Infants are quieter, sleep more, and have lower heart rates when swaddled under the experimental conditions we employed.
When swaddled and experimentally stimulated, some infants show no difference and may even manifest greater responses in heart and respiratory rates than when free to move. Five of the 10 infants responded less when swaddled.
Overt motor responses alone do not account for heart-rate responses to stimulation.
Swaddling may prove to be a useful tool in the investigation of parameters of the neonatal nervous system functioning by allowing for more stable conditions during testing.
Infants differ considerably in many physiologic parameters under these conditions. These differences are currently under investigation.