The effect of two schedules of primary and conditioned reinforcement

Of 23 pigeons, 11 received continuous reinforcement for key pecking, and 12 received an FR 10 schedule of reinforcement. The birds were then tested without food, but with potential conditioned reinforcers presented either on the same schedule as in training, on the other schedule, or not at all. Each bird in the subgroup trained on CRF and tested with S^r's at FR 10 not only gave more responses in testing than did each bird in both subgroups receiving no S^r's, but also gave more responses than did each bird in the S^r subgroup receiving CRF training and S^r's at CRF. Cumulative records are presented to show the effects of different schedules of conditioned reinforcers.     

The importance of inhalation volume when measuring smoking behavior

Theoretical and technical considerations of measuring puff and inhalation volumes during cigarette smoking are reviewed. Measures of smoking behavior using a flowmeter and inductance plethysmography are described and demonstrated with seven subjects smoking over a 3-to 4-h period. Puff volume and duration, inhaled volume and duration, interpuff and intercigarette interval, and number of puffs varied for each individual over the session. The ratio of puff volume to inhaled volume changed with successive cigarettes. Smokers adjust the concentration of smoke by blending air with the smoke. Thus, to completely characterize smoking behavior, the volume of smoke and air inhaled into the lungs must be measured directly.     

One-trial overshadowing

Two experiments on conditioned suppression in rats examined the extent to which conditioning to a tone was overshadowed by the presence of a light. When animals received four conditioning trials, a light of moderate intensity significantly overshadowed the tone. On the first trial of conditioning, however, the light had no effect on conditioning to the tone, unless (Experiment I) its intensity was increased, or (Experiment II) it occurred in closer temporal contiguity to reinforcement than the tone. The results establish that overshadowing can occur on the first trial of conditioning, contrary to the predictions of several theories, but suggest that this may be for different reasons from those operating to produce overshadowing over a series of conditioning trials.     

The Role of Families and Care Givers as Risk and Protective Factors in Preventing Youth Violence

This paper reviews research which discusses the risk and protective functions that families and other caregivers provide in influencing the development of aggressive behavior in youth. Currently, there is an emphasis on providing violence prevention programs in the school environment, typically with little parental or caregiver involvement. By enhancing the role of families and caregivers in youth violence prevention programs, we assert that an unique opportunity exists to both address specific risk factors for violence while enhancing the protective features of the family. Relatedly, the risk literature on youth violence indicates that the most influential risk factors (i.e., the family, community, and peers) have their principle impact on youth aggression outside the school. We suggest a shift in the focus of violence prevention programming that is more inclusive of families as both a risk and protective agent. In support of this position, relevant theory and reviews of exemplary family-involved programs are offered. Challenges to involving youth caregivers are identified and recommendations for overcoming those challenges suggested. Last, recommendations for future research and public policy in the prevention of youth violence are offered.     

略论《周易》对中国古代历法的影响--兼与李申先生商榷

在古代历法的发展过程中,<周易>起了积极的作用,而且这种作用在不同时期有着不同的特征.早期主要表现为用易数解释历数,这种作用在唐以后逐渐消失;"卦气说"曾在一段时期内被作为历法的内容;而<周易>的"治历明时"思想对于历法研究一直起着积极的作用,成为重要的治历原则之一.无论如何,<周易>对于古代历法发展的作用是不可低估的.     

Practical Memory Concerns of Older Adults

We examine practical memory concerns in a sample of community-dwelling older adults. Participants responded to open-ended questions that were designed to solicit information regarding memory self-efficacy, memory management, memory remediation, and fears about memory aging in adulthood. Results indicated that (a) important dates, such as birthdays and anniversaries, were easily remembered, but names were not; (b) external memory aids were used most frequently; (c) a desire to improve memory for names and certain types of verbal information was expressed; and (d) loss of independence emerged as a fear associated with memory aging. Implications of these findings for the design of strategies to improve everyday memory performance and clinical memory management in older adults are discussed.