The Science of Babywearing

            This week is International Babywearing Week , sponsored by Babywearing International.  My husband and I love babywearing.  While I heard all of the wonderful facts about babywearing ( baby cries less; baby is more attached to parents; healthier development for babies, especially premies,) I was initially drawn to it because, frankly, it was easier to carry Q-ball in a carrier than in my arms, especially when shopping or doing chores.   But, I recently read about the science behind some of the benefits of babywearing and learned about benefits that typically aren’t mentioned.  These have made me love babywearing even more!

            It’s a common fact that babies love motion- rocking in their parents’ arms, swinging in swings, and bouncing in chairs.  The reason behind this is that babies have a very sensitive vestibular system (ranking with touch in terms of most sensitive sense in a newborn), which controls the body’s ability to sense movement and balance.   The vestibular system is located in the inner ear (which explains why balance is sometimes affected during ear infections).  In adults, we know that our vestibular system is working when we don’t notice it; it is what keeps our field of vision constant when doing and activity like jogging- even though our eyes are bouncing up and down, our view remains steady.  When our vestibular system is off, dizziness and motion sickness can result.

 Now back to babies- in the womb, it’s one of the first brain structures to develop- at only 10 weeks old, a fetus can detect movement!  An eight-month fetus’s vestibular system is so developed that it actually sets off a baby’s first reflexes!  When a mama changes from sitting to standing, the change can activate the Moro reflex or startle reflex which is seen in newborns until about 3 months.  Even the fetus’s ability to position itself downward when it is time for labor and delivery is a result of a well-developed vestibular system.  After birth, nearly all newborn reflexes continue to be the result of activity in the vestibular system, including the doll’s eye reflex (in which baby will continue to look forward, although you may move his head) and asymmetrical neck reflex (identified by Gesell and discussed in this post.)  In fact, a human’s vestibular system reaches its peak of sensitivity between six to eight months of age.  So, any rocking or swinging of baby (like when baby is in a baby carrier) between these ages will especially activate the vestibular system. 

So, how does this help baby?  The vestibular system is the primary method that a newborn experiences their new surroundings, so it is likely that activating the vestibular system may improve their ability to take in all of the new sights and sounds.  This increased sensitivity could improve the development of motor, cognitive, and even emotional abilities. 

An experiment tested this hypothesis.  Infants between 3 to 13 months were put through 16 sessions of chair spinning, during which they were held by a researcher and spun around in a swivel chair.  Super fun for the infants!!  But, a control group was just held by the researchers in the swivel chair- no spinning and certainly not as much fun.  Well, the infants who got to spin around in the chairs also demonstrated more advanced development in reflexes and motor skills, especially walking, sitting, crawling, and standing.  This was even true for a set of fraternal twins- one of which had the joy of spinning in the chair and the other that just had to sit in the researcher’s lap. 

Another sign of the benefits of vestibular stimulation can be seen in neonatal units.  Preterm babies that are rocked, carried in baby carriers, or able to rock themselves in specially made baby water beds (I need to look into purchasing one of these as it could lead to 3 hours of uninterrupted sleep…) gained weight faster, breathed more regularly, slept more, and had more quiet, alert time than babies who did not experience vestibular stimulation. 

Parents also likely know one of the best aspects of continued vestibular stimulation.  A sleepy baby!  Babywearing provides as awesome opportunity to stimulate the vestibular system with the continuous, gentle rocking the babies (and toddlers!) feel.  Babies will be better able to experience the world around them, while being close to and encouraged by their parents.  So, strap on your baby carrier and start babywearing today!

We love our Erog and teething pads from RedCharlotte!

Sources:

"Babywearing International Resources." Babywearing International. Babywearing International, n.d. Web. 10 Oct 2011. <http://babywearinginternational.org/articles.php?article=1>.

Eliot, L. (1999). What’s going on in there? How the brain and mind develop in the first five years of life. Bantam Books: USA.

Beyond Physcial Milestones, Part IV: Direct Perception

            In the late 1970s, American psychologist James Gibson proposed a new way to solve Bernstein’s problem.  Unlike the theory of information processing, Gibson’s direct perception approach argues that knowledge and observations about the environment do need to be organized and stored in the brain in order to be used.  Instead, information can be used directly by the infant, which Gibson refers to as “affordances.”  Affordances describe the environment in which the human is moving.  Humans learn to adapt to affordances; in the Tour de France, a biker will shift weight forward when faced with a large uphill climb, while they will shift back when rushing downhill. 

