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201.
In recent years the developmental implications of menarche have garnered particular attention. Investigators have determined that this developmental event tends to affect three significant domains of the adolescent girl's function: psychological status, relationships with peers, and role in the family. This paper explores these issues and introduces a new technique, referred to as previewing, that may help the teenage girl acclimate to the status of sexual maturity. Derived from the early life interactions of caregiver and infant, previewing promotes representational skills and enhances self-esteem as the adolescent confronts developmental challenges.  相似文献   
202.
In the mid 1980s it was apparent that the need for organ donors exceeded those willing to donate. Some University of Pittsburgh Medical Center (UPMC) physicians initiated discussion of possible new organ donor categories including individuals pronounced dead by traditional cardiac criteria. However, they reached no conclusion and dropped the discussion. In the late 1980s and the early 1990s, four cases arose in which dying patients or their families requested organ donation following the elective removal of mechanical ventilation. Controversy surrounding these cases precipitated open discussion of the use of organ donors pronounced dead on the basis of cardiac criteria. Prolonged deliberations by many committees in the absence of precedent ultimately resulted in what is, to our knowledge, the country's first policy for organ donation following elective removal of life support. The policy is intricate and conservative. Care was taken to include as many interested parties as possible in an effort to achieve representative and broad based support. This paper describes the development of the UPMC policy on non-heart-beating organ donation.  相似文献   
203.
Previous studies of infants’ ability to integrate and to utilize relative motion as information for form in the absence of structural cues have primarily involved motions that are uniform in rate, direction, and path within the form to be constructed. In the present study, we examined infants’ ability to integrate relative motion information from motions that are nonuniform along these dimensions, and from this integrative process to construct a coherently rotating two-dimensional form. Infants’ ability to integrate nonuniform motion was measured with regard to their ability to discriminate the rotating form from a noncoherent control display containing the same absolute motions. The results showed that discrimination of the coherent and incoherent displays was not demonstrated until 7 months of age. Two additional experiments were conducted to rule out the possibility that this discrimination was based on the detection of local regions of coherence, rather than the perception of the global rotating form. In both experiments, the results did not support discrimination based exclusively on local cues alone. From the combined results of all three experiments, we conclude that infants demonstrate the capacity to integrate the information contained within nonuniform trajectories into a coherent structure by 7 months of age.  相似文献   
204.
The concept of systemic quantization of behavior was used to study the interaction between dominant motivation and reinforcement on brain neurons. Feeding and escape were used as experimental models. Results showed that feeding and escape motivations are based on the mechanisms of ascending activating influences of lateral or ventromedial hypothalamic centers, respectively, on cortical neurons. Feeding and escape motivations evoked by electrical stimulation of hypothalamus, or the ones occurring naturally, modify the responses of single neurons of sensorimotor and insular cortex to sensory stimuli, to microiontophoretic application of neurotransmitters and neuropeptides, and especially to reinforcement. Dominant motivations are reflected in the burst-like activity and in a specific pattern of interpulse intervals of single units in various brain structures. Reinforcement transforms this activity into a regular pattern and also changes the neuronal responses of hypothalamic feeding and escape centers, to electrical stimulation and to microiontophoretic application of oligopeptides. Specific patterns of the unit responses to conditioned stimuli in the course of consecutive reinforcement was determined. After several instances of reinforcement, especially after repetitive reinforcement, the brain neurons influenced by the dominant motivation begin to produce specific protein molecules that are important for organization of an appropriate type of behavior. This process can be blocked by protein synthesis inhibitors.  相似文献   
205.
