Synchronous brain activity in newborn infants and their mothers during parent-led multimodal pain alleviation with skin-to-skin contact, breastfeeding and lullaby singing: Study protocol for a fNIRS hyperscanning study. - Eriksson, Mats; Lund, Majja; Msghina, Mussie; Reingardt, Maria; Ullsten, Alexandra (PLoS ONE, 2026)