If it's worth saying, but not worth its own post (even in Discussion), then it goes here.
Notes for future OT posters:
1. Please add the 'open_thread' tag.
2. Check if there is an active Open Thread before posting a new one. (Immediately before; refresh the list-of-threads page before posting.)
3. Open Threads should be posted in Discussion, and not Main.
4. Open Threads should start on Monday, and end on Sunday.
These pieces seem relevant:
http://www.ncbi.nlm.nih.gov/pubmed/24702833
http://www.ncbi.nlm.nih.gov/pubmed/24005703
http://www.ncbi.nlm.nih.gov/pubmed/23906385
http://www.ncbi.nlm.nih.gov/pubmed/23276127
http://www.ncbi.nlm.nih.gov/pubmed/22352981
http://www.ncbi.nlm.nih.gov/pubmed/17474045
http://www.ncbi.nlm.nih.gov/pubmed/16557357
http://www.ncbi.nlm.nih.gov/pubmed/16033667
http://www.ncbi.nlm.nih.gov/pubmed/12687924
http://www.ncbi.nlm.nih.gov/pubmed/12518979
Thanks a lot! Highly useful. The evidence seems to be mixed, though good feedback does increase performance. Very nice of you to dig up all those links so quickly! :)