What has been found regarding the impact of sleep on people's ability to perform a sequenced finger-tapping task?
a. practicing two skills on the same day can interfere with retention of the second skill practiced.
b. practicing two skills on the same day can interfere with retention of the first skill practiced.
c. reviewing a recently learned skill before beginning to practice a new one can interfere with retention of the new skill.
d. reviewing a recently learned skill before beginning to practice a new one can interfere with retention of both skills?