On inserting questions before or after segments of text

It has been concluded in all major reviews of adjunct question research that a group given questions after related text segments (postquestions) yields greater recall than a group given questions before related text segments (prequestions) or one not given any questions at all. However, closer examination of the earlier research and an analysis of recent research reveals that for certain types of verbatim questions and for certain high level questions, postquestions produce recall equivalent to or less than prequestions. Moreover, in many studies wherein postquestions exceed prequestions, the postquestion group equals the reading-only control group in recall of nonquestioned (incidental) material. Hence, despite frequent pronouncements to the contrary, no firm recommendation can be made regarding the optimal placement of adjunct questions in text material.     

Background factors and success in college physics

The author has cast a new light on some old myths concerning predictors of success in college physics.     

Effects of competition, exercise, and mental stress on secretory immunity

It has been suggested that the psychological stress associated with competitive sports events may help to explain the increased susceptibility to respiratory infections due to reductions in secretory immunity. In the current study, we investigated the influence of competitive exercise and psychological stress on secretory immunoglobulin A (s-IgA). Salivary s-IgA and heart rate were measured in 62 healthy young recreationally active men at rest and, in a between-subjects design, following one of four 8-min tasks: mental arithmetic, cycling at workloads of 60 to 180 W (mean = 146 W), mental arithmetic while cycling, or competitive cycling. Mental arithmetic was associated with significant increases in s-IgA concentration (mean = 49 microg.min(-1)) and s-IgA secretion rate (mean = 25 microg.ml(-1)) compared with rest, while mental arithmetic combined with exercise was associated with a significant increase in s-IgA concentration only (mean = 124 microg.min(-1)). In contrast, competitive exercise and exercise alone did not influence s-IgA concentration or secretion rate. Heart rate increased modestly to mental arithmetic (mean = 7 beats.min(-1)) and substantially, and similarly, to the three exercise tasks (mean = 56(62 beats.min(-1)). The hypothesis that the psychological stress of competitive exercise contributes to increased susceptibility to infection via reductions in s-IgA requires further investigation.