In your entire professional experience in healthcare, have you ever advised a bottle-feeding family to alternate different styles of artificial nipples that differ in contour, diameter, length, and/or texture from one feeding to the next or from one day to the next, from week to week, or even on a month-to-month basis, particularly during the infant’s early skill acquisition for bottle-feeding skills?  

In your entire professional experience, have you ever observed such infant feeding advice being given to a family by a physician or nurse? 

If you are a parent who has bottle-fed your infant, have you ever received such professional advice for feeding your infant? 

Have you ever received such advice from family members or friends? 

In regard to the use of a pacifier/soother/dummy, have you ever given or received professional advice to switch pacifier styles from one use to another over the course of a day or from day to day, week to week, or from month to month?  Have you ever received such advice from family members or friends?   

I wholly support The Ten Steps to Successful Breastfeeding, although this post is primarily focused on bottle-fed infants who may be receiving all mother's milk in a bottle, human donor milk by bottle, artificial infant milk by bottle, or a mixture of any of these milks via bottle.  In my long career as a registered nurse and IBCLC, not once have I heard such switching advice given to bottle-feeding families and/or to families who are giving pacifiers/soothers/dummies to their infants. 

What I have occasionally overheard while passing through a hospital’s well-baby nursery or a neonatal intensive care unit (NICU) is an outgoing nurse giving report to an incoming nurse during shift change, stating that Baby Jones “does better” with a particular type of artificial nipple.  Although hospitals do not stock a wide variety of artificial nipples, typically there are at least two to 3 styles of artificial nipples for the nursing staff's selection.   

The departing nurse intends that both the incoming nurse and her small patient will benefit from her observations of how her infant patient fed during her shift.  We can interpret the departing nurse’s phrase, “does better,” as a reference to the infant’s motor learning toward increasingly greater motor control for the oral grasp of a particular artificial nipple, as well as motor learning for effective suckling toward adequate transfer of milk, all while learning how to coordinate suck and swallow with breathing.  “Does better” infers that with consistent practice that is specific to the task, the infant's family, as well as the nursing staff, can expect to observe greater speed and accuracy by the infant for the oral grasp of the artificial nipple, as well as greater motor control for milk transfer from the bottle.  Motor learning is a complex process, and the healthy term infant who is bottle-fed will gradually build robust motor memory for bottle-feeding skills that are associated with a specific design of an artificial nipple, and there may be learning that is specific to the design of a bottle as well.   

Step 9 of the Ten Steps to Successful Breastfeeding reflects the basic need for the newborn to have frequent and consistent task-specific practice for learning breastfeeding skills, toward gradual building of robust motor memory for these skills.       

When a six-month-old infant begins to learn drinking skills from a sippee-cup, we often intuitively give the same style of sippee cup to the baby day after day, in order to provide task-specific practice sessions in sippee-cup drinking.  If we were to offer alternating styles of sippee cups from one day to the next, we would surely observe the infant’s difficulties in task-switching from one style of sippee cup to another.    

A key aspect of our executive functions is our cognitive flexibility, the ability to adapt our thinking and/or behavior in response to changes in the environment.  In the developmental sciences, there is a well-known developmental progression for our cognitive flexibility: 

We possess the least cognitive flexibility in infancy.

We display more cognitive flexibility in childhood than in infancy. 

We display even greater cognitive flexibility in adolescence. 

We possess still greater cognitive flexibility in adulthood, although task-switching often results in decreased speed and/or accuracy for the task, regardless of age.  Consider the expected miserable experience for the serious golfer who forgets her clubs and must use a loaner set in order to participate in a scheduled game or tournament.  

Task-switching is heavily studied in the cognitive sciences, as are the switch costs of decreased speed and accuracy that often occur during task-switching.  Measurement parameters include reaction time (RT), the interval between the presentation of a stimulus and the initiation of a response; movement time (MT), the interval between the initiation of a movement and its completion or termination; response time, the interval from the presentation of a stimulus to the completion of a movement (the sum of reaction time and movement time); and inhibition of return (IOR), the delay in responding to the previously cued (or orienting) stimulus. 

Today’s PubMed search using the term “task-switching” yielded 1,384 search results.  Note that when using the search term “task switching” without a hyphen between “task” and “switching,” the yield is nearly three-fold at 3,018 search results.  

The first of the below publications is a well-known 2005 study from Adele Diamond and Natasha Kirkham on task switching and cognitive flexibility, followed by one new study and one new review paper by Kirkham and colleagues: 

1)     Title: Not Quite As Grown-Up As We Like To Think:  Parallels Between Childhood and Adulthood.

Authors: Adele Diamond, Natasha Kirkham.

In:  Psychological Science 2005 Apr;16(4):291-297.  doi.10.1111/j.0956-7976.2005.01530.x


2)    Title:  Incidental Category Learning and Cognitive Load in a Multisensory Environment Across Childhood.

Authors:  H.J. Broadbent, T. Osborne, M. Rea, A. Peng, D. Mareschal, N.Z. Kirkham.

In:  Developmental Psychology 2018; 54(6), 1020-1028.



3)    Title:  Infant Statistical Learning.

Authors:  Jenny R. Saffran and Natasha Z. Kirkham

In:  Annual Reviews in Psychology 2018 January 04;69:181-203.