In this same way, infants learn to adapt their crawl or walk to their environment.  However, they do not create one set of rules that tell them how to move around different obstacles.  Instead, as they directly experience their environments, they decide how to move.  Because babies and young children grow so quickly, their bodies and especially their legs undergo major changes in a quick period of time.  As such, it would only confuse them to learn to scoot with short, chubby legs one week and longer, skinner legs the next.  In addition to the changes they are experiencing in themselves, they are in a constantly changing environment.  One day they might be crawling on soft carpet; the next a hard, slippery tiled floor or an uneven surface like grass. As adults, we adjust to these affordances everyday, most likely without a second thought (unless I am maneuvering these obstacles in heels- then the surface I’m encountering is likely in all of my thoughts.)  Babies are always having to learn to adapt to something new!

Research in the field of ecological psychology has revealed some findings that I find really interesting, funny, or that make me even more amazed in my little one!  Here are some of them:

·         It has been found that baby fat has profound influences on infant locomotion.  All babies are born with the “stepping reflex,” but it was commonly believed to disappear after about 2 months. Researchers have since learned, however, that the reflex exists much longer, but babies legs become too weighed down with fat for their little muscles to respond to the reflex!

·         Babies with about 6 weeks of crawling experience will know to avoid “drop-offs” or cliffs.  These experiments are completed by having infants crawl over raised plexiglass covered surfaces.  The babies start at an end where a brightly colored material is under the plexiglass, so they know they are moving on a solid surface.  Suddenly, the material is removed, but the plexiglass remains, giving the illusion that there is nothing supporting the baby.  Remarkably, the infants know to stop at this point.  Some do explore that space by touch, and will, eventually, trust that they can crawl over the space. 

·         Infants face more hurtles than adults when trying to maintain balance while crawling, standing, or walking.  This is because their shorter, smaller builds fall faster and require quicker reaction times to correct falls and they smaller feet and knees mean that they have a smaller base supporting their bodies. 

·         While we often lure infants across the carpet or around the room with toys, most infant movement is “means-end exploration.”  Many infants may not take the most direct path to get to the toy as they ultimately just want to test their motor skills. 

Sources:

Hirsch-Pasek, K. & Golinkoff, R.M. (2003). USA:Rodale.

Adolph, K., Bertenthal, B. Boker, S., Goldfield, E., & Gibson, E.J. (1997). Learning in the development of infant locomotion. Monographs of the Society for Research in Child Development, 62(3), 1-162

Beyond Physical Milestones: Part I, Introduction

        (Please note, this is an updated version of a previously published post...)

         Typically, when I look at a list of baby milestones for physical development, it reads something like this-

1 Month- Lifts head

2 Months- Holds head up

3 Months- Does mini push-up

            Well, there’s obviously got to be more going on than that.  What inside of baby is suddenly clicking to make this stuff happen? 

            The vast majority of all physical movements in the first three months of life are just reflexes, most with rather obvious evolutionary survival functions.  In fact, human infants appear to have the least developed motor capabilities when compared to other vertebrate animals, making reflexes all the more essential.  The first reflexes that parents are most likely to observe are the rooting and sucking reflexes, necessary for nourishment.  Other reflexes ensure the proximity of the caretaker to the infant- the grasping reflex, the Moro reflex (this happens when baby is startled- he clenches his arms around his chest in an effort to hold on to his caretaker who would be holding him- demonstrating the  evolutionary roots of baby-wearing), and even crying.

            Around month 3, many of these reflexes start to diminish and are replaced by movements initiated by the infant, indicating increased strength and the ability to manage their muscles.  However, these new movements do not only indicate increased strength of the muscle groups employed.  The development of the musculoskeletal system is related to the development of the brain. As explained by the Russian psychologist Nikolai Bernstein in 1967, the movements require coordination. His work explained that the human body- composed of countless joints, muscles, and bones- is unable to control the movement of individual joints and muscles, thus the need for coordination between the separate components. Bernstein called this new field of study “biodynamics.” Beyond the many, many body parts involved in a movement, the central nervous system sends countless signals to initiate movement.  Moreover, more than one signal can initiate the same movement or the same signal can lead to different movements, which Bernstein termed as redundancy.  Given these findings, Bernstein concluded the human body has an infinite number of degrees of freedom, or the movement or rotation of various parts- imagine rotating your arm.   

            So, how does the human body learn to master these movements, given an infant’s starting point is based solely on reflexes?  This question has been coined “Bernstein’s problem.”  Various theories explain how humans develop to overcome Bernstein’s problem.  In this look into infant physical development, I will explore the following major theories:

1.    1.  Maturation (Neural Networks)

2.   2.   Information Processing

3.   3.   Direct Processing

4.    4.  Dynamic Systems Approach

5.    5.  Constraints Model

Sources:

Crain, William. (2011). Theories of development: Concepts and applications. New Jersey:      Prentice Hall.

 Salkind, Neil. (2004). An introduction to the theories of human development. California: Sage Publications.

 Sporns, Olaf & Gerald Edelman. (1993). Solving Bernstein's problem: A proposal for the development of coordinated movement by selection. Child Development. 64(4). 960-981.