It has become clear that sleep after learning has beneficial effects on the later retrieval of newly acquired memories. The neural mechanisms underlying these effects are becoming increasingly clear as well, particularly those of non-REM sleep. However, much is still unknown about the sleep and memory relationship: the sleep state or features of sleep physiology that associate with memory performance often vary by task or experimental design, and the nature of this variability is not entirely clear. This paper describes pertinent features of sleep physiology and provides a detailed review of the scientific literature indicating beneficial effects of post-learning sleep on memory retrieval. This paper additionally introduces a hypothesis which attributes these beneficial effects of post-learning sleep to separable processes of memory reinforcement and memory refinement whereby reinforcement supports one's ability to retrieve a given memory and refinement supports the precision of that memory retrieval in the context of competitive alternatives. It is observed that features of non-REM sleep are involved in a post-learning substantiation of memory representations that benefit memory performance; thus, memory reinforcement is primarily attributed to non-REM sleep. Memory refinement is primarily attributed to REM sleep given evidence of bidirectional synaptic plasticity in REM sleep and findings from studies of selective REM sleep deprivation.

To determine sex-related differences in the skin-blood-flow (SkBF) response to exercise, local heating, and acetylcholine (ACh) in children. Additionally, the contribution of nitric oxide (NO) was examined. Methods: Forearm SkBF during local heating (44˚C), ACh iontophoresis, and exercise (30 min cycling, 60% OV 2max) was assessed, using Laser-Doppler fluxmetry, in 12 boys and 12 girls (7–13 yrs old), with and without NO synthase inhibition, using Nω-nitro-L-arginine methyl ester (L-NAME) iontophoresis. Results: Local-heating-induced and ACh-induced SkBF increase were not different between boys and girls (Local heating: 1445±900% and 1432±582% of baseline, , p=.57; ACh: 673±434% and 558±405% of baseline, respectively, p=0.18). Exercise-induced increase in SkBF was greater in boys than girls (528±290 and 374±192% of baseline, respectively, p=0.03). L-NAME blunted the SkBF response to ACh and during exercise (p<0.001), with no difference between sexes. Summary: SkBF responses to ACh and local heat stimuli were similar in boys and girls, while the increase in SkBF during exercise was greater in boys. The apparent role of NO was not different between boys and girls. It is suggested that the greater SkBF response in the boys during exercise is related to greater relative heat production and dissipation needs during this exercise intensity. The response to body-size-related workload should be further examined.

The epistemology of disagreement (EoD) has developed around a highly idealized notion of epistemic peers. The analysis of examples in the literature has not been very effective at mitigating this idealization, due to a tendency to focus on cases of extant philosophical disputes. This makes it difficult to spotlight the respects in which discussants are non-ideal, because the discussants are disciplinary colleagues. At the same time, widespread attitudes in academic philosophy about the importance of raw intelligence in doing philosophy can mislead us about the fragility and unpredictability of expertise. The use of such examples is not strong methodology.