ABSTRACT The just noticeable difference (jnd) unit of classical psycho-physics is introduced as a new way to describe accuracy and agreement in observer evaluations of personality. A formula for estimating jnd's from typically available summary statistics is derived from Thurstone's law of comparative judgment. A study examining four traits judged in 10 samples of subjects where the design permitted the calculation of jnd's by the method of paired comparisons indicated that the formula predicted the empirically derived jnd's associated with the mean judge ratings with considerable precision. Jnd's of criterion measures were also predicted, and while fit was somewhat less impressive in this case, there was still appreciable convergence between predicted and empirical values. The implications of jnd measures of agreement and accuracy are discussed. These implications include (a) possibilities for increased understanding of bias in observer judgments, (b) a new recognition that equal correlations to external criteria do not necessarily imply equal accuracy, and (c) alternative ways of describing the magnitude of effect in psychological research.  相似文献   
206.
A criterion of adequacy is proposed for theories of relevant consequence. According to the criterion, scientists whose deductive reasoning is limited to some proposed subset of the standard consequence relation must not thereby suffer a reduction in scientific competence. A simple theory of relevant consequence is introduced and shown to satisfy the criterion with respect to a formally defined paradigm of empirical inquiry.Research support was provided by the Office of Naval Research under contract No. N00014-89-J-1725 to Osherson and Weinstein, Swiss National Science Foundation under contract No. 21-32399.91 and by a Siemens Corporation grant to Osherson.  相似文献   
207.
208.
Six-hundred-fifty-one citizens were stopped in public places and tested for prompted recall of physical characteristics of a young woman to whom they had spoken for approximately 15 s, 2 min earlier. Recall differed as a function of the two targets used on five of eight characteristics, but no significant differences were found for either target as a function of the gender or age group of the witnesses. Young adults (18-29 years of age) in general were superior to middle-aged adults (30-44), who in turn were superior to older adults (45-65). Women were significantly more accurate than men in accuracy of recall for weight, and for characteristics judged to be more important than less important for person memory. Male and female witnesses were equally confident in their recall performance. Young and middle-aged groups were significantly more confident in recall than the oldest group. Significant correlations were found between confidence and accuracy of recall for men and for women, and for each age group. Women made significantly longer duration estimates of the encounters with the targets than did men. Men overestimated the duration by a 2:1 ratio, and women overestimated by a 3:1 ratio. No significant correlations were found between accuracy of duration estimates and confidence in reports. The results were interpreted in terms of their forensic importance.  相似文献   
209.
This paper prospectively examined relations between marital status, predivorce parenting practices, and children's adjustment, using data from the New York Longitudinal Study (NYLS). Prospective analyses of children's predivorce adjustment indicated that neither boys nor girls showed more problematic behavior prior to parental separation, and only boys had more difficulties after divorce. However, parents of to-be-divorced families reported more difficulties in childcare practices before divorce than did parents of always-married families. Parenting difficulties in to-be-divorced families were found consistently for boys but not for girls. Results suggest that the difficulties found among boys after divorce may be linked with parenting problems that begin before divorce.The authors are indebted to Alexander Thomas and Stella Chess, the original investigators of the project. We also would like to thank Jacqueline and Richard Lerner, and the John D. and Catherine MacArthur Foundation for their efforts in preserving this data base.  相似文献   
210.
Twenty-six infants, 3 to 23 months old, were trained on fixed-interval schedules ranging from 10 s to 80 s. The operant response was touching an illuminated location on a touch-sensitive screen, and 20 s of cartoon presentation was the reinforcer. The subjects were also trained in a six-phase self-control procedure in which the critical phases involved choice between 20 s of cartoon available after a 0.5-s delay (impulsive choice) and 40 s of cartoon delayed for 40 s (self-controlled choice). All the youngest children (3 to 5 months) showed long postreinforcement pauses on the fixed-interval schedule, with most intervals involving the emission of a single, reinforced, response, and all made self-controlled choices. Older subjects (9 to 23 months) either produced the same pattern as the younger ones on the fixed-interval schedule (classified as pause-sensitive subjects) or produced short pauses and higher steady response rates (classified as pause-insensitive subjects). All pause-sensitive subjects made self-controlled choices in the self-control condition, and all pause-insensitive subjects made impulsive ones.  相似文献   
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