers. In the present study, subjects trained in the phonetic mnemonic method failed to learn lists of two-, four-, and six-digit numbers better than control subjects. The second experiment partially replicated the first, the differences being that training in the phonetic mnemonic method was strengthened, and time allotted for number recall was extended. Under these circumstances the phonetic mnemonic group recalled the two-, four-, and six-digit numbers significantly better than the control groups, a finding conforming with Morris and Greer's (1984) results. The third experiment partially replicated the second, everything being the same except that, in this case, subjects constructed their own key words representing each number, instead of these words being supplied by the experimenter. Under these conditions, subjects trained in the phonetic mnemonic method recalled significantly fewer numbers than control subjects.     

TESTICULAR SELF-EXAMINATION: VALIDATION OF A TRAINING STRATEGY FOR EARLY CANCER DETECTION

Testicular self-examination (TSE) can lead to early diagnosis and treatment of testicular cancer, the third leading cause of death in young men. We evaluated the effectiveness of a brief and specific checklist for teaching TSE skills. Ten men were videotaped while performing testicular self-examinations before and after training. The TSE training resulted in large and significant increases in the number of TSE steps completed and duration of the TSE. Two urological validation measures supported the improvements observed in the mens' self-examinations. Subjects reported continued performance of TSE during a follow-up telephone interview. This pilot study indicates that a brief and specific checklist is an effective strategy for teaching early cancer detection skills.     

Factor structure of the Lorr and More assertiveness inventory

Previous research among university students has identified four classes of assertive behavior, namely, Directiveness, Social Assertiveness, Defense of One's Rights and Interests and Independence. Scores on the Lorr and More (1980) Assertiveness Inventory, obtained from a general population sample, were subjected to Varimax rotatio. Results revealed only three classes of assertiveness. It is argued that Directiveness may be inferred from various forms of assertiveness, rather than being a separate and distinct class of assertive behavior.