Exploring the within-person coupling of sleep and cognition in older African Americans

This study examined the within-person relationship between sleep and cognitive functioning. Fifty community-dwelling African Americans (age range = 50-80 years) were asked to report their sleep duration and quality the previous evening and to complete cognitive measures over 8 occasions within a 2-3 week period. A within-person daily change in sleep duration was significantly associated with worse global cognitive performance. The greater an individual deviated away from his or her average sleep duration on a particular day, the more likely his or her performance would decline. These results demonstrate that the sleep-cognition relationship can be observed at a within-person level of analysis.     

Prompt Density,Rate of Reinforcement,and the Persistence of Manding

The Psychological Record - Previous research has documented the effects of prompting mands at a relatively high rate (i.e., rich schedule) or low rate (i.e., lean schedule). These previous studies...     

Analysis of appetitive motivation in preweanling rats: application of bromocryptine mesylate

Two experiments investigated discrimination learning with preweanling rats (Rattus norvegicus) following different experimental deprivation treatments. In Experiment 1, 10- to 11-day-old Sprague-Dawley rats were deprived for 24 h of either nutrients and maternal contact through placement in an incubator or only nutrients by placement in the nest of a bromocryptine mesylate-treated dam. Bromocryptine mesylate inhibits prolactin release and thereby prevents lactation with only minimal effect on maternal behaviors. After the deprivation period, pups were trained to perform a spatial discrimination for milk infusion into the oral cavity or for the opportunity to suckle the dry nipples of an anesthetized dam. The results revealed, irrespective of deprivation treatment, that pups failed to acquire a simple T-maze spatial discrimination for milk reward although they rapidly learned to approach and locate an anesthetized dam to suckle. Experiment 2 followed up with a different procedure. Results indicated that during bouts of suckling rat pups preferred an active, lactating dam letting down milk to an identical dam not letting down milk due to her pretreatment with bromocryptine mesylate. These results illustrate a constraint on learning which affects immature rats. The capability to learn on appetitively motivated spatial discrimination appears intricately tied to the context in which training occurs. Results are discussed according to how the organism's expectancy can mediate performance.