Babies develop memories from the time they are born. Shortly after birth, newborns can recognise their mother's voice.1- DeCasper A.J., Fifer W.P. (1980). Of human bonding: newborns prefer their mothers’ voices. Science. ;208(4448):1174–1176.
By three to four days old, they can remember and recognise their mothers' face.2- Simion, F., & Giorgio, E. D. (2015). Face perception and processing in early infancy: inborn predispositions and developmental changes. Frontiers in psychology, 6, 969. doi:10.3389/fpsyg.2015.00969
Studies found that infants initially preferred to look at that which is familiar as they begin to process a stimulus. Once processing becomes more advanced, their preference shifts to the novel. Hence providing new things for infants to look at will help stimulate the brain and encourage memory and processing.3- Rose SA, Feldman JF, Jankowski JJ. (2001). Attention and recognition memory in the 1st year of life: A longitudinal study of preterm and full-term infants. Dev Psychol.; 37(1):135-151.