I researched this topic a little as it was related to work I was doing in my PhD 2-3 years ago. I'm mostly going from memory here. I think Kaufman is largely incorrect for skill learning in real-life. Walker et al. (2002) found sleep improved motor skill compared to the same amount of time spent awake, but a similar improvement was found after nightime sleep whether participants learned at 10 am or 10pm.
Walker study: https://www.sciencedirect.com/science/article/pii/S0896627302007468
Possibly, Kauffman based his claim on Robertson's studies which found interference between a motor skill task and a verbal task is minimized with sleep but Robertson doesn't directly test the claim as I think he only tests the learn in the morning group after 12 hours but not 24 hours and I tend to be skeptical even of Robertson's basic finding as when I was doing research on the topic independent researchers hadn't replicated it http://www.jneurosci.org/content/27/39/10468.short.
I also found these articles that might be of interest:
https://academic.oup.com/sleep/article/40/4/zsx036/3765296
https://onlinelibrary.wiley.com/doi/full/10.1111/tops.12232
Overall, spacing your practice will be a much more significant variable than the time of day you practice.
Thank you! The Walker study is exactly what I was looking for.
For those following along at home, this is the relevant graph.
It looks like a sleep session produces a comparatively huge boost in skill performance, regardless of the timing of the practice.
Now I want to know if this has replicated for larger (or just other) samples.
Finally, I'm curious what people make of the last paper psychs listed ("Testing Sleep Consolidation in Skill Learning: A Field Study Using an Online Game"). They didn't find any evidence for a sleep consolidation effect over and above non-sleep breaks.
This is a very surprising result, and I'm not sure what to make of it.
They give some possible reasons for that result in the discussion section, but none of them reduce my surprise much.
...which found interference between a motor skill task and a verbal task is minimized...
A verbal task and a motor task can interfere with each other? I thought that interference only occurs between similar tasks.
I remember by having listened to the Rhonda Patrick and Matthew Walker podcast where they go over the relationship between sleep and learning. He even gives some insights into how the actual process of consolidation happens while we are sleeping. (It may not be what you are exactly looking for but nonetheless I think it's helpful).
Unrelated to that it's my own experience; If i spend some time at night coding/reading about Mathematics I will usually go to sleep and think about the specific problems and how to go about it in the next morning. It seems to really help my decision solving the next day.
It is well known that sleep (both mid-day naps and nighttime sleep) has a large effect on the efficacy of motor skill acquisition. Performance on a newly learned task improves, often markedly, following a period of sleep.
A few citations (you can find many more by searching "motor skill acquisition sleep" or similar in google scholar) :
I want to know if the _timing_ of practice, relative to sleep, makes a difference for skill acquisition.
For instance, if you practice a skill at 7:00 PM, shortly before a night of sleep, will your performance be better in the morning than if you had practiced at 7:00 AM had a full day of wakefulness, and _then_ gone to sleep? If so, what is the effect size?
Josh Kaufman makes a claim to this effect in his book, The First 20 Hours. I have no particular reason to doubt him, 40 minutes of searching on google scholar did not turn up any papers about the importance of sleep and practice timing.
Can you point me at a relevant citation?
