Have there been studies about the effect of idle time vs time pressure in learning? There is a discussion in our institute about how much of their time students should spend on lectures and homework.

My own experience has been that idle time and wandering of the mind is necessary for seeing the big picture, but I understand that this depends on personality, context etc.

Are you aware of any papers which discuss this issue? What are the keywords for this topic?
There is an article on college students under pressure. It details on the effects and the health related issues involved.


  Amy Novotney, "Students under pressure," American Psychological Association, Vol 45, No. 8, pp. 36 September 2014.


Although it doesn't explicitly account on idle time, you should be able to draw conclusions from the content provided.