Perrault and team investigated the benefits of gentle rocking. They “previously showed that a gentle rocking stimulation (0.25 Hz), during an afternoon nap, facilitates wake-sleep transition and boosts endogenous brain oscillations. . . . [in the current study the team] analyzed EEG brain responses . . . from . . . participants while they had a full night of sleep on a rocking bed. . . . compared to a stationary night, continuous rocking shortened the latency to non-REM (NREM) sleep and strengthened sleep maintenance. . . . during the rocking night, overnight memory consolidation was enhanced.” So, gentle rocking leads to better sleep (falling sleep faster, sleeping more soundly, and waking up fewer times after going to sleep) and enhanced memory consolidation. For more on memory consolidation, see this webpage: https://en.wikipedia.org/wiki/Memory_consolidation.
Aurore Perrault, Abbas Khani, Charles Quairiaux, Konstantinos Kompotis, Paul Franken, Michel Muhlethaler, Sophie Schwartz, and Laurence Bayer. “Whole-Night Continuous Rocking Entrains Spontaneous Neural Oscillations with Benefits for Sleep and Memory.” Current Biology, in press, DOI: https://doi.org/10.1016/j.cub.2018.12.028