We clinicians often observe youngest newborns who display improved skill (greater speed and accuracy) for the oral grasp and nutritive suckling after a short nap between breasts and after a longer stretch of sleep. Consolidation is a term from the cognitive sciences that refers to the building of memory, including motor memory, into a robust state. Sleep is a critical aspect of memory consolidation.
As babies become progressively more skilled in milk-feeding, increasingly less sleep is required by the infant. Although sleep is critical in building robust memory, interference in learning can impede memory consolidation, in spite of adequate sleep. In their 1995 paper providing the first formal definition on nipple confusion, authors Mary Ann Neifert, Ruth Lawrence, and Joy Seacat discussed interference as a factor in breastfeeding difficulties that often follow an infant's learning experience with an artificial nipple.
This fascinating new study from Switzerland was done on adults, looking at whole-night rocking and its impact on sleep and memory. Does frequent rocking also benefit preterm infants, as well as babies in general? There is often an intrinsic need to rock one's infant, and to stand and sway back and forth with the little one.
Title: Whole-Night Continuous Rocking Entrains Spontaneous Neural Oscillations with Benefits for Sleep and Memory.
In: Current Biology 2019 Jan 11. pii: S0960-9822(18)31662-2. doi: 10.1016/j.cub.2018.12.028. [Epub ahead of print]
Study Authors: Perrault AA, Khani A, Quairiaux C, Kompotis K, Franken P, Muhlethaler M, Schwartz S, Bayer L.
The following 1989 study associated rocking of preterm infants with improved neuromuscular development.
Title: Effects of rocking on neuromuscular development in the premature.
Authors: Clark DL, Cordero L, Goss KC, Manos D.
In: Biology of the Neonate 1989;56(6):306-314.