Domestic chicks perceive stereokinetic illusions

Stereokinetic illusions occur when certain 2-D patterns are set in slow rotation in a plane perpendicular to the line of sight. Such phenomena have never been investigated in animal species other than our own. We used the domestic chick (Gallus gallus) to check whether these illusions are experienced by non-human species, taking advantage of filial imprinting. Newly hatched visually naive chicks were individually exposed for 4 h to 2-D stimuli producing, to a human observer, the perception of a stereokinetic cone (experiment 1) or of a stereokinetic cylinder (experiment 2). Thereafter, each chick underwent a free-choice test between a solid 3-D cone and a solid 3-D cylinder. A control group of newly hatched but not imprinted chicks underwent the same testing procedure, to check for the presence of any spontaneous preference for one or other of the two solid objects. Imprinted chicks approached the 3-D stimulus closely resembling the stimulus they had been exposed to during imprinting (the cone in experiment 1 and the cylinder in experiment 2). Non-imprinted chicks did not show any preference. These results suggest that domestic chicks experience stereokinetic illusions.     

Predictive Testing of Eighteen Year Olds: Counseling Challenges

Genetic counseling of teenagers is challenging and complex. The ability to think abstractly, a sense of self and independence from family all develop during adolescence. Predictive genetic testing counseling protocols presuppose that these qualities exist, requiring the at-risk individual to consider the short and long term consequences of testing as well as their motivations. Eighteen year olds are in transition from adolescence to adulthood; eligible for predictive genetic testing, they may not yet be independent of their family or able to articulate their feelings. This paper presents case studies from the authors' clinical practice to illustrate some of the difficulties faced by genetic counselors when 18 year olds request predictive testing for Hereditary Non-Polyposis Colorectal Cancer. By reflecting upon their experiences with these young adults and their families, the authors' intention is to generate discussion about genetic counseling strategies, particularly for predictive genetic testing, that are both age-appropriate and family-sensitive.     

A Comparison of Phonological Awareness Skills in Early French Immersion and English Children

This 2-year study examined the effects of early second language exposure on phonological awareness skills. Syllable, onset-rime and phoneme awareness skills of 72 anglophone children attending English or French immersion programs in primary and grade 1 were investigated. Three-way mixed ANOVAS revealed the following effects and interactions. In terms of grade effect, grade 1 students performed significantly better than primary students on phoneme and onset-rime tasks. A stimulus language effect was observed for the three levels of phonological awareness. All children performed better on English tasks than on French ones. Interaction effects of stimulus language by program were revealed for phoneme as well as syllable tasks. Posthoc analyses revealed that French students performed better on English phoneme and syllable tasks than on French, while English students performed better than French immersion students on French syllable tasks. Correlational analyses revealed significant relationships between reading and phoneme and onset-rime phonological awareness tasks regardless of program of instruction (English, French immersion) or language of reading test (English, French). Syllable awareness was only significantly correlated with the French non-word reading task for the French immersion students.     

Simultaneous multiple stressors in the environment: physiological stress reactions, performance, and stress evaluation

Interactive effects of two environmental stressors when simultaneous ly present, i.e., noise and crowding, were analyzed. Four experimental conditions with two intensities of stress for each stressor (high versus low) were created. The stressors were concurrently introduced in laboratory conditions and their effects analyzed using several methodological approaches. More intense and negative effects were expected when the two highest intensities of noise and crowding concurred. 40 people (20 men and 20 women) participated in a study with a 2 x 2 factorial design. Analysis showed an increase in the measures of hemodynamic, endocrine, and neuroendocrine values of participants after being exposed simultaneously to noise and crowding. Similarly, their performance on complex tasks decreased, and they reported a subjective increase in stress. Capacity to cope was indicated by a statistically significant lower mean on the Dimension of Stress scale, tolerance of frustration during the multiple stress condition.     

Ethics of research involving mandatory drug testing of high school athletes in Oregon

There is consensus that children have questionable decisional capacity and, therefore, in general a parent or a guardian must give permission to enroll a child in a research study. Moreover, freedom from duress and coercion, the cardinal rule in research involving adults, is even more important for children. This principle is embodied prominently in the Nuremberg Code (1947) and is embodied in various federal human research protection regulations. In a program named "SATURN" (Student Athletic Testing Using Random Notification), each school in the Oregon public-school system may implement a mandatory drug-testing program for high school student athletes. A prospective study to identify drug use among student-athletes, SATURN is designed both to evaluate the influence of random drug testing and to validate the survey data through identification of individuals who do not report drug use. The enrollment of students in the drug-testing study is a requirement for playing a school sport. In addition to the coercive nature of this study design, there were ethically questionable practices in recruitment, informed consent, and confidentiality. This article concerns the question of whether research can be conducted with high school students in conjunction with a mandatory drug-testing program, while adhering to prevailing ethical standards regarding human-subjects research and specifically the participation of children in research.     

The influence of contrast and spatial factors in the perceived shape of boundaries

When an edge can be perceived to continue either with a collinear edge of the opposite contrast polarity or with a noncollinear edge of the same contrast polarity, observers perceive an alignment between the edges of the same contrast polarity, even though they are noncollinear. Using several stimulus configurations and both free and tachistoscopic viewing, we studied the luminance and spatial factors affecting the perceived distortion and binding. The results showed that the two noncollinear edges tended to align when they had the same contrast polarity (Experiment 1A) and to misalign when they had opposite contrast polarity (Experiment 2), providing that (1) they were separated by a distance larger than 1 arcmin and smaller than 3-4 arcmin (for all configurations) and (2) they laterally overlapped for about 7 arcmin (Experiment 1B). The results also showed that the direction of apparent distortion depended on the direction of overlapping. The results of Experiment 3 ruled out the local attraction/repulsion explanation but, instead, supported the suggestion that the interaction concerned the global edges, or part of them, and produced an inward tilt, which made the edges of the same contrast polarity perceptually to align, or an outward tilt, so that the edges of opposite contrast polarity were perceived to be more misaligned. From the overlap and distance limits found, it can be inferred that for two noncollinear contours to join perceptually, the tilt must not exceed 18 degrees, a limit compatible with the orientation bandwidth of contrast-sensitive early cortical mechanisms.     

Self-esteem,race, and job satisfaction

The present study investigated relationships between self-esteem (SE) and job satisfaction among black and white employees. The sample consisted of 523 (45% black) employees of a large, urban school system. There was a positive relationship between SE and job satisfaction for members of both racial groups. In addition, the correlation between need satisfaction and job satisfaction was stronger for high SE persons than for low SE persons. The relationships between two social reference variables (the perceived satisfaction of other employees and improved standard of living) and job satisfaction were, as predicted, stronger for low SE whites than for high SE whites. Among blacks, however, the social reference variables were strongly related to job satisfaction regardless of level of SE.