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891.
Equal-hue discriminability steps for the pigeon are shown as tabular entries that can be summed or interpolated to produce sequences of equal discriminability steps of various step size. Equal-hue discriminability sequences can be constructed where the number of stimuli and spectral range are specified, or where an interval in one spectral region is to be equated to an interval in another spectral region.  相似文献   
892.
Three negative reinforcement experiments employing a key-peck response are described. In Experiment I, pigeons shocked on the average of twice per minute (imposed condition) could produce, by pecking a key, an alternate condition with correlated stimuli. Delayed shocks were added, across sessions, to the alternate condition until pecking stopped. Two of three pigeons continued to peck despite a 100% increase in shock frequency. In Experiment II, pigeons were shocked in the imposed condition four times per minute. The postresponse delay to shock was held constant by delivering, in the alternate condition, the next shock, or the next two, three, or four shocks from the imposed-condition shock schedule. All three subjects continued to peck with no change in delay to the first two postresponse shocks but with a 75% reduction in shock frequency. In Experiment III, a response produced an immediate shock followed by a shock-free period. Three of four subjects continued to respond despite reduced delay to shock. Delay-to-shock or shock-frequency reduction was sufficient to maintain key pecking, but neither was necessary. The conditions that negatively reinforce the pigeon's key peck were similar to conditions that negatively reinforce the rat's bar press.  相似文献   
893.
Pigeons were exposed to two different reinforcement schedules under different stimulus conditions in each of two daily sessions separated by 6 hr (Experiments 1 and 2) or in a single session (Experiment 3). Following this, either a fixed-interval (Experiment 1) or a variable-interval schedule (Experiments 2 and 3) was effected in both stimulus conditions. In the first two experiments, exposure to fixed-ratio or differential-reinforcement-of-low-rate schedules led to response-rate, but not pattern, differences in subsequent performance on fixed- or variable-interval schedules that persisted for up to 60 sessions. The effects of reinforcement-schedule history on fixed-interval schedule performance generally were more persistent. In Experiment 3, a history of high and low response rates in different components of a multiple schedule resulted in subsequent response-rate differences under identical variable-interval schedules. Higher response rates initially occurred in the component previously correlated with high response rates. For 3 of 4 subjects, the differences persisted for 20 or more sessions. Previous demonstrations of behavioral history effects have been confined largely to between-subject comparisons. By contrast, the present results demonstrate strong behavioral effects of schedule histories under stimulus control within individual subjects.  相似文献   
894.
The effect of training on the rate of behavior-specific praise for two fourth-grade teachers was investigated within a multiple-baseline design. Training teachers to identify instances of behavior-specific praise on videotaped presentations (discrimination training) combined with instructions to use praise, and audiotape recordings of the teachers' classroom interactions as feedback, increased the rates of behavior-specific praise. However, the effects were restricted to subject-matter areas in which training was conducted.  相似文献   
895.
The hypothesis that parental alcoholism and co-occurring antisocial behavior would be indirectly linked to child externalizing behavior problems through child lack of control, current levels of parent depression, family conflict, and parent–child conflict was tested using manifest variable regression analysis. Participants were a community sample of 125 families with an alcoholic father and 83 ecologically matched but nonsubstance abusing families involved in the first 2 waves of an ongoing longitudinal study (with 3 years between each wave). All families had a biological son who was 3–5 years old at study onset. Results revealed that child lack of control mediated the relation between paternal alcoholism and the son's subsequent externalizing behavior problems. Family conflict was a significant mediator of maternal and paternal lifetime antisocial behavior effects and father–son conflict mediated paternal lifetime antisocial behavior effects. Study implications are discussed within the context of parental socialization of antisocial behavior.  相似文献   
896.
长期以来以专科划分为主的医疗发展方式确实促进了现代医学的进步.然而,人是一个整体不应该被割裂对待.所以,这种医学发展趋势应该加以控制,否则必然会阻碍医学事业的健康发展.另外,如果只关注局部治疗想要取得突破已经越来越难.因此,整合临床医学势在必行.本文分别从阻塞性睡眠呼吸暂停的病因、临床表现(包括合并症)及诊断和治疗三个方面阐述了只有全面进行医学整合才能提高阻塞性睡眠呼吸暂停的整体防控水平.  相似文献   
897.
为了更好地了解吉林省医务人员的吸烟状况,为进一步开展控烟工作提供科学依据,对吉林省50家医疗机构的3787名医务人员进行问卷调查,调查结果显示,男性医务人员吸烟率较高;医务人员对烟草危害认识不全面,控烟意识较为薄弱.应加强对医务人员烟害知识等方面的培训,以改变其吸烟行为、提高控烟责任意识.  相似文献   
898.
Poor upper-limb coordination is a common difficulty for children with developmental coordination disorder (DCD). One hypothesis is that deviant muscle timing in proximal muscle groups results in poor postural and movement control. The relationship between muscle timing, arm motion and children's upper-limb coordination deficits has not previously been studied. The aim of this study was to investigate the relationship between functional difficulties with upper-limb motor skills and neuromuscular components of postural stability and coordination. Sixty-four children aged 8-10 years, 32 with DCD and 32 without DCD, participated in the study. The study investigated timing of muscle activity and resultant arm movement during a rapid, voluntary, goal-directed arm movement. Results showed that compared to children without DCD, children with DCD took significantly longer to respond to visual signals and longer to complete the goal-directed movement. Children with DCD also demonstrated altered activity in postural muscles. In particular, shoulder muscles, except for serratus anterior, and posterior trunk muscles demonstrated early activation. Further, anterior trunk muscles demonstrated delayed activation. In children with DCD, anticipatory function was not present in three of the four anterior trunk muscles. These differences support the hypothesis that in children with DCD, altered postural muscle activity may contribute to poor proximal stability and consequently poor arm movement control when performing goal-directed movement. These results have educational and functional implications for children at school and during activities of daily living and leisure activities and for clinicians assessing and treating children with DCD.  相似文献   
899.
As an introduction to the special issue on neurocognitive factors underlying age effects, we discuss a number of recent developments in the literature on aging. The classic distinction between generalized and process-specific cognitive changes with old age has reappeared in the distinctions between the frontal lobe hypothesis and more differentiated views of neurocognitive aging. We argue that neurological decay in the frontal cortex has important implications for cognitive control, but that the frontal lobe hypothesis does not capture the plethora of changes that characterize aging and incorrectly suggests a unitary effect.  相似文献   
900.
This article examines the interrelationship between old age, professional power, and social policy. In particular, dominant theoretical models in social gerontology are reviewed and an alternative framework for understanding social gerontological issues—Foucauldian gerontology—is advanced. Foucauldian narratives are employed to delineate the historical relationship between professional social work and recent social policy for older people in the United Kingdom. In addition, a Foucauldian framework employed to examine identity formation, professional practices, and policy narratives enriches and widens the disciplinary subject matter of theorizing aging studies. The structure of this article is in three parts: review of theories of aging with an introduction of Foucault's potential contribution to gerontological analysis, the historical overview of the instigation of professional intervention in modernity and the changing roles and responsibilities in relation to older people utilizing Foucault's (1977) genealogical method, and the exploration and application of Foucault's key notion of governmentality (1977; Rose & Miller, 1992) in the analysis of social policy for older people.  相似文献   
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